diff options
Diffstat (limited to 'drivers/nvdimm/pmem.c')
| -rw-r--r-- | drivers/nvdimm/pmem.c | 613 |
1 files changed, 613 insertions, 0 deletions
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c new file mode 100644 index 000000000..d6f981f6e --- /dev/null +++ b/drivers/nvdimm/pmem.c @@ -0,0 +1,613 @@ +/* + * 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 - 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 = memcpy_mcsafe(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_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); +} + +/* + * Use the 'no check' versions of copy_from_iter_flushcache() and + * copy_to_iter_mcsafe() 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_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(struct percpu_ref *ref) +{ + struct request_queue *q; + + q = container_of(ref, typeof(*q), 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 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; + pmem->pgmap.kill = pmem_freeze_queue; + 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)); + } + + 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, NULL); + 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"); |