scsi: cxlflash: Remove unused buffer from AFU command
authorMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Tue, 29 Nov 2016 00:42:01 +0000 (18:42 -0600)
committerMartin K. Petersen <martin.petersen@oracle.com>
Thu, 1 Dec 2016 00:53:01 +0000 (19:53 -0500)
The cxlflash driver originally required a per-command 4K buffer that
hosted data passed to the AFU. When the routines that initiate AFU
and internal SCSI commands were refactored to use scsi_execute(), the
need for this buffer became obsolete. As it is no longer necessary,
the buffer is removed.

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
drivers/scsi/cxlflash/common.h
drivers/scsi/cxlflash/main.c

index ef2943d..4525514 100644 (file)
@@ -134,7 +134,6 @@ struct afu_cmd {
        struct sisl_ioasa sa;   /* IOASA must follow IOARCB */
        spinlock_t slock;
        struct completion cevent;
-       char *buf;              /* per command buffer */
        struct afu *parent;
        int slot;
        atomic_t free;
index 1292a74..9f2821d 100644 (file)
@@ -41,8 +41,7 @@ MODULE_LICENSE("GPL");
  * Commands are checked out in a round-robin fashion. Note that since
  * the command pool is larger than the hardware queue, the majority of
  * times we will only loop once or twice before getting a command. The
- * buffer and CDB within the command are initialized (zeroed) prior to
- * returning.
+ * CDB within the command is initialized (zeroed) prior to returning.
  *
  * Return: The checked out command or NULL when command pool is empty.
  */
@@ -59,7 +58,6 @@ static struct afu_cmd *cmd_checkout(struct afu *afu)
                if (!atomic_dec_if_positive(&cmd->free)) {
                        pr_devel("%s: returning found index=%d cmd=%p\n",
                                 __func__, cmd->slot, cmd);
-                       memset(cmd->buf, 0, CMD_BUFSIZE);
                        memset(cmd->rcb.cdb, 0, sizeof(cmd->rcb.cdb));
                        return cmd;
                }
@@ -590,17 +588,9 @@ static void cxlflash_wait_for_pci_err_recovery(struct cxlflash_cfg *cfg)
  */
 static void free_mem(struct cxlflash_cfg *cfg)
 {
-       int i;
-       char *buf = NULL;
        struct afu *afu = cfg->afu;
 
        if (cfg->afu) {
-               for (i = 0; i < CXLFLASH_NUM_CMDS; i++) {
-                       buf = afu->cmd[i].buf;
-                       if (!((u64)buf & (PAGE_SIZE - 1)))
-                               free_page((ulong)buf);
-               }
-
                free_pages((ulong)afu, get_order(sizeof(struct afu)));
                cfg->afu = NULL;
        }
@@ -849,7 +839,6 @@ static int alloc_mem(struct cxlflash_cfg *cfg)
 {
        int rc = 0;
        int i;
-       char *buf = NULL;
        struct device *dev = &cfg->dev->dev;
 
        /* AFU is ~12k, i.e. only one 64k page or up to four 4k pages */
@@ -864,20 +853,7 @@ static int alloc_mem(struct cxlflash_cfg *cfg)
        cfg->afu->parent = cfg;
        cfg->afu->afu_map = NULL;
 
-       for (i = 0; i < CXLFLASH_NUM_CMDS; buf += CMD_BUFSIZE, i++) {
-               if (!((u64)buf & (PAGE_SIZE - 1))) {
-                       buf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
-                       if (unlikely(!buf)) {
-                               dev_err(dev,
-                                       "%s: Allocate command buffers fail!\n",
-                                      __func__);
-                               rc = -ENOMEM;
-                               free_mem(cfg);
-                               goto out;
-                       }
-               }
-
-               cfg->afu->cmd[i].buf = buf;
+       for (i = 0; i < CXLFLASH_NUM_CMDS; i++) {
                atomic_set(&cfg->afu->cmd[i].free, 1);
                cfg->afu->cmd[i].slot = i;
        }