// SPDX-License-Identifier: GPL-2.0-only /* * Persistent Memory Driver * * Copyright (c) 2014-2015, Intel Corporation. * Copyright (c) 2015, Christoph Hellwig . * Copyright (c) 2015, Boaz Harrosh . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pmem.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 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 - 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 = sector * 512 + pmem->data_offset; 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) { 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; /* * 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, page_off, len); if (unlikely(bad_pmem)) { rc = pmem_clear_poison(pmem, pmem_off, len); write_pmem(pmem_addr, page, page_off, len); } return rc; } static blk_qc_t 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); 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_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, 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, .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, void **kaddr, pfn_t *pfn) { struct pmem_device *pmem = dax_get_private(dax_dev); return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn); } /* * Use the 'no check' versions of copy_from_iter_flushcache() and * copy_mc_to_iter() to bypass HARDENED_USERCOPY overhead. Bounds * checking, both file offset and device offset, is handled by * dax_iomap_actor() */ 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_mc_to_iter(addr, bytes, i); } static const struct dax_operations pmem_dax_ops = { .direct_access = pmem_dax_direct_access, .dax_supported = generic_fsdax_supported, .copy_from_iter = pmem_copy_from_iter, .copy_to_iter = pmem_copy_to_iter, .zero_page_range = pmem_dax_zero_page_range, }; static const struct attribute_group *pmem_attribute_groups[] = { &dax_attribute_group, NULL, }; static void pmem_pagemap_cleanup(struct dev_pagemap *pgmap) { struct request_queue *q = container_of(pgmap->ref, struct request_queue, q_usage_counter); blk_cleanup_queue(q); } static void pmem_release_queue(void *pgmap) { pmem_pagemap_cleanup(pgmap); } static void pmem_pagemap_kill(struct dev_pagemap *pgmap) { struct request_queue *q = container_of(pgmap->ref, struct request_queue, q_usage_counter); 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 const struct dev_pagemap_ops fsdax_pagemap_ops = { .kill = pmem_pagemap_kill, .cleanup = pmem_pagemap_cleanup, }; 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 device *gendev; struct gendisk *disk; void *addr; int rc; unsigned long flags = 0UL; 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; } q = blk_alloc_queue(dev_to_node(dev)); if (!q) return -ENOMEM; pmem->pfn_flags = PFN_DEV; pmem->pgmap.ref = &q->q_usage_counter; 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 { if (devm_add_action_or_reset(dev, pmem_release_queue, &pmem->pgmap)) return -ENOMEM; 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)) return PTR_ERR(addr); 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 = 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->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; if (is_nvdimm_sync(nd_region)) flags = DAXDEV_F_SYNC; dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops, flags); if (IS_ERR(dax_dev)) { put_disk(disk); return PTR_ERR(dax_dev); } 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, NULL); 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; } 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 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 nd_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); return 0; } static void nd_pmem_shutdown(struct device *dev) { nvdimm_flush(to_nd_region(dev->parent), NULL); } 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 badblocks *bb; struct range range; 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); } 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); } 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 "); MODULE_LICENSE("GPL v2");