diff options
| author | Ilias Tsitsimpis <iliastsi@arrikto.com> | 2015-04-23 21:30:09 +0300 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-05-30 22:41:47 -0700 |
| commit | e4648b014e03baee45d5f5146c1219b19e4e5f2f (patch) | |
| tree | 652bf355631417eb402589d9a479454507d8c444 /drivers/target | |
| parent | f97ec7db1606875666366bfcba8476f8c917db96 (diff) | |
target/user: Add support for bidirectional commands
Enable TCMU to handle bidirectional SCSI commands. In such cases,
entries in iov[] cover both the Data-In and the Data-Out buffers. The
first iov_cnt entries correspond to the Data-Out buffer, while the
remaining iov_bidi_cnt entries correspond to the Data-In buffer.
Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Vangelis Koukis <vkoukis@arrikto.com>
Reviewed-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target')
| -rw-r--r-- | drivers/target/target_core_user.c | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 2b0d26e268be..60330e00f59d 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -167,6 +167,11 @@ static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd) tcmu_cmd->tcmu_dev = udev; tcmu_cmd->data_length = se_cmd->data_length; + if (se_cmd->se_cmd_flags & SCF_BIDI) { + BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents)); + tcmu_cmd->data_length += se_cmd->t_bidi_data_sg->length; + } + tcmu_cmd->deadline = jiffies + msecs_to_jiffies(TCMU_TIME_OUT); idr_preload(GFP_KERNEL); @@ -387,7 +392,8 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) * b/c size == offsetof one-past-element. */ base_command_size = max(offsetof(struct tcmu_cmd_entry, - req.iov[se_cmd->t_data_nents + 2]), + req.iov[se_cmd->t_bidi_data_nents + + se_cmd->t_data_nents + 2]), sizeof(struct tcmu_cmd_entry)); command_size = base_command_size + round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE); @@ -456,13 +462,19 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) */ iov = &entry->req.iov[0]; iov_cnt = 0; - copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE); + copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE + || se_cmd->se_cmd_flags & SCF_BIDI); alloc_and_scatter_data_area(udev, se_cmd->t_data_sg, se_cmd->t_data_nents, &iov, &iov_cnt, copy_to_data_area); entry->req.iov_cnt = iov_cnt; - entry->req.iov_bidi_cnt = 0; entry->req.iov_dif_cnt = 0; + /* Handle BIDI commands */ + iov_cnt = 0; + alloc_and_scatter_data_area(udev, se_cmd->t_bidi_data_sg, + se_cmd->t_bidi_data_nents, &iov, &iov_cnt, false); + entry->req.iov_bidi_cnt = iov_cnt; + /* All offsets relative to mb_addr, not start of entry! */ cdb_off = CMDR_OFF + cmd_head + base_command_size; memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb)); @@ -535,8 +547,15 @@ static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry * se_cmd->scsi_sense_length); UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size); - } - else if (se_cmd->data_direction == DMA_FROM_DEVICE) { + } else if (se_cmd->se_cmd_flags & SCF_BIDI) { + /* Discard data_out buffer */ + UPDATE_HEAD(udev->data_tail, + (size_t)se_cmd->t_data_sg->length, udev->data_size); + + /* Get Data-In buffer */ + gather_and_free_data_area(udev, + se_cmd->t_bidi_data_sg, se_cmd->t_bidi_data_nents); + } else if (se_cmd->data_direction == DMA_FROM_DEVICE) { gather_and_free_data_area(udev, se_cmd->t_data_sg, se_cmd->t_data_nents); } else if (se_cmd->data_direction == DMA_TO_DEVICE) { |