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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: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
Peter Tyser 2010-03-10 15:23:15 -08:00 committed by Linus Torvalds
parent 8de5c1a165
commit 8004fd2ad6
1 changed files with 107 additions and 0 deletions
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107
drivers/edac/e752x_edac.c
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@ -75,6 +75,14 @@ static struct edac_pci_ctl_info *e752x_pci;
#define E752X_NR_CSROWS 8 /* number of csrows */
/* 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_DRA 0x70 /* DRAM row attribute register (8b) */
/*
@ -240,6 +248,41 @@ static const struct e752x_dev_info e752x_devs[] = {
.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,
unsigned long page)
{
@ -915,6 +958,68 @@ static void e752x_check(struct mem_ctl_info *mci)
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. */
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->edac_check = e752x_check;
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
* Must be set before e752x_init_csrows in case csrow mapping