v4.19.13 snapshot.
diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig
new file mode 100644
index 0000000..ed3b785
--- /dev/null
+++ b/drivers/dma-buf/Kconfig
@@ -0,0 +1,33 @@
+menu "DMABUF options"
+
+config SYNC_FILE
+ bool "Explicit Synchronization Framework"
+ default n
+ select ANON_INODES
+ select DMA_SHARED_BUFFER
+ ---help---
+ The Sync File Framework adds explicit syncronization via
+ userspace. It enables send/receive 'struct dma_fence' objects to/from
+ userspace via Sync File fds for synchronization between drivers via
+ userspace components. It has been ported from Android.
+
+ The first and main user for this is graphics in which a fence is
+ associated with a buffer. When a job is submitted to the GPU a fence
+ is attached to the buffer and is transferred via userspace, using Sync
+ Files fds, to the DRM driver for example. More details at
+ Documentation/sync_file.txt.
+
+config SW_SYNC
+ bool "Sync File Validation Framework"
+ default n
+ depends on SYNC_FILE
+ depends on DEBUG_FS
+ ---help---
+ A sync object driver that uses a 32bit counter to coordinate
+ synchronization. Useful when there is no hardware primitive backing
+ the synchronization.
+
+ WARNING: improper use of this can result in deadlocking kernel
+ drivers from userspace. Intended for test and debug only.
+
+endmenu
diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
new file mode 100644
index 0000000..c33bf88
--- /dev/null
+++ b/drivers/dma-buf/Makefile
@@ -0,0 +1,3 @@
+obj-y := dma-buf.o dma-fence.o dma-fence-array.o reservation.o seqno-fence.o
+obj-$(CONFIG_SYNC_FILE) += sync_file.o
+obj-$(CONFIG_SW_SYNC) += sw_sync.o sync_debug.o
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
new file mode 100644
index 0000000..1388447
--- /dev/null
+++ b/drivers/dma-buf/dma-buf.c
@@ -0,0 +1,1161 @@
+/*
+ * Framework for buffer objects that can be shared across devices/subsystems.
+ *
+ * Copyright(C) 2011 Linaro Limited. All rights reserved.
+ * Author: Sumit Semwal <sumit.semwal@ti.com>
+ *
+ * Many thanks to linaro-mm-sig list, and specially
+ * Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and
+ * Daniel Vetter <daniel@ffwll.ch> for their support in creation and
+ * refining of this idea.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-fence.h>
+#include <linux/anon_inodes.h>
+#include <linux/export.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/poll.h>
+#include <linux/reservation.h>
+#include <linux/mm.h>
+
+#include <uapi/linux/dma-buf.h>
+
+static inline int is_dma_buf_file(struct file *);
+
+struct dma_buf_list {
+ struct list_head head;
+ struct mutex lock;
+};
+
+static struct dma_buf_list db_list;
+
+static int dma_buf_release(struct inode *inode, struct file *file)
+{
+ struct dma_buf *dmabuf;
+
+ if (!is_dma_buf_file(file))
+ return -EINVAL;
+
+ dmabuf = file->private_data;
+
+ BUG_ON(dmabuf->vmapping_counter);
+
+ /*
+ * Any fences that a dma-buf poll can wait on should be signaled
+ * before releasing dma-buf. This is the responsibility of each
+ * driver that uses the reservation objects.
+ *
+ * If you hit this BUG() it means someone dropped their ref to the
+ * dma-buf while still having pending operation to the buffer.
+ */
+ BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active);
+
+ dmabuf->ops->release(dmabuf);
+
+ mutex_lock(&db_list.lock);
+ list_del(&dmabuf->list_node);
+ mutex_unlock(&db_list.lock);
+
+ if (dmabuf->resv == (struct reservation_object *)&dmabuf[1])
+ reservation_object_fini(dmabuf->resv);
+
+ module_put(dmabuf->owner);
+ kfree(dmabuf);
+ return 0;
+}
+
+static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
+{
+ struct dma_buf *dmabuf;
+
+ if (!is_dma_buf_file(file))
+ return -EINVAL;
+
+ dmabuf = file->private_data;
+
+ /* check for overflowing the buffer's size */
+ if (vma->vm_pgoff + vma_pages(vma) >
+ dmabuf->size >> PAGE_SHIFT)
+ return -EINVAL;
+
+ return dmabuf->ops->mmap(dmabuf, vma);
+}
+
+static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence)
+{
+ struct dma_buf *dmabuf;
+ loff_t base;
+
+ if (!is_dma_buf_file(file))
+ return -EBADF;
+
+ dmabuf = file->private_data;
+
+ /* only support discovering the end of the buffer,
+ but also allow SEEK_SET to maintain the idiomatic
+ SEEK_END(0), SEEK_CUR(0) pattern */
+ if (whence == SEEK_END)
+ base = dmabuf->size;
+ else if (whence == SEEK_SET)
+ base = 0;
+ else
+ return -EINVAL;
+
+ if (offset != 0)
+ return -EINVAL;
+
+ return base + offset;
+}
+
+/**
+ * DOC: fence polling
+ *
+ * To support cross-device and cross-driver synchronization of buffer access
+ * implicit fences (represented internally in the kernel with &struct fence) can
+ * be attached to a &dma_buf. The glue for that and a few related things are
+ * provided in the &reservation_object structure.
+ *
+ * Userspace can query the state of these implicitly tracked fences using poll()
+ * and related system calls:
+ *
+ * - Checking for EPOLLIN, i.e. read access, can be use to query the state of the
+ * most recent write or exclusive fence.
+ *
+ * - Checking for EPOLLOUT, i.e. write access, can be used to query the state of
+ * all attached fences, shared and exclusive ones.
+ *
+ * Note that this only signals the completion of the respective fences, i.e. the
+ * DMA transfers are complete. Cache flushing and any other necessary
+ * preparations before CPU access can begin still need to happen.
+ */
+
+static void dma_buf_poll_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
+{
+ struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dcb->poll->lock, flags);
+ wake_up_locked_poll(dcb->poll, dcb->active);
+ dcb->active = 0;
+ spin_unlock_irqrestore(&dcb->poll->lock, flags);
+}
+
+static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
+{
+ struct dma_buf *dmabuf;
+ struct reservation_object *resv;
+ struct reservation_object_list *fobj;
+ struct dma_fence *fence_excl;
+ __poll_t events;
+ unsigned shared_count, seq;
+
+ dmabuf = file->private_data;
+ if (!dmabuf || !dmabuf->resv)
+ return EPOLLERR;
+
+ resv = dmabuf->resv;
+
+ poll_wait(file, &dmabuf->poll, poll);
+
+ events = poll_requested_events(poll) & (EPOLLIN | EPOLLOUT);
+ if (!events)
+ return 0;
+
+retry:
+ seq = read_seqcount_begin(&resv->seq);
+ rcu_read_lock();
+
+ fobj = rcu_dereference(resv->fence);
+ if (fobj)
+ shared_count = fobj->shared_count;
+ else
+ shared_count = 0;
+ fence_excl = rcu_dereference(resv->fence_excl);
+ if (read_seqcount_retry(&resv->seq, seq)) {
+ rcu_read_unlock();
+ goto retry;
+ }
+
+ if (fence_excl && (!(events & EPOLLOUT) || shared_count == 0)) {
+ struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl;
+ __poll_t pevents = EPOLLIN;
+
+ if (shared_count == 0)
+ pevents |= EPOLLOUT;
+
+ spin_lock_irq(&dmabuf->poll.lock);
+ if (dcb->active) {
+ dcb->active |= pevents;
+ events &= ~pevents;
+ } else
+ dcb->active = pevents;
+ spin_unlock_irq(&dmabuf->poll.lock);
+
+ if (events & pevents) {
+ if (!dma_fence_get_rcu(fence_excl)) {
+ /* force a recheck */
+ events &= ~pevents;
+ dma_buf_poll_cb(NULL, &dcb->cb);
+ } else if (!dma_fence_add_callback(fence_excl, &dcb->cb,
+ dma_buf_poll_cb)) {
+ events &= ~pevents;
+ dma_fence_put(fence_excl);
+ } else {
+ /*
+ * No callback queued, wake up any additional
+ * waiters.
+ */
+ dma_fence_put(fence_excl);
+ dma_buf_poll_cb(NULL, &dcb->cb);
+ }
+ }
+ }
+
+ if ((events & EPOLLOUT) && shared_count > 0) {
+ struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared;
+ int i;
+
+ /* Only queue a new callback if no event has fired yet */
+ spin_lock_irq(&dmabuf->poll.lock);
+ if (dcb->active)
+ events &= ~EPOLLOUT;
+ else
+ dcb->active = EPOLLOUT;
+ spin_unlock_irq(&dmabuf->poll.lock);
+
+ if (!(events & EPOLLOUT))
+ goto out;
+
+ for (i = 0; i < shared_count; ++i) {
+ struct dma_fence *fence = rcu_dereference(fobj->shared[i]);
+
+ if (!dma_fence_get_rcu(fence)) {
+ /*
+ * fence refcount dropped to zero, this means
+ * that fobj has been freed
+ *
+ * call dma_buf_poll_cb and force a recheck!
+ */
+ events &= ~EPOLLOUT;
+ dma_buf_poll_cb(NULL, &dcb->cb);
+ break;
+ }
+ if (!dma_fence_add_callback(fence, &dcb->cb,
+ dma_buf_poll_cb)) {
+ dma_fence_put(fence);
+ events &= ~EPOLLOUT;
+ break;
+ }
+ dma_fence_put(fence);
+ }
+
+ /* No callback queued, wake up any additional waiters. */
+ if (i == shared_count)
+ dma_buf_poll_cb(NULL, &dcb->cb);
+ }
+
+out:
+ rcu_read_unlock();
+ return events;
+}
+
+static long dma_buf_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct dma_buf *dmabuf;
+ struct dma_buf_sync sync;
+ enum dma_data_direction direction;
+ int ret;
+
+ dmabuf = file->private_data;
+
+ switch (cmd) {
+ case DMA_BUF_IOCTL_SYNC:
+ if (copy_from_user(&sync, (void __user *) arg, sizeof(sync)))
+ return -EFAULT;
+
+ if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK)
+ return -EINVAL;
+
+ switch (sync.flags & DMA_BUF_SYNC_RW) {
+ case DMA_BUF_SYNC_READ:
+ direction = DMA_FROM_DEVICE;
+ break;
+ case DMA_BUF_SYNC_WRITE:
+ direction = DMA_TO_DEVICE;
+ break;
+ case DMA_BUF_SYNC_RW:
+ direction = DMA_BIDIRECTIONAL;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (sync.flags & DMA_BUF_SYNC_END)
+ ret = dma_buf_end_cpu_access(dmabuf, direction);
+ else
+ ret = dma_buf_begin_cpu_access(dmabuf, direction);
+
+ return ret;
+ default:
+ return -ENOTTY;
+ }
+}
+
+static const struct file_operations dma_buf_fops = {
+ .release = dma_buf_release,
+ .mmap = dma_buf_mmap_internal,
+ .llseek = dma_buf_llseek,
+ .poll = dma_buf_poll,
+ .unlocked_ioctl = dma_buf_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = dma_buf_ioctl,
+#endif
+};
+
+/*
+ * is_dma_buf_file - Check if struct file* is associated with dma_buf
+ */
+static inline int is_dma_buf_file(struct file *file)
+{
+ return file->f_op == &dma_buf_fops;
+}
+
+/**
+ * DOC: dma buf device access
+ *
+ * For device DMA access to a shared DMA buffer the usual sequence of operations
+ * is fairly simple:
+ *
+ * 1. The exporter defines his exporter instance using
+ * DEFINE_DMA_BUF_EXPORT_INFO() and calls dma_buf_export() to wrap a private
+ * buffer object into a &dma_buf. It then exports that &dma_buf to userspace
+ * as a file descriptor by calling dma_buf_fd().
+ *
+ * 2. Userspace passes this file-descriptors to all drivers it wants this buffer
+ * to share with: First the filedescriptor is converted to a &dma_buf using
+ * dma_buf_get(). Then the buffer is attached to the device using
+ * dma_buf_attach().
+ *
+ * Up to this stage the exporter is still free to migrate or reallocate the
+ * backing storage.
+ *
+ * 3. Once the buffer is attached to all devices userspace can initiate DMA
+ * access to the shared buffer. In the kernel this is done by calling
+ * dma_buf_map_attachment() and dma_buf_unmap_attachment().
+ *
+ * 4. Once a driver is done with a shared buffer it needs to call
+ * dma_buf_detach() (after cleaning up any mappings) and then release the
+ * reference acquired with dma_buf_get by calling dma_buf_put().
+ *
+ * For the detailed semantics exporters are expected to implement see
+ * &dma_buf_ops.
+ */
+
+/**
+ * dma_buf_export - Creates a new dma_buf, and associates an anon file
+ * with this buffer, so it can be exported.
+ * Also connect the allocator specific data and ops to the buffer.
+ * Additionally, provide a name string for exporter; useful in debugging.
+ *
+ * @exp_info: [in] holds all the export related information provided
+ * by the exporter. see &struct dma_buf_export_info
+ * for further details.
+ *
+ * Returns, on success, a newly created dma_buf object, which wraps the
+ * supplied private data and operations for dma_buf_ops. On either missing
+ * ops, or error in allocating struct dma_buf, will return negative error.
+ *
+ * For most cases the easiest way to create @exp_info is through the
+ * %DEFINE_DMA_BUF_EXPORT_INFO macro.
+ */
+struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
+{
+ struct dma_buf *dmabuf;
+ struct reservation_object *resv = exp_info->resv;
+ struct file *file;
+ size_t alloc_size = sizeof(struct dma_buf);
+ int ret;
+
+ if (!exp_info->resv)
+ alloc_size += sizeof(struct reservation_object);
+ else
+ /* prevent &dma_buf[1] == dma_buf->resv */
+ alloc_size += 1;
+
+ if (WARN_ON(!exp_info->priv
+ || !exp_info->ops
+ || !exp_info->ops->map_dma_buf
+ || !exp_info->ops->unmap_dma_buf
+ || !exp_info->ops->release
+ || !exp_info->ops->map
+ || !exp_info->ops->mmap)) {
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!try_module_get(exp_info->owner))
+ return ERR_PTR(-ENOENT);
+
+ dmabuf = kzalloc(alloc_size, GFP_KERNEL);
+ if (!dmabuf) {
+ ret = -ENOMEM;
+ goto err_module;
+ }
+
+ dmabuf->priv = exp_info->priv;
+ dmabuf->ops = exp_info->ops;
+ dmabuf->size = exp_info->size;
+ dmabuf->exp_name = exp_info->exp_name;
+ dmabuf->owner = exp_info->owner;
+ init_waitqueue_head(&dmabuf->poll);
+ dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll;
+ dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0;
+
+ if (!resv) {
+ resv = (struct reservation_object *)&dmabuf[1];
+ reservation_object_init(resv);
+ }
+ dmabuf->resv = resv;
+
+ file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf,
+ exp_info->flags);
+ if (IS_ERR(file)) {
+ ret = PTR_ERR(file);
+ goto err_dmabuf;
+ }
+
+ file->f_mode |= FMODE_LSEEK;
+ dmabuf->file = file;
+
+ mutex_init(&dmabuf->lock);
+ INIT_LIST_HEAD(&dmabuf->attachments);
+
+ mutex_lock(&db_list.lock);
+ list_add(&dmabuf->list_node, &db_list.head);
+ mutex_unlock(&db_list.lock);
+
+ return dmabuf;
+
+err_dmabuf:
+ kfree(dmabuf);
+err_module:
+ module_put(exp_info->owner);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(dma_buf_export);
+
+/**
+ * dma_buf_fd - returns a file descriptor for the given dma_buf
+ * @dmabuf: [in] pointer to dma_buf for which fd is required.
+ * @flags: [in] flags to give to fd
+ *
+ * On success, returns an associated 'fd'. Else, returns error.
+ */
+int dma_buf_fd(struct dma_buf *dmabuf, int flags)
+{
+ int fd;
+
+ if (!dmabuf || !dmabuf->file)
+ return -EINVAL;
+
+ fd = get_unused_fd_flags(flags);
+ if (fd < 0)
+ return fd;
+
+ fd_install(fd, dmabuf->file);
+
+ return fd;
+}
+EXPORT_SYMBOL_GPL(dma_buf_fd);
+
+/**
+ * dma_buf_get - returns the dma_buf structure related to an fd
+ * @fd: [in] fd associated with the dma_buf to be returned
+ *
+ * On success, returns the dma_buf structure associated with an fd; uses
+ * file's refcounting done by fget to increase refcount. returns ERR_PTR
+ * otherwise.
+ */
+struct dma_buf *dma_buf_get(int fd)
+{
+ struct file *file;
+
+ file = fget(fd);
+
+ if (!file)
+ return ERR_PTR(-EBADF);
+
+ if (!is_dma_buf_file(file)) {
+ fput(file);
+ return ERR_PTR(-EINVAL);
+ }
+
+ return file->private_data;
+}
+EXPORT_SYMBOL_GPL(dma_buf_get);
+
+/**
+ * dma_buf_put - decreases refcount of the buffer
+ * @dmabuf: [in] buffer to reduce refcount of
+ *
+ * Uses file's refcounting done implicitly by fput().
+ *
+ * If, as a result of this call, the refcount becomes 0, the 'release' file
+ * operation related to this fd is called. It calls &dma_buf_ops.release vfunc
+ * in turn, and frees the memory allocated for dmabuf when exported.
+ */
+void dma_buf_put(struct dma_buf *dmabuf)
+{
+ if (WARN_ON(!dmabuf || !dmabuf->file))
+ return;
+
+ fput(dmabuf->file);
+}
+EXPORT_SYMBOL_GPL(dma_buf_put);
+
+/**
+ * dma_buf_attach - Add the device to dma_buf's attachments list; optionally,
+ * calls attach() of dma_buf_ops to allow device-specific attach functionality
+ * @dmabuf: [in] buffer to attach device to.
+ * @dev: [in] device to be attached.
+ *
+ * Returns struct dma_buf_attachment pointer for this attachment. Attachments
+ * must be cleaned up by calling dma_buf_detach().
+ *
+ * Returns:
+ *
+ * A pointer to newly created &dma_buf_attachment on success, or a negative
+ * error code wrapped into a pointer on failure.
+ *
+ * Note that this can fail if the backing storage of @dmabuf is in a place not
+ * accessible to @dev, and cannot be moved to a more suitable place. This is
+ * indicated with the error code -EBUSY.
+ */
+struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
+ struct device *dev)
+{
+ struct dma_buf_attachment *attach;
+ int ret;
+
+ if (WARN_ON(!dmabuf || !dev))
+ return ERR_PTR(-EINVAL);
+
+ attach = kzalloc(sizeof(*attach), GFP_KERNEL);
+ if (!attach)
+ return ERR_PTR(-ENOMEM);
+
+ attach->dev = dev;
+ attach->dmabuf = dmabuf;
+
+ mutex_lock(&dmabuf->lock);
+
+ if (dmabuf->ops->attach) {
+ ret = dmabuf->ops->attach(dmabuf, attach);
+ if (ret)
+ goto err_attach;
+ }
+ list_add(&attach->node, &dmabuf->attachments);
+
+ mutex_unlock(&dmabuf->lock);
+ return attach;
+
+err_attach:
+ kfree(attach);
+ mutex_unlock(&dmabuf->lock);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(dma_buf_attach);
+
+/**
+ * dma_buf_detach - Remove the given attachment from dmabuf's attachments list;
+ * optionally calls detach() of dma_buf_ops for device-specific detach
+ * @dmabuf: [in] buffer to detach from.
+ * @attach: [in] attachment to be detached; is free'd after this call.
+ *
+ * Clean up a device attachment obtained by calling dma_buf_attach().
+ */
+void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
+{
+ if (WARN_ON(!dmabuf || !attach))
+ return;
+
+ mutex_lock(&dmabuf->lock);
+ list_del(&attach->node);
+ if (dmabuf->ops->detach)
+ dmabuf->ops->detach(dmabuf, attach);
+
+ mutex_unlock(&dmabuf->lock);
+ kfree(attach);
+}
+EXPORT_SYMBOL_GPL(dma_buf_detach);
+
+/**
+ * dma_buf_map_attachment - Returns the scatterlist table of the attachment;
+ * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the
+ * dma_buf_ops.
+ * @attach: [in] attachment whose scatterlist is to be returned
+ * @direction: [in] direction of DMA transfer
+ *
+ * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR
+ * on error. May return -EINTR if it is interrupted by a signal.
+ *
+ * A mapping must be unmapped by using dma_buf_unmap_attachment(). Note that
+ * the underlying backing storage is pinned for as long as a mapping exists,
+ * therefore users/importers should not hold onto a mapping for undue amounts of
+ * time.
+ */
+struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
+ enum dma_data_direction direction)
+{
+ struct sg_table *sg_table;
+
+ might_sleep();
+
+ if (WARN_ON(!attach || !attach->dmabuf))
+ return ERR_PTR(-EINVAL);
+
+ sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
+ if (!sg_table)
+ sg_table = ERR_PTR(-ENOMEM);
+
+ return sg_table;
+}
+EXPORT_SYMBOL_GPL(dma_buf_map_attachment);
+
+/**
+ * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
+ * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
+ * dma_buf_ops.
+ * @attach: [in] attachment to unmap buffer from
+ * @sg_table: [in] scatterlist info of the buffer to unmap
+ * @direction: [in] direction of DMA transfer
+ *
+ * This unmaps a DMA mapping for @attached obtained by dma_buf_map_attachment().
+ */
+void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
+ struct sg_table *sg_table,
+ enum dma_data_direction direction)
+{
+ might_sleep();
+
+ if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
+ return;
+
+ attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,
+ direction);
+}
+EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
+
+/**
+ * DOC: cpu access
+ *
+ * There are mutliple reasons for supporting CPU access to a dma buffer object:
+ *
+ * - Fallback operations in the kernel, for example when a device is connected
+ * over USB and the kernel needs to shuffle the data around first before
+ * sending it away. Cache coherency is handled by braketing any transactions
+ * with calls to dma_buf_begin_cpu_access() and dma_buf_end_cpu_access()
+ * access.
+ *
+ * To support dma_buf objects residing in highmem cpu access is page-based
+ * using an api similar to kmap. Accessing a dma_buf is done in aligned chunks
+ * of PAGE_SIZE size. Before accessing a chunk it needs to be mapped, which
+ * returns a pointer in kernel virtual address space. Afterwards the chunk
+ * needs to be unmapped again. There is no limit on how often a given chunk
+ * can be mapped and unmapped, i.e. the importer does not need to call
+ * begin_cpu_access again before mapping the same chunk again.
+ *
+ * Interfaces::
+ * void \*dma_buf_kmap(struct dma_buf \*, unsigned long);
+ * void dma_buf_kunmap(struct dma_buf \*, unsigned long, void \*);
+ *
+ * Implementing the functions is optional for exporters and for importers all
+ * the restrictions of using kmap apply.
+ *
+ * dma_buf kmap calls outside of the range specified in begin_cpu_access are
+ * undefined. If the range is not PAGE_SIZE aligned, kmap needs to succeed on
+ * the partial chunks at the beginning and end but may return stale or bogus
+ * data outside of the range (in these partial chunks).
+ *
+ * For some cases the overhead of kmap can be too high, a vmap interface
+ * is introduced. This interface should be used very carefully, as vmalloc
+ * space is a limited resources on many architectures.
+ *
+ * Interfaces::
+ * void \*dma_buf_vmap(struct dma_buf \*dmabuf)
+ * void dma_buf_vunmap(struct dma_buf \*dmabuf, void \*vaddr)
+ *
+ * The vmap call can fail if there is no vmap support in the exporter, or if
+ * it runs out of vmalloc space. Fallback to kmap should be implemented. Note
+ * that the dma-buf layer keeps a reference count for all vmap access and
+ * calls down into the exporter's vmap function only when no vmapping exists,
+ * and only unmaps it once. Protection against concurrent vmap/vunmap calls is
+ * provided by taking the dma_buf->lock mutex.
+ *
+ * - For full compatibility on the importer side with existing userspace
+ * interfaces, which might already support mmap'ing buffers. This is needed in
+ * many processing pipelines (e.g. feeding a software rendered image into a
+ * hardware pipeline, thumbnail creation, snapshots, ...). Also, Android's ION
+ * framework already supported this and for DMA buffer file descriptors to
+ * replace ION buffers mmap support was needed.
+ *
+ * There is no special interfaces, userspace simply calls mmap on the dma-buf
+ * fd. But like for CPU access there's a need to braket the actual access,
+ * which is handled by the ioctl (DMA_BUF_IOCTL_SYNC). Note that
+ * DMA_BUF_IOCTL_SYNC can fail with -EAGAIN or -EINTR, in which case it must
+ * be restarted.
+ *
+ * Some systems might need some sort of cache coherency management e.g. when
+ * CPU and GPU domains are being accessed through dma-buf at the same time.
+ * To circumvent this problem there are begin/end coherency markers, that
+ * forward directly to existing dma-buf device drivers vfunc hooks. Userspace
+ * can make use of those markers through the DMA_BUF_IOCTL_SYNC ioctl. The
+ * sequence would be used like following:
+ *
+ * - mmap dma-buf fd
+ * - for each drawing/upload cycle in CPU 1. SYNC_START ioctl, 2. read/write
+ * to mmap area 3. SYNC_END ioctl. This can be repeated as often as you
+ * want (with the new data being consumed by say the GPU or the scanout
+ * device)
+ * - munmap once you don't need the buffer any more
+ *
+ * For correctness and optimal performance, it is always required to use
+ * SYNC_START and SYNC_END before and after, respectively, when accessing the
+ * mapped address. Userspace cannot rely on coherent access, even when there
+ * are systems where it just works without calling these ioctls.
+ *
+ * - And as a CPU fallback in userspace processing pipelines.
+ *
+ * Similar to the motivation for kernel cpu access it is again important that
+ * the userspace code of a given importing subsystem can use the same
+ * interfaces with a imported dma-buf buffer object as with a native buffer
+ * object. This is especially important for drm where the userspace part of
+ * contemporary OpenGL, X, and other drivers is huge, and reworking them to
+ * use a different way to mmap a buffer rather invasive.
+ *
+ * The assumption in the current dma-buf interfaces is that redirecting the
+ * initial mmap is all that's needed. A survey of some of the existing
+ * subsystems shows that no driver seems to do any nefarious thing like
+ * syncing up with outstanding asynchronous processing on the device or
+ * allocating special resources at fault time. So hopefully this is good
+ * enough, since adding interfaces to intercept pagefaults and allow pte
+ * shootdowns would increase the complexity quite a bit.
+ *
+ * Interface::
+ * int dma_buf_mmap(struct dma_buf \*, struct vm_area_struct \*,
+ * unsigned long);
+ *
+ * If the importing subsystem simply provides a special-purpose mmap call to
+ * set up a mapping in userspace, calling do_mmap with dma_buf->file will
+ * equally achieve that for a dma-buf object.
+ */
+
+static int __dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
+ enum dma_data_direction direction)
+{
+ bool write = (direction == DMA_BIDIRECTIONAL ||
+ direction == DMA_TO_DEVICE);
+ struct reservation_object *resv = dmabuf->resv;
+ long ret;
+
+ /* Wait on any implicit rendering fences */
+ ret = reservation_object_wait_timeout_rcu(resv, write, true,
+ MAX_SCHEDULE_TIMEOUT);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+/**
+ * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the
+ * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific
+ * preparations. Coherency is only guaranteed in the specified range for the
+ * specified access direction.
+ * @dmabuf: [in] buffer to prepare cpu access for.
+ * @direction: [in] length of range for cpu access.
+ *
+ * After the cpu access is complete the caller should call
+ * dma_buf_end_cpu_access(). Only when cpu access is braketed by both calls is
+ * it guaranteed to be coherent with other DMA access.
+ *
+ * Can return negative error values, returns 0 on success.
+ */
+int dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
+ enum dma_data_direction direction)
+{
+ int ret = 0;
+
+ if (WARN_ON(!dmabuf))
+ return -EINVAL;
+
+ if (dmabuf->ops->begin_cpu_access)
+ ret = dmabuf->ops->begin_cpu_access(dmabuf, direction);
+
+ /* Ensure that all fences are waited upon - but we first allow
+ * the native handler the chance to do so more efficiently if it
+ * chooses. A double invocation here will be reasonably cheap no-op.
+ */
+ if (ret == 0)
+ ret = __dma_buf_begin_cpu_access(dmabuf, direction);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access);
+
+/**
+ * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the
+ * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific
+ * actions. Coherency is only guaranteed in the specified range for the
+ * specified access direction.
+ * @dmabuf: [in] buffer to complete cpu access for.
+ * @direction: [in] length of range for cpu access.
+ *
+ * This terminates CPU access started with dma_buf_begin_cpu_access().
+ *
+ * Can return negative error values, returns 0 on success.
+ */
+int dma_buf_end_cpu_access(struct dma_buf *dmabuf,
+ enum dma_data_direction direction)
+{
+ int ret = 0;
+
+ WARN_ON(!dmabuf);
+
+ if (dmabuf->ops->end_cpu_access)
+ ret = dmabuf->ops->end_cpu_access(dmabuf, direction);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access);
+
+/**
+ * dma_buf_kmap - Map a page of the buffer object into kernel address space. The
+ * same restrictions as for kmap and friends apply.
+ * @dmabuf: [in] buffer to map page from.
+ * @page_num: [in] page in PAGE_SIZE units to map.
+ *
+ * This call must always succeed, any necessary preparations that might fail
+ * need to be done in begin_cpu_access.
+ */
+void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num)
+{
+ WARN_ON(!dmabuf);
+
+ if (!dmabuf->ops->map)
+ return NULL;
+ return dmabuf->ops->map(dmabuf, page_num);
+}
+EXPORT_SYMBOL_GPL(dma_buf_kmap);
+
+/**
+ * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap.
+ * @dmabuf: [in] buffer to unmap page from.
+ * @page_num: [in] page in PAGE_SIZE units to unmap.
+ * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap.
+ *
+ * This call must always succeed.
+ */
+void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num,
+ void *vaddr)
+{
+ WARN_ON(!dmabuf);
+
+ if (dmabuf->ops->unmap)
+ dmabuf->ops->unmap(dmabuf, page_num, vaddr);
+}
+EXPORT_SYMBOL_GPL(dma_buf_kunmap);
+
+
+/**
+ * dma_buf_mmap - Setup up a userspace mmap with the given vma
+ * @dmabuf: [in] buffer that should back the vma
+ * @vma: [in] vma for the mmap
+ * @pgoff: [in] offset in pages where this mmap should start within the
+ * dma-buf buffer.
+ *
+ * This function adjusts the passed in vma so that it points at the file of the
+ * dma_buf operation. It also adjusts the starting pgoff and does bounds
+ * checking on the size of the vma. Then it calls the exporters mmap function to
+ * set up the mapping.
+ *
+ * Can return negative error values, returns 0 on success.
+ */
+int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
+ unsigned long pgoff)
+{
+ struct file *oldfile;
+ int ret;
+
+ if (WARN_ON(!dmabuf || !vma))
+ return -EINVAL;
+
+ /* check for offset overflow */
+ if (pgoff + vma_pages(vma) < pgoff)
+ return -EOVERFLOW;
+
+ /* check for overflowing the buffer's size */
+ if (pgoff + vma_pages(vma) >
+ dmabuf->size >> PAGE_SHIFT)
+ return -EINVAL;
+
+ /* readjust the vma */
+ get_file(dmabuf->file);
+ oldfile = vma->vm_file;
+ vma->vm_file = dmabuf->file;
+ vma->vm_pgoff = pgoff;
+
+ ret = dmabuf->ops->mmap(dmabuf, vma);
+ if (ret) {
+ /* restore old parameters on failure */
+ vma->vm_file = oldfile;
+ fput(dmabuf->file);
+ } else {
+ if (oldfile)
+ fput(oldfile);
+ }
+ return ret;
+
+}
+EXPORT_SYMBOL_GPL(dma_buf_mmap);
+
+/**
+ * dma_buf_vmap - Create virtual mapping for the buffer object into kernel
+ * address space. Same restrictions as for vmap and friends apply.
+ * @dmabuf: [in] buffer to vmap
+ *
+ * This call may fail due to lack of virtual mapping address space.
+ * These calls are optional in drivers. The intended use for them
+ * is for mapping objects linear in kernel space for high use objects.
+ * Please attempt to use kmap/kunmap before thinking about these interfaces.
+ *
+ * Returns NULL on error.
+ */
+void *dma_buf_vmap(struct dma_buf *dmabuf)
+{
+ void *ptr;
+
+ if (WARN_ON(!dmabuf))
+ return NULL;
+
+ if (!dmabuf->ops->vmap)
+ return NULL;
+
+ mutex_lock(&dmabuf->lock);
+ if (dmabuf->vmapping_counter) {
+ dmabuf->vmapping_counter++;
+ BUG_ON(!dmabuf->vmap_ptr);
+ ptr = dmabuf->vmap_ptr;
+ goto out_unlock;
+ }
+
+ BUG_ON(dmabuf->vmap_ptr);
+
+ ptr = dmabuf->ops->vmap(dmabuf);
+ if (WARN_ON_ONCE(IS_ERR(ptr)))
+ ptr = NULL;
+ if (!ptr)
+ goto out_unlock;
+
+ dmabuf->vmap_ptr = ptr;
+ dmabuf->vmapping_counter = 1;
+
+out_unlock:
+ mutex_unlock(&dmabuf->lock);
+ return ptr;
+}
+EXPORT_SYMBOL_GPL(dma_buf_vmap);
+
+/**
+ * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
+ * @dmabuf: [in] buffer to vunmap
+ * @vaddr: [in] vmap to vunmap
+ */
+void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
+{
+ if (WARN_ON(!dmabuf))
+ return;
+
+ BUG_ON(!dmabuf->vmap_ptr);
+ BUG_ON(dmabuf->vmapping_counter == 0);
+ BUG_ON(dmabuf->vmap_ptr != vaddr);
+
+ mutex_lock(&dmabuf->lock);
+ if (--dmabuf->vmapping_counter == 0) {
+ if (dmabuf->ops->vunmap)
+ dmabuf->ops->vunmap(dmabuf, vaddr);
+ dmabuf->vmap_ptr = NULL;
+ }
+ mutex_unlock(&dmabuf->lock);
+}
+EXPORT_SYMBOL_GPL(dma_buf_vunmap);
+
+#ifdef CONFIG_DEBUG_FS
+static int dma_buf_debug_show(struct seq_file *s, void *unused)
+{
+ int ret;
+ struct dma_buf *buf_obj;
+ struct dma_buf_attachment *attach_obj;
+ struct reservation_object *robj;
+ struct reservation_object_list *fobj;
+ struct dma_fence *fence;
+ unsigned seq;
+ int count = 0, attach_count, shared_count, i;
+ size_t size = 0;
+
+ ret = mutex_lock_interruptible(&db_list.lock);
+
+ if (ret)
+ return ret;
+
+ seq_puts(s, "\nDma-buf Objects:\n");
+ seq_printf(s, "%-8s\t%-8s\t%-8s\t%-8s\texp_name\n",
+ "size", "flags", "mode", "count");
+
+ list_for_each_entry(buf_obj, &db_list.head, list_node) {
+ ret = mutex_lock_interruptible(&buf_obj->lock);
+
+ if (ret) {
+ seq_puts(s,
+ "\tERROR locking buffer object: skipping\n");
+ continue;
+ }
+
+ seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n",
+ buf_obj->size,
+ buf_obj->file->f_flags, buf_obj->file->f_mode,
+ file_count(buf_obj->file),
+ buf_obj->exp_name);
+
+ robj = buf_obj->resv;
+ while (true) {
+ seq = read_seqcount_begin(&robj->seq);
+ rcu_read_lock();
+ fobj = rcu_dereference(robj->fence);
+ shared_count = fobj ? fobj->shared_count : 0;
+ fence = rcu_dereference(robj->fence_excl);
+ if (!read_seqcount_retry(&robj->seq, seq))
+ break;
+ rcu_read_unlock();
+ }
+
+ if (fence)
+ seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n",
+ fence->ops->get_driver_name(fence),
+ fence->ops->get_timeline_name(fence),
+ dma_fence_is_signaled(fence) ? "" : "un");
+ for (i = 0; i < shared_count; i++) {
+ fence = rcu_dereference(fobj->shared[i]);
+ if (!dma_fence_get_rcu(fence))
+ continue;
+ seq_printf(s, "\tShared fence: %s %s %ssignalled\n",
+ fence->ops->get_driver_name(fence),
+ fence->ops->get_timeline_name(fence),
+ dma_fence_is_signaled(fence) ? "" : "un");
+ }
+ rcu_read_unlock();
+
+ seq_puts(s, "\tAttached Devices:\n");
+ attach_count = 0;
+
+ list_for_each_entry(attach_obj, &buf_obj->attachments, node) {
+ seq_printf(s, "\t%s\n", dev_name(attach_obj->dev));
+ attach_count++;
+ }
+
+ seq_printf(s, "Total %d devices attached\n\n",
+ attach_count);
+
+ count++;
+ size += buf_obj->size;
+ mutex_unlock(&buf_obj->lock);
+ }
+
+ seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size);
+
+ mutex_unlock(&db_list.lock);
+ return 0;
+}
+
+static int dma_buf_debug_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, dma_buf_debug_show, NULL);
+}
+
+static const struct file_operations dma_buf_debug_fops = {
+ .open = dma_buf_debug_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static struct dentry *dma_buf_debugfs_dir;
+
+static int dma_buf_init_debugfs(void)
+{
+ struct dentry *d;
+ int err = 0;
+
+ d = debugfs_create_dir("dma_buf", NULL);
+ if (IS_ERR(d))
+ return PTR_ERR(d);
+
+ dma_buf_debugfs_dir = d;
+
+ d = debugfs_create_file("bufinfo", S_IRUGO, dma_buf_debugfs_dir,
+ NULL, &dma_buf_debug_fops);
+ if (IS_ERR(d)) {
+ pr_debug("dma_buf: debugfs: failed to create node bufinfo\n");
+ debugfs_remove_recursive(dma_buf_debugfs_dir);
+ dma_buf_debugfs_dir = NULL;
+ err = PTR_ERR(d);
+ }
+
+ return err;
+}
+
+static void dma_buf_uninit_debugfs(void)
+{
+ debugfs_remove_recursive(dma_buf_debugfs_dir);
+}
+#else
+static inline int dma_buf_init_debugfs(void)
+{
+ return 0;
+}
+static inline void dma_buf_uninit_debugfs(void)
+{
+}
+#endif
+
+static int __init dma_buf_init(void)
+{
+ mutex_init(&db_list.lock);
+ INIT_LIST_HEAD(&db_list.head);
+ dma_buf_init_debugfs();
+ return 0;
+}
+subsys_initcall(dma_buf_init);
+
+static void __exit dma_buf_deinit(void)
+{
+ dma_buf_uninit_debugfs();
+}
+__exitcall(dma_buf_deinit);
diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c
new file mode 100644
index 0000000..a8c2544
--- /dev/null
+++ b/drivers/dma-buf/dma-fence-array.c
@@ -0,0 +1,181 @@
+/*
+ * dma-fence-array: aggregate fences to be waited together
+ *
+ * Copyright (C) 2016 Collabora Ltd
+ * Copyright (C) 2016 Advanced Micro Devices, Inc.
+ * Authors:
+ * Gustavo Padovan <gustavo@padovan.org>
+ * Christian König <christian.koenig@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/dma-fence-array.h>
+
+static const char *dma_fence_array_get_driver_name(struct dma_fence *fence)
+{
+ return "dma_fence_array";
+}
+
+static const char *dma_fence_array_get_timeline_name(struct dma_fence *fence)
+{
+ return "unbound";
+}
+
+static void irq_dma_fence_array_work(struct irq_work *wrk)
+{
+ struct dma_fence_array *array = container_of(wrk, typeof(*array), work);
+
+ dma_fence_signal(&array->base);
+ dma_fence_put(&array->base);
+}
+
+static void dma_fence_array_cb_func(struct dma_fence *f,
+ struct dma_fence_cb *cb)
+{
+ struct dma_fence_array_cb *array_cb =
+ container_of(cb, struct dma_fence_array_cb, cb);
+ struct dma_fence_array *array = array_cb->array;
+
+ if (atomic_dec_and_test(&array->num_pending))
+ irq_work_queue(&array->work);
+ else
+ dma_fence_put(&array->base);
+}
+
+static bool dma_fence_array_enable_signaling(struct dma_fence *fence)
+{
+ struct dma_fence_array *array = to_dma_fence_array(fence);
+ struct dma_fence_array_cb *cb = (void *)(&array[1]);
+ unsigned i;
+
+ for (i = 0; i < array->num_fences; ++i) {
+ cb[i].array = array;
+ /*
+ * As we may report that the fence is signaled before all
+ * callbacks are complete, we need to take an additional
+ * reference count on the array so that we do not free it too
+ * early. The core fence handling will only hold the reference
+ * until we signal the array as complete (but that is now
+ * insufficient).
+ */
+ dma_fence_get(&array->base);
+ if (dma_fence_add_callback(array->fences[i], &cb[i].cb,
+ dma_fence_array_cb_func)) {
+ dma_fence_put(&array->base);
+ if (atomic_dec_and_test(&array->num_pending))
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static bool dma_fence_array_signaled(struct dma_fence *fence)
+{
+ struct dma_fence_array *array = to_dma_fence_array(fence);
+
+ return atomic_read(&array->num_pending) <= 0;
+}
+
+static void dma_fence_array_release(struct dma_fence *fence)
+{
+ struct dma_fence_array *array = to_dma_fence_array(fence);
+ unsigned i;
+
+ for (i = 0; i < array->num_fences; ++i)
+ dma_fence_put(array->fences[i]);
+
+ kfree(array->fences);
+ dma_fence_free(fence);
+}
+
+const struct dma_fence_ops dma_fence_array_ops = {
+ .get_driver_name = dma_fence_array_get_driver_name,
+ .get_timeline_name = dma_fence_array_get_timeline_name,
+ .enable_signaling = dma_fence_array_enable_signaling,
+ .signaled = dma_fence_array_signaled,
+ .release = dma_fence_array_release,
+};
+EXPORT_SYMBOL(dma_fence_array_ops);
+
+/**
+ * dma_fence_array_create - Create a custom fence array
+ * @num_fences: [in] number of fences to add in the array
+ * @fences: [in] array containing the fences
+ * @context: [in] fence context to use
+ * @seqno: [in] sequence number to use
+ * @signal_on_any: [in] signal on any fence in the array
+ *
+ * Allocate a dma_fence_array object and initialize the base fence with
+ * dma_fence_init().
+ * In case of error it returns NULL.
+ *
+ * The caller should allocate the fences array with num_fences size
+ * and fill it with the fences it wants to add to the object. Ownership of this
+ * array is taken and dma_fence_put() is used on each fence on release.
+ *
+ * If @signal_on_any is true the fence array signals if any fence in the array
+ * signals, otherwise it signals when all fences in the array signal.
+ */
+struct dma_fence_array *dma_fence_array_create(int num_fences,
+ struct dma_fence **fences,
+ u64 context, unsigned seqno,
+ bool signal_on_any)
+{
+ struct dma_fence_array *array;
+ size_t size = sizeof(*array);
+
+ /* Allocate the callback structures behind the array. */
+ size += num_fences * sizeof(struct dma_fence_array_cb);
+ array = kzalloc(size, GFP_KERNEL);
+ if (!array)
+ return NULL;
+
+ spin_lock_init(&array->lock);
+ dma_fence_init(&array->base, &dma_fence_array_ops, &array->lock,
+ context, seqno);
+ init_irq_work(&array->work, irq_dma_fence_array_work);
+
+ array->num_fences = num_fences;
+ atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences);
+ array->fences = fences;
+
+ return array;
+}
+EXPORT_SYMBOL(dma_fence_array_create);
+
+/**
+ * dma_fence_match_context - Check if all fences are from the given context
+ * @fence: [in] fence or fence array
+ * @context: [in] fence context to check all fences against
+ *
+ * Checks the provided fence or, for a fence array, all fences in the array
+ * against the given context. Returns false if any fence is from a different
+ * context.
+ */
+bool dma_fence_match_context(struct dma_fence *fence, u64 context)
+{
+ struct dma_fence_array *array = to_dma_fence_array(fence);
+ unsigned i;
+
+ if (!dma_fence_is_array(fence))
+ return fence->context == context;
+
+ for (i = 0; i < array->num_fences; i++) {
+ if (array->fences[i]->context != context)
+ return false;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL(dma_fence_match_context);
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
new file mode 100644
index 0000000..1551ca7
--- /dev/null
+++ b/drivers/dma-buf/dma-fence.c
@@ -0,0 +1,634 @@
+/*
+ * Fence mechanism for dma-buf and to allow for asynchronous dma access
+ *
+ * Copyright (C) 2012 Canonical Ltd
+ * Copyright (C) 2012 Texas Instruments
+ *
+ * Authors:
+ * Rob Clark <robdclark@gmail.com>
+ * Maarten Lankhorst <maarten.lankhorst@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/atomic.h>
+#include <linux/dma-fence.h>
+#include <linux/sched/signal.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/dma_fence.h>
+
+EXPORT_TRACEPOINT_SYMBOL(dma_fence_emit);
+EXPORT_TRACEPOINT_SYMBOL(dma_fence_enable_signal);
+
+/*
+ * fence context counter: each execution context should have its own
+ * fence context, this allows checking if fences belong to the same
+ * context or not. One device can have multiple separate contexts,
+ * and they're used if some engine can run independently of another.
+ */
+static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0);
+
+/**
+ * DOC: DMA fences overview
+ *
+ * DMA fences, represented by &struct dma_fence, are the kernel internal
+ * synchronization primitive for DMA operations like GPU rendering, video
+ * encoding/decoding, or displaying buffers on a screen.
+ *
+ * A fence is initialized using dma_fence_init() and completed using
+ * dma_fence_signal(). Fences are associated with a context, allocated through
+ * dma_fence_context_alloc(), and all fences on the same context are
+ * fully ordered.
+ *
+ * Since the purposes of fences is to facilitate cross-device and
+ * cross-application synchronization, there's multiple ways to use one:
+ *
+ * - Individual fences can be exposed as a &sync_file, accessed as a file
+ * descriptor from userspace, created by calling sync_file_create(). This is
+ * called explicit fencing, since userspace passes around explicit
+ * synchronization points.
+ *
+ * - Some subsystems also have their own explicit fencing primitives, like
+ * &drm_syncobj. Compared to &sync_file, a &drm_syncobj allows the underlying
+ * fence to be updated.
+ *
+ * - Then there's also implicit fencing, where the synchronization points are
+ * implicitly passed around as part of shared &dma_buf instances. Such
+ * implicit fences are stored in &struct reservation_object through the
+ * &dma_buf.resv pointer.
+ */
+
+/**
+ * dma_fence_context_alloc - allocate an array of fence contexts
+ * @num: amount of contexts to allocate
+ *
+ * This function will return the first index of the number of fence contexts
+ * allocated. The fence context is used for setting &dma_fence.context to a
+ * unique number by passing the context to dma_fence_init().
+ */
+u64 dma_fence_context_alloc(unsigned num)
+{
+ WARN_ON(!num);
+ return atomic64_add_return(num, &dma_fence_context_counter) - num;
+}
+EXPORT_SYMBOL(dma_fence_context_alloc);
+
+/**
+ * dma_fence_signal_locked - signal completion of a fence
+ * @fence: the fence to signal
+ *
+ * Signal completion for software callbacks on a fence, this will unblock
+ * dma_fence_wait() calls and run all the callbacks added with
+ * dma_fence_add_callback(). Can be called multiple times, but since a fence
+ * can only go from the unsignaled to the signaled state and not back, it will
+ * only be effective the first time.
+ *
+ * Unlike dma_fence_signal(), this function must be called with &dma_fence.lock
+ * held.
+ *
+ * Returns 0 on success and a negative error value when @fence has been
+ * signalled already.
+ */
+int dma_fence_signal_locked(struct dma_fence *fence)
+{
+ struct dma_fence_cb *cur, *tmp;
+ int ret = 0;
+
+ lockdep_assert_held(fence->lock);
+
+ if (WARN_ON(!fence))
+ return -EINVAL;
+
+ if (test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
+ ret = -EINVAL;
+
+ /*
+ * we might have raced with the unlocked dma_fence_signal,
+ * still run through all callbacks
+ */
+ } else {
+ fence->timestamp = ktime_get();
+ set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags);
+ trace_dma_fence_signaled(fence);
+ }
+
+ list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) {
+ list_del_init(&cur->node);
+ cur->func(fence, cur);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(dma_fence_signal_locked);
+
+/**
+ * dma_fence_signal - signal completion of a fence
+ * @fence: the fence to signal
+ *
+ * Signal completion for software callbacks on a fence, this will unblock
+ * dma_fence_wait() calls and run all the callbacks added with
+ * dma_fence_add_callback(). Can be called multiple times, but since a fence
+ * can only go from the unsignaled to the signaled state and not back, it will
+ * only be effective the first time.
+ *
+ * Returns 0 on success and a negative error value when @fence has been
+ * signalled already.
+ */
+int dma_fence_signal(struct dma_fence *fence)
+{
+ unsigned long flags;
+
+ if (!fence)
+ return -EINVAL;
+
+ if (test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
+ return -EINVAL;
+
+ fence->timestamp = ktime_get();
+ set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags);
+ trace_dma_fence_signaled(fence);
+
+ if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags)) {
+ struct dma_fence_cb *cur, *tmp;
+
+ spin_lock_irqsave(fence->lock, flags);
+ list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) {
+ list_del_init(&cur->node);
+ cur->func(fence, cur);
+ }
+ spin_unlock_irqrestore(fence->lock, flags);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(dma_fence_signal);
+
+/**
+ * dma_fence_wait_timeout - sleep until the fence gets signaled
+ * or until timeout elapses
+ * @fence: the fence to wait on
+ * @intr: if true, do an interruptible wait
+ * @timeout: timeout value in jiffies, or MAX_SCHEDULE_TIMEOUT
+ *
+ * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or the
+ * remaining timeout in jiffies on success. Other error values may be
+ * returned on custom implementations.
+ *
+ * Performs a synchronous wait on this fence. It is assumed the caller
+ * directly or indirectly (buf-mgr between reservation and committing)
+ * holds a reference to the fence, otherwise the fence might be
+ * freed before return, resulting in undefined behavior.
+ *
+ * See also dma_fence_wait() and dma_fence_wait_any_timeout().
+ */
+signed long
+dma_fence_wait_timeout(struct dma_fence *fence, bool intr, signed long timeout)
+{
+ signed long ret;
+
+ if (WARN_ON(timeout < 0))
+ return -EINVAL;
+
+ trace_dma_fence_wait_start(fence);
+ if (fence->ops->wait)
+ ret = fence->ops->wait(fence, intr, timeout);
+ else
+ ret = dma_fence_default_wait(fence, intr, timeout);
+ trace_dma_fence_wait_end(fence);
+ return ret;
+}
+EXPORT_SYMBOL(dma_fence_wait_timeout);
+
+/**
+ * dma_fence_release - default relese function for fences
+ * @kref: &dma_fence.recfount
+ *
+ * This is the default release functions for &dma_fence. Drivers shouldn't call
+ * this directly, but instead call dma_fence_put().
+ */
+void dma_fence_release(struct kref *kref)
+{
+ struct dma_fence *fence =
+ container_of(kref, struct dma_fence, refcount);
+
+ trace_dma_fence_destroy(fence);
+
+ /* Failed to signal before release, could be a refcounting issue */
+ WARN_ON(!list_empty(&fence->cb_list));
+
+ if (fence->ops->release)
+ fence->ops->release(fence);
+ else
+ dma_fence_free(fence);
+}
+EXPORT_SYMBOL(dma_fence_release);
+
+/**
+ * dma_fence_free - default release function for &dma_fence.
+ * @fence: fence to release
+ *
+ * This is the default implementation for &dma_fence_ops.release. It calls
+ * kfree_rcu() on @fence.
+ */
+void dma_fence_free(struct dma_fence *fence)
+{
+ kfree_rcu(fence, rcu);
+}
+EXPORT_SYMBOL(dma_fence_free);
+
+/**
+ * dma_fence_enable_sw_signaling - enable signaling on fence
+ * @fence: the fence to enable
+ *
+ * This will request for sw signaling to be enabled, to make the fence
+ * complete as soon as possible. This calls &dma_fence_ops.enable_signaling
+ * internally.
+ */
+void dma_fence_enable_sw_signaling(struct dma_fence *fence)
+{
+ unsigned long flags;
+
+ if (!test_and_set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
+ &fence->flags) &&
+ !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) &&
+ fence->ops->enable_signaling) {
+ trace_dma_fence_enable_signal(fence);
+
+ spin_lock_irqsave(fence->lock, flags);
+
+ if (!fence->ops->enable_signaling(fence))
+ dma_fence_signal_locked(fence);
+
+ spin_unlock_irqrestore(fence->lock, flags);
+ }
+}
+EXPORT_SYMBOL(dma_fence_enable_sw_signaling);
+
+/**
+ * dma_fence_add_callback - add a callback to be called when the fence
+ * is signaled
+ * @fence: the fence to wait on
+ * @cb: the callback to register
+ * @func: the function to call
+ *
+ * @cb will be initialized by dma_fence_add_callback(), no initialization
+ * by the caller is required. Any number of callbacks can be registered
+ * to a fence, but a callback can only be registered to one fence at a time.
+ *
+ * Note that the callback can be called from an atomic context. If
+ * fence is already signaled, this function will return -ENOENT (and
+ * *not* call the callback).
+ *
+ * Add a software callback to the fence. Same restrictions apply to
+ * refcount as it does to dma_fence_wait(), however the caller doesn't need to
+ * keep a refcount to fence afterward dma_fence_add_callback() has returned:
+ * when software access is enabled, the creator of the fence is required to keep
+ * the fence alive until after it signals with dma_fence_signal(). The callback
+ * itself can be called from irq context.
+ *
+ * Returns 0 in case of success, -ENOENT if the fence is already signaled
+ * and -EINVAL in case of error.
+ */
+int dma_fence_add_callback(struct dma_fence *fence, struct dma_fence_cb *cb,
+ dma_fence_func_t func)
+{
+ unsigned long flags;
+ int ret = 0;
+ bool was_set;
+
+ if (WARN_ON(!fence || !func))
+ return -EINVAL;
+
+ if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
+ INIT_LIST_HEAD(&cb->node);
+ return -ENOENT;
+ }
+
+ spin_lock_irqsave(fence->lock, flags);
+
+ was_set = test_and_set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
+ &fence->flags);
+
+ if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
+ ret = -ENOENT;
+ else if (!was_set && fence->ops->enable_signaling) {
+ trace_dma_fence_enable_signal(fence);
+
+ if (!fence->ops->enable_signaling(fence)) {
+ dma_fence_signal_locked(fence);
+ ret = -ENOENT;
+ }
+ }
+
+ if (!ret) {
+ cb->func = func;
+ list_add_tail(&cb->node, &fence->cb_list);
+ } else
+ INIT_LIST_HEAD(&cb->node);
+ spin_unlock_irqrestore(fence->lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(dma_fence_add_callback);
+
+/**
+ * dma_fence_get_status - returns the status upon completion
+ * @fence: the dma_fence to query
+ *
+ * This wraps dma_fence_get_status_locked() to return the error status
+ * condition on a signaled fence. See dma_fence_get_status_locked() for more
+ * details.
+ *
+ * Returns 0 if the fence has not yet been signaled, 1 if the fence has
+ * been signaled without an error condition, or a negative error code
+ * if the fence has been completed in err.
+ */
+int dma_fence_get_status(struct dma_fence *fence)
+{
+ unsigned long flags;
+ int status;
+
+ spin_lock_irqsave(fence->lock, flags);
+ status = dma_fence_get_status_locked(fence);
+ spin_unlock_irqrestore(fence->lock, flags);
+
+ return status;
+}
+EXPORT_SYMBOL(dma_fence_get_status);
+
+/**
+ * dma_fence_remove_callback - remove a callback from the signaling list
+ * @fence: the fence to wait on
+ * @cb: the callback to remove
+ *
+ * Remove a previously queued callback from the fence. This function returns
+ * true if the callback is successfully removed, or false if the fence has
+ * already been signaled.
+ *
+ * *WARNING*:
+ * Cancelling a callback should only be done if you really know what you're
+ * doing, since deadlocks and race conditions could occur all too easily. For
+ * this reason, it should only ever be done on hardware lockup recovery,
+ * with a reference held to the fence.
+ *
+ * Behaviour is undefined if @cb has not been added to @fence using
+ * dma_fence_add_callback() beforehand.
+ */
+bool
+dma_fence_remove_callback(struct dma_fence *fence, struct dma_fence_cb *cb)
+{
+ unsigned long flags;
+ bool ret;
+
+ spin_lock_irqsave(fence->lock, flags);
+
+ ret = !list_empty(&cb->node);
+ if (ret)
+ list_del_init(&cb->node);
+
+ spin_unlock_irqrestore(fence->lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(dma_fence_remove_callback);
+
+struct default_wait_cb {
+ struct dma_fence_cb base;
+ struct task_struct *task;
+};
+
+static void
+dma_fence_default_wait_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
+{
+ struct default_wait_cb *wait =
+ container_of(cb, struct default_wait_cb, base);
+
+ wake_up_state(wait->task, TASK_NORMAL);
+}
+
+/**
+ * dma_fence_default_wait - default sleep until the fence gets signaled
+ * or until timeout elapses
+ * @fence: the fence to wait on
+ * @intr: if true, do an interruptible wait
+ * @timeout: timeout value in jiffies, or MAX_SCHEDULE_TIMEOUT
+ *
+ * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or the
+ * remaining timeout in jiffies on success. If timeout is zero the value one is
+ * returned if the fence is already signaled for consistency with other
+ * functions taking a jiffies timeout.
+ */
+signed long
+dma_fence_default_wait(struct dma_fence *fence, bool intr, signed long timeout)
+{
+ struct default_wait_cb cb;
+ unsigned long flags;
+ signed long ret = timeout ? timeout : 1;
+ bool was_set;
+
+ if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
+ return ret;
+
+ spin_lock_irqsave(fence->lock, flags);
+
+ if (intr && signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ goto out;
+ }
+
+ was_set = test_and_set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
+ &fence->flags);
+
+ if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
+ goto out;
+
+ if (!was_set && fence->ops->enable_signaling) {
+ trace_dma_fence_enable_signal(fence);
+
+ if (!fence->ops->enable_signaling(fence)) {
+ dma_fence_signal_locked(fence);
+ goto out;
+ }
+ }
+
+ if (!timeout) {
+ ret = 0;
+ goto out;
+ }
+
+ cb.base.func = dma_fence_default_wait_cb;
+ cb.task = current;
+ list_add(&cb.base.node, &fence->cb_list);
+
+ while (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) && ret > 0) {
+ if (intr)
+ __set_current_state(TASK_INTERRUPTIBLE);
+ else
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ spin_unlock_irqrestore(fence->lock, flags);
+
+ ret = schedule_timeout(ret);
+
+ spin_lock_irqsave(fence->lock, flags);
+ if (ret > 0 && intr && signal_pending(current))
+ ret = -ERESTARTSYS;
+ }
+
+ if (!list_empty(&cb.base.node))
+ list_del(&cb.base.node);
+ __set_current_state(TASK_RUNNING);
+
+out:
+ spin_unlock_irqrestore(fence->lock, flags);
+ return ret;
+}
+EXPORT_SYMBOL(dma_fence_default_wait);
+
+static bool
+dma_fence_test_signaled_any(struct dma_fence **fences, uint32_t count,
+ uint32_t *idx)
+{
+ int i;
+
+ for (i = 0; i < count; ++i) {
+ struct dma_fence *fence = fences[i];
+ if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
+ if (idx)
+ *idx = i;
+ return true;
+ }
+ }
+ return false;
+}
+
+/**
+ * dma_fence_wait_any_timeout - sleep until any fence gets signaled
+ * or until timeout elapses
+ * @fences: array of fences to wait on
+ * @count: number of fences to wait on
+ * @intr: if true, do an interruptible wait
+ * @timeout: timeout value in jiffies, or MAX_SCHEDULE_TIMEOUT
+ * @idx: used to store the first signaled fence index, meaningful only on
+ * positive return
+ *
+ * Returns -EINVAL on custom fence wait implementation, -ERESTARTSYS if
+ * interrupted, 0 if the wait timed out, or the remaining timeout in jiffies
+ * on success.
+ *
+ * Synchronous waits for the first fence in the array to be signaled. The
+ * caller needs to hold a reference to all fences in the array, otherwise a
+ * fence might be freed before return, resulting in undefined behavior.
+ *
+ * See also dma_fence_wait() and dma_fence_wait_timeout().
+ */
+signed long
+dma_fence_wait_any_timeout(struct dma_fence **fences, uint32_t count,
+ bool intr, signed long timeout, uint32_t *idx)
+{
+ struct default_wait_cb *cb;
+ signed long ret = timeout;
+ unsigned i;
+
+ if (WARN_ON(!fences || !count || timeout < 0))
+ return -EINVAL;
+
+ if (timeout == 0) {
+ for (i = 0; i < count; ++i)
+ if (dma_fence_is_signaled(fences[i])) {
+ if (idx)
+ *idx = i;
+ return 1;
+ }
+
+ return 0;
+ }
+
+ cb = kcalloc(count, sizeof(struct default_wait_cb), GFP_KERNEL);
+ if (cb == NULL) {
+ ret = -ENOMEM;
+ goto err_free_cb;
+ }
+
+ for (i = 0; i < count; ++i) {
+ struct dma_fence *fence = fences[i];
+
+ cb[i].task = current;
+ if (dma_fence_add_callback(fence, &cb[i].base,
+ dma_fence_default_wait_cb)) {
+ /* This fence is already signaled */
+ if (idx)
+ *idx = i;
+ goto fence_rm_cb;
+ }
+ }
+
+ while (ret > 0) {
+ if (intr)
+ set_current_state(TASK_INTERRUPTIBLE);
+ else
+ set_current_state(TASK_UNINTERRUPTIBLE);
+
+ if (dma_fence_test_signaled_any(fences, count, idx))
+ break;
+
+ ret = schedule_timeout(ret);
+
+ if (ret > 0 && intr && signal_pending(current))
+ ret = -ERESTARTSYS;
+ }
+
+ __set_current_state(TASK_RUNNING);
+
+fence_rm_cb:
+ while (i-- > 0)
+ dma_fence_remove_callback(fences[i], &cb[i].base);
+
+err_free_cb:
+ kfree(cb);
+
+ return ret;
+}
+EXPORT_SYMBOL(dma_fence_wait_any_timeout);
+
+/**
+ * dma_fence_init - Initialize a custom fence.
+ * @fence: the fence to initialize
+ * @ops: the dma_fence_ops for operations on this fence
+ * @lock: the irqsafe spinlock to use for locking this fence
+ * @context: the execution context this fence is run on
+ * @seqno: a linear increasing sequence number for this context
+ *
+ * Initializes an allocated fence, the caller doesn't have to keep its
+ * refcount after committing with this fence, but it will need to hold a
+ * refcount again if &dma_fence_ops.enable_signaling gets called.
+ *
+ * context and seqno are used for easy comparison between fences, allowing
+ * to check which fence is later by simply using dma_fence_later().
+ */
+void
+dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops,
+ spinlock_t *lock, u64 context, unsigned seqno)
+{
+ BUG_ON(!lock);
+ BUG_ON(!ops || !ops->get_driver_name || !ops->get_timeline_name);
+
+ kref_init(&fence->refcount);
+ fence->ops = ops;
+ INIT_LIST_HEAD(&fence->cb_list);
+ fence->lock = lock;
+ fence->context = context;
+ fence->seqno = seqno;
+ fence->flags = 0UL;
+ fence->error = 0;
+
+ trace_dma_fence_init(fence);
+}
+EXPORT_SYMBOL(dma_fence_init);
diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
new file mode 100644
index 0000000..6c95f61
--- /dev/null
+++ b/drivers/dma-buf/reservation.c
@@ -0,0 +1,638 @@
+/*
+ * Copyright (C) 2012-2014 Canonical Ltd (Maarten Lankhorst)
+ *
+ * Based on bo.c which bears the following copyright notice,
+ * but is dual licensed:
+ *
+ * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+/*
+ * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
+ */
+
+#include <linux/reservation.h>
+#include <linux/export.h>
+
+/**
+ * DOC: Reservation Object Overview
+ *
+ * The reservation object provides a mechanism to manage shared and
+ * exclusive fences associated with a buffer. A reservation object
+ * can have attached one exclusive fence (normally associated with
+ * write operations) or N shared fences (read operations). The RCU
+ * mechanism is used to protect read access to fences from locked
+ * write-side updates.
+ */
+
+DEFINE_WD_CLASS(reservation_ww_class);
+EXPORT_SYMBOL(reservation_ww_class);
+
+struct lock_class_key reservation_seqcount_class;
+EXPORT_SYMBOL(reservation_seqcount_class);
+
+const char reservation_seqcount_string[] = "reservation_seqcount";
+EXPORT_SYMBOL(reservation_seqcount_string);
+
+/**
+ * reservation_object_reserve_shared - Reserve space to add a shared
+ * fence to a reservation_object.
+ * @obj: reservation object
+ *
+ * Should be called before reservation_object_add_shared_fence(). Must
+ * be called with obj->lock held.
+ *
+ * RETURNS
+ * Zero for success, or -errno
+ */
+int reservation_object_reserve_shared(struct reservation_object *obj)
+{
+ struct reservation_object_list *fobj, *old;
+ u32 max;
+
+ old = reservation_object_get_list(obj);
+
+ if (old && old->shared_max) {
+ if (old->shared_count < old->shared_max) {
+ /* perform an in-place update */
+ kfree(obj->staged);
+ obj->staged = NULL;
+ return 0;
+ } else
+ max = old->shared_max * 2;
+ } else
+ max = 4;
+
+ /*
+ * resize obj->staged or allocate if it doesn't exist,
+ * noop if already correct size
+ */
+ fobj = krealloc(obj->staged, offsetof(typeof(*fobj), shared[max]),
+ GFP_KERNEL);
+ if (!fobj)
+ return -ENOMEM;
+
+ obj->staged = fobj;
+ fobj->shared_max = max;
+ return 0;
+}
+EXPORT_SYMBOL(reservation_object_reserve_shared);
+
+static void
+reservation_object_add_shared_inplace(struct reservation_object *obj,
+ struct reservation_object_list *fobj,
+ struct dma_fence *fence)
+{
+ struct dma_fence *signaled = NULL;
+ u32 i, signaled_idx;
+
+ dma_fence_get(fence);
+
+ preempt_disable();
+ write_seqcount_begin(&obj->seq);
+
+ for (i = 0; i < fobj->shared_count; ++i) {
+ struct dma_fence *old_fence;
+
+ old_fence = rcu_dereference_protected(fobj->shared[i],
+ reservation_object_held(obj));
+
+ if (old_fence->context == fence->context) {
+ /* memory barrier is added by write_seqcount_begin */
+ RCU_INIT_POINTER(fobj->shared[i], fence);
+ write_seqcount_end(&obj->seq);
+ preempt_enable();
+
+ dma_fence_put(old_fence);
+ return;
+ }
+
+ if (!signaled && dma_fence_is_signaled(old_fence)) {
+ signaled = old_fence;
+ signaled_idx = i;
+ }
+ }
+
+ /*
+ * memory barrier is added by write_seqcount_begin,
+ * fobj->shared_count is protected by this lock too
+ */
+ if (signaled) {
+ RCU_INIT_POINTER(fobj->shared[signaled_idx], fence);
+ } else {
+ BUG_ON(fobj->shared_count >= fobj->shared_max);
+ RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
+ fobj->shared_count++;
+ }
+
+ write_seqcount_end(&obj->seq);
+ preempt_enable();
+
+ dma_fence_put(signaled);
+}
+
+static void
+reservation_object_add_shared_replace(struct reservation_object *obj,
+ struct reservation_object_list *old,
+ struct reservation_object_list *fobj,
+ struct dma_fence *fence)
+{
+ unsigned i, j, k;
+
+ dma_fence_get(fence);
+
+ if (!old) {
+ RCU_INIT_POINTER(fobj->shared[0], fence);
+ fobj->shared_count = 1;
+ goto done;
+ }
+
+ /*
+ * no need to bump fence refcounts, rcu_read access
+ * requires the use of kref_get_unless_zero, and the
+ * references from the old struct are carried over to
+ * the new.
+ */
+ for (i = 0, j = 0, k = fobj->shared_max; i < old->shared_count; ++i) {
+ struct dma_fence *check;
+
+ check = rcu_dereference_protected(old->shared[i],
+ reservation_object_held(obj));
+
+ if (check->context == fence->context ||
+ dma_fence_is_signaled(check))
+ RCU_INIT_POINTER(fobj->shared[--k], check);
+ else
+ RCU_INIT_POINTER(fobj->shared[j++], check);
+ }
+ fobj->shared_count = j;
+ RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
+ fobj->shared_count++;
+
+done:
+ preempt_disable();
+ write_seqcount_begin(&obj->seq);
+ /*
+ * RCU_INIT_POINTER can be used here,
+ * seqcount provides the necessary barriers
+ */
+ RCU_INIT_POINTER(obj->fence, fobj);
+ write_seqcount_end(&obj->seq);
+ preempt_enable();
+
+ if (!old)
+ return;
+
+ /* Drop the references to the signaled fences */
+ for (i = k; i < fobj->shared_max; ++i) {
+ struct dma_fence *f;
+
+ f = rcu_dereference_protected(fobj->shared[i],
+ reservation_object_held(obj));
+ dma_fence_put(f);
+ }
+ kfree_rcu(old, rcu);
+}
+
+/**
+ * reservation_object_add_shared_fence - Add a fence to a shared slot
+ * @obj: the reservation object
+ * @fence: the shared fence to add
+ *
+ * Add a fence to a shared slot, obj->lock must be held, and
+ * reservation_object_reserve_shared() has been called.
+ */
+void reservation_object_add_shared_fence(struct reservation_object *obj,
+ struct dma_fence *fence)
+{
+ struct reservation_object_list *old, *fobj = obj->staged;
+
+ old = reservation_object_get_list(obj);
+ obj->staged = NULL;
+
+ if (!fobj)
+ reservation_object_add_shared_inplace(obj, old, fence);
+ else
+ reservation_object_add_shared_replace(obj, old, fobj, fence);
+}
+EXPORT_SYMBOL(reservation_object_add_shared_fence);
+
+/**
+ * reservation_object_add_excl_fence - Add an exclusive fence.
+ * @obj: the reservation object
+ * @fence: the shared fence to add
+ *
+ * Add a fence to the exclusive slot. The obj->lock must be held.
+ */
+void reservation_object_add_excl_fence(struct reservation_object *obj,
+ struct dma_fence *fence)
+{
+ struct dma_fence *old_fence = reservation_object_get_excl(obj);
+ struct reservation_object_list *old;
+ u32 i = 0;
+
+ old = reservation_object_get_list(obj);
+ if (old)
+ i = old->shared_count;
+
+ if (fence)
+ dma_fence_get(fence);
+
+ preempt_disable();
+ write_seqcount_begin(&obj->seq);
+ /* write_seqcount_begin provides the necessary memory barrier */
+ RCU_INIT_POINTER(obj->fence_excl, fence);
+ if (old)
+ old->shared_count = 0;
+ write_seqcount_end(&obj->seq);
+ preempt_enable();
+
+ /* inplace update, no shared fences */
+ while (i--)
+ dma_fence_put(rcu_dereference_protected(old->shared[i],
+ reservation_object_held(obj)));
+
+ dma_fence_put(old_fence);
+}
+EXPORT_SYMBOL(reservation_object_add_excl_fence);
+
+/**
+* reservation_object_copy_fences - Copy all fences from src to dst.
+* @dst: the destination reservation object
+* @src: the source reservation object
+*
+* Copy all fences from src to dst. dst-lock must be held.
+*/
+int reservation_object_copy_fences(struct reservation_object *dst,
+ struct reservation_object *src)
+{
+ struct reservation_object_list *src_list, *dst_list;
+ struct dma_fence *old, *new;
+ size_t size;
+ unsigned i;
+
+ rcu_read_lock();
+ src_list = rcu_dereference(src->fence);
+
+retry:
+ if (src_list) {
+ unsigned shared_count = src_list->shared_count;
+
+ size = offsetof(typeof(*src_list), shared[shared_count]);
+ rcu_read_unlock();
+
+ dst_list = kmalloc(size, GFP_KERNEL);
+ if (!dst_list)
+ return -ENOMEM;
+
+ rcu_read_lock();
+ src_list = rcu_dereference(src->fence);
+ if (!src_list || src_list->shared_count > shared_count) {
+ kfree(dst_list);
+ goto retry;
+ }
+
+ dst_list->shared_count = 0;
+ dst_list->shared_max = shared_count;
+ for (i = 0; i < src_list->shared_count; ++i) {
+ struct dma_fence *fence;
+
+ fence = rcu_dereference(src_list->shared[i]);
+ if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
+ &fence->flags))
+ continue;
+
+ if (!dma_fence_get_rcu(fence)) {
+ kfree(dst_list);
+ src_list = rcu_dereference(src->fence);
+ goto retry;
+ }
+
+ if (dma_fence_is_signaled(fence)) {
+ dma_fence_put(fence);
+ continue;
+ }
+
+ rcu_assign_pointer(dst_list->shared[dst_list->shared_count++], fence);
+ }
+ } else {
+ dst_list = NULL;
+ }
+
+ new = dma_fence_get_rcu_safe(&src->fence_excl);
+ rcu_read_unlock();
+
+ kfree(dst->staged);
+ dst->staged = NULL;
+
+ src_list = reservation_object_get_list(dst);
+ old = reservation_object_get_excl(dst);
+
+ preempt_disable();
+ write_seqcount_begin(&dst->seq);
+ /* write_seqcount_begin provides the necessary memory barrier */
+ RCU_INIT_POINTER(dst->fence_excl, new);
+ RCU_INIT_POINTER(dst->fence, dst_list);
+ write_seqcount_end(&dst->seq);
+ preempt_enable();
+
+ if (src_list)
+ kfree_rcu(src_list, rcu);
+ dma_fence_put(old);
+
+ return 0;
+}
+EXPORT_SYMBOL(reservation_object_copy_fences);
+
+/**
+ * reservation_object_get_fences_rcu - Get an object's shared and exclusive
+ * fences without update side lock held
+ * @obj: the reservation object
+ * @pfence_excl: the returned exclusive fence (or NULL)
+ * @pshared_count: the number of shared fences returned
+ * @pshared: the array of shared fence ptrs returned (array is krealloc'd to
+ * the required size, and must be freed by caller)
+ *
+ * Retrieve all fences from the reservation object. If the pointer for the
+ * exclusive fence is not specified the fence is put into the array of the
+ * shared fences as well. Returns either zero or -ENOMEM.
+ */
+int reservation_object_get_fences_rcu(struct reservation_object *obj,
+ struct dma_fence **pfence_excl,
+ unsigned *pshared_count,
+ struct dma_fence ***pshared)
+{
+ struct dma_fence **shared = NULL;
+ struct dma_fence *fence_excl;
+ unsigned int shared_count;
+ int ret = 1;
+
+ do {
+ struct reservation_object_list *fobj;
+ unsigned int i, seq;
+ size_t sz = 0;
+
+ shared_count = i = 0;
+
+ rcu_read_lock();
+ seq = read_seqcount_begin(&obj->seq);
+
+ fence_excl = rcu_dereference(obj->fence_excl);
+ if (fence_excl && !dma_fence_get_rcu(fence_excl))
+ goto unlock;
+
+ fobj = rcu_dereference(obj->fence);
+ if (fobj)
+ sz += sizeof(*shared) * fobj->shared_max;
+
+ if (!pfence_excl && fence_excl)
+ sz += sizeof(*shared);
+
+ if (sz) {
+ struct dma_fence **nshared;
+
+ nshared = krealloc(shared, sz,
+ GFP_NOWAIT | __GFP_NOWARN);
+ if (!nshared) {
+ rcu_read_unlock();
+ nshared = krealloc(shared, sz, GFP_KERNEL);
+ if (nshared) {
+ shared = nshared;
+ continue;
+ }
+
+ ret = -ENOMEM;
+ break;
+ }
+ shared = nshared;
+ shared_count = fobj ? fobj->shared_count : 0;
+ for (i = 0; i < shared_count; ++i) {
+ shared[i] = rcu_dereference(fobj->shared[i]);
+ if (!dma_fence_get_rcu(shared[i]))
+ break;
+ }
+
+ if (!pfence_excl && fence_excl) {
+ shared[i] = fence_excl;
+ fence_excl = NULL;
+ ++i;
+ ++shared_count;
+ }
+ }
+
+ if (i != shared_count || read_seqcount_retry(&obj->seq, seq)) {
+ while (i--)
+ dma_fence_put(shared[i]);
+ dma_fence_put(fence_excl);
+ goto unlock;
+ }
+
+ ret = 0;
+unlock:
+ rcu_read_unlock();
+ } while (ret);
+
+ if (!shared_count) {
+ kfree(shared);
+ shared = NULL;
+ }
+
+ *pshared_count = shared_count;
+ *pshared = shared;
+ if (pfence_excl)
+ *pfence_excl = fence_excl;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(reservation_object_get_fences_rcu);
+
+/**
+ * reservation_object_wait_timeout_rcu - Wait on reservation's objects
+ * shared and/or exclusive fences.
+ * @obj: the reservation object
+ * @wait_all: if true, wait on all fences, else wait on just exclusive fence
+ * @intr: if true, do interruptible wait
+ * @timeout: timeout value in jiffies or zero to return immediately
+ *
+ * RETURNS
+ * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or
+ * greater than zer on success.
+ */
+long reservation_object_wait_timeout_rcu(struct reservation_object *obj,
+ bool wait_all, bool intr,
+ unsigned long timeout)
+{
+ struct dma_fence *fence;
+ unsigned seq, shared_count;
+ long ret = timeout ? timeout : 1;
+ int i;
+
+retry:
+ shared_count = 0;
+ seq = read_seqcount_begin(&obj->seq);
+ rcu_read_lock();
+ i = -1;
+
+ fence = rcu_dereference(obj->fence_excl);
+ if (fence && !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
+ if (!dma_fence_get_rcu(fence))
+ goto unlock_retry;
+
+ if (dma_fence_is_signaled(fence)) {
+ dma_fence_put(fence);
+ fence = NULL;
+ }
+
+ } else {
+ fence = NULL;
+ }
+
+ if (wait_all) {
+ struct reservation_object_list *fobj =
+ rcu_dereference(obj->fence);
+
+ if (fobj)
+ shared_count = fobj->shared_count;
+
+ for (i = 0; !fence && i < shared_count; ++i) {
+ struct dma_fence *lfence = rcu_dereference(fobj->shared[i]);
+
+ if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
+ &lfence->flags))
+ continue;
+
+ if (!dma_fence_get_rcu(lfence))
+ goto unlock_retry;
+
+ if (dma_fence_is_signaled(lfence)) {
+ dma_fence_put(lfence);
+ continue;
+ }
+
+ fence = lfence;
+ break;
+ }
+ }
+
+ rcu_read_unlock();
+ if (fence) {
+ if (read_seqcount_retry(&obj->seq, seq)) {
+ dma_fence_put(fence);
+ goto retry;
+ }
+
+ ret = dma_fence_wait_timeout(fence, intr, ret);
+ dma_fence_put(fence);
+ if (ret > 0 && wait_all && (i + 1 < shared_count))
+ goto retry;
+ }
+ return ret;
+
+unlock_retry:
+ rcu_read_unlock();
+ goto retry;
+}
+EXPORT_SYMBOL_GPL(reservation_object_wait_timeout_rcu);
+
+
+static inline int
+reservation_object_test_signaled_single(struct dma_fence *passed_fence)
+{
+ struct dma_fence *fence, *lfence = passed_fence;
+ int ret = 1;
+
+ if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &lfence->flags)) {
+ fence = dma_fence_get_rcu(lfence);
+ if (!fence)
+ return -1;
+
+ ret = !!dma_fence_is_signaled(fence);
+ dma_fence_put(fence);
+ }
+ return ret;
+}
+
+/**
+ * reservation_object_test_signaled_rcu - Test if a reservation object's
+ * fences have been signaled.
+ * @obj: the reservation object
+ * @test_all: if true, test all fences, otherwise only test the exclusive
+ * fence
+ *
+ * RETURNS
+ * true if all fences signaled, else false
+ */
+bool reservation_object_test_signaled_rcu(struct reservation_object *obj,
+ bool test_all)
+{
+ unsigned seq, shared_count;
+ int ret;
+
+ rcu_read_lock();
+retry:
+ ret = true;
+ shared_count = 0;
+ seq = read_seqcount_begin(&obj->seq);
+
+ if (test_all) {
+ unsigned i;
+
+ struct reservation_object_list *fobj =
+ rcu_dereference(obj->fence);
+
+ if (fobj)
+ shared_count = fobj->shared_count;
+
+ for (i = 0; i < shared_count; ++i) {
+ struct dma_fence *fence = rcu_dereference(fobj->shared[i]);
+
+ ret = reservation_object_test_signaled_single(fence);
+ if (ret < 0)
+ goto retry;
+ else if (!ret)
+ break;
+ }
+
+ if (read_seqcount_retry(&obj->seq, seq))
+ goto retry;
+ }
+
+ if (!shared_count) {
+ struct dma_fence *fence_excl = rcu_dereference(obj->fence_excl);
+
+ if (fence_excl) {
+ ret = reservation_object_test_signaled_single(
+ fence_excl);
+ if (ret < 0)
+ goto retry;
+
+ if (read_seqcount_retry(&obj->seq, seq))
+ goto retry;
+ }
+ }
+
+ rcu_read_unlock();
+ return ret;
+}
+EXPORT_SYMBOL_GPL(reservation_object_test_signaled_rcu);
diff --git a/drivers/dma-buf/seqno-fence.c b/drivers/dma-buf/seqno-fence.c
new file mode 100644
index 0000000..f47112a
--- /dev/null
+++ b/drivers/dma-buf/seqno-fence.c
@@ -0,0 +1,79 @@
+/*
+ * seqno-fence, using a dma-buf to synchronize fencing
+ *
+ * Copyright (C) 2012 Texas Instruments
+ * Copyright (C) 2012-2014 Canonical Ltd
+ * Authors:
+ * Rob Clark <robdclark@gmail.com>
+ * Maarten Lankhorst <maarten.lankhorst@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/seqno-fence.h>
+
+static const char *seqno_fence_get_driver_name(struct dma_fence *fence)
+{
+ struct seqno_fence *seqno_fence = to_seqno_fence(fence);
+
+ return seqno_fence->ops->get_driver_name(fence);
+}
+
+static const char *seqno_fence_get_timeline_name(struct dma_fence *fence)
+{
+ struct seqno_fence *seqno_fence = to_seqno_fence(fence);
+
+ return seqno_fence->ops->get_timeline_name(fence);
+}
+
+static bool seqno_enable_signaling(struct dma_fence *fence)
+{
+ struct seqno_fence *seqno_fence = to_seqno_fence(fence);
+
+ return seqno_fence->ops->enable_signaling(fence);
+}
+
+static bool seqno_signaled(struct dma_fence *fence)
+{
+ struct seqno_fence *seqno_fence = to_seqno_fence(fence);
+
+ return seqno_fence->ops->signaled && seqno_fence->ops->signaled(fence);
+}
+
+static void seqno_release(struct dma_fence *fence)
+{
+ struct seqno_fence *f = to_seqno_fence(fence);
+
+ dma_buf_put(f->sync_buf);
+ if (f->ops->release)
+ f->ops->release(fence);
+ else
+ dma_fence_free(&f->base);
+}
+
+static signed long seqno_wait(struct dma_fence *fence, bool intr,
+ signed long timeout)
+{
+ struct seqno_fence *f = to_seqno_fence(fence);
+
+ return f->ops->wait(fence, intr, timeout);
+}
+
+const struct dma_fence_ops seqno_fence_ops = {
+ .get_driver_name = seqno_fence_get_driver_name,
+ .get_timeline_name = seqno_fence_get_timeline_name,
+ .enable_signaling = seqno_enable_signaling,
+ .signaled = seqno_signaled,
+ .wait = seqno_wait,
+ .release = seqno_release,
+};
+EXPORT_SYMBOL(seqno_fence_ops);
diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
new file mode 100644
index 0000000..53c1d6d
--- /dev/null
+++ b/drivers/dma-buf/sw_sync.c
@@ -0,0 +1,423 @@
+/*
+ * Sync File validation framework
+ *
+ * Copyright (C) 2012 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/sync_file.h>
+
+#include "sync_debug.h"
+
+#define CREATE_TRACE_POINTS
+#include "sync_trace.h"
+
+/*
+ * SW SYNC validation framework
+ *
+ * A sync object driver that uses a 32bit counter to coordinate
+ * synchronization. Useful when there is no hardware primitive backing
+ * the synchronization.
+ *
+ * To start the framework just open:
+ *
+ * <debugfs>/sync/sw_sync
+ *
+ * That will create a sync timeline, all fences created under this timeline
+ * file descriptor will belong to the this timeline.
+ *
+ * The 'sw_sync' file can be opened many times as to create different
+ * timelines.
+ *
+ * Fences can be created with SW_SYNC_IOC_CREATE_FENCE ioctl with struct
+ * sw_sync_create_fence_data as parameter.
+ *
+ * To increment the timeline counter, SW_SYNC_IOC_INC ioctl should be used
+ * with the increment as u32. This will update the last signaled value
+ * from the timeline and signal any fence that has a seqno smaller or equal
+ * to it.
+ *
+ * struct sw_sync_create_fence_data
+ * @value: the seqno to initialise the fence with
+ * @name: the name of the new sync point
+ * @fence: return the fd of the new sync_file with the created fence
+ */
+struct sw_sync_create_fence_data {
+ __u32 value;
+ char name[32];
+ __s32 fence; /* fd of new fence */
+};
+
+#define SW_SYNC_IOC_MAGIC 'W'
+
+#define SW_SYNC_IOC_CREATE_FENCE _IOWR(SW_SYNC_IOC_MAGIC, 0,\
+ struct sw_sync_create_fence_data)
+
+#define SW_SYNC_IOC_INC _IOW(SW_SYNC_IOC_MAGIC, 1, __u32)
+
+static const struct dma_fence_ops timeline_fence_ops;
+
+static inline struct sync_pt *dma_fence_to_sync_pt(struct dma_fence *fence)
+{
+ if (fence->ops != &timeline_fence_ops)
+ return NULL;
+ return container_of(fence, struct sync_pt, base);
+}
+
+/**
+ * sync_timeline_create() - creates a sync object
+ * @name: sync_timeline name
+ *
+ * Creates a new sync_timeline. Returns the sync_timeline object or NULL in
+ * case of error.
+ */
+static struct sync_timeline *sync_timeline_create(const char *name)
+{
+ struct sync_timeline *obj;
+
+ obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+ if (!obj)
+ return NULL;
+
+ kref_init(&obj->kref);
+ obj->context = dma_fence_context_alloc(1);
+ strlcpy(obj->name, name, sizeof(obj->name));
+
+ obj->pt_tree = RB_ROOT;
+ INIT_LIST_HEAD(&obj->pt_list);
+ spin_lock_init(&obj->lock);
+
+ sync_timeline_debug_add(obj);
+
+ return obj;
+}
+
+static void sync_timeline_free(struct kref *kref)
+{
+ struct sync_timeline *obj =
+ container_of(kref, struct sync_timeline, kref);
+
+ sync_timeline_debug_remove(obj);
+
+ kfree(obj);
+}
+
+static void sync_timeline_get(struct sync_timeline *obj)
+{
+ kref_get(&obj->kref);
+}
+
+static void sync_timeline_put(struct sync_timeline *obj)
+{
+ kref_put(&obj->kref, sync_timeline_free);
+}
+
+static const char *timeline_fence_get_driver_name(struct dma_fence *fence)
+{
+ return "sw_sync";
+}
+
+static const char *timeline_fence_get_timeline_name(struct dma_fence *fence)
+{
+ struct sync_timeline *parent = dma_fence_parent(fence);
+
+ return parent->name;
+}
+
+static void timeline_fence_release(struct dma_fence *fence)
+{
+ struct sync_pt *pt = dma_fence_to_sync_pt(fence);
+ struct sync_timeline *parent = dma_fence_parent(fence);
+
+ if (!list_empty(&pt->link)) {
+ unsigned long flags;
+
+ spin_lock_irqsave(fence->lock, flags);
+ if (!list_empty(&pt->link)) {
+ list_del(&pt->link);
+ rb_erase(&pt->node, &parent->pt_tree);
+ }
+ spin_unlock_irqrestore(fence->lock, flags);
+ }
+
+ sync_timeline_put(parent);
+ dma_fence_free(fence);
+}
+
+static bool timeline_fence_signaled(struct dma_fence *fence)
+{
+ struct sync_timeline *parent = dma_fence_parent(fence);
+
+ return !__dma_fence_is_later(fence->seqno, parent->value);
+}
+
+static bool timeline_fence_enable_signaling(struct dma_fence *fence)
+{
+ return true;
+}
+
+static void timeline_fence_value_str(struct dma_fence *fence,
+ char *str, int size)
+{
+ snprintf(str, size, "%d", fence->seqno);
+}
+
+static void timeline_fence_timeline_value_str(struct dma_fence *fence,
+ char *str, int size)
+{
+ struct sync_timeline *parent = dma_fence_parent(fence);
+
+ snprintf(str, size, "%d", parent->value);
+}
+
+static const struct dma_fence_ops timeline_fence_ops = {
+ .get_driver_name = timeline_fence_get_driver_name,
+ .get_timeline_name = timeline_fence_get_timeline_name,
+ .enable_signaling = timeline_fence_enable_signaling,
+ .signaled = timeline_fence_signaled,
+ .release = timeline_fence_release,
+ .fence_value_str = timeline_fence_value_str,
+ .timeline_value_str = timeline_fence_timeline_value_str,
+};
+
+/**
+ * sync_timeline_signal() - signal a status change on a sync_timeline
+ * @obj: sync_timeline to signal
+ * @inc: num to increment on timeline->value
+ *
+ * A sync implementation should call this any time one of it's fences
+ * has signaled or has an error condition.
+ */
+static void sync_timeline_signal(struct sync_timeline *obj, unsigned int inc)
+{
+ struct sync_pt *pt, *next;
+
+ trace_sync_timeline(obj);
+
+ spin_lock_irq(&obj->lock);
+
+ obj->value += inc;
+
+ list_for_each_entry_safe(pt, next, &obj->pt_list, link) {
+ if (!timeline_fence_signaled(&pt->base))
+ break;
+
+ list_del_init(&pt->link);
+ rb_erase(&pt->node, &obj->pt_tree);
+
+ /*
+ * A signal callback may release the last reference to this
+ * fence, causing it to be freed. That operation has to be
+ * last to avoid a use after free inside this loop, and must
+ * be after we remove the fence from the timeline in order to
+ * prevent deadlocking on timeline->lock inside
+ * timeline_fence_release().
+ */
+ dma_fence_signal_locked(&pt->base);
+ }
+
+ spin_unlock_irq(&obj->lock);
+}
+
+/**
+ * sync_pt_create() - creates a sync pt
+ * @obj: parent sync_timeline
+ * @value: value of the fence
+ *
+ * Creates a new sync_pt (fence) as a child of @parent. @size bytes will be
+ * allocated allowing for implementation specific data to be kept after
+ * the generic sync_timeline struct. Returns the sync_pt object or
+ * NULL in case of error.
+ */
+static struct sync_pt *sync_pt_create(struct sync_timeline *obj,
+ unsigned int value)
+{
+ struct sync_pt *pt;
+
+ pt = kzalloc(sizeof(*pt), GFP_KERNEL);
+ if (!pt)
+ return NULL;
+
+ sync_timeline_get(obj);
+ dma_fence_init(&pt->base, &timeline_fence_ops, &obj->lock,
+ obj->context, value);
+ INIT_LIST_HEAD(&pt->link);
+
+ spin_lock_irq(&obj->lock);
+ if (!dma_fence_is_signaled_locked(&pt->base)) {
+ struct rb_node **p = &obj->pt_tree.rb_node;
+ struct rb_node *parent = NULL;
+
+ while (*p) {
+ struct sync_pt *other;
+ int cmp;
+
+ parent = *p;
+ other = rb_entry(parent, typeof(*pt), node);
+ cmp = value - other->base.seqno;
+ if (cmp > 0) {
+ p = &parent->rb_right;
+ } else if (cmp < 0) {
+ p = &parent->rb_left;
+ } else {
+ if (dma_fence_get_rcu(&other->base)) {
+ dma_fence_put(&pt->base);
+ pt = other;
+ goto unlock;
+ }
+ p = &parent->rb_left;
+ }
+ }
+ rb_link_node(&pt->node, parent, p);
+ rb_insert_color(&pt->node, &obj->pt_tree);
+
+ parent = rb_next(&pt->node);
+ list_add_tail(&pt->link,
+ parent ? &rb_entry(parent, typeof(*pt), node)->link : &obj->pt_list);
+ }
+unlock:
+ spin_unlock_irq(&obj->lock);
+
+ return pt;
+}
+
+/*
+ * *WARNING*
+ *
+ * improper use of this can result in deadlocking kernel drivers from userspace.
+ */
+
+/* opening sw_sync create a new sync obj */
+static int sw_sync_debugfs_open(struct inode *inode, struct file *file)
+{
+ struct sync_timeline *obj;
+ char task_comm[TASK_COMM_LEN];
+
+ get_task_comm(task_comm, current);
+
+ obj = sync_timeline_create(task_comm);
+ if (!obj)
+ return -ENOMEM;
+
+ file->private_data = obj;
+
+ return 0;
+}
+
+static int sw_sync_debugfs_release(struct inode *inode, struct file *file)
+{
+ struct sync_timeline *obj = file->private_data;
+ struct sync_pt *pt, *next;
+
+ spin_lock_irq(&obj->lock);
+
+ list_for_each_entry_safe(pt, next, &obj->pt_list, link) {
+ dma_fence_set_error(&pt->base, -ENOENT);
+ dma_fence_signal_locked(&pt->base);
+ }
+
+ spin_unlock_irq(&obj->lock);
+
+ sync_timeline_put(obj);
+ return 0;
+}
+
+static long sw_sync_ioctl_create_fence(struct sync_timeline *obj,
+ unsigned long arg)
+{
+ int fd = get_unused_fd_flags(O_CLOEXEC);
+ int err;
+ struct sync_pt *pt;
+ struct sync_file *sync_file;
+ struct sw_sync_create_fence_data data;
+
+ if (fd < 0)
+ return fd;
+
+ if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
+ err = -EFAULT;
+ goto err;
+ }
+
+ pt = sync_pt_create(obj, data.value);
+ if (!pt) {
+ err = -ENOMEM;
+ goto err;
+ }
+
+ sync_file = sync_file_create(&pt->base);
+ dma_fence_put(&pt->base);
+ if (!sync_file) {
+ err = -ENOMEM;
+ goto err;
+ }
+
+ data.fence = fd;
+ if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
+ fput(sync_file->file);
+ err = -EFAULT;
+ goto err;
+ }
+
+ fd_install(fd, sync_file->file);
+
+ return 0;
+
+err:
+ put_unused_fd(fd);
+ return err;
+}
+
+static long sw_sync_ioctl_inc(struct sync_timeline *obj, unsigned long arg)
+{
+ u32 value;
+
+ if (copy_from_user(&value, (void __user *)arg, sizeof(value)))
+ return -EFAULT;
+
+ while (value > INT_MAX) {
+ sync_timeline_signal(obj, INT_MAX);
+ value -= INT_MAX;
+ }
+
+ sync_timeline_signal(obj, value);
+
+ return 0;
+}
+
+static long sw_sync_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct sync_timeline *obj = file->private_data;
+
+ switch (cmd) {
+ case SW_SYNC_IOC_CREATE_FENCE:
+ return sw_sync_ioctl_create_fence(obj, arg);
+
+ case SW_SYNC_IOC_INC:
+ return sw_sync_ioctl_inc(obj, arg);
+
+ default:
+ return -ENOTTY;
+ }
+}
+
+const struct file_operations sw_sync_debugfs_fops = {
+ .open = sw_sync_debugfs_open,
+ .release = sw_sync_debugfs_release,
+ .unlocked_ioctl = sw_sync_ioctl,
+ .compat_ioctl = sw_sync_ioctl,
+};
diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c
new file mode 100644
index 0000000..c4c8ecb
--- /dev/null
+++ b/drivers/dma-buf/sync_debug.c
@@ -0,0 +1,235 @@
+/*
+ * Sync File validation framework and debug information
+ *
+ * Copyright (C) 2012 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/debugfs.h>
+#include "sync_debug.h"
+
+static struct dentry *dbgfs;
+
+static LIST_HEAD(sync_timeline_list_head);
+static DEFINE_SPINLOCK(sync_timeline_list_lock);
+static LIST_HEAD(sync_file_list_head);
+static DEFINE_SPINLOCK(sync_file_list_lock);
+
+void sync_timeline_debug_add(struct sync_timeline *obj)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sync_timeline_list_lock, flags);
+ list_add_tail(&obj->sync_timeline_list, &sync_timeline_list_head);
+ spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
+}
+
+void sync_timeline_debug_remove(struct sync_timeline *obj)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sync_timeline_list_lock, flags);
+ list_del(&obj->sync_timeline_list);
+ spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
+}
+
+void sync_file_debug_add(struct sync_file *sync_file)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sync_file_list_lock, flags);
+ list_add_tail(&sync_file->sync_file_list, &sync_file_list_head);
+ spin_unlock_irqrestore(&sync_file_list_lock, flags);
+}
+
+void sync_file_debug_remove(struct sync_file *sync_file)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sync_file_list_lock, flags);
+ list_del(&sync_file->sync_file_list);
+ spin_unlock_irqrestore(&sync_file_list_lock, flags);
+}
+
+static const char *sync_status_str(int status)
+{
+ if (status < 0)
+ return "error";
+
+ if (status > 0)
+ return "signaled";
+
+ return "active";
+}
+
+static void sync_print_fence(struct seq_file *s,
+ struct dma_fence *fence, bool show)
+{
+ struct sync_timeline *parent = dma_fence_parent(fence);
+ int status;
+
+ status = dma_fence_get_status_locked(fence);
+
+ seq_printf(s, " %s%sfence %s",
+ show ? parent->name : "",
+ show ? "_" : "",
+ sync_status_str(status));
+
+ if (test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags)) {
+ struct timespec64 ts64 =
+ ktime_to_timespec64(fence->timestamp);
+
+ seq_printf(s, "@%lld.%09ld", (s64)ts64.tv_sec, ts64.tv_nsec);
+ }
+
+ if (fence->ops->timeline_value_str &&
+ fence->ops->fence_value_str) {
+ char value[64];
+ bool success;
+
+ fence->ops->fence_value_str(fence, value, sizeof(value));
+ success = strlen(value);
+
+ if (success) {
+ seq_printf(s, ": %s", value);
+
+ fence->ops->timeline_value_str(fence, value,
+ sizeof(value));
+
+ if (strlen(value))
+ seq_printf(s, " / %s", value);
+ }
+ }
+
+ seq_putc(s, '\n');
+}
+
+static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
+{
+ struct list_head *pos;
+
+ seq_printf(s, "%s: %d\n", obj->name, obj->value);
+
+ spin_lock_irq(&obj->lock);
+ list_for_each(pos, &obj->pt_list) {
+ struct sync_pt *pt = container_of(pos, struct sync_pt, link);
+ sync_print_fence(s, &pt->base, false);
+ }
+ spin_unlock_irq(&obj->lock);
+}
+
+static void sync_print_sync_file(struct seq_file *s,
+ struct sync_file *sync_file)
+{
+ char buf[128];
+ int i;
+
+ seq_printf(s, "[%p] %s: %s\n", sync_file,
+ sync_file_get_name(sync_file, buf, sizeof(buf)),
+ sync_status_str(dma_fence_get_status(sync_file->fence)));
+
+ if (dma_fence_is_array(sync_file->fence)) {
+ struct dma_fence_array *array = to_dma_fence_array(sync_file->fence);
+
+ for (i = 0; i < array->num_fences; ++i)
+ sync_print_fence(s, array->fences[i], true);
+ } else {
+ sync_print_fence(s, sync_file->fence, true);
+ }
+}
+
+static int sync_debugfs_show(struct seq_file *s, void *unused)
+{
+ struct list_head *pos;
+
+ seq_puts(s, "objs:\n--------------\n");
+
+ spin_lock_irq(&sync_timeline_list_lock);
+ list_for_each(pos, &sync_timeline_list_head) {
+ struct sync_timeline *obj =
+ container_of(pos, struct sync_timeline,
+ sync_timeline_list);
+
+ sync_print_obj(s, obj);
+ seq_putc(s, '\n');
+ }
+ spin_unlock_irq(&sync_timeline_list_lock);
+
+ seq_puts(s, "fences:\n--------------\n");
+
+ spin_lock_irq(&sync_file_list_lock);
+ list_for_each(pos, &sync_file_list_head) {
+ struct sync_file *sync_file =
+ container_of(pos, struct sync_file, sync_file_list);
+
+ sync_print_sync_file(s, sync_file);
+ seq_putc(s, '\n');
+ }
+ spin_unlock_irq(&sync_file_list_lock);
+ return 0;
+}
+
+static int sync_info_debugfs_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, sync_debugfs_show, inode->i_private);
+}
+
+static const struct file_operations sync_info_debugfs_fops = {
+ .open = sync_info_debugfs_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static __init int sync_debugfs_init(void)
+{
+ dbgfs = debugfs_create_dir("sync", NULL);
+
+ /*
+ * The debugfs files won't ever get removed and thus, there is
+ * no need to protect it against removal races. The use of
+ * debugfs_create_file_unsafe() is actually safe here.
+ */
+ debugfs_create_file_unsafe("info", 0444, dbgfs, NULL,
+ &sync_info_debugfs_fops);
+ debugfs_create_file_unsafe("sw_sync", 0644, dbgfs, NULL,
+ &sw_sync_debugfs_fops);
+
+ return 0;
+}
+late_initcall(sync_debugfs_init);
+
+#define DUMP_CHUNK 256
+static char sync_dump_buf[64 * 1024];
+void sync_dump(void)
+{
+ struct seq_file s = {
+ .buf = sync_dump_buf,
+ .size = sizeof(sync_dump_buf) - 1,
+ };
+ int i;
+
+ sync_debugfs_show(&s, NULL);
+
+ for (i = 0; i < s.count; i += DUMP_CHUNK) {
+ if ((s.count - i) > DUMP_CHUNK) {
+ char c = s.buf[i + DUMP_CHUNK];
+
+ s.buf[i + DUMP_CHUNK] = 0;
+ pr_cont("%s", s.buf + i);
+ s.buf[i + DUMP_CHUNK] = c;
+ } else {
+ s.buf[s.count] = 0;
+ pr_cont("%s", s.buf + i);
+ }
+ }
+}
diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h
new file mode 100644
index 0000000..05e33f9
--- /dev/null
+++ b/drivers/dma-buf/sync_debug.h
@@ -0,0 +1,73 @@
+/*
+ * Sync File validation framework and debug infomation
+ *
+ * Copyright (C) 2012 Google, Inc.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_SYNC_H
+#define _LINUX_SYNC_H
+
+#include <linux/list.h>
+#include <linux/rbtree.h>
+#include <linux/spinlock.h>
+#include <linux/dma-fence.h>
+
+#include <linux/sync_file.h>
+#include <uapi/linux/sync_file.h>
+
+/**
+ * struct sync_timeline - sync object
+ * @kref: reference count on fence.
+ * @name: name of the sync_timeline. Useful for debugging
+ * @lock: lock protecting @pt_list and @value
+ * @pt_tree: rbtree of active (unsignaled/errored) sync_pts
+ * @pt_list: list of active (unsignaled/errored) sync_pts
+ * @sync_timeline_list: membership in global sync_timeline_list
+ */
+struct sync_timeline {
+ struct kref kref;
+ char name[32];
+
+ /* protected by lock */
+ u64 context;
+ int value;
+
+ struct rb_root pt_tree;
+ struct list_head pt_list;
+ spinlock_t lock;
+
+ struct list_head sync_timeline_list;
+};
+
+static inline struct sync_timeline *dma_fence_parent(struct dma_fence *fence)
+{
+ return container_of(fence->lock, struct sync_timeline, lock);
+}
+
+/**
+ * struct sync_pt - sync_pt object
+ * @base: base fence object
+ * @link: link on the sync timeline's list
+ * @node: node in the sync timeline's tree
+ */
+struct sync_pt {
+ struct dma_fence base;
+ struct list_head link;
+ struct rb_node node;
+};
+
+extern const struct file_operations sw_sync_debugfs_fops;
+
+void sync_timeline_debug_add(struct sync_timeline *obj);
+void sync_timeline_debug_remove(struct sync_timeline *obj);
+void sync_file_debug_add(struct sync_file *fence);
+void sync_file_debug_remove(struct sync_file *fence);
+void sync_dump(void);
+
+#endif /* _LINUX_SYNC_H */
diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c
new file mode 100644
index 0000000..35dd064
--- /dev/null
+++ b/drivers/dma-buf/sync_file.c
@@ -0,0 +1,492 @@
+/*
+ * drivers/dma-buf/sync_file.c
+ *
+ * Copyright (C) 2012 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/export.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/anon_inodes.h>
+#include <linux/sync_file.h>
+#include <uapi/linux/sync_file.h>
+
+static const struct file_operations sync_file_fops;
+
+static struct sync_file *sync_file_alloc(void)
+{
+ struct sync_file *sync_file;
+
+ sync_file = kzalloc(sizeof(*sync_file), GFP_KERNEL);
+ if (!sync_file)
+ return NULL;
+
+ sync_file->file = anon_inode_getfile("sync_file", &sync_file_fops,
+ sync_file, 0);
+ if (IS_ERR(sync_file->file))
+ goto err;
+
+ init_waitqueue_head(&sync_file->wq);
+
+ INIT_LIST_HEAD(&sync_file->cb.node);
+
+ return sync_file;
+
+err:
+ kfree(sync_file);
+ return NULL;
+}
+
+static void fence_check_cb_func(struct dma_fence *f, struct dma_fence_cb *cb)
+{
+ struct sync_file *sync_file;
+
+ sync_file = container_of(cb, struct sync_file, cb);
+
+ wake_up_all(&sync_file->wq);
+}
+
+/**
+ * sync_file_create() - creates a sync file
+ * @fence: fence to add to the sync_fence
+ *
+ * Creates a sync_file containg @fence. This function acquires and additional
+ * reference of @fence for the newly-created &sync_file, if it succeeds. The
+ * sync_file can be released with fput(sync_file->file). Returns the
+ * sync_file or NULL in case of error.
+ */
+struct sync_file *sync_file_create(struct dma_fence *fence)
+{
+ struct sync_file *sync_file;
+
+ sync_file = sync_file_alloc();
+ if (!sync_file)
+ return NULL;
+
+ sync_file->fence = dma_fence_get(fence);
+
+ return sync_file;
+}
+EXPORT_SYMBOL(sync_file_create);
+
+static struct sync_file *sync_file_fdget(int fd)
+{
+ struct file *file = fget(fd);
+
+ if (!file)
+ return NULL;
+
+ if (file->f_op != &sync_file_fops)
+ goto err;
+
+ return file->private_data;
+
+err:
+ fput(file);
+ return NULL;
+}
+
+/**
+ * sync_file_get_fence - get the fence related to the sync_file fd
+ * @fd: sync_file fd to get the fence from
+ *
+ * Ensures @fd references a valid sync_file and returns a fence that
+ * represents all fence in the sync_file. On error NULL is returned.
+ */
+struct dma_fence *sync_file_get_fence(int fd)
+{
+ struct sync_file *sync_file;
+ struct dma_fence *fence;
+
+ sync_file = sync_file_fdget(fd);
+ if (!sync_file)
+ return NULL;
+
+ fence = dma_fence_get(sync_file->fence);
+ fput(sync_file->file);
+
+ return fence;
+}
+EXPORT_SYMBOL(sync_file_get_fence);
+
+/**
+ * sync_file_get_name - get the name of the sync_file
+ * @sync_file: sync_file to get the fence from
+ * @buf: destination buffer to copy sync_file name into
+ * @len: available size of destination buffer.
+ *
+ * Each sync_file may have a name assigned either by the user (when merging
+ * sync_files together) or created from the fence it contains. In the latter
+ * case construction of the name is deferred until use, and so requires
+ * sync_file_get_name().
+ *
+ * Returns: a string representing the name.
+ */
+char *sync_file_get_name(struct sync_file *sync_file, char *buf, int len)
+{
+ if (sync_file->user_name[0]) {
+ strlcpy(buf, sync_file->user_name, len);
+ } else {
+ struct dma_fence *fence = sync_file->fence;
+
+ snprintf(buf, len, "%s-%s%llu-%d",
+ fence->ops->get_driver_name(fence),
+ fence->ops->get_timeline_name(fence),
+ fence->context,
+ fence->seqno);
+ }
+
+ return buf;
+}
+
+static int sync_file_set_fence(struct sync_file *sync_file,
+ struct dma_fence **fences, int num_fences)
+{
+ struct dma_fence_array *array;
+
+ /*
+ * The reference for the fences in the new sync_file and held
+ * in add_fence() during the merge procedure, so for num_fences == 1
+ * we already own a new reference to the fence. For num_fence > 1
+ * we own the reference of the dma_fence_array creation.
+ */
+ if (num_fences == 1) {
+ sync_file->fence = fences[0];
+ kfree(fences);
+ } else {
+ array = dma_fence_array_create(num_fences, fences,
+ dma_fence_context_alloc(1),
+ 1, false);
+ if (!array)
+ return -ENOMEM;
+
+ sync_file->fence = &array->base;
+ }
+
+ return 0;
+}
+
+static struct dma_fence **get_fences(struct sync_file *sync_file,
+ int *num_fences)
+{
+ if (dma_fence_is_array(sync_file->fence)) {
+ struct dma_fence_array *array = to_dma_fence_array(sync_file->fence);
+
+ *num_fences = array->num_fences;
+ return array->fences;
+ }
+
+ *num_fences = 1;
+ return &sync_file->fence;
+}
+
+static void add_fence(struct dma_fence **fences,
+ int *i, struct dma_fence *fence)
+{
+ fences[*i] = fence;
+
+ if (!dma_fence_is_signaled(fence)) {
+ dma_fence_get(fence);
+ (*i)++;
+ }
+}
+
+/**
+ * sync_file_merge() - merge two sync_files
+ * @name: name of new fence
+ * @a: sync_file a
+ * @b: sync_file b
+ *
+ * Creates a new sync_file which contains copies of all the fences in both
+ * @a and @b. @a and @b remain valid, independent sync_file. Returns the
+ * new merged sync_file or NULL in case of error.
+ */
+static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
+ struct sync_file *b)
+{
+ struct sync_file *sync_file;
+ struct dma_fence **fences, **nfences, **a_fences, **b_fences;
+ int i, i_a, i_b, num_fences, a_num_fences, b_num_fences;
+
+ sync_file = sync_file_alloc();
+ if (!sync_file)
+ return NULL;
+
+ a_fences = get_fences(a, &a_num_fences);
+ b_fences = get_fences(b, &b_num_fences);
+ if (a_num_fences > INT_MAX - b_num_fences)
+ return NULL;
+
+ num_fences = a_num_fences + b_num_fences;
+
+ fences = kcalloc(num_fences, sizeof(*fences), GFP_KERNEL);
+ if (!fences)
+ goto err;
+
+ /*
+ * Assume sync_file a and b are both ordered and have no
+ * duplicates with the same context.
+ *
+ * If a sync_file can only be created with sync_file_merge
+ * and sync_file_create, this is a reasonable assumption.
+ */
+ for (i = i_a = i_b = 0; i_a < a_num_fences && i_b < b_num_fences; ) {
+ struct dma_fence *pt_a = a_fences[i_a];
+ struct dma_fence *pt_b = b_fences[i_b];
+
+ if (pt_a->context < pt_b->context) {
+ add_fence(fences, &i, pt_a);
+
+ i_a++;
+ } else if (pt_a->context > pt_b->context) {
+ add_fence(fences, &i, pt_b);
+
+ i_b++;
+ } else {
+ if (pt_a->seqno - pt_b->seqno <= INT_MAX)
+ add_fence(fences, &i, pt_a);
+ else
+ add_fence(fences, &i, pt_b);
+
+ i_a++;
+ i_b++;
+ }
+ }
+
+ for (; i_a < a_num_fences; i_a++)
+ add_fence(fences, &i, a_fences[i_a]);
+
+ for (; i_b < b_num_fences; i_b++)
+ add_fence(fences, &i, b_fences[i_b]);
+
+ if (i == 0)
+ fences[i++] = dma_fence_get(a_fences[0]);
+
+ if (num_fences > i) {
+ nfences = krealloc(fences, i * sizeof(*fences),
+ GFP_KERNEL);
+ if (!nfences)
+ goto err;
+
+ fences = nfences;
+ }
+
+ if (sync_file_set_fence(sync_file, fences, i) < 0) {
+ kfree(fences);
+ goto err;
+ }
+
+ strlcpy(sync_file->user_name, name, sizeof(sync_file->user_name));
+ return sync_file;
+
+err:
+ fput(sync_file->file);
+ return NULL;
+
+}
+
+static int sync_file_release(struct inode *inode, struct file *file)
+{
+ struct sync_file *sync_file = file->private_data;
+
+ if (test_bit(POLL_ENABLED, &sync_file->flags))
+ dma_fence_remove_callback(sync_file->fence, &sync_file->cb);
+ dma_fence_put(sync_file->fence);
+ kfree(sync_file);
+
+ return 0;
+}
+
+static __poll_t sync_file_poll(struct file *file, poll_table *wait)
+{
+ struct sync_file *sync_file = file->private_data;
+
+ poll_wait(file, &sync_file->wq, wait);
+
+ if (list_empty(&sync_file->cb.node) &&
+ !test_and_set_bit(POLL_ENABLED, &sync_file->flags)) {
+ if (dma_fence_add_callback(sync_file->fence, &sync_file->cb,
+ fence_check_cb_func) < 0)
+ wake_up_all(&sync_file->wq);
+ }
+
+ return dma_fence_is_signaled(sync_file->fence) ? EPOLLIN : 0;
+}
+
+static long sync_file_ioctl_merge(struct sync_file *sync_file,
+ unsigned long arg)
+{
+ int fd = get_unused_fd_flags(O_CLOEXEC);
+ int err;
+ struct sync_file *fence2, *fence3;
+ struct sync_merge_data data;
+
+ if (fd < 0)
+ return fd;
+
+ if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
+ err = -EFAULT;
+ goto err_put_fd;
+ }
+
+ if (data.flags || data.pad) {
+ err = -EINVAL;
+ goto err_put_fd;
+ }
+
+ fence2 = sync_file_fdget(data.fd2);
+ if (!fence2) {
+ err = -ENOENT;
+ goto err_put_fd;
+ }
+
+ data.name[sizeof(data.name) - 1] = '\0';
+ fence3 = sync_file_merge(data.name, sync_file, fence2);
+ if (!fence3) {
+ err = -ENOMEM;
+ goto err_put_fence2;
+ }
+
+ data.fence = fd;
+ if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
+ err = -EFAULT;
+ goto err_put_fence3;
+ }
+
+ fd_install(fd, fence3->file);
+ fput(fence2->file);
+ return 0;
+
+err_put_fence3:
+ fput(fence3->file);
+
+err_put_fence2:
+ fput(fence2->file);
+
+err_put_fd:
+ put_unused_fd(fd);
+ return err;
+}
+
+static int sync_fill_fence_info(struct dma_fence *fence,
+ struct sync_fence_info *info)
+{
+ strlcpy(info->obj_name, fence->ops->get_timeline_name(fence),
+ sizeof(info->obj_name));
+ strlcpy(info->driver_name, fence->ops->get_driver_name(fence),
+ sizeof(info->driver_name));
+
+ info->status = dma_fence_get_status(fence);
+ while (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) &&
+ !test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags))
+ cpu_relax();
+ info->timestamp_ns =
+ test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags) ?
+ ktime_to_ns(fence->timestamp) :
+ ktime_set(0, 0);
+
+ return info->status;
+}
+
+static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
+ unsigned long arg)
+{
+ struct sync_file_info info;
+ struct sync_fence_info *fence_info = NULL;
+ struct dma_fence **fences;
+ __u32 size;
+ int num_fences, ret, i;
+
+ if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
+ return -EFAULT;
+
+ if (info.flags || info.pad)
+ return -EINVAL;
+
+ fences = get_fences(sync_file, &num_fences);
+
+ /*
+ * Passing num_fences = 0 means that userspace doesn't want to
+ * retrieve any sync_fence_info. If num_fences = 0 we skip filling
+ * sync_fence_info and return the actual number of fences on
+ * info->num_fences.
+ */
+ if (!info.num_fences) {
+ info.status = dma_fence_is_signaled(sync_file->fence);
+ goto no_fences;
+ } else {
+ info.status = 1;
+ }
+
+ if (info.num_fences < num_fences)
+ return -EINVAL;
+
+ size = num_fences * sizeof(*fence_info);
+ fence_info = kzalloc(size, GFP_KERNEL);
+ if (!fence_info)
+ return -ENOMEM;
+
+ for (i = 0; i < num_fences; i++) {
+ int status = sync_fill_fence_info(fences[i], &fence_info[i]);
+ info.status = info.status <= 0 ? info.status : status;
+ }
+
+ if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info,
+ size)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+no_fences:
+ sync_file_get_name(sync_file, info.name, sizeof(info.name));
+ info.num_fences = num_fences;
+
+ if (copy_to_user((void __user *)arg, &info, sizeof(info)))
+ ret = -EFAULT;
+ else
+ ret = 0;
+
+out:
+ kfree(fence_info);
+
+ return ret;
+}
+
+static long sync_file_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct sync_file *sync_file = file->private_data;
+
+ switch (cmd) {
+ case SYNC_IOC_MERGE:
+ return sync_file_ioctl_merge(sync_file, arg);
+
+ case SYNC_IOC_FILE_INFO:
+ return sync_file_ioctl_fence_info(sync_file, arg);
+
+ default:
+ return -ENOTTY;
+ }
+}
+
+static const struct file_operations sync_file_fops = {
+ .release = sync_file_release,
+ .poll = sync_file_poll,
+ .unlocked_ioctl = sync_file_ioctl,
+ .compat_ioctl = sync_file_ioctl,
+};
diff --git a/drivers/dma-buf/sync_trace.h b/drivers/dma-buf/sync_trace.h
new file mode 100644
index 0000000..06e468a
--- /dev/null
+++ b/drivers/dma-buf/sync_trace.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_INCLUDE_PATH ../../drivers/dma-buf
+#define TRACE_SYSTEM sync_trace
+
+#if !defined(_TRACE_SYNC_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SYNC_H
+
+#include "sync_debug.h"
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(sync_timeline,
+ TP_PROTO(struct sync_timeline *timeline),
+
+ TP_ARGS(timeline),
+
+ TP_STRUCT__entry(
+ __string(name, timeline->name)
+ __field(u32, value)
+ ),
+
+ TP_fast_assign(
+ __assign_str(name, timeline->name);
+ __entry->value = timeline->value;
+ ),
+
+ TP_printk("name=%s value=%d", __get_str(name), __entry->value)
+);
+
+#endif /* if !defined(_TRACE_SYNC_H) || defined(TRACE_HEADER_MULTI_READ) */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>