Commit 3d3f9d56 authored by Bodo Stroesser's avatar Bodo Stroesser Committed by Martin K. Petersen
Browse files

scsi: target: tcmu: Factor out new helper ring_insert_padding 

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: default avatarMike Christie <michael.christie@oracle.com>
Signed-off-by: default avatarBodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent c9684927

drivers/target/target_core_user.c

+30 −21
Original line number Diff line number Diff line
@@ -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);

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