- 根目录:
- drivers
- target
- target_core_rd.c
/*******************************************************************************
* Filename: target_core_rd.c
*
* This file contains the Storage Engine <-> Ramdisk transport
* specific functions.
*
* (c) Copyright 2003-2013 Datera, Inc.
*
* 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/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 inline struct rd_dev *RD_DEV(struct se_device *dev)
{
return container_of(dev, struct rd_dev, dev);
}
/* 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);
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;
}
static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
u32 sg_table_count)
{
struct page *pg;
struct scatterlist *sg;
u32 i, j, page_count = 0, sg_per_table;
for (i = 0; i < 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);
}
kfree(sg_table);
return page_count;
}
static void rd_release_device_space(struct rd_dev *rd_dev)
{
u32 page_count;
if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
return;
page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
rd_dev->sg_table_count);
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);
rd_dev->sg_table_array = NULL;
rd_dev->sg_table_count = 0;
}
/* rd_build_device_space():
*
*
*/
static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
u32 total_sg_needed, unsigned char init_payload)
{
u32 i = 0, j, page_offset = 0, sg_per_table;
u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
sizeof(struct scatterlist));
struct page *pg;
struct scatterlist *sg;
unsigned char *p;
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;
p = kmap(pg);
memset(p, init_payload, PAGE_SIZE);
kunmap(pg);
}
page_offset += sg_per_table;
total_sg_needed -= sg_per_table;
}
return 0;
}
static int rd_build_device_space(struct rd_dev *rd_dev)
{
struct rd_dev_sg_table *sg_table;
u32 sg_tables, total_sg_needed;
u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
sizeof(struct scatterlist));
int rc;
if (rd_dev->rd_page_count <= 0) {
pr_err("Illegal page count: %u for Ramdisk device\n",
rd_dev->rd_page_count);
return -EINVAL;
}
/* Don't need backing pages for NULLIO */
if (rd_dev->rd_flags & RDF_NULLIO)
return 0;
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;
rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
if (rc)
return rc;
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_release_prot_space(struct rd_dev *rd_dev)
{
u32 page_count;
if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
return;
page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
rd_dev->sg_prot_count);
pr_debug("CORE_RD[%u] - Released protection 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);
rd_dev->sg_prot_array = NULL;
rd_dev->sg_prot_count = 0;
}
static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length)
{
struct rd_dev_sg_table *sg_table;
u32 total_sg_needed, sg_tables;
u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
sizeof(struct scatterlist));
int rc;
if (rd_dev->rd_flags & RDF_NULLIO)
return 0;
total_sg_needed = rd_dev->rd_page_count / prot_length;
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 protection"
" scatterlist tables\n");
return -ENOMEM;
}
rd_dev->sg_prot_array = sg_table;
rd_dev->sg_prot_count = sg_tables;
rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
if (rc)
return rc;
pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
" %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
return 0;
}
static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
{
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;
return &rd_dev->dev;
}
static int rd_configure_device(struct se_device *dev)
{
struct rd_dev *rd_dev = RD_DEV(dev);
struct rd_host *rd_host = dev->se_hba->hba_ptr;
int ret;
if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
pr_debug("Missing rd_pages= parameter\n");
return -EINVAL;
}
ret = rd_build_device_space(rd_dev);
if (ret < 0)
goto fail;
dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
dev->dev_attrib.hw_max_sectors = UINT_MAX;
dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
" %u pages in %u tables, %lu total bytes\n",
rd_host->rd_host_id, 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 0;
fail:
rd_release_device_space(rd_dev);
return ret;
}
static void rd_free_device(struct se_device *dev)
{
struct rd_dev *rd_dev = RD_DEV(dev);
rd_release_device_space(rd_dev);
kfree(rd_dev);
}
static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
{
struct rd_dev_sg_table *sg_table;
u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
sizeof(struct scatterlist));
i = page / sg_per_table;
if (i < rd_dev->sg_table_count) {
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 struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
{
struct rd_dev_sg_table *sg_table;
u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
sizeof(struct scatterlist));
i = page / sg_per_table;
if (i < rd_dev->sg_prot_count) {
sg_table = &rd_dev->sg_prot_array[i];
if ((sg_table->page_start_offset <= page) &&
(sg_table->page_end_offset >= page))
return sg_table;
}
pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
page);
return NULL;
}
static sense_reason_t
rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
enum dma_data_direction data_direction)
{
struct se_device *se_dev = cmd->se_dev;
struct rd_dev *dev = RD_DEV(se_dev);
struct rd_dev_sg_table *table;
struct scatterlist *rd_sg;
struct sg_mapping_iter m;
u32 rd_offset;
u32 rd_size;
u32 rd_page;
u32 src_len;
u64 tmp;
sense_reason_t rc;
if (dev->rd_flags & RDF_NULLIO) {
target_complete_cmd(cmd, SAM_STAT_GOOD);
return 0;
}
tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
rd_offset = do_div(tmp, PAGE_SIZE);
rd_page = tmp;
rd_size = cmd->data_length;
table = rd_get_sg_table(dev, rd_page);
if (!table)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
rd_sg = &table->sg_table[rd_page - table->page_start_offset];
pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
dev->rd_dev_id,
data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
cmd->t_task_lba, rd_size, rd_page, rd_offset);
if (cmd->prot_type && data_direction == DMA_TO_DEVICE) {
struct rd_dev_sg_table *prot_table;
struct scatterlist *prot_sg;
u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
u32 prot_offset, prot_page;
tmp = cmd->t_task_lba * se_dev->prot_length;
prot_offset = do_div(tmp, PAGE_SIZE);
prot_page = tmp;
prot_table = rd_get_prot_table(dev, prot_page);
if (!prot_table)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset];
rc = sbc_dif_verify_write(cmd, cmd->t_task_lba, sectors, 0,
prot_sg, prot_offset);
if (rc)
return rc;
}
src_len = PAGE_SIZE - rd_offset;
sg_miter_start(&m, sgl, sgl_nents,
data_direction == DMA_FROM_DEVICE ?
SG_MITER_TO_SG : SG_MITER_FROM_SG);
while (rd_size) {
u32 len;
void *rd_addr;
sg_miter_next(&m);
if (!(u32)m.length) {
pr_debug("RD[%u]: invalid sgl %p len %zu\n",
dev->rd_dev_id, m.addr, m.length);
sg_miter_stop(&m);
return TCM_INCORRECT_AMOUNT_OF_DATA;
}
len = min((u32)m.length, src_len);
if (len > rd_size) {
pr_debug("RD[%u]: size underrun page %d offset %d "
"size %d\n", dev->rd_dev_id,
rd_page, rd_offset, rd_size);
len = rd_size;
}
m.consumed = len;
rd_addr = sg_virt(rd_sg) + rd_offset;
if (data_direction == DMA_FROM_DEVICE)
memcpy(m.addr, rd_addr, len);
else
memcpy(rd_addr, m.addr, len);
rd_size -= len;
if (!rd_size)
continue;
src_len -= len;
if (src_len) {
rd_offset += len;
continue;
}
/* rd page completed, next one please */
rd_page++;
rd_offset = 0;
src_len = PAGE_SIZE;
if (rd_page <= table->page_end_offset) {
rd_sg++;
continue;
}
table = rd_get_sg_table(dev, rd_page);
if (!table) {
sg_miter_stop(&m);
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
/* since we increment, the first sg entry is correct */
rd_sg = table->sg_table;
}
sg_miter_stop(&m);
if (cmd->prot_type && data_direction == DMA_FROM_DEVICE) {
struct rd_dev_sg_table *prot_table;
struct scatterlist *prot_sg;
u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
u32 prot_offset, prot_page;
tmp = cmd->t_task_lba * se_dev->prot_length;
prot_offset = do_div(tmp, PAGE_SIZE);
prot_page = tmp;
prot_table = rd_get_prot_table(dev, prot_page);
if (!prot_table)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset];
rc = sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
prot_sg, prot_offset);
if (rc)
return rc;
}
target_complete_cmd(cmd, SAM_STAT_GOOD);
return 0;
}
enum {
Opt_rd_pages, Opt_rd_nullio, Opt_err
};
static match_table_t tokens = {
{Opt_rd_pages, "rd_pages=%d"},
{Opt_rd_nullio, "rd_nullio=%d"},
{Opt_err, NULL}
};
static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
const char *page, ssize_t count)
{
struct rd_dev *rd_dev = RD_DEV(dev);
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;
case Opt_rd_nullio:
match_int(args, &arg);
if (arg != 1)
break;
pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
rd_dev->rd_flags |= RDF_NULLIO;
break;
default:
break;
}
}
kfree(orig);
return (!ret) ? count : ret;
}
static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
{
struct rd_dev *rd_dev = RD_DEV(dev);
ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
rd_dev->rd_dev_id);
bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu"
" SG_table_count: %u nullio: %d\n", rd_dev->rd_page_count,
PAGE_SIZE, rd_dev->sg_table_count,
!!(rd_dev->rd_flags & RDF_NULLIO));
return bl;
}
static sector_t rd_get_blocks(struct se_device *dev)
{
struct rd_dev *rd_dev = RD_DEV(dev);
unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
dev->dev_attrib.block_size) - 1;
return blocks_long;
}
static int rd_init_prot(struct se_device *dev)
{
struct rd_dev *rd_dev = RD_DEV(dev);
if (!dev->dev_attrib.pi_prot_type)
return 0;
return rd_build_prot_space(rd_dev, dev->prot_length);
}
static void rd_free_prot(struct se_device *dev)
{
struct rd_dev *rd_dev = RD_DEV(dev);
rd_release_prot_space(rd_dev);
}
static struct sbc_ops rd_sbc_ops = {
.execute_rw = rd_execute_rw,
};
static sense_reason_t
rd_parse_cdb(struct se_cmd *cmd)
{
return sbc_parse_cdb(cmd, &rd_sbc_ops);
}
static struct se_subsystem_api rd_mcp_template = {
.name = "rd_mcp",
.inquiry_prod = "RAMDISK-MCP",
.inquiry_rev = RD_MCP_VERSION,
.transport_type = TRANSPORT_PLUGIN_VHBA_VDEV,
.attach_hba = rd_attach_hba,
.detach_hba = rd_detach_hba,
.alloc_device = rd_alloc_device,
.configure_device = rd_configure_device,
.free_device = rd_free_device,
.parse_cdb = rd_parse_cdb,
.set_configfs_dev_params = rd_set_configfs_dev_params,
.show_configfs_dev_params = rd_show_configfs_dev_params,
.get_device_type = sbc_get_device_type,
.get_blocks = rd_get_blocks,
.init_prot = rd_init_prot,
.free_prot = rd_free_prot,
};
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);
}