+++ /dev/null
-/*
- * Persistent Memory Driver
- *
- * Copyright (c) 2014, 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>
-
-#define PMEM_MINORS 16
-
-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 atomic_t pmem_index;
-
-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)
-{
- struct pmem_device *pmem;
- struct gendisk *disk;
- int idx, err;
-
- err = -ENOMEM;
- pmem = kzalloc(sizeof(*pmem), GFP_KERNEL);
- if (!pmem)
- goto out;
-
- pmem->phys_addr = res->start;
- pmem->size = resource_size(res);
-
- err = -EINVAL;
- if (!request_mem_region(pmem->phys_addr, pmem->size, "pmem")) {
- dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n", &pmem->phys_addr, pmem->size);
- goto out_free_dev;
- }
-
- /*
- * Map the memory as non-cachable, as we can't write back the contents
- * of the CPU caches in case of a crash.
- */
- err = -ENOMEM;
- pmem->virt_addr = ioremap_nocache(pmem->phys_addr, pmem->size);
- if (!pmem->virt_addr)
- goto out_release_region;
-
- pmem->pmem_queue = blk_alloc_queue(GFP_KERNEL);
- if (!pmem->pmem_queue)
- goto out_unmap;
-
- 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(PMEM_MINORS);
- if (!disk)
- goto out_free_queue;
-
- idx = atomic_inc_return(&pmem_index) - 1;
-
- disk->major = pmem_major;
- disk->first_minor = PMEM_MINORS * idx;
- 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", idx);
- disk->driverfs_dev = dev;
- set_capacity(disk, pmem->size >> 9);
- pmem->pmem_disk = disk;
-
- add_disk(disk);
-
- return pmem;
-
-out_free_queue:
- blk_cleanup_queue(pmem->pmem_queue);
-out_unmap:
- iounmap(pmem->virt_addr);
-out_release_region:
- release_mem_region(pmem->phys_addr, pmem->size);
-out_free_dev:
- kfree(pmem);
-out:
- return ERR_PTR(err);
-}
-
-static void pmem_free(struct pmem_device *pmem)
-{
- del_gendisk(pmem->pmem_disk);
- put_disk(pmem->pmem_disk);
- blk_cleanup_queue(pmem->pmem_queue);
- iounmap(pmem->virt_addr);
- release_mem_region(pmem->phys_addr, pmem->size);
- kfree(pmem);
-}
-
-static int pmem_probe(struct platform_device *pdev)
-{
- struct pmem_device *pmem;
- struct resource *res;
-
- if (WARN_ON(pdev->num_resources > 1))
- return -ENXIO;
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res)
- return -ENXIO;
-
- pmem = pmem_alloc(&pdev->dev, res);
- if (IS_ERR(pmem))
- return PTR_ERR(pmem);
-
- platform_set_drvdata(pdev, pmem);
-
- return 0;
-}
-
-static int pmem_remove(struct platform_device *pdev)
-{
- struct pmem_device *pmem = platform_get_drvdata(pdev);
-
- pmem_free(pmem);
- return 0;
-}
-
-static struct platform_driver pmem_driver = {
- .probe = pmem_probe,
- .remove = pmem_remove,
- .driver = {
- .owner = THIS_MODULE,
- .name = "pmem",
- },
-};
-
-static int __init pmem_init(void)
-{
- int error;
-
- pmem_major = register_blkdev(0, "pmem");
- if (pmem_major < 0)
- return pmem_major;
-
- error = platform_driver_register(&pmem_driver);
- if (error)
- unregister_blkdev(pmem_major, "pmem");
- return error;
-}
-module_init(pmem_init);
-
-static void pmem_exit(void)
-{
- platform_driver_unregister(&pmem_driver);
- 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