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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
commite5fd91f1ef340da553f7a79da9540c3db711c937 (patch)
treeb11842027dc6641da63f4bcc524f8678263304a3 /drivers/nvdimm/pmem.c
parent2a9b0348e685a63d97486f6749622b61e9e3292f (diff)
Linux-libre 4.2-gnu
Diffstat (limited to 'drivers/nvdimm/pmem.c')
-rw-r--r--drivers/nvdimm/pmem.c301
1 files changed, 301 insertions, 0 deletions
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
new file mode 100644
index 000000000..ade9eb917
--- /dev/null
+++ b/drivers/nvdimm/pmem.c
@@ -0,0 +1,301 @@
+/*
+ * 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/slab.h>
+#include <linux/pmem.h>
+#include <linux/nd.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;
+ 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);
+ size_t pmem_off = sector << 9;
+ 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 void 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, 0);
+}
+
+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);
+ page_endio(page, rw & WRITE, 0);
+
+ return 0;
+}
+
+static long pmem_direct_access(struct block_device *bdev, sector_t sector,
+ void **kaddr, unsigned long *pfn, long size)
+{
+ struct pmem_device *pmem = bdev->bd_disk->private_data;
+ size_t offset = sector << 9;
+
+ if (!pmem)
+ return -ENODEV;
+
+ /* FIXME convert DAX to comprehend that this mapping has a lifetime */
+ *kaddr = (void __force *) 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 = kzalloc(sizeof(*pmem), GFP_KERNEL);
+ if (!pmem)
+ return ERR_PTR(-ENOMEM);
+
+ pmem->phys_addr = res->start;
+ pmem->size = resource_size(res);
+ if (!arch_has_pmem_api())
+ dev_warn(dev, "unable to guarantee persistence of writes\n");
+
+ if (!request_mem_region(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);
+ kfree(pmem);
+ return ERR_PTR(-EBUSY);
+ }
+
+ pmem->virt_addr = memremap_pmem(pmem->phys_addr, pmem->size);
+ if (!pmem->virt_addr) {
+ release_mem_region(pmem->phys_addr, pmem->size);
+ kfree(pmem);
+ return ERR_PTR(-ENXIO);
+ }
+
+ return pmem;
+}
+
+static void pmem_detach_disk(struct pmem_device *pmem)
+{
+ del_gendisk(pmem->pmem_disk);
+ put_disk(pmem->pmem_disk);
+ blk_cleanup_queue(pmem->pmem_queue);
+}
+
+static int pmem_attach_disk(struct nd_namespace_common *ndns,
+ struct pmem_device *pmem)
+{
+ struct gendisk *disk;
+
+ pmem->pmem_queue = blk_alloc_queue(GFP_KERNEL);
+ if (!pmem->pmem_queue)
+ return -ENOMEM;
+
+ blk_queue_make_request(pmem->pmem_queue, pmem_make_request);
+ 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(0);
+ 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 = &ndns->dev;
+ set_capacity(disk, pmem->size >> 9);
+ 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 void pmem_free(struct pmem_device *pmem)
+{
+ memunmap_pmem(pmem->virt_addr);
+ release_mem_region(pmem->phys_addr, pmem->size);
+ kfree(pmem);
+}
+
+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;
+ int rc;
+
+ 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);
+
+ dev_set_drvdata(dev, pmem);
+ ndns->rw_bytes = pmem_rw_bytes;
+ if (is_nd_btt(dev))
+ rc = nvdimm_namespace_attach_btt(ndns);
+ else if (nd_btt_probe(ndns, pmem) == 0) {
+ /* we'll come back as btt-pmem */
+ rc = -ENXIO;
+ } else
+ rc = pmem_attach_disk(ndns, pmem);
+ if (rc)
+ pmem_free(pmem);
+ return rc;
+}
+
+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)->ndns);
+ else
+ pmem_detach_disk(pmem);
+ pmem_free(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");