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
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+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') ||