diff options
Diffstat (limited to 'drivers/target/target_core_rd.c')
| -rw-r--r-- | drivers/target/target_core_rd.c | 577 |
1 files changed, 577 insertions, 0 deletions
diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c new file mode 100644 index 00000000..8b68f7b8 --- /dev/null +++ b/drivers/target/target_core_rd.c @@ -0,0 +1,577 @@ +/******************************************************************************* + * Filename: target_core_rd.c + * + * This file contains the Storage Engine <-> Ramdisk transport + * specific functions. + * + * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc. + * Copyright (c) 2005, 2006, 2007 SBE, Inc. + * Copyright (c) 2007-2010 Rising Tide Systems + * Copyright (c) 2008-2010 Linux-iSCSI.org + * + * Nicholas A. Bellinger <nab@kernel.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + ******************************************************************************/ + +#include <linux/string.h> +#include <linux/parser.h> +#include <linux/timer.h> +#include <linux/blkdev.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <scsi/scsi.h> +#include <scsi/scsi_host.h> + +#include <target/target_core_base.h> +#include <target/target_core_backend.h> + +#include "target_core_rd.h" + +static struct se_subsystem_api rd_mcp_template; + +/* rd_attach_hba(): (Part of se_subsystem_api_t template) + * + * + */ +static int rd_attach_hba(struct se_hba *hba, u32 host_id) +{ + struct rd_host *rd_host; + + rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL); + if (!rd_host) { + pr_err("Unable to allocate memory for struct rd_host\n"); + return -ENOMEM; + } + + rd_host->rd_host_id = host_id; + + hba->hba_ptr = rd_host; + + pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on" + " Generic Target Core Stack %s\n", hba->hba_id, + RD_HBA_VERSION, TARGET_CORE_MOD_VERSION); + pr_debug("CORE_HBA[%d] - Attached Ramdisk HBA: %u to Generic" + " MaxSectors: %u\n", hba->hba_id, + rd_host->rd_host_id, RD_MAX_SECTORS); + + return 0; +} + +static void rd_detach_hba(struct se_hba *hba) +{ + struct rd_host *rd_host = hba->hba_ptr; + + pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from" + " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id); + + kfree(rd_host); + hba->hba_ptr = NULL; +} + +/* rd_release_device_space(): + * + * + */ +static void rd_release_device_space(struct rd_dev *rd_dev) +{ + u32 i, j, page_count = 0, sg_per_table; + struct rd_dev_sg_table *sg_table; + struct page *pg; + struct scatterlist *sg; + + if (!rd_dev->sg_table_array || !rd_dev->sg_table_count) + return; + + sg_table = rd_dev->sg_table_array; + + for (i = 0; i < rd_dev->sg_table_count; i++) { + sg = sg_table[i].sg_table; + sg_per_table = sg_table[i].rd_sg_count; + + for (j = 0; j < sg_per_table; j++) { + pg = sg_page(&sg[j]); + if (pg) { + __free_page(pg); + page_count++; + } + } + + kfree(sg); + } + + pr_debug("CORE_RD[%u] - Released device space for Ramdisk" + " Device ID: %u, pages %u in %u tables total bytes %lu\n", + rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count, + rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE); + + kfree(sg_table); + rd_dev->sg_table_array = NULL; + rd_dev->sg_table_count = 0; +} + + +/* rd_build_device_space(): + * + * + */ +static int rd_build_device_space(struct rd_dev *rd_dev) +{ + u32 i = 0, j, page_offset = 0, sg_per_table, sg_tables, total_sg_needed; + u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE / + sizeof(struct scatterlist)); + struct rd_dev_sg_table *sg_table; + struct page *pg; + struct scatterlist *sg; + + if (rd_dev->rd_page_count <= 0) { + pr_err("Illegal page count: %u for Ramdisk device\n", + rd_dev->rd_page_count); + return -EINVAL; + } + total_sg_needed = rd_dev->rd_page_count; + + sg_tables = (total_sg_needed / max_sg_per_table) + 1; + + sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL); + if (!sg_table) { + pr_err("Unable to allocate memory for Ramdisk" + " scatterlist tables\n"); + return -ENOMEM; + } + + rd_dev->sg_table_array = sg_table; + rd_dev->sg_table_count = sg_tables; + + while (total_sg_needed) { + sg_per_table = (total_sg_needed > max_sg_per_table) ? + max_sg_per_table : total_sg_needed; + + sg = kzalloc(sg_per_table * sizeof(struct scatterlist), + GFP_KERNEL); + if (!sg) { + pr_err("Unable to allocate scatterlist array" + " for struct rd_dev\n"); + return -ENOMEM; + } + + sg_init_table(sg, sg_per_table); + + sg_table[i].sg_table = sg; + sg_table[i].rd_sg_count = sg_per_table; + sg_table[i].page_start_offset = page_offset; + sg_table[i++].page_end_offset = (page_offset + sg_per_table) + - 1; + + for (j = 0; j < sg_per_table; j++) { + pg = alloc_pages(GFP_KERNEL, 0); + if (!pg) { + pr_err("Unable to allocate scatterlist" + " pages for struct rd_dev_sg_table\n"); + return -ENOMEM; + } + sg_assign_page(&sg[j], pg); + sg[j].length = PAGE_SIZE; + } + + page_offset += sg_per_table; + total_sg_needed -= sg_per_table; + } + + pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of" + " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id, + rd_dev->rd_dev_id, rd_dev->rd_page_count, + rd_dev->sg_table_count); + + return 0; +} + +static void *rd_allocate_virtdevice( + struct se_hba *hba, + const char *name, + int rd_direct) +{ + struct rd_dev *rd_dev; + struct rd_host *rd_host = hba->hba_ptr; + + rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL); + if (!rd_dev) { + pr_err("Unable to allocate memory for struct rd_dev\n"); + return NULL; + } + + rd_dev->rd_host = rd_host; + rd_dev->rd_direct = rd_direct; + + return rd_dev; +} + +static void *rd_MEMCPY_allocate_virtdevice(struct se_hba *hba, const char *name) +{ + return rd_allocate_virtdevice(hba, name, 0); +} + +/* rd_create_virtdevice(): + * + * + */ +static struct se_device *rd_create_virtdevice( + struct se_hba *hba, + struct se_subsystem_dev *se_dev, + void *p, + int rd_direct) +{ + struct se_device *dev; + struct se_dev_limits dev_limits; + struct rd_dev *rd_dev = p; + struct rd_host *rd_host = hba->hba_ptr; + int dev_flags = 0, ret; + char prod[16], rev[4]; + + memset(&dev_limits, 0, sizeof(struct se_dev_limits)); + + ret = rd_build_device_space(rd_dev); + if (ret < 0) + goto fail; + + snprintf(prod, 16, "RAMDISK-%s", (rd_dev->rd_direct) ? "DR" : "MCP"); + snprintf(rev, 4, "%s", (rd_dev->rd_direct) ? RD_DR_VERSION : + RD_MCP_VERSION); + + dev_limits.limits.logical_block_size = RD_BLOCKSIZE; + dev_limits.limits.max_hw_sectors = RD_MAX_SECTORS; + dev_limits.limits.max_sectors = RD_MAX_SECTORS; + dev_limits.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH; + dev_limits.queue_depth = RD_DEVICE_QUEUE_DEPTH; + + dev = transport_add_device_to_core_hba(hba, + &rd_mcp_template, se_dev, dev_flags, rd_dev, + &dev_limits, prod, rev); + if (!dev) + goto fail; + + rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++; + rd_dev->rd_queue_depth = dev->queue_depth; + + pr_debug("CORE_RD[%u] - Added TCM %s Ramdisk Device ID: %u of" + " %u pages in %u tables, %lu total bytes\n", + rd_host->rd_host_id, (!rd_dev->rd_direct) ? "MEMCPY" : + "DIRECT", rd_dev->rd_dev_id, rd_dev->rd_page_count, + rd_dev->sg_table_count, + (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE)); + + return dev; + +fail: + rd_release_device_space(rd_dev); + return ERR_PTR(ret); +} + +static struct se_device *rd_MEMCPY_create_virtdevice( + struct se_hba *hba, + struct se_subsystem_dev *se_dev, + void *p) +{ + return rd_create_virtdevice(hba, se_dev, p, 0); +} + +/* rd_free_device(): (Part of se_subsystem_api_t template) + * + * + */ +static void rd_free_device(void *p) +{ + struct rd_dev *rd_dev = p; + + rd_release_device_space(rd_dev); + kfree(rd_dev); +} + +static inline struct rd_request *RD_REQ(struct se_task *task) +{ + return container_of(task, struct rd_request, rd_task); +} + +static struct se_task * +rd_alloc_task(unsigned char *cdb) +{ + struct rd_request *rd_req; + + rd_req = kzalloc(sizeof(struct rd_request), GFP_KERNEL); + if (!rd_req) { + pr_err("Unable to allocate struct rd_request\n"); + return NULL; + } + + return &rd_req->rd_task; +} + +/* rd_get_sg_table(): + * + * + */ +static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page) +{ + u32 i; + struct rd_dev_sg_table *sg_table; + + for (i = 0; i < rd_dev->sg_table_count; i++) { + sg_table = &rd_dev->sg_table_array[i]; + if ((sg_table->page_start_offset <= page) && + (sg_table->page_end_offset >= page)) + return sg_table; + } + + pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n", + page); + + return NULL; +} + +static int rd_MEMCPY(struct rd_request *req, u32 read_rd) +{ + struct se_task *task = &req->rd_task; + struct rd_dev *dev = req->rd_task.task_se_cmd->se_dev->dev_ptr; + struct rd_dev_sg_table *table; + struct scatterlist *rd_sg; + struct sg_mapping_iter m; + u32 rd_offset = req->rd_offset; + u32 src_len; + + table = rd_get_sg_table(dev, req->rd_page); + if (!table) + return -EINVAL; + + rd_sg = &table->sg_table[req->rd_page - table->page_start_offset]; + + pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n", + dev->rd_dev_id, read_rd ? "Read" : "Write", + task->task_lba, req->rd_size, req->rd_page, + rd_offset); + + src_len = PAGE_SIZE - rd_offset; + sg_miter_start(&m, task->task_sg, task->task_sg_nents, + read_rd ? SG_MITER_TO_SG : SG_MITER_FROM_SG); + while (req->rd_size) { + u32 len; + void *rd_addr; + + sg_miter_next(&m); + len = min((u32)m.length, src_len); + m.consumed = len; + + rd_addr = sg_virt(rd_sg) + rd_offset; + + if (read_rd) + memcpy(m.addr, rd_addr, len); + else + memcpy(rd_addr, m.addr, len); + + req->rd_size -= len; + if (!req->rd_size) + continue; + + src_len -= len; + if (src_len) { + rd_offset += len; + continue; + } + + /* rd page completed, next one please */ + req->rd_page++; + rd_offset = 0; + src_len = PAGE_SIZE; + if (req->rd_page <= table->page_end_offset) { + rd_sg++; + continue; + } + + table = rd_get_sg_table(dev, req->rd_page); + if (!table) { + sg_miter_stop(&m); + return -EINVAL; + } + + /* since we increment, the first sg entry is correct */ + rd_sg = table->sg_table; + } + sg_miter_stop(&m); + return 0; +} + +/* rd_MEMCPY_do_task(): (Part of se_subsystem_api_t template) + * + * + */ +static int rd_MEMCPY_do_task(struct se_task *task) +{ + struct se_device *dev = task->task_se_cmd->se_dev; + struct rd_request *req = RD_REQ(task); + u64 tmp; + int ret; + + tmp = task->task_lba * dev->se_sub_dev->se_dev_attrib.block_size; + req->rd_offset = do_div(tmp, PAGE_SIZE); + req->rd_page = tmp; + req->rd_size = task->task_size; + + ret = rd_MEMCPY(req, task->task_data_direction == DMA_FROM_DEVICE); + if (ret != 0) + return ret; + + task->task_scsi_status = GOOD; + transport_complete_task(task, 1); + return 0; +} + +/* rd_free_task(): (Part of se_subsystem_api_t template) + * + * + */ +static void rd_free_task(struct se_task *task) +{ + kfree(RD_REQ(task)); +} + +enum { + Opt_rd_pages, Opt_err +}; + +static match_table_t tokens = { + {Opt_rd_pages, "rd_pages=%d"}, + {Opt_err, NULL} +}; + +static ssize_t rd_set_configfs_dev_params( + struct se_hba *hba, + struct se_subsystem_dev *se_dev, + const char *page, + ssize_t count) +{ + struct rd_dev *rd_dev = se_dev->se_dev_su_ptr; + char *orig, *ptr, *opts; + substring_t args[MAX_OPT_ARGS]; + int ret = 0, arg, token; + + opts = kstrdup(page, GFP_KERNEL); + if (!opts) + return -ENOMEM; + + orig = opts; + + while ((ptr = strsep(&opts, ",\n")) != NULL) { + if (!*ptr) + continue; + + token = match_token(ptr, tokens, args); + switch (token) { + case Opt_rd_pages: + match_int(args, &arg); + rd_dev->rd_page_count = arg; + pr_debug("RAMDISK: Referencing Page" + " Count: %u\n", rd_dev->rd_page_count); + rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT; + break; + default: + break; + } + } + + kfree(orig); + return (!ret) ? count : ret; +} + +static ssize_t rd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev) +{ + struct rd_dev *rd_dev = se_dev->se_dev_su_ptr; + + if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) { + pr_debug("Missing rd_pages= parameter\n"); + return -EINVAL; + } + + return 0; +} + +static ssize_t rd_show_configfs_dev_params( + struct se_hba *hba, + struct se_subsystem_dev *se_dev, + char *b) +{ + struct rd_dev *rd_dev = se_dev->se_dev_su_ptr; + ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: %s\n", + rd_dev->rd_dev_id, (rd_dev->rd_direct) ? + "rd_direct" : "rd_mcp"); + bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu" + " SG_table_count: %u\n", rd_dev->rd_page_count, + PAGE_SIZE, rd_dev->sg_table_count); + return bl; +} + +static u32 rd_get_device_rev(struct se_device *dev) +{ + return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */ +} + +static u32 rd_get_device_type(struct se_device *dev) +{ + return TYPE_DISK; +} + +static sector_t rd_get_blocks(struct se_device *dev) +{ + struct rd_dev *rd_dev = dev->dev_ptr; + unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) / + dev->se_sub_dev->se_dev_attrib.block_size) - 1; + + return blocks_long; +} + +static struct se_subsystem_api rd_mcp_template = { + .name = "rd_mcp", + .transport_type = TRANSPORT_PLUGIN_VHBA_VDEV, + .attach_hba = rd_attach_hba, + .detach_hba = rd_detach_hba, + .allocate_virtdevice = rd_MEMCPY_allocate_virtdevice, + .create_virtdevice = rd_MEMCPY_create_virtdevice, + .free_device = rd_free_device, + .alloc_task = rd_alloc_task, + .do_task = rd_MEMCPY_do_task, + .free_task = rd_free_task, + .check_configfs_dev_params = rd_check_configfs_dev_params, + .set_configfs_dev_params = rd_set_configfs_dev_params, + .show_configfs_dev_params = rd_show_configfs_dev_params, + .get_device_rev = rd_get_device_rev, + .get_device_type = rd_get_device_type, + .get_blocks = rd_get_blocks, +}; + +int __init rd_module_init(void) +{ + int ret; + + ret = transport_subsystem_register(&rd_mcp_template); + if (ret < 0) { + return ret; + } + + return 0; +} + +void rd_module_exit(void) +{ + transport_subsystem_release(&rd_mcp_template); +} |