--- /dev/null
+/*
+ * 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/memory_hotplug.h>
+#include <linux/moduleparam.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/pmem.h>
+#include <linux/nd.h>
+#include "pfn.h"
+#include "nd.h"
+
+struct pmem_device {
+ struct request_queue *pmem_queue;
+ struct gendisk *pmem_disk;
+ struct nd_namespace_common *ndns;
+
+ /* 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;
+ void __pmem *virt_addr;
+ size_t size;
+};
+
+static int pmem_major;
+
+static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
+ unsigned int len, unsigned int off, int rw,
+ sector_t sector)
+{
+ 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 (rw == READ) {
+ memcpy_from_pmem(mem + off, pmem_addr, len);
+ flush_dcache_page(page);
+ } else {
+ flush_dcache_page(page);
+ memcpy_to_pmem(pmem_addr, mem + off, len);
+ }
+
+ kunmap_atomic(mem);
+}
+
+static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
+{
+ bool do_acct;
+ unsigned long start;
+ struct bio_vec bvec;
+ struct bvec_iter iter;
+ struct block_device *bdev = bio->bi_bdev;
+ struct pmem_device *pmem = bdev->bd_disk->private_data;
+
+ do_acct = nd_iostat_start(bio, &start);
+ bio_for_each_segment(bvec, bio, iter)
+ pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, bvec.bv_offset,
+ bio_data_dir(bio), iter.bi_sector);
+ 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_disk->private_data;
+
+ pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector);
+ if (rw & WRITE)
+ wmb_pmem();
+ page_endio(page, rw & WRITE, 0);
+
+ return 0;
+}
+
+static long pmem_direct_access(struct block_device *bdev, sector_t sector,
+ void __pmem **kaddr, unsigned long *pfn)
+{
+ struct pmem_device *pmem = bdev->bd_disk->private_data;
+ resource_size_t offset = sector * 512 + pmem->data_offset;
+
+ *kaddr = pmem->virt_addr + offset;
+ *pfn = (pmem->phys_addr + offset) >> PAGE_SHIFT;
+
+ return pmem->size - 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 struct pmem_device *pmem_alloc(struct device *dev,
+ struct resource *res, int id)
+{
+ struct pmem_device *pmem;
+
+ pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
+ if (!pmem)
+ return ERR_PTR(-ENOMEM);
+
+ 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, pmem->phys_addr, pmem->size,
+ dev_name(dev))) {
+ dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",
+ &pmem->phys_addr, pmem->size);
+ return ERR_PTR(-EBUSY);
+ }
+
+ if (pmem_should_map_pages(dev))
+ pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, res);
+ else
+ pmem->virt_addr = (void __pmem *) devm_memremap(dev,
+ pmem->phys_addr, pmem->size,
+ ARCH_MEMREMAP_PMEM);
+
+ if (IS_ERR(pmem->virt_addr))
+ return (void __force *) pmem->virt_addr;
+
+ return pmem;
+}
+
+static void pmem_detach_disk(struct pmem_device *pmem)
+{
+ if (!pmem->pmem_disk)
+ return;
+
+ del_gendisk(pmem->pmem_disk);
+ put_disk(pmem->pmem_disk);
+ blk_cleanup_queue(pmem->pmem_queue);
+}
+
+static int pmem_attach_disk(struct device *dev,
+ struct nd_namespace_common *ndns, struct pmem_device *pmem)
+{
+ int nid = dev_to_node(dev);
+ struct gendisk *disk;
+
+ pmem->pmem_queue = blk_alloc_queue_node(GFP_KERNEL, nid);
+ if (!pmem->pmem_queue)
+ return -ENOMEM;
+
+ 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);
+
+ disk = alloc_disk_node(0, nid);
+ if (!disk) {
+ blk_cleanup_queue(pmem->pmem_queue);
+ return -ENOMEM;
+ }
+
+ disk->major = pmem_major;
+ disk->first_minor = 0;
+ disk->fops = &pmem_fops;
+ disk->private_data = pmem;
+ 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->data_offset) / 512);
+ pmem->pmem_disk = disk;
+
+ add_disk(disk);
+ revalidate_disk(disk);
+
+ return 0;
+}
+
+static int pmem_rw_bytes(struct nd_namespace_common *ndns,
+ resource_size_t offset, void *buf, size_t size, int rw)
+{
+ struct pmem_device *pmem = dev_get_drvdata(ndns->claim);
+
+ if (unlikely(offset + size > pmem->size)) {
+ dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
+ return -EFAULT;
+ }
+
+ if (rw == READ)
+ memcpy_from_pmem(buf, pmem->virt_addr + offset, size);
+ else {
+ memcpy_to_pmem(pmem->virt_addr + offset, buf, size);
+ wmb_pmem();
+ }
+
+ return 0;
+}
+
+static int nd_pfn_init(struct nd_pfn *nd_pfn)
+{
+ struct nd_pfn_sb *pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
+ struct pmem_device *pmem = dev_get_drvdata(&nd_pfn->dev);
+ struct nd_namespace_common *ndns = nd_pfn->ndns;
+ struct nd_region *nd_region;
+ unsigned long npfns;
+ phys_addr_t offset;
+ u64 checksum;
+ int rc;
+
+ if (!pfn_sb)
+ return -ENOMEM;
+
+ nd_pfn->pfn_sb = pfn_sb;
+ rc = nd_pfn_validate(nd_pfn);
+ if (rc == 0 || rc == -EBUSY)
+ return rc;
+
+ /* section alignment for simple hotplug */
+ if (nvdimm_namespace_capacity(ndns) < ND_PFN_ALIGN
+ || pmem->phys_addr & ND_PFN_MASK)
+ return -ENODEV;
+
+ 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));
+ goto err;
+ }
+
+ memset(pfn_sb, 0, sizeof(*pfn_sb));
+ npfns = (pmem->size - SZ_8K) / SZ_4K;
+ /*
+ * 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.
+ */
+ if (nd_pfn->mode == PFN_MODE_PMEM)
+ offset = ALIGN(SZ_8K + 64 * npfns, PMD_SIZE);
+ else if (nd_pfn->mode == PFN_MODE_RAM)
+ offset = SZ_8K;
+ else
+ goto err;
+
+ npfns = (pmem->size - offset) / 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);
+ pfn_sb->version_major = cpu_to_le16(1);
+ checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
+ pfn_sb->checksum = cpu_to_le64(checksum);
+
+ rc = nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
+ if (rc)
+ goto err;
+
+ return 0;
+ err:
+ nd_pfn->pfn_sb = NULL;
+ kfree(pfn_sb);
+ return -ENXIO;
+}
+
+static int nvdimm_namespace_detach_pfn(struct nd_namespace_common *ndns)
+{
+ struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
+ struct pmem_device *pmem;
+
+ /* free pmem disk */
+ pmem = dev_get_drvdata(&nd_pfn->dev);
+ pmem_detach_disk(pmem);
+
+ /* release nd_pfn resources */
+ kfree(nd_pfn->pfn_sb);
+ nd_pfn->pfn_sb = NULL;
+
+ return 0;
+}
+
+static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
+{
+ struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+ struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
+ struct device *dev = &nd_pfn->dev;
+ struct vmem_altmap *altmap;
+ struct nd_region *nd_region;
+ struct nd_pfn_sb *pfn_sb;
+ struct pmem_device *pmem;
+ phys_addr_t offset;
+ int rc;
+
+ if (!nd_pfn->uuid || !nd_pfn->ndns)
+ return -ENODEV;
+
+ nd_region = to_nd_region(dev->parent);
+ rc = nd_pfn_init(nd_pfn);
+ if (rc)
+ return rc;
+
+ if (PAGE_SIZE != SZ_4K) {
+ dev_err(dev, "only supported on systems with 4K PAGE_SIZE\n");
+ return -ENXIO;
+ }
+ if (nsio->res.start & ND_PFN_MASK) {
+ dev_err(dev, "%s not memory hotplug section aligned\n",
+ dev_name(&ndns->dev));
+ return -ENXIO;
+ }
+
+ pfn_sb = nd_pfn->pfn_sb;
+ offset = le64_to_cpu(pfn_sb->dataoff);
+ nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
+ if (nd_pfn->mode == PFN_MODE_RAM) {
+ if (offset != SZ_8K)
+ return -EINVAL;
+ nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
+ altmap = NULL;
+ } else {
+ rc = -ENXIO;
+ goto err;
+ }
+
+ /* establish pfn range for lookup, and switch to direct map */
+ pmem = dev_get_drvdata(dev);
+ devm_memunmap(dev, (void __force *) pmem->virt_addr);
+ pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &nsio->res);
+ if (IS_ERR(pmem->virt_addr)) {
+ rc = PTR_ERR(pmem->virt_addr);
+ goto err;
+ }
+
+ /* attach pmem disk in "pfn-mode" */
+ pmem->data_offset = offset;
+ rc = pmem_attach_disk(dev, ndns, pmem);
+ if (rc)
+ goto err;
+
+ return rc;
+ err:
+ nvdimm_namespace_detach_pfn(ndns);
+ return rc;
+}
+
+static int nd_pmem_probe(struct device *dev)
+{
+ struct nd_region *nd_region = to_nd_region(dev->parent);
+ struct nd_namespace_common *ndns;
+ struct nd_namespace_io *nsio;
+ struct pmem_device *pmem;
+
+ ndns = nvdimm_namespace_common_probe(dev);
+ if (IS_ERR(ndns))
+ return PTR_ERR(ndns);
+
+ nsio = to_nd_namespace_io(&ndns->dev);
+ pmem = pmem_alloc(dev, &nsio->res, nd_region->id);
+ if (IS_ERR(pmem))
+ return PTR_ERR(pmem);
+
+ pmem->ndns = ndns;
+ dev_set_drvdata(dev, pmem);
+ ndns->rw_bytes = pmem_rw_bytes;
+
+ if (is_nd_btt(dev))
+ return nvdimm_namespace_attach_btt(ndns);
+
+ if (is_nd_pfn(dev))
+ return nvdimm_namespace_attach_pfn(ndns);
+
+ if (nd_btt_probe(ndns, pmem) == 0) {
+ /* we'll come back as btt-pmem */
+ return -ENXIO;
+ }
+
+ if (nd_pfn_probe(ndns, pmem) == 0) {
+ /* we'll come back as pfn-pmem */
+ return -ENXIO;
+ }
+
+ return pmem_attach_disk(dev, ndns, pmem);
+}
+
+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(pmem->ndns);
+ else if (is_nd_pfn(dev))
+ nvdimm_namespace_detach_pfn(pmem->ndns);
+ else
+ pmem_detach_disk(pmem);
+
+ return 0;
+}
+
+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,
+ .drv = {
+ .name = "nd_pmem",
+ },
+ .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
+};
+
+static int __init pmem_init(void)
+{
+ int error;
+
+ pmem_major = register_blkdev(0, "pmem");
+ if (pmem_major < 0)
+ return pmem_major;
+
+ error = nd_driver_register(&nd_pmem_driver);
+ if (error) {
+ unregister_blkdev(pmem_major, "pmem");
+ return error;
+ }
+
+ return 0;
+}
+module_init(pmem_init);
+
+static void pmem_exit(void)
+{
+ driver_unregister(&nd_pmem_driver.drv);
+ unregister_blkdev(pmem_major, "pmem");
+}
+module_exit(pmem_exit);
+
+MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff