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/*******************************************************************************
* 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_device.h>
#include <target/target_core_transport.h>
#include <target/target_core_fabric_ops.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, ",")) != 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);
}
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