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scsi: target: tcmu: Factor out new helper ring_insert_padding

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The new helper ring_insert_padding is split off from and then called by
queue_cmd_ring. It inserts a padding if necessary.  The new helper will in
a subsequent patch be used during writing of TMR notifications to command
ring.

Link: https://lore.kernel.org/r/20200726153510.13077-6-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Bodo Stroesser 2020-07-26 17:35:07 +02:00 committed by Martin K. Petersen
parent c968492762
commit 3d3f9d56a5
1 changed files with 30 additions and 21 deletions
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51
drivers/target/target_core_user.c
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@ -926,6 +926,34 @@ static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
return 0;
}
static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
{
struct tcmu_cmd_entry_hdr *hdr;
struct tcmu_mailbox *mb = udev->mb_addr;
uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
/* Insert a PAD if end-of-ring space is too small */
if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
hdr = (void *) mb + CMDR_OFF + cmd_head;
tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
tcmu_hdr_set_len(&hdr->len_op, pad_size);
hdr->cmd_id = 0; /* not used for PAD */
hdr->kflags = 0;
hdr->uflags = 0;
tcmu_flush_dcache_range(hdr, sizeof(*hdr));
UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
tcmu_flush_dcache_range(mb, sizeof(*mb));
cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
WARN_ON(cmd_head != 0);
}
return cmd_head;
}
/**
* queue_cmd_ring - queue cmd to ring or internally
* @tcmu_cmd: cmd to queue
@ -941,7 +969,7 @@ static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
size_t base_command_size, command_size;
struct tcmu_mailbox *mb;
struct tcmu_mailbox *mb = udev->mb_addr;
struct tcmu_cmd_entry *entry;
struct iovec *iov;
int iov_cnt, cmd_id;
@ -980,8 +1008,6 @@ static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
if (!list_empty(&udev->qfull_queue))
goto queue;
mb = udev->mb_addr;
cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
if ((command_size > (udev->cmdr_size / 2)) ||
data_length > udev->data_size) {
pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu "
@ -1001,24 +1027,7 @@ static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
goto queue;
}
/* Insert a PAD if end-of-ring space is too small */
if (head_to_end(cmd_head, udev->cmdr_size) < command_size) {
size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
entry = (void *) mb + CMDR_OFF + cmd_head;
tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD);
tcmu_hdr_set_len(&entry->hdr.len_op, pad_size);
entry->hdr.cmd_id = 0; /* not used for PAD */
entry->hdr.kflags = 0;
entry->hdr.uflags = 0;
tcmu_flush_dcache_range(entry, sizeof(entry->hdr));
UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
tcmu_flush_dcache_range(mb, sizeof(*mb));
cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
WARN_ON(cmd_head != 0);
}
cmd_head = ring_insert_padding(udev, command_size);
entry = (void *) mb + CMDR_OFF + cmd_head;
memset(entry, 0, command_size);