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");