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Commit 33079b21 authored by Mike Miller's avatar Mike Miller Committed by Linus Torvalds
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[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: default avatarDon Brace <dab@hp.com>
Signed-off-by: default avatarMike Miller <mike.miller@hp.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent ddd47442

drivers/block/cciss.c

+65 −5
Original line number Diff line number Diff line
@@ -174,6 +174,8 @@ static int sendcmd_withirq(__u8 cmd, int ctlr, void *buff, size_t size, 
	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 @@ static CommandList_struct * cmd_alloc(ctlr_info_t *h, int get_from_pool) 
                 	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 @@ static CommandList_struct * cmd_alloc(ctlr_info_t *h, int get_from_pool) 
		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 @@ static void do_cciss_request(request_queue_t *q) 
	/* 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 @@ static irqreturn_t do_cciss_intr(int irq, void *dev_id, struct pt_regs *regs) 
	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 @@ static irqreturn_t do_cciss_intr(int irq, void *dev_id, struct pt_regs *regs) 
		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 @@ static irqreturn_t do_cciss_intr(int irq, void *dev_id, struct pt_regs *regs) 
				if (c == h->cmpQ) 

					break;

			}

			}

			/*

			 * If we've found the command, take it off the

			 * completion Q and free it
@@ -3124,5 +3146,43 @@ static void __exit cciss_cleanup(void) 
	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);

drivers/block/cciss.h

+1 −0
Original line number Diff line number Diff line
@@ -101,6 +101,7 @@ struct ctlr_info 
#ifdef CONFIG_CISS_SCSI_TAPE

	void *scsi_ctlr; /* ptr to structure containing scsi related stuff */

#endif

	unsigned char alive;

};



/*  Defining the diffent access_menthods */

drivers/block/cciss_cmd.h

+6 −2
Original line number Diff line number Diff line
@@ -226,6 +226,10 @@ typedef struct _ErrorInfo_struct { 
#define CMD_MSG_DONE	0x04

#define CMD_MSG_TIMEOUT 0x05



/* This structure needs to be divisible by 8 for new

 * indexing method.

 */

#define PADSIZE (sizeof(long) - 4)

typedef struct _CommandList_struct {

  CommandListHeader_struct Header;

  RequestBlock_struct      Request;
@@ -236,14 +240,14 @@ typedef struct _CommandList_struct { 
  ErrorInfo_struct * 	   err_info; /* pointer to the allocated mem */ 

  int			   ctlr;

  int			   cmd_type; 

  long			   cmdindex;

  struct _CommandList_struct *prev;

  struct _CommandList_struct *next;

  struct request *	   rq;

  struct completion *waiting;

  int	 retry_count;

#ifdef CONFIG_CISS_SCSI_TAPE

  void * scsi_cmd;

#endif

  char   pad[PADSIZE];

} CommandList_struct;



//Configuration Table Structure

drivers/block/cciss_scsi.c

+1 −0
Original line number Diff line number Diff line
@@ -93,6 +93,7 @@ struct cciss_scsi_cmd_stack_elem_t { 
	CommandList_struct cmd;

	ErrorInfo_struct Err;

	__u32 busaddr;

	__u32 pad;

};



#pragma pack()