From 8004fd2ad6042ae24d3913cf5089909781db3a25 Mon Sep 17 00:00:00 2001 From: Peter Tyser Date: Wed, 10 Mar 2010 15:23:15 -0800 Subject: [PATCH] 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 Signed-off-by: Doug Thompson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/edac/e752x_edac.c | 107 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) diff --git a/drivers/edac/e752x_edac.c b/drivers/edac/e752x_edac.c index 795fcd1eec1c..243e9aacad69 100644 --- a/drivers/edac/e752x_edac.c +++ b/drivers/edac/e752x_edac.c @@ -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 -- 2.20.1