From 535e9c78e1a80946283cecc742b687b3a5ff5109 Mon Sep 17 00:00:00 2001 From: Nils Carlson Date: Mon, 8 Aug 2011 06:21:26 -0300 Subject: [PATCH] i7core_edac: scrubbing fixups Get a more reliable DCLK value from DMI, name the SCRUBINTERVAL mask and guard against potential overflow in the scrub rate computations. Signed-off-by: Nils Carlson --- drivers/edac/i7core_edac.c | 141 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 133 insertions(+), 8 deletions(-) diff --git a/drivers/edac/i7core_edac.c b/drivers/edac/i7core_edac.c index 6ae7795..7cb68de 100644 --- a/drivers/edac/i7core_edac.c +++ b/drivers/edac/i7core_edac.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -107,6 +108,7 @@ MODULE_PARM_DESC(use_pci_fixup, "Enable PCI fixup to seek for hidden devices"); #define MC_SCRUB_CONTROL 0x4c #define STARTSCRUB (1 << 24) + #define SCRUBINTERVAL_MASK 0xffffff #define MC_COR_ECC_CNT_0 0x80 #define MC_COR_ECC_CNT_1 0x84 @@ -275,6 +277,9 @@ struct i7core_pvt { /* Count indicator to show errors not got */ unsigned mce_overrun; + /* DCLK Frequency used for computing scrub rate */ + int dclk_freq; + /* Struct to control EDAC polling */ struct edac_pci_ctl_info *i7core_pci; }; @@ -1952,6 +1957,112 @@ static struct notifier_block i7_mce_dec = { .notifier_call = i7core_mce_check_error, }; +struct memdev_dmi_entry { + u8 type; + u8 length; + u16 handle; + u16 phys_mem_array_handle; + u16 mem_err_info_handle; + u16 total_width; + u16 data_width; + u16 size; + u8 form; + u8 device_set; + u8 device_locator; + u8 bank_locator; + u8 memory_type; + u16 type_detail; + u16 speed; + u8 manufacturer; + u8 serial_number; + u8 asset_tag; + u8 part_number; + u8 attributes; + u32 extended_size; + u16 conf_mem_clk_speed; +} __attribute__((__packed__)); + + +/* + * Decode the DRAM Clock Frequency, be paranoid, make sure that all + * memory devices show the same speed, and if they don't then consider + * all speeds to be invalid. + */ +static void decode_dclk(const struct dmi_header *dh, void *_dclk_freq) +{ + int *dclk_freq = _dclk_freq; + u16 dmi_mem_clk_speed; + + if (*dclk_freq == -1) + return; + + if (dh->type == DMI_ENTRY_MEM_DEVICE) { + struct memdev_dmi_entry *memdev_dmi_entry = + (struct memdev_dmi_entry *)dh; + unsigned long conf_mem_clk_speed_offset = + (unsigned long)&memdev_dmi_entry->conf_mem_clk_speed - + (unsigned long)&memdev_dmi_entry->type; + unsigned long speed_offset = + (unsigned long)&memdev_dmi_entry->speed - + (unsigned long)&memdev_dmi_entry->type; + + /* Check that a DIMM is present */ + if (memdev_dmi_entry->size == 0) + return; + + /* + * Pick the configured speed if it's available, otherwise + * pick the DIMM speed, or we don't have a speed. + */ + if (memdev_dmi_entry->length > conf_mem_clk_speed_offset) { + dmi_mem_clk_speed = + memdev_dmi_entry->conf_mem_clk_speed; + } else if (memdev_dmi_entry->length > speed_offset) { + dmi_mem_clk_speed = memdev_dmi_entry->speed; + } else { + *dclk_freq = -1; + return; + } + + if (*dclk_freq == 0) { + /* First pass, speed was 0 */ + if (dmi_mem_clk_speed > 0) { + /* Set speed if a valid speed is read */ + *dclk_freq = dmi_mem_clk_speed; + } else { + /* Otherwise we don't have a valid speed */ + *dclk_freq = -1; + } + } else if (*dclk_freq > 0 && + *dclk_freq != dmi_mem_clk_speed) { + /* + * If we have a speed, check that all DIMMS are the same + * speed, otherwise set the speed as invalid. + */ + *dclk_freq = -1; + } + } +} + +/* + * The default DCLK frequency is used as a fallback if we + * fail to find anything reliable in the DMI. The value + * is taken straight from the datasheet. + */ +#define DEFAULT_DCLK_FREQ 800 + +static int get_dclk_freq(void) +{ + int dclk_freq = 0; + + dmi_walk(decode_dclk, (void *)&dclk_freq); + + if (dclk_freq < 1) + return DEFAULT_DCLK_FREQ; + + return dclk_freq; +} + /* * set_sdram_scrub_rate This routine sets byte/sec bandwidth scrub rate * to hardware according to SCRUBINTERVAL formula @@ -1961,8 +2072,6 @@ static int set_sdram_scrub_rate(struct mem_ctl_info *mci, u32 new_bw) { struct i7core_pvt *pvt = mci->pvt_info; struct pci_dev *pdev; - const u32 cache_line_size = 64; - const u32 freq_dclk = 800*1000000; u32 dw_scrub; u32 dw_ssr; @@ -1977,18 +2086,28 @@ static int set_sdram_scrub_rate(struct mem_ctl_info *mci, u32 new_bw) /* Prepare to disable petrol scrub */ dw_scrub &= ~STARTSCRUB; /* Stop the patrol scrub engine */ - write_and_test(pdev, MC_SCRUB_CONTROL, dw_scrub & ~0x00ffffff); + write_and_test(pdev, MC_SCRUB_CONTROL, + dw_scrub & ~SCRUBINTERVAL_MASK); /* Get current status of scrub rate and set bit to disable */ pci_read_config_dword(pdev, MC_SSRCONTROL, &dw_ssr); dw_ssr &= ~SSR_MODE_MASK; dw_ssr |= SSR_MODE_DISABLE; } else { + const int cache_line_size = 64; + const u32 freq_dclk_mhz = pvt->dclk_freq; + unsigned long long scrub_interval; /* * Translate the desired scrub rate to a register value and - * program the cooresponding register value. + * program the corresponding register value. */ - dw_scrub = 0x00ffffff & (cache_line_size * freq_dclk / new_bw); + scrub_interval = (unsigned long long)freq_dclk_mhz * + cache_line_size * 1000000 / new_bw; + + if (!scrub_interval || scrub_interval > SCRUBINTERVAL_MASK) + return -EINVAL; + + dw_scrub = SCRUBINTERVAL_MASK & scrub_interval; /* Start the patrol scrub engine */ pci_write_config_dword(pdev, MC_SCRUB_CONTROL, @@ -2015,7 +2134,8 @@ static int get_sdram_scrub_rate(struct mem_ctl_info *mci) struct i7core_pvt *pvt = mci->pvt_info; struct pci_dev *pdev; const u32 cache_line_size = 64; - const u32 freq_dclk = 800*1000000; + const u32 freq_dclk_mhz = pvt->dclk_freq; + unsigned long long scrub_rate; u32 scrubval; /* Get data from the MC register, function 2 */ @@ -2027,12 +2147,14 @@ static int get_sdram_scrub_rate(struct mem_ctl_info *mci) pci_read_config_dword(pdev, MC_SCRUB_CONTROL, &scrubval); /* Mask highest 8-bits to 0 */ - scrubval &= 0x00ffffff; + scrubval &= SCRUBINTERVAL_MASK; if (!scrubval) return 0; /* Calculate scrub rate value into byte/sec bandwidth */ - return 0xffffffff & (cache_line_size * freq_dclk / (u64) scrubval); + scrub_rate = (unsigned long long)freq_dclk_mhz * + 1000000 * cache_line_size / scrubval; + return (int)scrub_rate; } static void enable_sdram_scrub_setting(struct mem_ctl_info *mci) @@ -2204,6 +2326,9 @@ static int i7core_register_mci(struct i7core_dev *i7core_dev) /* allocating generic PCI control info */ i7core_pci_ctl_create(pvt); + /* DCLK for scrub rate setting */ + pvt->dclk_freq = get_dclk_freq(); + atomic_notifier_chain_register(&x86_mce_decoder_chain, &i7_mce_dec); return 0; -- 2.7.4