Commit 8004fd2a authored by Peter Tyser's avatar Peter Tyser Committed by Linus Torvalds
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edac: e752x: add dram scrubbing support 

Add support to scrub DRAM using the e752x integrated memory scrubbing
engine.  The e7320/7520/e7525 chipsets support scrubbing at one rate while
the i3100 chipset supports a normal and fast rate.

A similar patch was originally sent back in 2008:
http://sourceforge.net/mailarchive/forum.php?thread_name=1204835866.25206.70.camel@localhost.localdomain&forum_name=bluesmoke-devel



This version has the following updates:
- Use 16-bit PCI config cycles to access MCHSCRB register
    e7320/7520/e7525 docs say register is 16bits wide, i3100 says 8.  I
    tested 16bits on the i3100 to be safe.
- Recalcuate and round actual scrub rates

The changes have been tested on an i3100-based board.

Signed-off-by: default avatarPeter Tyser <ptyser@xes-inc.com>
Signed-off-by: default avatarDoug Thompson <dougthompson@xmission.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8de5c1a1

drivers/edac/e752x_edac.c

+107 −0
Original line number Original line Diff line number Diff line
@@ -75,6 +75,14 @@ static struct edac_pci_ctl_info *e752x_pci; 
#define E752X_NR_CSROWS		8	/* number of csrows */

#define E752X_NR_CSROWS		8	/* number of csrows */





/* E752X register addresses - device 0 function 0 */

/* E752X register addresses - device 0 function 0 */

#define E752X_MCHSCRB		0x52	/* Memory Scrub register (16b) */

					/*

					 * 6:5     Scrub Completion Count

					 * 3:2     Scrub Rate (i3100 only)

					 *      01=fast 10=normal

					 * 1:0     Scrub Mode enable

					 *      00=off 10=on

					 */

#define E752X_DRB		0x60	/* DRAM row boundary register (8b) */

#define E752X_DRB		0x60	/* DRAM row boundary register (8b) */

#define E752X_DRA		0x70	/* DRAM row attribute register (8b) */

#define E752X_DRA		0x70	/* DRAM row attribute register (8b) */

					/*

					/*
@@ -240,6 +248,41 @@ static const struct e752x_dev_info e752x_devs[] = { 
		.ctl_name = "3100"},

		.ctl_name = "3100"},

};

};





/* Valid scrub rates for the e752x/3100 hardware memory scrubber. We

 * map the scrubbing bandwidth to a hardware register value. The 'set'

 * operation finds the 'matching or higher value'.  Note that scrubbing

 * on the e752x can only be enabled/disabled.  The 3100 supports

 * a normal and fast mode.

 */



#define SDRATE_EOT 0xFFFFFFFF



struct scrubrate {

	u32 bandwidth;	/* bandwidth consumed by scrubbing in bytes/sec */

	u16 scrubval;	/* register value for scrub rate */

};



/* Rate below assumes same performance as i3100 using PC3200 DDR2 in

 * normal mode.  e752x bridges don't support choosing normal or fast mode,

 * so the scrubbing bandwidth value isn't all that important - scrubbing is

 * either on or off.

 */

static const struct scrubrate scrubrates_e752x[] = {

	{0,		0x00},	/* Scrubbing Off */

	{500000,	0x02},	/* Scrubbing On */

	{SDRATE_EOT,	0x00}	/* End of Table */

};



/* Fast mode: 2 GByte PC3200 DDR2 scrubbed in 33s = 63161283 bytes/s

 * Normal mode: 125 (32000 / 256) times slower than fast mode.

 */

static const struct scrubrate scrubrates_i3100[] = {

	{0,		0x00},	/* Scrubbing Off */

	{500000,	0x0a},	/* Normal mode - 32k clocks */

	{62500000,	0x06},	/* Fast mode - 256 clocks */

	{SDRATE_EOT,	0x00}	/* End of Table */

};



static unsigned long ctl_page_to_phys(struct mem_ctl_info *mci,

static unsigned long ctl_page_to_phys(struct mem_ctl_info *mci,

				unsigned long page)

				unsigned long page)

{

{
@@ -915,6 +958,68 @@ static void e752x_check(struct mem_ctl_info *mci) 
	e752x_process_error_info(mci, &info, 1);

	e752x_process_error_info(mci, &info, 1);

}

}





/* Program byte/sec bandwidth scrub rate to hardware */

static int set_sdram_scrub_rate(struct mem_ctl_info *mci, u32 *new_bw)

{

	const struct scrubrate *scrubrates;

	struct e752x_pvt *pvt = (struct e752x_pvt *) mci->pvt_info;

	struct pci_dev *pdev = pvt->dev_d0f0;

	int i;



	if (pvt->dev_info->ctl_dev == PCI_DEVICE_ID_INTEL_3100_0)

		scrubrates = scrubrates_i3100;

	else

		scrubrates = scrubrates_e752x;



	/* Translate the desired scrub rate to a e752x/3100 register value.

	 * Search for the bandwidth that is equal or greater than the

	 * desired rate and program the cooresponding register value.

	 */

	for (i = 0; scrubrates[i].bandwidth != SDRATE_EOT; i++)

		if (scrubrates[i].bandwidth >= *new_bw)

			break;



	if (scrubrates[i].bandwidth == SDRATE_EOT)

		return -1;



	pci_write_config_word(pdev, E752X_MCHSCRB, scrubrates[i].scrubval);



	return 0;

}



/* Convert current scrub rate value into byte/sec bandwidth */

static int get_sdram_scrub_rate(struct mem_ctl_info *mci, u32 *bw)

{

	const struct scrubrate *scrubrates;

	struct e752x_pvt *pvt = (struct e752x_pvt *) mci->pvt_info;

	struct pci_dev *pdev = pvt->dev_d0f0;

	u16 scrubval;

	int i;



	if (pvt->dev_info->ctl_dev == PCI_DEVICE_ID_INTEL_3100_0)

		scrubrates = scrubrates_i3100;

	else

		scrubrates = scrubrates_e752x;



	/* Find the bandwidth matching the memory scrubber configuration */

	pci_read_config_word(pdev, E752X_MCHSCRB, &scrubval);

	scrubval = scrubval & 0x0f;



	for (i = 0; scrubrates[i].bandwidth != SDRATE_EOT; i++)

		if (scrubrates[i].scrubval == scrubval)

			break;



	if (scrubrates[i].bandwidth == SDRATE_EOT) {

		e752x_printk(KERN_WARNING,

			"Invalid sdram scrub control value: 0x%x\n", scrubval);

		return -1;

	}



	*bw = scrubrates[i].bandwidth;



	return 0;

}



/* Return 1 if dual channel mode is active.  Else return 0. */

/* Return 1 if dual channel mode is active.  Else return 0. */

static inline int dual_channel_active(u16 ddrcsr)

static inline int dual_channel_active(u16 ddrcsr)

{

{
@@ -1181,6 +1286,8 @@ static int e752x_probe1(struct pci_dev *pdev, int dev_idx) 
	mci->dev_name = pci_name(pdev);

	mci->dev_name = pci_name(pdev);

	mci->edac_check = e752x_check;

	mci->edac_check = e752x_check;

	mci->ctl_page_to_phys = ctl_page_to_phys;

	mci->ctl_page_to_phys = ctl_page_to_phys;

	mci->set_sdram_scrub_rate = set_sdram_scrub_rate;

	mci->get_sdram_scrub_rate = get_sdram_scrub_rate;





	/* set the map type.  1 = normal, 0 = reversed

	/* set the map type.  1 = normal, 0 = reversed

	 * Must be set before e752x_init_csrows in case csrow mapping

	 * Must be set before e752x_init_csrows in case csrow mapping

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