// SPDX-License-Identifier: GPL-2.0-only /* * 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>. */ #include <linux/blkdev.h> #include <linux/pagemap.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/mm.h> #include <asm/cacheflush.h> #include "pmem.h" #include "btt.h" #include "pfn.h" #include "nd.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 phys_addr_t pmem_to_phys(struct pmem_device *pmem, phys_addr_t offset) { return pmem->phys_addr + offset; } static sector_t to_sect(struct pmem_device *pmem, phys_addr_t offset) { return (offset - pmem->data_offset) >> SECTOR_SHIFT; } static phys_addr_t to_offset(struct pmem_device *pmem, sector_t sector) { return (sector << SECTOR_SHIFT) + pmem->data_offset; } static void pmem_mkpage_present(struct pmem_device *pmem, phys_addr_t offset, unsigned int len) { phys_addr_t phys = pmem_to_phys(pmem, offset); 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 void pmem_clear_bb(struct pmem_device *pmem, sector_t sector, long blks) { if (blks == 0) return; badblocks_clear(&pmem->bb, sector, blks); if (pmem->bb_state) sysfs_notify_dirent(pmem->bb_state); } static long __pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset, unsigned int len) { phys_addr_t phys = pmem_to_phys(pmem, offset); long cleared = nvdimm_clear_poison(to_dev(pmem), phys, len); if (cleared > 0) { pmem_mkpage_present(pmem, offset, cleared); arch_invalidate_pmem(pmem->virt_addr + offset, len); } return cleared; } static blk_status_t pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset, unsigned int len) { long cleared = __pmem_clear_poison(pmem, offset, len); if (cleared < 0) return BLK_STS_IOERR; pmem_clear_bb(pmem, to_sect(pmem, offset), cleared >> SECTOR_SHIFT); if (cleared < len) return BLK_STS_IOERR; return BLK_STS_OK; } 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 - off); memcpy_flushcache(pmem_addr, mem + off, chunk); kunmap_atomic(mem); len -= chunk; off = 0; page++; pmem_addr += chunk; } } 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 - off); rem = copy_mc_to_kernel(mem + off, pmem_addr, chunk); kunmap_atomic(mem); if (rem) return BLK_STS_IOERR; len -= chunk; off = 0; page++; pmem_addr += chunk; } return BLK_STS_OK; } static blk_status_t pmem_do_read(struct pmem_device *pmem, struct page *page, unsigned int page_off, sector_t sector, unsigned int len) { blk_status_t rc; phys_addr_t pmem_off = to_offset(pmem, sector); void *pmem_addr = pmem->virt_addr + pmem_off; if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) return BLK_STS_IOERR; rc = read_pmem(page, page_off, pmem_addr, len); flush_dcache_page(page); return rc; } static blk_status_t pmem_do_write(struct pmem_device *pmem, struct page *page, unsigned int page_off, sector_t sector, unsigned int len) { phys_addr_t pmem_off = to_offset(pmem, sector); void *pmem_addr = pmem->virt_addr + pmem_off; if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) { blk_status_t rc = pmem_clear_poison(pmem, pmem_off, len); if (rc != BLK_STS_OK) return rc; } flush_dcache_page(page); write_pmem(pmem_addr, page, page_off, len); return BLK_STS_OK; } static void pmem_submit_bio(struct bio *bio) { int ret = 0; blk_status_t rc = 0; bool do_acct; unsigned long start; struct bio_vec bvec; struct bvec_iter iter; struct pmem_device *pmem = bio->bi_bdev->bd_disk->private_data; struct nd_region *nd_region = to_region(pmem); if (bio->bi_opf & REQ_PREFLUSH) ret = nvdimm_flush(nd_region, bio); do_acct = blk_queue_io_stat(bio->bi_bdev->bd_disk->queue); if (do_acct) start = bio_start_io_acct(bio); bio_for_each_segment(bvec, bio, iter) { if (op_is_write(bio_op(bio))) rc = pmem_do_write(pmem, bvec.bv_page, bvec.bv_offset, iter.bi_sector, bvec.bv_len); else rc = pmem_do_read(pmem, bvec.bv_page, bvec.bv_offset, iter.bi_sector, bvec.bv_len); if (rc) { bio->bi_status = rc; break; } } if (do_acct) bio_end_io_acct(bio, start); if (bio->bi_opf & REQ_FUA) ret = nvdimm_flush(nd_region, bio); if (ret) bio->bi_status = errno_to_blk_status(ret); bio_endio(bio); } static int pmem_rw_page(struct block_device *bdev, sector_t sector, struct page *page, enum req_op op) { struct pmem_device *pmem = bdev->bd_disk->private_data; blk_status_t rc; if (op_is_write(op)) rc = pmem_do_write(pmem, page, 0, sector, thp_size(page)); else rc = pmem_do_read(pmem, page, 0, sector, thp_size(page)); /* * 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, enum dax_access_mode mode, void **kaddr, pfn_t *pfn) { resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset; sector_t sector = PFN_PHYS(pgoff) >> SECTOR_SHIFT; unsigned int num = PFN_PHYS(nr_pages) >> SECTOR_SHIFT; struct badblocks *bb = &pmem->bb; sector_t first_bad; int num_bad; if (kaddr) *kaddr = pmem->virt_addr + offset; if (pfn) *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags); if (bb->count && badblocks_check(bb, sector, num, &first_bad, &num_bad)) { long actual_nr; if (mode != DAX_RECOVERY_WRITE) return -EIO; /* * Set the recovery stride is set to kernel page size because * the underlying driver and firmware clear poison functions * don't appear to handle large chunk(such as 2MiB) reliably. */ actual_nr = PHYS_PFN( PAGE_ALIGN((first_bad - sector) << SECTOR_SHIFT)); dev_dbg(pmem->bb.dev, "start sector(%llu), nr_pages(%ld), first_bad(%llu), actual_nr(%ld)\n", sector, nr_pages, first_bad, actual_nr); if (actual_nr) return actual_nr; return 1; } /* * If badblocks are present but not in the range, limit known good range * to the requested range. */ if (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, .submit_bio = pmem_submit_bio, .rw_page = pmem_rw_page, }; static int pmem_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, size_t nr_pages) { struct pmem_device *pmem = dax_get_private(dax_dev); return blk_status_to_errno(pmem_do_write(pmem, ZERO_PAGE(0), 0, PFN_PHYS(pgoff) >> SECTOR_SHIFT, PAGE_SIZE)); } static long pmem_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, enum dax_access_mode mode, void **kaddr, pfn_t *pfn) { struct pmem_device *pmem = dax_get_private(dax_dev); return __pmem_direct_access(pmem, pgoff, nr_pages, mode, kaddr, pfn); } /* * The recovery write thread started out as a normal pwrite thread and * when the filesystem was told about potential media error in the * range, filesystem turns the normal pwrite to a dax_recovery_write. * * The recovery write consists of clearing media poison, clearing page * HWPoison bit, reenable page-wide read-write permission, flush the * caches and finally write. A competing pread thread will be held * off during the recovery process since data read back might not be * valid, and this is achieved by clearing the badblock records after * the recovery write is complete. Competing recovery write threads * are already serialized by writer lock held by dax_iomap_rw(). */ static size_t pmem_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i) { struct pmem_device *pmem = dax_get_private(dax_dev); size_t olen, len, off; phys_addr_t pmem_off; struct device *dev = pmem->bb.dev; long cleared; off = offset_in_page(addr); len = PFN_PHYS(PFN_UP(off + bytes)); if (!is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) >> SECTOR_SHIFT, len)) return _copy_from_iter_flushcache(addr, bytes, i); /* * Not page-aligned range cannot be recovered. This should not * happen unless something else went wrong. */ if (off || !PAGE_ALIGNED(bytes)) { dev_dbg(dev, "Found poison, but addr(%p) or bytes(%#zx) not page aligned\n", addr, bytes); return 0; } pmem_off = PFN_PHYS(pgoff) + pmem->data_offset; cleared = __pmem_clear_poison(pmem, pmem_off, len); if (cleared > 0 && cleared < len) { dev_dbg(dev, "poison cleared only %ld out of %zu bytes\n", cleared, len); return 0; } if (cleared < 0) { dev_dbg(dev, "poison clear failed: %ld\n", cleared); return 0; } olen = _copy_from_iter_flushcache(addr, bytes, i); pmem_clear_bb(pmem, to_sect(pmem, pmem_off), cleared >> SECTOR_SHIFT); return olen; } static const struct dax_operations pmem_dax_ops = { .direct_access = pmem_dax_direct_access, .zero_page_range = pmem_dax_zero_page_range, .recovery_write = pmem_recovery_write, }; static ssize_t write_cache_show(struct device *dev, struct device_attribute *attr, char *buf) { struct pmem_device *pmem = dev_to_disk(dev)->private_data; return sprintf(buf, "%d\n", !!dax_write_cache_enabled(pmem->dax_dev)); } static ssize_t write_cache_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct pmem_device *pmem = dev_to_disk(dev)->private_data; bool write_cache; int rc; rc = strtobool(buf, &write_cache); if (rc) return rc; dax_write_cache(pmem->dax_dev, write_cache); return len; } static DEVICE_ATTR_RW(write_cache); static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n) { #ifndef CONFIG_ARCH_HAS_PMEM_API if (a == &dev_attr_write_cache.attr) return 0; #endif return a->mode; } static struct attribute *dax_attributes[] = { &dev_attr_write_cache.attr, NULL, }; static const struct attribute_group dax_attribute_group = { .name = "dax", .attrs = dax_attributes, .is_visible = dax_visible, }; static const struct attribute_group *pmem_attribute_groups[] = { &dax_attribute_group, NULL, }; static void pmem_release_disk(void *__pmem) { struct pmem_device *pmem = __pmem; dax_remove_host(pmem->disk); kill_dax(pmem->dax_dev); put_dax(pmem->dax_dev); del_gendisk(pmem->disk); put_disk(pmem->disk); } static int pmem_pagemap_memory_failure(struct dev_pagemap *pgmap, unsigned long pfn, unsigned long nr_pages, int mf_flags) { struct pmem_device *pmem = container_of(pgmap, struct pmem_device, pgmap); u64 offset = PFN_PHYS(pfn) - pmem->phys_addr - pmem->data_offset; u64 len = nr_pages << PAGE_SHIFT; return dax_holder_notify_failure(pmem->dax_dev, offset, len, mf_flags); } static const struct dev_pagemap_ops fsdax_pagemap_ops = { .memory_failure = pmem_pagemap_memory_failure, }; 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 range bb_range; 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 gendisk *disk; void *addr; int rc; pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL); if (!pmem) return -ENOMEM; rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve()); if (rc) return rc; /* 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_namespace_disable(dev, ndns); 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; } disk = blk_alloc_disk(nid); if (!disk) return -ENOMEM; q = disk->queue; pmem->disk = disk; pmem->pgmap.owner = pmem; pmem->pfn_flags = PFN_DEV; if (is_nd_pfn(dev)) { pmem->pgmap.type = MEMORY_DEVICE_FS_DAX; pmem->pgmap.ops = &fsdax_pagemap_ops; 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) - range_len(&pmem->pgmap.range); pmem->pfn_flags |= PFN_MAP; bb_range = pmem->pgmap.range; bb_range.start += pmem->data_offset; } else if (pmem_should_map_pages(dev)) { pmem->pgmap.range.start = res->start; pmem->pgmap.range.end = res->end; pmem->pgmap.nr_range = 1; pmem->pgmap.type = MEMORY_DEVICE_FS_DAX; pmem->pgmap.ops = &fsdax_pagemap_ops; addr = devm_memremap_pages(dev, &pmem->pgmap); pmem->pfn_flags |= PFN_MAP; bb_range = pmem->pgmap.range; } else { addr = devm_memremap(dev, pmem->phys_addr, pmem->size, ARCH_MEMREMAP_PMEM); bb_range.start = res->start; bb_range.end = res->end; } if (IS_ERR(addr)) { rc = PTR_ERR(addr); goto out; } pmem->virt_addr = addr; blk_queue_write_cache(q, true, fua); 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); disk->fops = &pmem_fops; disk->private_data = pmem; 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_range); disk->bb = &pmem->bb; dax_dev = alloc_dax(pmem, &pmem_dax_ops); if (IS_ERR(dax_dev)) { rc = PTR_ERR(dax_dev); goto out; } set_dax_nocache(dax_dev); set_dax_nomc(dax_dev); if (is_nvdimm_sync(nd_region)) set_dax_synchronous(dax_dev); rc = dax_add_host(dax_dev, disk); if (rc) goto out_cleanup_dax; dax_write_cache(dax_dev, nvdimm_has_cache(nd_region)); pmem->dax_dev = dax_dev; rc = device_add_disk(dev, disk, pmem_attribute_groups); if (rc) goto out_remove_host; if (devm_add_action_or_reset(dev, pmem_release_disk, pmem)) return -ENOMEM; nvdimm_check_and_set_ro(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; out_remove_host: dax_remove_host(pmem->disk); out_cleanup_dax: kill_dax(pmem->dax_dev); put_dax(pmem->dax_dev); out: put_disk(pmem->disk); return rc; } static int nd_pmem_probe(struct device *dev) { int ret; struct nd_namespace_common *ndns; ndns = nvdimm_namespace_common_probe(dev); if (IS_ERR(ndns)) return PTR_ERR(ndns); if (is_nd_btt(dev)) return nvdimm_namespace_attach_btt(ndns); if (is_nd_pfn(dev)) return pmem_attach_disk(dev, ndns); ret = devm_namespace_enable(dev, ndns, nd_info_block_reserve()); if (ret) return ret; ret = nd_btt_probe(dev, ndns); if (ret == 0) return -ENXIO; /* * We have two failure conditions here, there is no * info reserver block or we found a valid info reserve block * but failed to initialize the pfn superblock. * * For the first case consider namespace as a raw pmem namespace * and attach a disk. * * For the latter, consider this a success and advance the namespace * seed. */ ret = nd_pfn_probe(dev, ndns); if (ret == 0) return -ENXIO; else if (ret == -EOPNOTSUPP) return ret; ret = nd_dax_probe(dev, ndns); if (ret == 0) return -ENXIO; else if (ret == -EOPNOTSUPP) return ret; /* probe complete, attach handles namespace enabling */ devm_namespace_disable(dev, ndns); return pmem_attach_disk(dev, ndns); } static void 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), NULL); } static void nd_pmem_shutdown(struct device *dev) { nvdimm_flush(to_nd_region(dev->parent), NULL); } static void pmem_revalidate_poison(struct device *dev) { struct nd_region *nd_region; resource_size_t offset = 0, end_trunc = 0; struct nd_namespace_common *ndns; struct nd_namespace_io *nsio; struct badblocks *bb; struct range range; struct kernfs_node *bb_state; 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); } range.start = nsio->res.start + offset; range.end = nsio->res.end - end_trunc; nvdimm_badblocks_populate(nd_region, bb, &range); if (bb_state) sysfs_notify_dirent(bb_state); } static void pmem_revalidate_region(struct device *dev) { struct pmem_device *pmem; if (is_nd_btt(dev)) { struct nd_btt *nd_btt = to_nd_btt(dev); struct btt *btt = nd_btt->btt; nvdimm_check_and_set_ro(btt->btt_disk); return; } pmem = dev_get_drvdata(dev); nvdimm_check_and_set_ro(pmem->disk); } static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) { switch (event) { case NVDIMM_REVALIDATE_POISON: pmem_revalidate_poison(dev); break; case NVDIMM_REVALIDATE_REGION: pmem_revalidate_region(dev); break; default: dev_WARN_ONCE(dev, 1, "notify: unknown event: %d\n", event); break; } } 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");