[PATCH] cciss: direct lookup for command completions
This patch changes the way we complete commands. In the old method when we
got a completion we searched our command list from the top until we find it.
This method uses a tag associated with each command (not SCSI command tagging)
to index us directly to the completed command. This helps performance.
Signed-off-by: Don Brace <dab@hp.com>
Signed-off-by: Mike Miller <mike.miller@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 3c6a6a2..a12b95e 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -174,6 +174,8 @@
unsigned int use_unit_num, unsigned int log_unit, __u8 page_code,
int cmd_type);
+static void fail_all_cmds(unsigned long ctlr);
+
#ifdef CONFIG_PROC_FS
static int cciss_proc_get_info(char *buffer, char **start, off_t offset,
int length, int *eof, void *data);
@@ -387,6 +389,8 @@
return NULL;
memset(c, 0, sizeof(CommandList_struct));
+ c->cmdindex = -1;
+
c->err_info = (ErrorInfo_struct *)pci_alloc_consistent(
h->pdev, sizeof(ErrorInfo_struct),
&err_dma_handle);
@@ -417,6 +421,8 @@
err_dma_handle = h->errinfo_pool_dhandle
+ i*sizeof(ErrorInfo_struct);
h->nr_allocs++;
+
+ c->cmdindex = i;
}
c->busaddr = (__u32) cmd_dma_handle;
@@ -2257,7 +2263,11 @@
/* fill in the request */
drv = creq->rq_disk->private_data;
c->Header.ReplyQueue = 0; // unused in simple mode
- c->Header.Tag.lower = c->busaddr; // use the physical address the cmd block for tag
+ /* got command from pool, so use the command block index instead */
+ /* for direct lookups. */
+ /* The first 2 bits are reserved for controller error reporting. */
+ c->Header.Tag.lower = (c->cmdindex << 3);
+ c->Header.Tag.lower |= 0x04; /* flag for direct lookup. */
c->Header.LUN.LogDev.VolId= drv->LunID;
c->Header.LUN.LogDev.Mode = 1;
c->Request.CDBLen = 10; // 12 byte commands not in FW yet;
@@ -2332,7 +2342,7 @@
ctlr_info_t *h = dev_id;
CommandList_struct *c;
unsigned long flags;
- __u32 a, a1;
+ __u32 a, a1, a2;
int j;
int start_queue = h->next_to_run;
@@ -2350,10 +2360,21 @@
while((a = h->access.command_completed(h)) != FIFO_EMPTY)
{
a1 = a;
+ if ((a & 0x04)) {
+ a2 = (a >> 3);
+ if (a2 >= NR_CMDS) {
+ printk(KERN_WARNING "cciss: controller cciss%d failed, stopping.\n", h->ctlr);
+ fail_all_cmds(h->ctlr);
+ return IRQ_HANDLED;
+ }
+
+ c = h->cmd_pool + a2;
+ a = c->busaddr;
+
+ } else {
a &= ~3;
- if ((c = h->cmpQ) == NULL)
- {
- printk(KERN_WARNING "cciss: Completion of %08lx ignored\n", (unsigned long)a1);
+ if ((c = h->cmpQ) == NULL) {
+ printk(KERN_WARNING "cciss: Completion of %08x ignored\n", a1);
continue;
}
while(c->busaddr != a) {
@@ -2361,6 +2382,7 @@
if (c == h->cmpQ)
break;
}
+ }
/*
* If we've found the command, take it off the
* completion Q and free it
@@ -3124,5 +3146,43 @@
remove_proc_entry("cciss", proc_root_driver);
}
+static void fail_all_cmds(unsigned long ctlr)
+{
+ /* If we get here, the board is apparently dead. */
+ ctlr_info_t *h = hba[ctlr];
+ CommandList_struct *c;
+ unsigned long flags;
+
+ printk(KERN_WARNING "cciss%d: controller not responding.\n", h->ctlr);
+ h->alive = 0; /* the controller apparently died... */
+
+ spin_lock_irqsave(CCISS_LOCK(ctlr), flags);
+
+ pci_disable_device(h->pdev); /* Make sure it is really dead. */
+
+ /* move everything off the request queue onto the completed queue */
+ while( (c = h->reqQ) != NULL ) {
+ removeQ(&(h->reqQ), c);
+ h->Qdepth--;
+ addQ (&(h->cmpQ), c);
+ }
+
+ /* Now, fail everything on the completed queue with a HW error */
+ while( (c = h->cmpQ) != NULL ) {
+ removeQ(&h->cmpQ, c);
+ c->err_info->CommandStatus = CMD_HARDWARE_ERR;
+ if (c->cmd_type == CMD_RWREQ) {
+ complete_command(h, c, 0);
+ } else if (c->cmd_type == CMD_IOCTL_PEND)
+ complete(c->waiting);
+#ifdef CONFIG_CISS_SCSI_TAPE
+ else if (c->cmd_type == CMD_SCSI)
+ complete_scsi_command(c, 0, 0);
+#endif
+ }
+ spin_unlock_irqrestore(CCISS_LOCK(ctlr), flags);
+ return;
+}
+
module_init(cciss_init);
module_exit(cciss_cleanup);