[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / drivers / nvdimm / pmem.c

/*
 * 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/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			*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;

	if (rw == READ) {
		memcpy(mem + off, pmem->virt_addr + pmem_off, len);
		flush_dcache_page(page);
	} else {
		flush_dcache_page(page);
		memcpy(pmem->virt_addr + pmem_off, mem + off, len);
	}

	kunmap_atomic(mem);
}

static void pmem_make_request(struct request_queue *q, struct bio *bio)
{
	struct block_device *bdev = bio->bi_bdev;
	struct pmem_device *pmem = bdev->bd_disk->private_data;
	int rw;
	struct bio_vec bvec;
	sector_t sector;
	struct bvec_iter iter;
	int err = 0;

	if (bio_end_sector(bio) > get_capacity(bdev->bd_disk)) {
		err = -EIO;
		goto out;
	}

	BUG_ON(bio->bi_rw & REQ_DISCARD);

	rw = bio_data_dir(bio);
	sector = bio->bi_iter.bi_sector;
	bio_for_each_segment(bvec, bio, iter) {
		pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, bvec.bv_offset,
			     rw, sector);
		sector += bvec.bv_len >> 9;
	}

out:
	bio_endio(bio, err);
}

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;

	*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,
};

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 (!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);
	}

	/*
	 * Map the memory as non-cachable, as we can't write back the contents
	 * of the CPU caches in case of a crash.
	 */
	pmem->virt_addr = ioremap_nocache(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 nd_region *nd_region = to_nd_region(ndns->dev.parent);
	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, 1024);
	blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);

	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;
	sprintf(disk->disk_name, "pmem%d", nd_region->id);
	disk->driverfs_dev = &ndns->dev;
	set_capacity(disk, pmem->size >> 9);
	pmem->pmem_disk = disk;

	add_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(buf, pmem->virt_addr + offset, size);
	else
		memcpy(pmem->virt_addr + offset, buf, size);

	return 0;
}

static int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns)
{
	/* TODO */
	return -ENXIO;
}

static void nvdimm_namespace_detach_btt(struct nd_namespace_common *ndns)
{
	/* TODO */
}

static void pmem_free(struct pmem_device *pmem)
{
	iounmap(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");
Commit	Line	Data
9e853f23 RZ	1	/*
	2	* Persistent Memory Driver
	3	*
9f53f9fa	4	* Copyright (c) 2014-2015, Intel Corporation.
9e853f23 RZ	5	* Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
	6	* Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms and conditions of the GNU General Public License,
	10	* version 2, as published by the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope it will be useful, but WITHOUT
	13	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	14	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	15	* more details.
	16	*/
	17
	18	#include <asm/cacheflush.h>
	19	#include <linux/blkdev.h>
	20	#include <linux/hdreg.h>
	21	#include <linux/init.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/module.h>
	24	#include <linux/moduleparam.h>
	25	#include <linux/slab.h>
9f53f9fa DW	26	#include <linux/nd.h>
9f53f9fa DW	27	#include "nd.h"
9e853f23 RZ	28
	29	struct pmem_device {
	30	struct request_queue *pmem_queue;
	31	struct gendisk *pmem_disk;
	32
	33	/* One contiguous memory region per device */
	34	phys_addr_t phys_addr;
	35	void *virt_addr;
	36	size_t size;
	37	};
	38
	39	static int pmem_major;
9e853f23 RZ	40
	41	static void pmem_do_bvec(struct pmem_device pmem, struct page page,
	42	unsigned int len, unsigned int off, int rw,
	43	sector_t sector)
	44	{
	45	void *mem = kmap_atomic(page);
	46	size_t pmem_off = sector << 9;
	47
	48	if (rw == READ) {
	49	memcpy(mem + off, pmem->virt_addr + pmem_off, len);
	50	flush_dcache_page(page);
	51	} else {
	52	flush_dcache_page(page);
	53	memcpy(pmem->virt_addr + pmem_off, mem + off, len);
	54	}
	55
	56	kunmap_atomic(mem);
	57	}
	58
	59	static void pmem_make_request(struct request_queue q, struct bio bio)
	60	{
	61	struct block_device *bdev = bio->bi_bdev;
	62	struct pmem_device *pmem = bdev->bd_disk->private_data;
	63	int rw;
	64	struct bio_vec bvec;
	65	sector_t sector;
	66	struct bvec_iter iter;
	67	int err = 0;
	68
	69	if (bio_end_sector(bio) > get_capacity(bdev->bd_disk)) {
	70	err = -EIO;
	71	goto out;
	72	}
	73
	74	BUG_ON(bio->bi_rw & REQ_DISCARD);
	75
	76	rw = bio_data_dir(bio);
	77	sector = bio->bi_iter.bi_sector;
	78	bio_for_each_segment(bvec, bio, iter) {
	79	pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, bvec.bv_offset,
	80	rw, sector);
	81	sector += bvec.bv_len >> 9;
	82	}
	83
	84	out:
	85	bio_endio(bio, err);
	86	}
	87
	88	static int pmem_rw_page(struct block_device *bdev, sector_t sector,
	89	struct page *page, int rw)
	90	{
	91	struct pmem_device *pmem = bdev->bd_disk->private_data;
	92
	93	pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector);
	94	page_endio(page, rw & WRITE, 0);
	95
	96	return 0;
	97	}
	98
	99	static long pmem_direct_access(struct block_device *bdev, sector_t sector,
	100	void *kaddr, unsigned long pfn, long size)
	101	{
	102	struct pmem_device *pmem = bdev->bd_disk->private_data;
	103	size_t offset = sector << 9;
104
105	if (!pmem)
106	return -ENODEV;
107
108	*kaddr = pmem->virt_addr + offset;
109	*pfn = (pmem->phys_addr + offset) >> PAGE_SHIFT;
110
111	return pmem->size - offset;
112	}
113
114	static const struct block_device_operations pmem_fops = {
115	.owner = THIS_MODULE,
116	.rw_page = pmem_rw_page,
117	.direct_access = pmem_direct_access,
118	};
119
9f53f9fa DW	120	static struct pmem_device pmem_alloc(struct device dev,
9f53f9fa DW	121	struct resource *res, int id)
9e853f23 RZ	122	{
9e853f23 RZ	123	struct pmem_device *pmem;
9e853f23	124
9e853f23 RZ	125	pmem = kzalloc(sizeof(*pmem), GFP_KERNEL);
9e853f23 RZ	126	if (!pmem)
8c2f7e86	127	return ERR_PTR(-ENOMEM);
9e853f23 RZ	128
	129	pmem->phys_addr = res->start;
	130	pmem->size = resource_size(res);
	131
8c2f7e86	132	if (!request_mem_region(pmem->phys_addr, pmem->size, dev_name(dev))) {
9f53f9fa DW	133	dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",
9f53f9fa DW	134	&pmem->phys_addr, pmem->size);
8c2f7e86 DW	135	kfree(pmem);
8c2f7e86 DW	136	return ERR_PTR(-EBUSY);
9e853f23 RZ	137	}
	138
	139	/*
	140	* Map the memory as non-cachable, as we can't write back the contents
	141	* of the CPU caches in case of a crash.
	142	*/
9e853f23	143	pmem->virt_addr = ioremap_nocache(pmem->phys_addr, pmem->size);
8c2f7e86 DW	144	if (!pmem->virt_addr) {
	145	release_mem_region(pmem->phys_addr, pmem->size);
	146	kfree(pmem);
	147	return ERR_PTR(-ENXIO);
	148	}
	149
	150	return pmem;
	151	}
	152
	153	static void pmem_detach_disk(struct pmem_device *pmem)
	154	{
	155	del_gendisk(pmem->pmem_disk);
	156	put_disk(pmem->pmem_disk);
	157	blk_cleanup_queue(pmem->pmem_queue);
	158	}
	159
	160	static int pmem_attach_disk(struct nd_namespace_common *ndns,
	161	struct pmem_device *pmem)
	162	{
	163	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
	164	struct gendisk *disk;
9e853f23 RZ	165
	166	pmem->pmem_queue = blk_alloc_queue(GFP_KERNEL);
	167	if (!pmem->pmem_queue)
8c2f7e86	168	return -ENOMEM;
9e853f23 RZ	169
	170	blk_queue_make_request(pmem->pmem_queue, pmem_make_request);
	171	blk_queue_max_hw_sectors(pmem->pmem_queue, 1024);
	172	blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);
	173
9f53f9fa	174	disk = alloc_disk(0);
8c2f7e86 DW	175	if (!disk) {
	176	blk_cleanup_queue(pmem->pmem_queue);
	177	return -ENOMEM;
	178	}
9e853f23	179
9e853f23	180	disk->major = pmem_major;
9f53f9fa	181	disk->first_minor = 0;
9e853f23 RZ	182	disk->fops = &pmem_fops;
	183	disk->private_data = pmem;
	184	disk->queue = pmem->pmem_queue;
	185	disk->flags = GENHD_FL_EXT_DEVT;
8c2f7e86 DW	186	sprintf(disk->disk_name, "pmem%d", nd_region->id);
8c2f7e86 DW	187	disk->driverfs_dev = &ndns->dev;
9e853f23 RZ	188	set_capacity(disk, pmem->size >> 9);
	189	pmem->pmem_disk = disk;
	190
	191	add_disk(disk);
	192
8c2f7e86 DW	193	return 0;
8c2f7e86 DW	194	}
9e853f23	195
8c2f7e86 DW	196	static int pmem_rw_bytes(struct nd_namespace_common *ndns,
	197	resource_size_t offset, void *buf, size_t size, int rw)
	198	{
	199	struct pmem_device *pmem = dev_get_drvdata(ndns->claim);
	200
	201	if (unlikely(offset + size > pmem->size)) {
	202	dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
	203	return -EFAULT;
	204	}
	205
	206	if (rw == READ)
	207	memcpy(buf, pmem->virt_addr + offset, size);
	208	else
	209	memcpy(pmem->virt_addr + offset, buf, size);
	210
	211	return 0;
	212	}
	213
	214	static int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns)
	215	{
	216	/* TODO */
	217	return -ENXIO;
	218	}
	219
	220	static void nvdimm_namespace_detach_btt(struct nd_namespace_common *ndns)
	221	{
	222	/* TODO */
9e853f23 RZ	223	}
	224
	225	static void pmem_free(struct pmem_device *pmem)
	226	{
9e853f23 RZ	227	iounmap(pmem->virt_addr);
	228	release_mem_region(pmem->phys_addr, pmem->size);
	229	kfree(pmem);
	230	}
	231
9f53f9fa	232	static int nd_pmem_probe(struct device *dev)
9e853f23	233	{
9f53f9fa	234	struct nd_region *nd_region = to_nd_region(dev->parent);
8c2f7e86 DW	235	struct nd_namespace_common *ndns;
8c2f7e86 DW	236	struct nd_namespace_io *nsio;
9e853f23	237	struct pmem_device *pmem;
8c2f7e86	238	int rc;
9e853f23	239
8c2f7e86 DW	240	ndns = nvdimm_namespace_common_probe(dev);
	241	if (IS_ERR(ndns))
	242	return PTR_ERR(ndns);
bf9bccc1	243
8c2f7e86	244	nsio = to_nd_namespace_io(&ndns->dev);
9f53f9fa	245	pmem = pmem_alloc(dev, &nsio->res, nd_region->id);
9e853f23 RZ	246	if (IS_ERR(pmem))
	247	return PTR_ERR(pmem);
	248
9f53f9fa	249	dev_set_drvdata(dev, pmem);
8c2f7e86 DW	250	ndns->rw_bytes = pmem_rw_bytes;
	251	if (is_nd_btt(dev))
	252	rc = nvdimm_namespace_attach_btt(ndns);
	253	else if (nd_btt_probe(ndns, pmem) == 0) {
	254	/* we'll come back as btt-pmem */
	255	rc = -ENXIO;
	256	} else
	257	rc = pmem_attach_disk(ndns, pmem);
	258	if (rc)
	259	pmem_free(pmem);
	260	return rc;
9e853f23 RZ	261	}
9e853f23 RZ	262
9f53f9fa	263	static int nd_pmem_remove(struct device *dev)
9e853f23	264	{
9f53f9fa	265	struct pmem_device *pmem = dev_get_drvdata(dev);
9e853f23	266
8c2f7e86 DW	267	if (is_nd_btt(dev))
	268	nvdimm_namespace_detach_btt(to_nd_btt(dev)->ndns);
	269	else
	270	pmem_detach_disk(pmem);
9e853f23	271	pmem_free(pmem);
8c2f7e86	272
9e853f23 RZ	273	return 0;
	274	}
	275
9f53f9fa DW	276	MODULE_ALIAS("pmem");
9f53f9fa DW	277	MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
bf9bccc1	278	MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
9f53f9fa DW	279	static struct nd_device_driver nd_pmem_driver = {
	280	.probe = nd_pmem_probe,
	281	.remove = nd_pmem_remove,
	282	.drv = {
	283	.name = "nd_pmem",
9e853f23	284	},
bf9bccc1	285	.type = ND_DRIVER_NAMESPACE_IO \| ND_DRIVER_NAMESPACE_PMEM,
9e853f23 RZ	286	};
	287
	288	static int __init pmem_init(void)
	289	{
	290	int error;
	291
	292	pmem_major = register_blkdev(0, "pmem");
	293	if (pmem_major < 0)
	294	return pmem_major;
	295
9f53f9fa DW	296	error = nd_driver_register(&nd_pmem_driver);
9f53f9fa DW	297	if (error) {
9e853f23	298	unregister_blkdev(pmem_major, "pmem");
9f53f9fa DW	299	return error;
	300	}
	301
	302	return 0;
9e853f23 RZ	303	}
	304	module_init(pmem_init);
	305
	306	static void pmem_exit(void)
	307	{
9f53f9fa	308	driver_unregister(&nd_pmem_driver.drv);
9e853f23 RZ	309	unregister_blkdev(pmem_major, "pmem");
	310	}
	311	module_exit(pmem_exit);
	312
	313	MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
	314	MODULE_LICENSE("GPL v2");