[1/8] pmem: Initial version of persistent memory driver

Message ID	54F84420.40209@plexistor.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-nvdimm-bounces@lists.01.org> Message-ID: <54F84420.40209@plexistor.com> Date: Thu, 05 Mar 2015 13:55:12 +0200 From: Boaz Harrosh <boaz@plexistor.com> User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Ingo Molnar <mingo@redhat.com>, x86@kernel.org, linux-kernel <linux-kernel@vger.kernel.org>, "Roger C. Pao" <rcpao.enmotus@gmail.com>, Dan Williams <dan.j.williams@intel.com>, Thomas Gleixner <tglx@linutronix.de>, linux-nvdimm <linux-nvdimm@lists.01.org>, "H. Peter Anvin" <hpa@zytor.com>, Matthew Wilcox <willy@linux.intel.com>, Andy Lutomirski <luto@amacapital.net>, Christoph Hellwig <hch@infradead.org> References: <54F82CE0.4040502@plexistor.com> <54F830D4.7030205@plexistor.com> In-Reply-To: <54F830D4.7030205@plexistor.com> Subject: [Linux-nvdimm] [PATCH 1/8] pmem: Initial version of persistent memory driver Precedence: list Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" <linux-nvdimm-bounces@lists.01.org>

diff --git a/MAINTAINERS b/MAINTAINERS index ddc5a8c..21c5384 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8053,6 +8053,13 @@ S: Maintained F: Documentation/blockdev/ramdisk.txt F: drivers/block/brd.c +PERSISTENT MEMORY DRIVER +M: Ross Zwisler <ross.zwisler@linux.intel.com> +M: Boaz Harrosh <boaz@plexistor.com> +L: linux-nvdimm@lists.01.org +S: Supported +F: drivers/block/pmem.c + RANDOM NUMBER DRIVER M: "Theodore Ts'o" <tytso@mit.edu> S: Maintained diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index 1b8094d..1530c2a 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -404,6 +404,24 @@ config BLK_DEV_RAM_DAX and will prevent RAM block device backing store memory from being allocated from highmem (only a problem for highmem systems). +config BLK_DEV_PMEM + tristate "pmem: Persistent memory block device support" + help + If you have Persistent memory in your system say Y/m + here. The driver can support real Persistent memory chips + such as NVDIMMs , as well as volatile memory that was set + aside from Kernel use by the "memmap" kernel parameter. + And/or any contiguous physical memory ranges that you want + to represent as a block device. (Even PCIE flat memory mapped + devices) + See Documentation/block/pmem.txt for how to use + + To compile this driver as a module, choose M here: the module will be + called pmem. Created Devices will be named: /dev/pmemX + + Most normal users won't need this functionality, and can thus say N + here. + config CDROM_PKTCDVD tristate "Packet writing on CD/DVD media" depends on !UML diff --git a/drivers/block/Makefile b/drivers/block/Makefile index 02b688d..9cc6c18 100644 --- a/drivers/block/Makefile +++ b/drivers/block/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_PS3_VRAM) += ps3vram.o obj-$(CONFIG_ATARI_FLOPPY) += ataflop.o obj-$(CONFIG_AMIGA_Z2RAM) += z2ram.o obj-$(CONFIG_BLK_DEV_RAM) += brd.o +obj-$(CONFIG_BLK_DEV_PMEM) += pmem.o obj-$(CONFIG_BLK_DEV_LOOP) += loop.o obj-$(CONFIG_BLK_CPQ_DA) += cpqarray.o obj-$(CONFIG_BLK_CPQ_CISS_DA) += cciss.o diff --git a/drivers/block/pmem.c b/drivers/block/pmem.c new file mode 100644 index 0000000..02cd118 --- /dev/null +++ b/drivers/block/pmem.c @@ -0,0 +1,334 @@ +/* + * Persistent Memory Driver + * Copyright (c) 2014, Intel Corporation. + * Copyright (c) 2014, 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. + * + * This driver's skeleton is based on drivers/block/brd.c. + * Copyright (C) 2007 Nick Piggin + * Copyright (C) 2007 Novell Inc. + */ + +#include <linux/blkdev.h> +#include <linux/hdreg.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/slab.h> +#include <linux/string.h> + +struct pmem_device { + struct request_queue *pmem_queue; + struct gendisk *pmem_disk; + struct list_head pmem_list; + + /* One contiguous memory region per device */ + phys_addr_t phys_addr; + void *virt_addr; + size_t size; +}; + +static void pmem_do_bvec(struct pmem_device *pmem, struct page *page, uint len, + uint off, int rw, sector_t sector) +{ + void *mem = kmap_atomic(page); + size_t pmem_off = sector << 9; + + BUG_ON(pmem_off >= pmem->size); + + if (rw == READ) { + memcpy(mem + off, pmem->virt_addr + pmem_off, len); + flush_dcache_page(page); + } else { + /* + * FIXME: Need more involved flushing to ensure that writes to + * NVDIMMs are actually durable before returning. + */ + 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 (unlikely(bio_end_sector(bio) > get_capacity(bdev->bd_disk))) { + err = -EIO; + goto out; + } + + if (WARN_ON(bio->bi_rw & REQ_DISCARD)) { + err = -EINVAL; + goto out; + } + + rw = bio_rw(bio); + if (rw == READA) + rw = READ; + + sector = bio->bi_iter.bi_sector; + bio_for_each_segment(bvec, bio, iter) { + /* NOTE: There is a legend saying that bv_len might be + * bigger than PAGE_SIZE in the case that bv_page points to + * a physical contiguous PFN set. But for us it is fine because + * it means the Kernel virtual mapping is also contiguous. And + * on the pmem side we are always contiguous both virtual and + * physical + */ + 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 const struct block_device_operations pmem_fops = { + .owner = THIS_MODULE, +}; + +/* Kernel module stuff */ +static char *map; +module_param(map, charp, S_IRUGO); +MODULE_PARM_DESC(map, + "pmem device mapping: map=mapS[,mapS...] where:\n" + "mapS=nn[KMG]$ss[KMG] or mapS=nn[KMG]@ss[KMG], nn=size, ss=offset."); + +static LIST_HEAD(pmem_devices); +static int pmem_major; + +/* pmem->phys_addr and pmem->size need to be set. + * Will then set virt_addr if successful. + */ +int pmem_mapmem(struct pmem_device *pmem) +{ + struct resource *res_mem; + int err; + + res_mem = request_mem_region_exclusive(pmem->phys_addr, pmem->size, + "pmem"); + if (unlikely(!res_mem)) { + pr_warn("pmem: request_mem_region_exclusive phys=0x%llx size=0x%zx failed\n", + pmem->phys_addr, pmem->size); + return -EINVAL; + } + + pmem->virt_addr = ioremap_cache(pmem->phys_addr, pmem->size); + if (unlikely(!pmem->virt_addr)) { + err = -ENXIO; + goto out_release; + } + return 0; + +out_release: + release_mem_region(pmem->phys_addr, pmem->size); + return err; +} + +void pmem_unmapmem(struct pmem_device *pmem) +{ + if (unlikely(!pmem->virt_addr)) + return; + + iounmap(pmem->virt_addr); + release_mem_region(pmem->phys_addr, pmem->size); + pmem->virt_addr = NULL; +} + +#define PMEM_ALIGNMEM PAGE_SIZE + +static struct pmem_device *pmem_alloc(phys_addr_t phys_addr, size_t disk_size, + int i) +{ + struct pmem_device *pmem; + struct gendisk *disk; + int err; + + if (unlikely((phys_addr & (PMEM_ALIGNMEM - 1)) || + (disk_size & (PMEM_ALIGNMEM - 1)))) { + pr_err("phys_addr=0x%llx disk_size=0x%zx must be 0x%lx aligned\n", + phys_addr, disk_size, PMEM_ALIGNMEM); + err = -EINVAL; + goto out; + } + + pmem = kzalloc(sizeof(*pmem), GFP_KERNEL); + if (unlikely(!pmem)) { + err = -ENOMEM; + goto out; + } + + pmem->phys_addr = phys_addr; + pmem->size = disk_size; + + err = pmem_mapmem(pmem); + if (unlikely(err)) + goto out_free_dev; + + pmem->pmem_queue = blk_alloc_queue(GFP_KERNEL); + if (unlikely(!pmem->pmem_queue)) { + err = -ENOMEM; + 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); + + /* This is so fdisk will align partitions on 4k, because of + * direct_access API needing 4k alignment, returning a PFN + */ + blk_queue_physical_block_size(pmem->pmem_queue, PAGE_SIZE); + + disk = alloc_disk(0); + if (unlikely(!disk)) { + err = -ENOMEM; + goto out_free_queue; + } + + 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", i); + set_capacity(disk, disk_size >> 9); + pmem->pmem_disk = disk; + + return pmem; + +out_free_queue: + blk_cleanup_queue(pmem->pmem_queue); +out_unmap: + pmem_unmapmem(pmem); +out_free_dev: + kfree(pmem); +out: + return ERR_PTR(err); +} + +static void pmem_free(struct pmem_device *pmem) +{ + put_disk(pmem->pmem_disk); + blk_cleanup_queue(pmem->pmem_queue); + pmem_unmapmem(pmem); + kfree(pmem); +} + +static void pmem_del_one(struct pmem_device *pmem) +{ + list_del(&pmem->pmem_list); + del_gendisk(pmem->pmem_disk); + pmem_free(pmem); +} + +static int pmem_parse_map_one(char *map, phys_addr_t *start, size_t *size) +{ + char *p = map; + + *size = (size_t)memparse(p, &p); + if ((p == map) || ((*p != '$') && (*p != '@'))) + return -EINVAL; + + if (!*(++p)) + return -EINVAL; + + *start = (phys_addr_t)memparse(p, &p); + + return *p == '\0' ? 0 : -EINVAL; +} + +static int __init pmem_init(void) +{ + int result, i; + struct pmem_device *pmem, *next; + char *p, *pmem_map, *map_dup; + + if (unlikely(!map || !*map)) { + pr_err("pmem: must specify map=nn@ss parameter.\n"); + return -EINVAL; + } + + result = register_blkdev(0, "pmem"); + if (unlikely(result < 0)) + return -EIO; + + pmem_major = result; + + map_dup = pmem_map = kstrdup(map, GFP_KERNEL); + if (unlikely(!pmem_map)) { + pr_debug("pmem_init strdup(%s) failed\n", map); + return -ENOMEM; + } + + i = 0; + while ((p = strsep(&pmem_map, ",")) != NULL) { + phys_addr_t phys_addr; + size_t disk_size; + + if (!*p) + continue; + result = pmem_parse_map_one(p, &phys_addr, &disk_size); + if (result) + goto out_free; + pmem = pmem_alloc(phys_addr, disk_size, i); + if (IS_ERR(pmem)) { + result = PTR_ERR(pmem); + goto out_free; + } + list_add_tail(&pmem->pmem_list, &pmem_devices); + ++i; + } + + list_for_each_entry(pmem, &pmem_devices, pmem_list) + add_disk(pmem->pmem_disk); + + pr_info("pmem: module loaded map=%s\n", map); + kfree(map_dup); + return 0; + +out_free: + list_for_each_entry_safe(pmem, next, &pmem_devices, pmem_list) { + list_del(&pmem->pmem_list); + pmem_free(pmem); + } + kfree(map_dup); + unregister_blkdev(pmem_major, "pmem"); + + return result; +} + +static void __exit pmem_exit(void) +{ + struct pmem_device *pmem, *next; + + list_for_each_entry_safe(pmem, next, &pmem_devices, pmem_list) + pmem_del_one(pmem); + + unregister_blkdev(pmem_major, "pmem"); + pr_info("pmem: module unloaded\n"); +} + +MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>"); +MODULE_LICENSE("GPL"); +module_init(pmem_init); +module_exit(pmem_exit);

[1/8] pmem: Initial version of persistent memory driver

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