1 files changed, 16 insertions, 15 deletions

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index ac37ce6be15c..9a1b314f6482 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -236,16 +236,26 @@ static inline size_t head_to_end(size_t head, size_t size)
  *
  * Called with ring lock held.
  */
-static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_needed, size_t data_needed)
+static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t data_needed)
 {
         struct tcmu_mailbox *mb = udev->mb_addr;
         size_t space;
         u32 cmd_head;
+        size_t cmd_needed;
 
         tcmu_flush_dcache_range(mb, sizeof(*mb));
 
         cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 
+        /*
+         * If cmd end-of-ring space is too small then we need space for a NOP plus
+         * original cmd - cmds are internally contiguous.
+         */
+        if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
+                cmd_needed = cmd_size;
+        else
+                cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
+
         space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
         if (space < cmd_needed) {
                 pr_debug("no cmd space: %u %u %u\n", cmd_head,
@@ -268,9 +278,7 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
         size_t base_command_size, command_size;
-        size_t cmdr_space_needed;
         struct tcmu_mailbox *mb;
-        size_t pad_size;
         struct tcmu_cmd_entry *entry;
         int i;
         struct scatterlist *sg;
@@ -307,17 +315,7 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
                         "cmd/data ring buffers\n", command_size, tcmu_cmd->data_length,
                         udev->cmdr_size, udev->data_size);
 
-        /*
-         * Cmd end-of-ring space is too small so we need space for a NOP plus
-         * original cmd - cmds are internally contiguous.
-         */
-        if (head_to_end(cmd_head, udev->cmdr_size) >= command_size)
-                pad_size = 0;
-        else
-                pad_size = head_to_end(cmd_head, udev->cmdr_size);
-        cmdr_space_needed = command_size + pad_size;
-
-        while (!is_ring_space_avail(udev, cmdr_space_needed, tcmu_cmd->data_length)) {
+        while (!is_ring_space_avail(udev, command_size, tcmu_cmd->data_length)) {
                 int ret;
                 DEFINE_WAIT(__wait);
 
@@ -338,7 +336,10 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
                 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
         }
 
-        if (pad_size) {
+        /* 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_flush_dcache_range(entry, sizeof(*entry));
                 tcmu_hdr_set_op(&entry->hdr, TCMU_OP_PAD);