v4.19.13 snapshot.
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
new file mode 100644
index 0000000..2082ae0
--- /dev/null
+++ b/drivers/nvdimm/pmem.c
@@ -0,0 +1,610 @@
+/*
+ * Persistent Memory Driver
+ *
+ * Copyright (c) 2014-2015, Intel Corporation.
+ * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
+ * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 <asm/cacheflush.h>
+#include <linux/blkdev.h>
+#include <linux/hdreg.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/set_memory.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/badblocks.h>
+#include <linux/memremap.h>
+#include <linux/vmalloc.h>
+#include <linux/blk-mq.h>
+#include <linux/pfn_t.h>
+#include <linux/slab.h>
+#include <linux/uio.h>
+#include <linux/dax.h>
+#include <linux/nd.h>
+#include <linux/backing-dev.h>
+#include "pmem.h"
+#include "pfn.h"
+#include "nd.h"
+#include "nd-core.h"
+
+static struct device *to_dev(struct pmem_device *pmem)
+{
+ /*
+ * nvdimm bus services need a 'dev' parameter, and we record the device
+ * at init in bb.dev.
+ */
+ return pmem->bb.dev;
+}
+
+static struct nd_region *to_region(struct pmem_device *pmem)
+{
+ return to_nd_region(to_dev(pmem)->parent);
+}
+
+static void hwpoison_clear(struct pmem_device *pmem,
+ phys_addr_t phys, unsigned int len)
+{
+ unsigned long pfn_start, pfn_end, pfn;
+
+ /* only pmem in the linear map supports HWPoison */
+ if (is_vmalloc_addr(pmem->virt_addr))
+ return;
+
+ pfn_start = PHYS_PFN(phys);
+ pfn_end = pfn_start + PHYS_PFN(len);
+ for (pfn = pfn_start; pfn < pfn_end; pfn++) {
+ struct page *page = pfn_to_page(pfn);
+
+ /*
+ * Note, no need to hold a get_dev_pagemap() reference
+ * here since we're in the driver I/O path and
+ * outstanding I/O requests pin the dev_pagemap.
+ */
+ if (test_and_clear_pmem_poison(page))
+ clear_mce_nospec(pfn);
+ }
+}
+
+static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
+ phys_addr_t offset, unsigned int len)
+{
+ struct device *dev = to_dev(pmem);
+ sector_t sector;
+ long cleared;
+ blk_status_t rc = BLK_STS_OK;
+
+ sector = (offset - pmem->data_offset) / 512;
+
+ cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
+ if (cleared < len)
+ rc = BLK_STS_IOERR;
+ if (cleared > 0 && cleared / 512) {
+ hwpoison_clear(pmem, pmem->phys_addr + offset, cleared);
+ cleared /= 512;
+ dev_dbg(dev, "%#llx clear %ld sector%s\n",
+ (unsigned long long) sector, cleared,
+ cleared > 1 ? "s" : "");
+ badblocks_clear(&pmem->bb, sector, cleared);
+ if (pmem->bb_state)
+ sysfs_notify_dirent(pmem->bb_state);
+ }
+
+ arch_invalidate_pmem(pmem->virt_addr + offset, len);
+
+ return rc;
+}
+
+static void write_pmem(void *pmem_addr, struct page *page,
+ unsigned int off, unsigned int len)
+{
+ unsigned int chunk;
+ void *mem;
+
+ while (len) {
+ mem = kmap_atomic(page);
+ chunk = min_t(unsigned int, len, PAGE_SIZE);
+ memcpy_flushcache(pmem_addr, mem + off, chunk);
+ kunmap_atomic(mem);
+ len -= chunk;
+ off = 0;
+ page++;
+ pmem_addr += PAGE_SIZE;
+ }
+}
+
+static blk_status_t read_pmem(struct page *page, unsigned int off,
+ void *pmem_addr, unsigned int len)
+{
+ unsigned int chunk;
+ unsigned long rem;
+ void *mem;
+
+ while (len) {
+ mem = kmap_atomic(page);
+ chunk = min_t(unsigned int, len, PAGE_SIZE);
+ rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
+ kunmap_atomic(mem);
+ if (rem)
+ return BLK_STS_IOERR;
+ len -= chunk;
+ off = 0;
+ page++;
+ pmem_addr += PAGE_SIZE;
+ }
+ return BLK_STS_OK;
+}
+
+static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
+ unsigned int len, unsigned int off, unsigned int op,
+ sector_t sector)
+{
+ blk_status_t rc = BLK_STS_OK;
+ bool bad_pmem = false;
+ phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
+ void *pmem_addr = pmem->virt_addr + pmem_off;
+
+ if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
+ bad_pmem = true;
+
+ if (!op_is_write(op)) {
+ if (unlikely(bad_pmem))
+ rc = BLK_STS_IOERR;
+ else {
+ rc = read_pmem(page, off, pmem_addr, len);
+ flush_dcache_page(page);
+ }
+ } else {
+ /*
+ * Note that we write the data both before and after
+ * clearing poison. The write before clear poison
+ * handles situations where the latest written data is
+ * preserved and the clear poison operation simply marks
+ * the address range as valid without changing the data.
+ * In this case application software can assume that an
+ * interrupted write will either return the new good
+ * data or an error.
+ *
+ * However, if pmem_clear_poison() leaves the data in an
+ * indeterminate state we need to perform the write
+ * after clear poison.
+ */
+ flush_dcache_page(page);
+ write_pmem(pmem_addr, page, off, len);
+ if (unlikely(bad_pmem)) {
+ rc = pmem_clear_poison(pmem, pmem_off, len);
+ write_pmem(pmem_addr, page, off, len);
+ }
+ }
+
+ return rc;
+}
+
+static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
+{
+ blk_status_t rc = 0;
+ bool do_acct;
+ unsigned long start;
+ struct bio_vec bvec;
+ struct bvec_iter iter;
+ struct pmem_device *pmem = q->queuedata;
+ struct nd_region *nd_region = to_region(pmem);
+
+ if (bio->bi_opf & REQ_PREFLUSH)
+ nvdimm_flush(nd_region);
+
+ do_acct = nd_iostat_start(bio, &start);
+ bio_for_each_segment(bvec, bio, iter) {
+ rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
+ bvec.bv_offset, bio_op(bio), iter.bi_sector);
+ if (rc) {
+ bio->bi_status = rc;
+ break;
+ }
+ }
+ if (do_acct)
+ nd_iostat_end(bio, start);
+
+ if (bio->bi_opf & REQ_FUA)
+ nvdimm_flush(nd_region);
+
+ bio_endio(bio);
+ return BLK_QC_T_NONE;
+}
+
+static int pmem_rw_page(struct block_device *bdev, sector_t sector,
+ struct page *page, unsigned int op)
+{
+ struct pmem_device *pmem = bdev->bd_queue->queuedata;
+ blk_status_t rc;
+
+ rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE,
+ 0, op, sector);
+
+ /*
+ * The ->rw_page interface is subtle and tricky. The core
+ * retries on any error, so we can only invoke page_endio() in
+ * the successful completion case. Otherwise, we'll see crashes
+ * caused by double completion.
+ */
+ if (rc == 0)
+ page_endio(page, op_is_write(op), 0);
+
+ return blk_status_to_errno(rc);
+}
+
+/* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
+__weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
+ long nr_pages, void **kaddr, pfn_t *pfn)
+{
+ resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
+
+ if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
+ PFN_PHYS(nr_pages))))
+ return -EIO;
+
+ if (kaddr)
+ *kaddr = pmem->virt_addr + offset;
+ if (pfn)
+ *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
+
+ /*
+ * If badblocks are present, limit known good range to the
+ * requested range.
+ */
+ if (unlikely(pmem->bb.count))
+ return nr_pages;
+ return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
+}
+
+static const struct block_device_operations pmem_fops = {
+ .owner = THIS_MODULE,
+ .rw_page = pmem_rw_page,
+ .revalidate_disk = nvdimm_revalidate_disk,
+};
+
+static long pmem_dax_direct_access(struct dax_device *dax_dev,
+ pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
+{
+ struct pmem_device *pmem = dax_get_private(dax_dev);
+
+ return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
+}
+
+static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
+ void *addr, size_t bytes, struct iov_iter *i)
+{
+ return copy_from_iter_flushcache(addr, bytes, i);
+}
+
+static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
+ void *addr, size_t bytes, struct iov_iter *i)
+{
+ return copy_to_iter_mcsafe(addr, bytes, i);
+}
+
+static const struct dax_operations pmem_dax_ops = {
+ .direct_access = pmem_dax_direct_access,
+ .copy_from_iter = pmem_copy_from_iter,
+ .copy_to_iter = pmem_copy_to_iter,
+};
+
+static const struct attribute_group *pmem_attribute_groups[] = {
+ &dax_attribute_group,
+ NULL,
+};
+
+static void pmem_release_queue(void *q)
+{
+ blk_cleanup_queue(q);
+}
+
+static void pmem_freeze_queue(void *q)
+{
+ blk_freeze_queue_start(q);
+}
+
+static void pmem_release_disk(void *__pmem)
+{
+ struct pmem_device *pmem = __pmem;
+
+ kill_dax(pmem->dax_dev);
+ put_dax(pmem->dax_dev);
+ del_gendisk(pmem->disk);
+ put_disk(pmem->disk);
+}
+
+static void pmem_release_pgmap_ops(void *__pgmap)
+{
+ dev_pagemap_put_ops();
+}
+
+static void fsdax_pagefree(struct page *page, void *data)
+{
+ wake_up_var(&page->_refcount);
+}
+
+static int setup_pagemap_fsdax(struct device *dev, struct dev_pagemap *pgmap)
+{
+ dev_pagemap_get_ops();
+ if (devm_add_action_or_reset(dev, pmem_release_pgmap_ops, pgmap))
+ return -ENOMEM;
+ pgmap->type = MEMORY_DEVICE_FS_DAX;
+ pgmap->page_free = fsdax_pagefree;
+
+ return 0;
+}
+
+static int pmem_attach_disk(struct device *dev,
+ struct nd_namespace_common *ndns)
+{
+ struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+ struct nd_region *nd_region = to_nd_region(dev->parent);
+ int nid = dev_to_node(dev), fua;
+ struct resource *res = &nsio->res;
+ struct resource bb_res;
+ struct nd_pfn *nd_pfn = NULL;
+ struct dax_device *dax_dev;
+ struct nd_pfn_sb *pfn_sb;
+ struct pmem_device *pmem;
+ struct request_queue *q;
+ struct device *gendev;
+ struct gendisk *disk;
+ void *addr;
+ int rc;
+
+ pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
+ if (!pmem)
+ return -ENOMEM;
+
+ /* while nsio_rw_bytes is active, parse a pfn info block if present */
+ if (is_nd_pfn(dev)) {
+ nd_pfn = to_nd_pfn(dev);
+ rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
+ if (rc)
+ return rc;
+ }
+
+ /* we're attaching a block device, disable raw namespace access */
+ devm_nsio_disable(dev, nsio);
+
+ dev_set_drvdata(dev, pmem);
+ pmem->phys_addr = res->start;
+ pmem->size = resource_size(res);
+ fua = nvdimm_has_flush(nd_region);
+ if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
+ dev_warn(dev, "unable to guarantee persistence of writes\n");
+ fua = 0;
+ }
+
+ if (!devm_request_mem_region(dev, res->start, resource_size(res),
+ dev_name(&ndns->dev))) {
+ dev_warn(dev, "could not reserve region %pR\n", res);
+ return -EBUSY;
+ }
+
+ q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev), NULL);
+ if (!q)
+ return -ENOMEM;
+
+ if (devm_add_action_or_reset(dev, pmem_release_queue, q))
+ return -ENOMEM;
+
+ pmem->pfn_flags = PFN_DEV;
+ pmem->pgmap.ref = &q->q_usage_counter;
+ if (is_nd_pfn(dev)) {
+ if (setup_pagemap_fsdax(dev, &pmem->pgmap))
+ return -ENOMEM;
+ addr = devm_memremap_pages(dev, &pmem->pgmap);
+ pfn_sb = nd_pfn->pfn_sb;
+ pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
+ pmem->pfn_pad = resource_size(res) -
+ resource_size(&pmem->pgmap.res);
+ pmem->pfn_flags |= PFN_MAP;
+ memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
+ bb_res.start += pmem->data_offset;
+ } else if (pmem_should_map_pages(dev)) {
+ memcpy(&pmem->pgmap.res, &nsio->res, sizeof(pmem->pgmap.res));
+ pmem->pgmap.altmap_valid = false;
+ if (setup_pagemap_fsdax(dev, &pmem->pgmap))
+ return -ENOMEM;
+ addr = devm_memremap_pages(dev, &pmem->pgmap);
+ pmem->pfn_flags |= PFN_MAP;
+ memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
+ } else {
+ addr = devm_memremap(dev, pmem->phys_addr,
+ pmem->size, ARCH_MEMREMAP_PMEM);
+ memcpy(&bb_res, &nsio->res, sizeof(bb_res));
+ }
+
+ /*
+ * At release time the queue must be frozen before
+ * devm_memremap_pages is unwound
+ */
+ if (devm_add_action_or_reset(dev, pmem_freeze_queue, q))
+ return -ENOMEM;
+
+ if (IS_ERR(addr))
+ return PTR_ERR(addr);
+ pmem->virt_addr = addr;
+
+ blk_queue_write_cache(q, true, fua);
+ blk_queue_make_request(q, pmem_make_request);
+ blk_queue_physical_block_size(q, PAGE_SIZE);
+ blk_queue_logical_block_size(q, pmem_sector_size(ndns));
+ blk_queue_max_hw_sectors(q, UINT_MAX);
+ blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
+ if (pmem->pfn_flags & PFN_MAP)
+ blk_queue_flag_set(QUEUE_FLAG_DAX, q);
+ q->queuedata = pmem;
+
+ disk = alloc_disk_node(0, nid);
+ if (!disk)
+ return -ENOMEM;
+ pmem->disk = disk;
+
+ disk->fops = &pmem_fops;
+ disk->queue = q;
+ disk->flags = GENHD_FL_EXT_DEVT;
+ disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO;
+ nvdimm_namespace_disk_name(ndns, disk->disk_name);
+ set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
+ / 512);
+ if (devm_init_badblocks(dev, &pmem->bb))
+ return -ENOMEM;
+ nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res);
+ disk->bb = &pmem->bb;
+
+ dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops);
+ if (!dax_dev) {
+ put_disk(disk);
+ return -ENOMEM;
+ }
+ dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
+ pmem->dax_dev = dax_dev;
+
+ gendev = disk_to_dev(disk);
+ gendev->groups = pmem_attribute_groups;
+
+ device_add_disk(dev, disk);
+ if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
+ return -ENOMEM;
+
+ revalidate_disk(disk);
+
+ pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
+ "badblocks");
+ if (!pmem->bb_state)
+ dev_warn(dev, "'badblocks' notification disabled\n");
+
+ return 0;
+}
+
+static int nd_pmem_probe(struct device *dev)
+{
+ struct nd_namespace_common *ndns;
+
+ ndns = nvdimm_namespace_common_probe(dev);
+ if (IS_ERR(ndns))
+ return PTR_ERR(ndns);
+
+ if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
+ return -ENXIO;
+
+ if (is_nd_btt(dev))
+ return nvdimm_namespace_attach_btt(ndns);
+
+ if (is_nd_pfn(dev))
+ return pmem_attach_disk(dev, ndns);
+
+ /* if we find a valid info-block we'll come back as that personality */
+ if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0
+ || nd_dax_probe(dev, ndns) == 0)
+ return -ENXIO;
+
+ /* ...otherwise we're just a raw pmem device */
+ return pmem_attach_disk(dev, ndns);
+}
+
+static int nd_pmem_remove(struct device *dev)
+{
+ struct pmem_device *pmem = dev_get_drvdata(dev);
+
+ if (is_nd_btt(dev))
+ nvdimm_namespace_detach_btt(to_nd_btt(dev));
+ else {
+ /*
+ * Note, this assumes device_lock() context to not race
+ * nd_pmem_notify()
+ */
+ sysfs_put(pmem->bb_state);
+ pmem->bb_state = NULL;
+ }
+ nvdimm_flush(to_nd_region(dev->parent));
+
+ return 0;
+}
+
+static void nd_pmem_shutdown(struct device *dev)
+{
+ nvdimm_flush(to_nd_region(dev->parent));
+}
+
+static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
+{
+ struct nd_region *nd_region;
+ resource_size_t offset = 0, end_trunc = 0;
+ struct nd_namespace_common *ndns;
+ struct nd_namespace_io *nsio;
+ struct resource res;
+ struct badblocks *bb;
+ struct kernfs_node *bb_state;
+
+ if (event != NVDIMM_REVALIDATE_POISON)
+ return;
+
+ if (is_nd_btt(dev)) {
+ struct nd_btt *nd_btt = to_nd_btt(dev);
+
+ ndns = nd_btt->ndns;
+ nd_region = to_nd_region(ndns->dev.parent);
+ nsio = to_nd_namespace_io(&ndns->dev);
+ bb = &nsio->bb;
+ bb_state = NULL;
+ } else {
+ struct pmem_device *pmem = dev_get_drvdata(dev);
+
+ nd_region = to_region(pmem);
+ bb = &pmem->bb;
+ bb_state = pmem->bb_state;
+
+ if (is_nd_pfn(dev)) {
+ struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+ struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+
+ ndns = nd_pfn->ndns;
+ offset = pmem->data_offset +
+ __le32_to_cpu(pfn_sb->start_pad);
+ end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
+ } else {
+ ndns = to_ndns(dev);
+ }
+
+ nsio = to_nd_namespace_io(&ndns->dev);
+ }
+
+ res.start = nsio->res.start + offset;
+ res.end = nsio->res.end - end_trunc;
+ nvdimm_badblocks_populate(nd_region, bb, &res);
+ if (bb_state)
+ sysfs_notify_dirent(bb_state);
+}
+
+MODULE_ALIAS("pmem");
+MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
+MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
+static struct nd_device_driver nd_pmem_driver = {
+ .probe = nd_pmem_probe,
+ .remove = nd_pmem_remove,
+ .notify = nd_pmem_notify,
+ .shutdown = nd_pmem_shutdown,
+ .drv = {
+ .name = "nd_pmem",
+ },
+ .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
+};
+
+module_nd_driver(nd_pmem_driver);
+
+MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
+MODULE_LICENSE("GPL v2");