v4.19.13 snapshot.
diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c
new file mode 100644
index 0000000..e6a6074
--- /dev/null
+++ b/drivers/misc/ocxl/file.c
@@ -0,0 +1,541 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2017 IBM Corp.
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/sched/signal.h>
+#include <linux/uaccess.h>
+#include <uapi/misc/ocxl.h>
+#include <asm/reg.h>
+#include <asm/switch_to.h>
+#include "ocxl_internal.h"
+
+
+#define OCXL_NUM_MINORS 256 /* Total to reserve */
+
+static dev_t ocxl_dev;
+static struct class *ocxl_class;
+static struct mutex minors_idr_lock;
+static struct idr minors_idr;
+
+static struct ocxl_afu *find_and_get_afu(dev_t devno)
+{
+ struct ocxl_afu *afu;
+ int afu_minor;
+
+ afu_minor = MINOR(devno);
+ /*
+ * We don't declare an RCU critical section here, as our AFU
+ * is protected by a reference counter on the device. By the time the
+ * minor number of a device is removed from the idr, the ref count of
+ * the device is already at 0, so no user API will access that AFU and
+ * this function can't return it.
+ */
+ afu = idr_find(&minors_idr, afu_minor);
+ if (afu)
+ ocxl_afu_get(afu);
+ return afu;
+}
+
+static int allocate_afu_minor(struct ocxl_afu *afu)
+{
+ int minor;
+
+ mutex_lock(&minors_idr_lock);
+ minor = idr_alloc(&minors_idr, afu, 0, OCXL_NUM_MINORS, GFP_KERNEL);
+ mutex_unlock(&minors_idr_lock);
+ return minor;
+}
+
+static void free_afu_minor(struct ocxl_afu *afu)
+{
+ mutex_lock(&minors_idr_lock);
+ idr_remove(&minors_idr, MINOR(afu->dev.devt));
+ mutex_unlock(&minors_idr_lock);
+}
+
+static int afu_open(struct inode *inode, struct file *file)
+{
+ struct ocxl_afu *afu;
+ struct ocxl_context *ctx;
+ int rc;
+
+ pr_debug("%s for device %x\n", __func__, inode->i_rdev);
+
+ afu = find_and_get_afu(inode->i_rdev);
+ if (!afu)
+ return -ENODEV;
+
+ ctx = ocxl_context_alloc();
+ if (!ctx) {
+ rc = -ENOMEM;
+ goto put_afu;
+ }
+
+ rc = ocxl_context_init(ctx, afu, inode->i_mapping);
+ if (rc)
+ goto put_afu;
+ file->private_data = ctx;
+ ocxl_afu_put(afu);
+ return 0;
+
+put_afu:
+ ocxl_afu_put(afu);
+ return rc;
+}
+
+static long afu_ioctl_attach(struct ocxl_context *ctx,
+ struct ocxl_ioctl_attach __user *uarg)
+{
+ struct ocxl_ioctl_attach arg;
+ u64 amr = 0;
+ int rc;
+
+ pr_debug("%s for context %d\n", __func__, ctx->pasid);
+
+ if (copy_from_user(&arg, uarg, sizeof(arg)))
+ return -EFAULT;
+
+ /* Make sure reserved fields are not set for forward compatibility */
+ if (arg.reserved1 || arg.reserved2 || arg.reserved3)
+ return -EINVAL;
+
+ amr = arg.amr & mfspr(SPRN_UAMOR);
+ rc = ocxl_context_attach(ctx, amr);
+ return rc;
+}
+
+static long afu_ioctl_get_metadata(struct ocxl_context *ctx,
+ struct ocxl_ioctl_metadata __user *uarg)
+{
+ struct ocxl_ioctl_metadata arg;
+
+ memset(&arg, 0, sizeof(arg));
+
+ arg.version = 0;
+
+ arg.afu_version_major = ctx->afu->config.version_major;
+ arg.afu_version_minor = ctx->afu->config.version_minor;
+ arg.pasid = ctx->pasid;
+ arg.pp_mmio_size = ctx->afu->config.pp_mmio_stride;
+ arg.global_mmio_size = ctx->afu->config.global_mmio_size;
+
+ if (copy_to_user(uarg, &arg, sizeof(arg)))
+ return -EFAULT;
+
+ return 0;
+}
+
+#ifdef CONFIG_PPC64
+static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx,
+ struct ocxl_ioctl_p9_wait __user *uarg)
+{
+ struct ocxl_ioctl_p9_wait arg;
+
+ memset(&arg, 0, sizeof(arg));
+
+ if (cpu_has_feature(CPU_FTR_P9_TIDR)) {
+ enum ocxl_context_status status;
+
+ // Locks both status & tidr
+ mutex_lock(&ctx->status_mutex);
+ if (!ctx->tidr) {
+ if (set_thread_tidr(current)) {
+ mutex_unlock(&ctx->status_mutex);
+ return -ENOENT;
+ }
+
+ ctx->tidr = current->thread.tidr;
+ }
+
+ status = ctx->status;
+ mutex_unlock(&ctx->status_mutex);
+
+ if (status == ATTACHED) {
+ int rc;
+ struct link *link = ctx->afu->fn->link;
+
+ rc = ocxl_link_update_pe(link, ctx->pasid, ctx->tidr);
+ if (rc)
+ return rc;
+ }
+
+ arg.thread_id = ctx->tidr;
+ } else
+ return -ENOENT;
+
+ if (copy_to_user(uarg, &arg, sizeof(arg)))
+ return -EFAULT;
+
+ return 0;
+}
+#endif
+
+
+static long afu_ioctl_get_features(struct ocxl_context *ctx,
+ struct ocxl_ioctl_features __user *uarg)
+{
+ struct ocxl_ioctl_features arg;
+
+ memset(&arg, 0, sizeof(arg));
+
+#ifdef CONFIG_PPC64
+ if (cpu_has_feature(CPU_FTR_P9_TIDR))
+ arg.flags[0] |= OCXL_IOCTL_FEATURES_FLAGS0_P9_WAIT;
+#endif
+
+ if (copy_to_user(uarg, &arg, sizeof(arg)))
+ return -EFAULT;
+
+ return 0;
+}
+
+#define CMD_STR(x) (x == OCXL_IOCTL_ATTACH ? "ATTACH" : \
+ x == OCXL_IOCTL_IRQ_ALLOC ? "IRQ_ALLOC" : \
+ x == OCXL_IOCTL_IRQ_FREE ? "IRQ_FREE" : \
+ x == OCXL_IOCTL_IRQ_SET_FD ? "IRQ_SET_FD" : \
+ x == OCXL_IOCTL_GET_METADATA ? "GET_METADATA" : \
+ x == OCXL_IOCTL_ENABLE_P9_WAIT ? "ENABLE_P9_WAIT" : \
+ x == OCXL_IOCTL_GET_FEATURES ? "GET_FEATURES" : \
+ "UNKNOWN")
+
+static long afu_ioctl(struct file *file, unsigned int cmd,
+ unsigned long args)
+{
+ struct ocxl_context *ctx = file->private_data;
+ struct ocxl_ioctl_irq_fd irq_fd;
+ u64 irq_offset;
+ long rc;
+
+ pr_debug("%s for context %d, command %s\n", __func__, ctx->pasid,
+ CMD_STR(cmd));
+
+ if (ctx->status == CLOSED)
+ return -EIO;
+
+ switch (cmd) {
+ case OCXL_IOCTL_ATTACH:
+ rc = afu_ioctl_attach(ctx,
+ (struct ocxl_ioctl_attach __user *) args);
+ break;
+
+ case OCXL_IOCTL_IRQ_ALLOC:
+ rc = ocxl_afu_irq_alloc(ctx, &irq_offset);
+ if (!rc) {
+ rc = copy_to_user((u64 __user *) args, &irq_offset,
+ sizeof(irq_offset));
+ if (rc) {
+ ocxl_afu_irq_free(ctx, irq_offset);
+ return -EFAULT;
+ }
+ }
+ break;
+
+ case OCXL_IOCTL_IRQ_FREE:
+ rc = copy_from_user(&irq_offset, (u64 __user *) args,
+ sizeof(irq_offset));
+ if (rc)
+ return -EFAULT;
+ rc = ocxl_afu_irq_free(ctx, irq_offset);
+ break;
+
+ case OCXL_IOCTL_IRQ_SET_FD:
+ rc = copy_from_user(&irq_fd, (u64 __user *) args,
+ sizeof(irq_fd));
+ if (rc)
+ return -EFAULT;
+ if (irq_fd.reserved)
+ return -EINVAL;
+ rc = ocxl_afu_irq_set_fd(ctx, irq_fd.irq_offset,
+ irq_fd.eventfd);
+ break;
+
+ case OCXL_IOCTL_GET_METADATA:
+ rc = afu_ioctl_get_metadata(ctx,
+ (struct ocxl_ioctl_metadata __user *) args);
+ break;
+
+#ifdef CONFIG_PPC64
+ case OCXL_IOCTL_ENABLE_P9_WAIT:
+ rc = afu_ioctl_enable_p9_wait(ctx,
+ (struct ocxl_ioctl_p9_wait __user *) args);
+ break;
+#endif
+
+ case OCXL_IOCTL_GET_FEATURES:
+ rc = afu_ioctl_get_features(ctx,
+ (struct ocxl_ioctl_features __user *) args);
+ break;
+
+ default:
+ rc = -EINVAL;
+ }
+ return rc;
+}
+
+static long afu_compat_ioctl(struct file *file, unsigned int cmd,
+ unsigned long args)
+{
+ return afu_ioctl(file, cmd, args);
+}
+
+static int afu_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct ocxl_context *ctx = file->private_data;
+
+ pr_debug("%s for context %d\n", __func__, ctx->pasid);
+ return ocxl_context_mmap(ctx, vma);
+}
+
+static bool has_xsl_error(struct ocxl_context *ctx)
+{
+ bool ret;
+
+ mutex_lock(&ctx->xsl_error_lock);
+ ret = !!ctx->xsl_error.addr;
+ mutex_unlock(&ctx->xsl_error_lock);
+
+ return ret;
+}
+
+/*
+ * Are there any events pending on the AFU
+ * ctx: The AFU context
+ * Returns: true if there are events pending
+ */
+static bool afu_events_pending(struct ocxl_context *ctx)
+{
+ if (has_xsl_error(ctx))
+ return true;
+ return false;
+}
+
+static unsigned int afu_poll(struct file *file, struct poll_table_struct *wait)
+{
+ struct ocxl_context *ctx = file->private_data;
+ unsigned int mask = 0;
+ bool closed;
+
+ pr_debug("%s for context %d\n", __func__, ctx->pasid);
+
+ poll_wait(file, &ctx->events_wq, wait);
+
+ mutex_lock(&ctx->status_mutex);
+ closed = (ctx->status == CLOSED);
+ mutex_unlock(&ctx->status_mutex);
+
+ if (afu_events_pending(ctx))
+ mask = EPOLLIN | EPOLLRDNORM;
+ else if (closed)
+ mask = EPOLLERR;
+
+ return mask;
+}
+
+/*
+ * Populate the supplied buffer with a single XSL error
+ * ctx: The AFU context to report the error from
+ * header: the event header to populate
+ * buf: The buffer to write the body into (should be at least
+ * AFU_EVENT_BODY_XSL_ERROR_SIZE)
+ * Return: the amount of buffer that was populated
+ */
+static ssize_t append_xsl_error(struct ocxl_context *ctx,
+ struct ocxl_kernel_event_header *header,
+ char __user *buf)
+{
+ struct ocxl_kernel_event_xsl_fault_error body;
+
+ memset(&body, 0, sizeof(body));
+
+ mutex_lock(&ctx->xsl_error_lock);
+ if (!ctx->xsl_error.addr) {
+ mutex_unlock(&ctx->xsl_error_lock);
+ return 0;
+ }
+
+ body.addr = ctx->xsl_error.addr;
+ body.dsisr = ctx->xsl_error.dsisr;
+ body.count = ctx->xsl_error.count;
+
+ ctx->xsl_error.addr = 0;
+ ctx->xsl_error.dsisr = 0;
+ ctx->xsl_error.count = 0;
+
+ mutex_unlock(&ctx->xsl_error_lock);
+
+ header->type = OCXL_AFU_EVENT_XSL_FAULT_ERROR;
+
+ if (copy_to_user(buf, &body, sizeof(body)))
+ return -EFAULT;
+
+ return sizeof(body);
+}
+
+#define AFU_EVENT_BODY_MAX_SIZE sizeof(struct ocxl_kernel_event_xsl_fault_error)
+
+/*
+ * Reports events on the AFU
+ * Format:
+ * Header (struct ocxl_kernel_event_header)
+ * Body (struct ocxl_kernel_event_*)
+ * Header...
+ */
+static ssize_t afu_read(struct file *file, char __user *buf, size_t count,
+ loff_t *off)
+{
+ struct ocxl_context *ctx = file->private_data;
+ struct ocxl_kernel_event_header header;
+ ssize_t rc;
+ ssize_t used = 0;
+ DEFINE_WAIT(event_wait);
+
+ memset(&header, 0, sizeof(header));
+
+ /* Require offset to be 0 */
+ if (*off != 0)
+ return -EINVAL;
+
+ if (count < (sizeof(struct ocxl_kernel_event_header) +
+ AFU_EVENT_BODY_MAX_SIZE))
+ return -EINVAL;
+
+ for (;;) {
+ prepare_to_wait(&ctx->events_wq, &event_wait,
+ TASK_INTERRUPTIBLE);
+
+ if (afu_events_pending(ctx))
+ break;
+
+ if (ctx->status == CLOSED)
+ break;
+
+ if (file->f_flags & O_NONBLOCK) {
+ finish_wait(&ctx->events_wq, &event_wait);
+ return -EAGAIN;
+ }
+
+ if (signal_pending(current)) {
+ finish_wait(&ctx->events_wq, &event_wait);
+ return -ERESTARTSYS;
+ }
+
+ schedule();
+ }
+
+ finish_wait(&ctx->events_wq, &event_wait);
+
+ if (has_xsl_error(ctx)) {
+ used = append_xsl_error(ctx, &header, buf + sizeof(header));
+ if (used < 0)
+ return used;
+ }
+
+ if (!afu_events_pending(ctx))
+ header.flags |= OCXL_KERNEL_EVENT_FLAG_LAST;
+
+ if (copy_to_user(buf, &header, sizeof(header)))
+ return -EFAULT;
+
+ used += sizeof(header);
+
+ rc = used;
+ return rc;
+}
+
+static int afu_release(struct inode *inode, struct file *file)
+{
+ struct ocxl_context *ctx = file->private_data;
+ int rc;
+
+ pr_debug("%s for device %x\n", __func__, inode->i_rdev);
+ rc = ocxl_context_detach(ctx);
+ mutex_lock(&ctx->mapping_lock);
+ ctx->mapping = NULL;
+ mutex_unlock(&ctx->mapping_lock);
+ wake_up_all(&ctx->events_wq);
+ if (rc != -EBUSY)
+ ocxl_context_free(ctx);
+ return 0;
+}
+
+static const struct file_operations ocxl_afu_fops = {
+ .owner = THIS_MODULE,
+ .open = afu_open,
+ .unlocked_ioctl = afu_ioctl,
+ .compat_ioctl = afu_compat_ioctl,
+ .mmap = afu_mmap,
+ .poll = afu_poll,
+ .read = afu_read,
+ .release = afu_release,
+};
+
+int ocxl_create_cdev(struct ocxl_afu *afu)
+{
+ int rc;
+
+ cdev_init(&afu->cdev, &ocxl_afu_fops);
+ rc = cdev_add(&afu->cdev, afu->dev.devt, 1);
+ if (rc) {
+ dev_err(&afu->dev, "Unable to add afu char device: %d\n", rc);
+ return rc;
+ }
+ return 0;
+}
+
+void ocxl_destroy_cdev(struct ocxl_afu *afu)
+{
+ cdev_del(&afu->cdev);
+}
+
+int ocxl_register_afu(struct ocxl_afu *afu)
+{
+ int minor;
+
+ minor = allocate_afu_minor(afu);
+ if (minor < 0)
+ return minor;
+ afu->dev.devt = MKDEV(MAJOR(ocxl_dev), minor);
+ afu->dev.class = ocxl_class;
+ return device_register(&afu->dev);
+}
+
+void ocxl_unregister_afu(struct ocxl_afu *afu)
+{
+ free_afu_minor(afu);
+}
+
+static char *ocxl_devnode(struct device *dev, umode_t *mode)
+{
+ return kasprintf(GFP_KERNEL, "ocxl/%s", dev_name(dev));
+}
+
+int ocxl_file_init(void)
+{
+ int rc;
+
+ mutex_init(&minors_idr_lock);
+ idr_init(&minors_idr);
+
+ rc = alloc_chrdev_region(&ocxl_dev, 0, OCXL_NUM_MINORS, "ocxl");
+ if (rc) {
+ pr_err("Unable to allocate ocxl major number: %d\n", rc);
+ return rc;
+ }
+
+ ocxl_class = class_create(THIS_MODULE, "ocxl");
+ if (IS_ERR(ocxl_class)) {
+ pr_err("Unable to create ocxl class\n");
+ unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS);
+ return PTR_ERR(ocxl_class);
+ }
+
+ ocxl_class->devnode = ocxl_devnode;
+ return 0;
+}
+
+void ocxl_file_exit(void)
+{
+ class_destroy(ocxl_class);
+ unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS);
+ idr_destroy(&minors_idr);
+}