/* * Persistent Memory Driver * * Copyright (c) 2014-2015, Intel Corporation. * Copyright (c) 2015, Christoph Hellwig . * Copyright (c) 2015, Boaz Harrosh . * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pfn.h" #include "nd.h" struct pmem_device { struct request_queue *pmem_queue; struct gendisk *pmem_disk; /* One contiguous memory region per device */ phys_addr_t phys_addr; /* when non-zero this device is hosting a 'pfn' instance */ phys_addr_t data_offset; u64 pfn_flags; void __pmem *virt_addr; /* immutable base size of the namespace */ size_t size; /* trim size when namespace capacity has been section aligned */ u32 pfn_pad; struct badblocks bb; }; static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset, unsigned int len) { struct device *dev = disk_to_dev(pmem->pmem_disk); sector_t sector; long cleared; sector = (offset - pmem->data_offset) / 512; cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len); if (cleared > 0 && cleared / 512) { dev_dbg(dev, "%s: %llx clear %ld sector%s\n", __func__, (unsigned long long) sector, cleared / 512, cleared / 512 > 1 ? "s" : ""); badblocks_clear(&pmem->bb, sector, cleared / 512); } invalidate_pmem(pmem->virt_addr + offset, len); } static int pmem_do_bvec(struct pmem_device *pmem, struct page *page, unsigned int len, unsigned int off, int rw, sector_t sector) { int rc = 0; bool bad_pmem = false; void *mem = kmap_atomic(page); phys_addr_t pmem_off = sector * 512 + pmem->data_offset; void __pmem *pmem_addr = pmem->virt_addr + pmem_off; if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) bad_pmem = true; if (rw == READ) { if (unlikely(bad_pmem)) rc = -EIO; else { rc = memcpy_from_pmem(mem + 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); memcpy_to_pmem(pmem_addr, mem + off, len); if (unlikely(bad_pmem)) { pmem_clear_poison(pmem, pmem_off, len); memcpy_to_pmem(pmem_addr, mem + off, len); } } kunmap_atomic(mem); return rc; } static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) { int rc = 0; bool do_acct; unsigned long start; struct bio_vec bvec; struct bvec_iter iter; struct pmem_device *pmem = q->queuedata; 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_data_dir(bio), iter.bi_sector); if (rc) { bio->bi_error = rc; break; } } if (do_acct) nd_iostat_end(bio, start); if (bio_data_dir(bio)) wmb_pmem(); bio_endio(bio); return BLK_QC_T_NONE; } static int pmem_rw_page(struct block_device *bdev, sector_t sector, struct page *page, int rw) { struct pmem_device *pmem = bdev->bd_queue->queuedata; int rc; rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, rw, sector); if (rw & WRITE) wmb_pmem(); /* * 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, rw & WRITE, 0); return rc; } static long pmem_direct_access(struct block_device *bdev, sector_t sector, void __pmem **kaddr, pfn_t *pfn) { struct pmem_device *pmem = bdev->bd_queue->queuedata; resource_size_t offset = sector * 512 + pmem->data_offset; *kaddr = pmem->virt_addr + offset; *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags); return pmem->size - pmem->pfn_pad - offset; } static const struct block_device_operations pmem_fops = { .owner = THIS_MODULE, .rw_page = pmem_rw_page, .direct_access = pmem_direct_access, .revalidate_disk = nvdimm_revalidate_disk, }; static void pmem_release_queue(void *q) { blk_cleanup_queue(q); } void pmem_release_disk(void *disk) { del_gendisk(disk); put_disk(disk); } static struct vmem_altmap *nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct resource *res, struct vmem_altmap *altmap); 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 vmem_altmap __altmap, *altmap = NULL; struct resource *res = &nsio->res; struct nd_pfn *nd_pfn = NULL; int nid = dev_to_node(dev); struct nd_pfn_sb *pfn_sb; struct pmem_device *pmem; struct resource pfn_res; struct request_queue *q; struct gendisk *disk; void *addr; /* while nsio_rw_bytes is active, parse a pfn info block if present */ if (is_nd_pfn(dev)) { nd_pfn = to_nd_pfn(dev); altmap = nvdimm_setup_pfn(nd_pfn, &pfn_res, &__altmap); if (IS_ERR(altmap)) return PTR_ERR(altmap); } /* we're attaching a block device, disable raw namespace access */ devm_nsio_disable(dev, nsio); pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL); if (!pmem) return -ENOMEM; dev_set_drvdata(dev, pmem); pmem->phys_addr = res->start; pmem->size = resource_size(res); if (!arch_has_wmb_pmem()) dev_warn(dev, "unable to guarantee persistence of writes\n"); if (!devm_request_mem_region(dev, res->start, resource_size(res), dev_name(dev))) { dev_warn(dev, "could not reserve region %pR\n", res); return -EBUSY; } q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev)); if (!q) return -ENOMEM; pmem->pmem_queue = q; pmem->pfn_flags = PFN_DEV; if (is_nd_pfn(dev)) { addr = devm_memremap_pages(dev, &pfn_res, &q->q_usage_counter, altmap); pfn_sb = nd_pfn->pfn_sb; pmem->data_offset = le64_to_cpu(pfn_sb->dataoff); pmem->pfn_pad = resource_size(res) - resource_size(&pfn_res); pmem->pfn_flags |= PFN_MAP; res = &pfn_res; /* for badblocks populate */ res->start += pmem->data_offset; } else if (pmem_should_map_pages(dev)) { addr = devm_memremap_pages(dev, &nsio->res, &q->q_usage_counter, NULL); pmem->pfn_flags |= PFN_MAP; } else addr = devm_memremap(dev, pmem->phys_addr, pmem->size, ARCH_MEMREMAP_PMEM); /* * At release time the queue must be dead before * devm_memremap_pages is unwound */ if (devm_add_action(dev, pmem_release_queue, q)) { blk_cleanup_queue(q); return -ENOMEM; } if (IS_ERR(addr)) return PTR_ERR(addr); pmem->virt_addr = (void __pmem *) addr; blk_queue_make_request(pmem->pmem_queue, pmem_make_request); blk_queue_physical_block_size(pmem->pmem_queue, PAGE_SIZE); blk_queue_max_hw_sectors(pmem->pmem_queue, UINT_MAX); blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY); queue_flag_set_unlocked(QUEUE_FLAG_NONROT, pmem->pmem_queue); pmem->pmem_queue->queuedata = pmem; disk = alloc_disk_node(0, nid); if (!disk) return -ENOMEM; if (devm_add_action(dev, pmem_release_disk, disk)) { put_disk(disk); return -ENOMEM; } disk->fops = &pmem_fops; disk->queue = pmem->pmem_queue; disk->flags = GENHD_FL_EXT_DEVT; nvdimm_namespace_disk_name(ndns, disk->disk_name); disk->driverfs_dev = dev; set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset) / 512); pmem->pmem_disk = disk; if (devm_init_badblocks(dev, &pmem->bb)) return -ENOMEM; nvdimm_badblocks_populate(to_nd_region(dev->parent), &pmem->bb, res); disk->bb = &pmem->bb; add_disk(disk); revalidate_disk(disk); return 0; } static int nd_pfn_init(struct nd_pfn *nd_pfn) { struct nd_namespace_common *ndns = nd_pfn->ndns; u32 start_pad = 0, end_trunc = 0; resource_size_t start, size; struct nd_namespace_io *nsio; struct nd_region *nd_region; struct nd_pfn_sb *pfn_sb; unsigned long npfns; phys_addr_t offset; u64 checksum; int rc; pfn_sb = devm_kzalloc(&nd_pfn->dev, sizeof(*pfn_sb), GFP_KERNEL); if (!pfn_sb) return -ENOMEM; nd_pfn->pfn_sb = pfn_sb; rc = nd_pfn_validate(nd_pfn); if (rc == -ENODEV) /* no info block, do init */; else return rc; nd_region = to_nd_region(nd_pfn->dev.parent); if (nd_region->ro) { dev_info(&nd_pfn->dev, "%s is read-only, unable to init metadata\n", dev_name(&nd_region->dev)); return -ENXIO; } memset(pfn_sb, 0, sizeof(*pfn_sb)); /* * Check if pmem collides with 'System RAM' when section aligned and * trim it accordingly */ nsio = to_nd_namespace_io(&ndns->dev); start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start); size = resource_size(&nsio->res); if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE) == REGION_MIXED) { start = nsio->res.start; start_pad = PHYS_SECTION_ALIGN_UP(start) - start; } start = nsio->res.start; size = PHYS_SECTION_ALIGN_UP(start + size) - start; if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE) == REGION_MIXED) { size = resource_size(&nsio->res); end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size); } if (start_pad + end_trunc) dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n", dev_name(&ndns->dev), start_pad + end_trunc); /* * Note, we use 64 here for the standard size of struct page, * debugging options may cause it to be larger in which case the * implementation will limit the pfns advertised through * ->direct_access() to those that are included in the memmap. */ start += start_pad; size = resource_size(&nsio->res); npfns = (size - start_pad - end_trunc - SZ_8K) / SZ_4K; if (nd_pfn->mode == PFN_MODE_PMEM) offset = ALIGN(start + SZ_8K + 64 * npfns, nd_pfn->align) - start; else if (nd_pfn->mode == PFN_MODE_RAM) offset = ALIGN(start + SZ_8K, nd_pfn->align) - start; else return -ENXIO; if (offset + start_pad + end_trunc >= size) { dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n", dev_name(&ndns->dev)); return -ENXIO; } npfns = (size - offset - start_pad - end_trunc) / SZ_4K; pfn_sb->mode = cpu_to_le32(nd_pfn->mode); pfn_sb->dataoff = cpu_to_le64(offset); pfn_sb->npfns = cpu_to_le64(npfns); memcpy(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN); memcpy(pfn_sb->uuid, nd_pfn->uuid, 16); memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16); pfn_sb->version_major = cpu_to_le16(1); pfn_sb->version_minor = cpu_to_le16(1); pfn_sb->start_pad = cpu_to_le32(start_pad); pfn_sb->end_trunc = cpu_to_le32(end_trunc); checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb); pfn_sb->checksum = cpu_to_le64(checksum); return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb)); } /* * We hotplug memory at section granularity, pad the reserved area from * the previous section base to the namespace base address. */ static unsigned long init_altmap_base(resource_size_t base) { unsigned long base_pfn = PHYS_PFN(base); return PFN_SECTION_ALIGN_DOWN(base_pfn); } static unsigned long init_altmap_reserve(resource_size_t base) { unsigned long reserve = PHYS_PFN(SZ_8K); unsigned long base_pfn = PHYS_PFN(base); reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn); return reserve; } static struct vmem_altmap *__nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct resource *res, struct vmem_altmap *altmap) { struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb; u64 offset = le64_to_cpu(pfn_sb->dataoff); u32 start_pad = __le32_to_cpu(pfn_sb->start_pad); u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc); struct nd_namespace_common *ndns = nd_pfn->ndns; struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); resource_size_t base = nsio->res.start + start_pad; struct vmem_altmap __altmap = { .base_pfn = init_altmap_base(base), .reserve = init_altmap_reserve(base), }; memcpy(res, &nsio->res, sizeof(*res)); res->start += start_pad; res->end -= end_trunc; nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode); if (nd_pfn->mode == PFN_MODE_RAM) { if (offset < SZ_8K) return ERR_PTR(-EINVAL); nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns); altmap = NULL; } else if (nd_pfn->mode == PFN_MODE_PMEM) { nd_pfn->npfns = (resource_size(res) - offset) / PAGE_SIZE; if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns) dev_info(&nd_pfn->dev, "number of pfns truncated from %lld to %ld\n", le64_to_cpu(nd_pfn->pfn_sb->npfns), nd_pfn->npfns); memcpy(altmap, &__altmap, sizeof(*altmap)); altmap->free = PHYS_PFN(offset - SZ_8K); altmap->alloc = 0; } else return ERR_PTR(-ENXIO); return altmap; } /* * Determine the effective resource range and vmem_altmap from an nd_pfn * instance. */ static struct vmem_altmap *nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct resource *res, struct vmem_altmap *altmap) { int rc; if (!nd_pfn->uuid || !nd_pfn->ndns) return ERR_PTR(-ENODEV); rc = nd_pfn_init(nd_pfn); if (rc) return ERR_PTR(rc); /* we need a valid pfn_sb before we can init a vmem_altmap */ return __nvdimm_setup_pfn(nd_pfn, res, altmap); } 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) return -ENXIO; /* ...otherwise we're just a raw pmem device */ return pmem_attach_disk(dev, ndns); } static int nd_pmem_remove(struct device *dev) { if (is_nd_btt(dev)) nvdimm_namespace_detach_btt(to_nd_btt(dev)); return 0; } static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) { struct nd_region *nd_region = to_nd_region(dev->parent); struct pmem_device *pmem = dev_get_drvdata(dev); resource_size_t offset = 0, end_trunc = 0; struct nd_namespace_common *ndns; struct nd_namespace_io *nsio; struct resource res; if (event != NVDIMM_REVALIDATE_POISON) return; if (is_nd_btt(dev)) { struct nd_btt *nd_btt = to_nd_btt(dev); ndns = nd_btt->ndns; } else 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, &pmem->bb, &res); } 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, .drv = { .name = "nd_pmem", }, .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM, }; static int __init pmem_init(void) { return nd_driver_register(&nd_pmem_driver); } module_init(pmem_init); static void pmem_exit(void) { driver_unregister(&nd_pmem_driver.drv); } module_exit(pmem_exit); MODULE_AUTHOR("Ross Zwisler "); MODULE_LICENSE("GPL v2");