static sense_reason_t
rd_execute_rw(struct se_cmd *cmd)
{
struct scatterlist *sgl = cmd->t_data_sg;
u32 sgl_nents = cmd->t_data_nents;
enum dma_data_direction data_direction = cmd->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;
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);
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);
target_complete_cmd(cmd, SAM_STAT_GOOD);
return 0;
}
/* rd_MEMCPY_write():
*
*
*/
static int rd_MEMCPY_write(struct rd_request *req)
{
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 *sg_d, *sg_s;
void *dst, *src;
u32 i = 0, j = 0, dst_offset = 0, src_offset = 0;
u32 length, page_end = 0, table_sg_end;
u32 rd_offset = req->rd_offset;
table = rd_get_sg_table(dev, req->rd_page);
if (!table)
return -EINVAL;
table_sg_end = (table->page_end_offset - req->rd_page);
sg_d = &table->sg_table[req->rd_page - table->page_start_offset];
sg_s = task->task_sg;
pr_debug("RD[%d] Write LBA: %llu, Size: %u, Page: %u,"
" Offset: %u\n", dev->rd_dev_id, task->task_lba, req->rd_size,
req->rd_page, req->rd_offset);
dst_offset = rd_offset;
while (req->rd_size) {
if ((sg_s[i].length - src_offset) <
(sg_d[j].length - dst_offset)) {
length = (sg_s[i].length - src_offset);
pr_debug("Step 1 - sg_s[%d]: %p length: %d"
" offset: %d sg_d[%d].length: %u\n", i,
&sg_s[i], sg_s[i].length, sg_s[i].offset,
j, sg_d[j].length);
pr_debug("Step 1 - length: %u src_offset: %u"
" dst_offset: %u\n", length, src_offset,
dst_offset);
if (length > req->rd_size)
length = req->rd_size;
src = sg_virt(&sg_s[i++]) + src_offset;
BUG_ON(!src);
dst = sg_virt(&sg_d[j]) + dst_offset;
BUG_ON(!dst);
src_offset = 0;
dst_offset = length;
page_end = 0;
} else {
length = (sg_d[j].length - dst_offset);
pr_debug("Step 2 - sg_s[%d]: %p length: %d"
" offset: %d sg_d[%d].length: %u\n", i,
&sg_s[i], sg_s[i].length, sg_s[i].offset,
j, sg_d[j].length);
pr_debug("Step 2 - length: %u src_offset: %u"
" dst_offset: %u\n", length, src_offset,
dst_offset);
if (length > req->rd_size)
length = req->rd_size;
src = sg_virt(&sg_s[i]) + src_offset;
BUG_ON(!src);
if (sg_s[i].length == length) {
i++;
src_offset = 0;
} else
src_offset = length;
dst = sg_virt(&sg_d[j++]) + dst_offset;
BUG_ON(!dst);
dst_offset = 0;
page_end = 1;
}
memcpy(dst, src, length);
pr_debug("page: %u, remaining size: %u, length: %u,"
" i: %u, j: %u\n", req->rd_page,
(req->rd_size - length), length, i, j);
req->rd_size -= length;
if (!req->rd_size)
return 0;
if (!page_end)
continue;
if (++req->rd_page <= table->page_end_offset) {
pr_debug("page: %u in same page table\n",
req->rd_page);
continue;
}
pr_debug("getting new page table for page: %u\n",
req->rd_page);
table = rd_get_sg_table(dev, req->rd_page);
if (!table)
return -EINVAL;
sg_d = &table->sg_table[j = 0];
}
return 0;
}
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;
}
