/* * 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/module.h> #include <linux/moduleparam.h> #include <linux/badblocks.h> #include <linux/memremap.h> #include <linux/vmalloc.h> #include <linux/pfn_t.h> #include <linux/slab.h> #include <linux/pmem.h> #include <linux/nd.h> #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 int 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; int rc = 0; sector = (offset - pmem->data_offset) / 512; cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len); if (cleared < len) rc = -EIO; if (cleared > 0 && cleared / 512) { cleared /= 512; dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", __func__, (unsigned long long) sector, cleared, cleared > 1 ? "s" : ""); badblocks_clear(&pmem->bb, sector, cleared); } 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) { void *mem = kmap_atomic(page); memcpy_to_pmem(pmem_addr, mem + off, len); kunmap_atomic(mem); } static int read_pmem(struct page *page, unsigned int off, void *pmem_addr, unsigned int len) { int rc; void *mem = kmap_atomic(page); rc = memcpy_from_pmem(mem + off, pmem_addr, len); kunmap_atomic(mem); if (rc) return -EIO; return 0; } static int pmem_do_bvec(struct pmem_device *pmem, struct page *page, unsigned int len, unsigned int off, bool is_write, sector_t sector) { int rc = 0; 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 (!is_write) { if (unlikely(bad_pmem)) rc = -EIO; 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; } /* account for REQ_FLUSH rename, replace with REQ_PREFLUSH after v4.8-rc1 */ #ifndef REQ_FLUSH #define REQ_FLUSH REQ_PREFLUSH #endif 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; struct nd_region *nd_region = to_region(pmem); if (bio->bi_opf & REQ_FLUSH) 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, op_is_write(bio_op(bio)), iter.bi_sector); if (rc) { bio->bi_error = 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, bool is_write) { struct pmem_device *pmem = bdev->bd_queue->queuedata; int rc; rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, is_write, 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, is_write, 0); return rc; } /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */ __weak long pmem_direct_access(struct block_device *bdev, sector_t sector, void **kaddr, pfn_t *pfn, long size) { struct pmem_device *pmem = bdev->bd_queue->queuedata; resource_size_t offset = sector * 512 + pmem->data_offset; if (unlikely(is_bad_pmem(&pmem->bb, sector, size))) return -EIO; *kaddr = pmem->virt_addr + offset; *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 size; 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); } static void pmem_release_disk(void *disk) { del_gendisk(disk); put_disk(disk); } 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); 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 (nvdimm_has_flush(nd_region) < 0) dev_warn(dev, "unable to guarantee persistence of writes\n"); 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)); if (!q) return -ENOMEM; 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_or_reset(dev, pmem_release_queue, q)) return -ENOMEM; if (IS_ERR(addr)) return PTR_ERR(addr); pmem->virt_addr = addr; blk_queue_write_cache(q, true, true); blk_queue_make_request(q, pmem_make_request); blk_queue_physical_block_size(q, PAGE_SIZE); blk_queue_max_hw_sectors(q, UINT_MAX); blk_queue_bounce_limit(q, BLK_BOUNCE_ANY); queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q); queue_flag_set_unlocked(QUEUE_FLAG_DAX, q); q->queuedata = pmem; disk = alloc_disk_node(0, nid); if (!disk) return -ENOMEM; disk->fops = &pmem_fops; disk->queue = q; disk->flags = GENHD_FL_EXT_DEVT; 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, res); disk->bb = &pmem->bb; device_add_disk(dev, disk); if (devm_add_action_or_reset(dev, pmem_release_disk, disk)) return -ENOMEM; revalidate_disk(disk); 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) { if (is_nd_btt(dev)) nvdimm_namespace_detach_btt(to_nd_btt(dev)); 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 pmem_device *pmem = dev_get_drvdata(dev); struct nd_region *nd_region = to_region(pmem); 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, .shutdown = nd_pmem_shutdown, .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 <ross.zwisler@linux.intel.com>"); MODULE_LICENSE("GPL v2");