Commit afadbf4b authored by Stephen M. Cameron's avatar Stephen M. Cameron Committed by Jens Axboe
Browse files

cciss: factor out cciss_find_board_params 



cciss: factor out cciss_find_board_params

Signed-off-by: default avatarStephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent da550321

drivers/block/cciss.c

+25 −27
Original line number Diff line number Diff line
@@ -4072,6 +4072,30 @@ static int __devinit cciss_find_cfgtables(ctlr_info_t *h) 
	return 0;

}



/* Interrogate the hardware for some limits:

 * max commands, max SG elements without chaining, and with chaining,

 * SG chain block size, etc.

 */

static void __devinit cciss_find_board_params(ctlr_info_t *h)

{

	h->max_commands = readl(&(h->cfgtable->MaxPerformantModeCommands));

	h->nr_cmds = h->max_commands - 4; /* Allow room for some ioctls */

	h->maxsgentries = readl(&(h->cfgtable->MaxSGElements));

	/*

	 * Limit in-command s/g elements to 32 save dma'able memory.

	 * Howvever spec says if 0, use 31

	 */

	h->max_cmd_sgentries = 31;

	if (h->maxsgentries > 512) {

		h->max_cmd_sgentries = 32;

		h->chainsize = h->maxsgentries - h->max_cmd_sgentries + 1;

		h->maxsgentries--; /* save one for chain pointer */

	} else {

		h->maxsgentries = 31; /* default to traditional values */

		h->chainsize = 0;

	}

}



static int __devinit cciss_pci_init(ctlr_info_t *c)

{

	int prod_index, err;
@@ -4127,34 +4151,8 @@ static int __devinit cciss_pci_init(ctlr_info_t *c) 
#ifdef CCISS_DEBUG

	print_cfg_table(c->cfgtable);

#endif				/* CCISS_DEBUG */

	cciss_find_board_params(c);



	/* Some controllers support Zero Memory Raid (ZMR).

	 * When configured in ZMR mode the number of supported

	 * commands drops to 64. So instead of just setting an

	 * arbitrary value we make the driver a little smarter.

	 * We read the config table to tell us how many commands

	 * are supported on the controller then subtract 4 to

	 * leave a little room for ioctl calls.

	 */

	c->max_commands = readl(&(c->cfgtable->MaxPerformantModeCommands));

	c->maxsgentries = readl(&(c->cfgtable->MaxSGElements));



	/*

	 * Limit native command to 32 s/g elements to save dma'able memory.

	 * Howvever spec says if 0, use 31

	 */



	c->max_cmd_sgentries = 31;

	if (c->maxsgentries > 512) {

		c->max_cmd_sgentries = 32;

		c->chainsize = c->maxsgentries - c->max_cmd_sgentries + 1;

		c->maxsgentries -= 1;   /* account for chain pointer */

	} else {

		c->maxsgentries = 31;   /* Default to traditional value */

		c->chainsize = 0;       /* traditional */

	}



	c->nr_cmds = c->max_commands - 4;

	if ((readb(&c->cfgtable->Signature[0]) != 'C') ||

	    (readb(&c->cfgtable->Signature[1]) != 'I') ||

	    (readb(&c->cfgtable->Signature[2]) != 'S') ||