From 2bc65418724a0ddbb20c9eeb9de8285af7748c16 Mon Sep 17 00:00:00 2001 From: Doug Thompson Date: Mon, 4 May 2009 20:11:14 +0200 Subject: amd64_edac: add memory scrubber interface Borislav: - fix/cleanup comments - fix function return value patterns - cleanup debug calls Reviewed-by: Mauro Carvalho Chehab Signed-off-by: Doug Thompson Signed-off-by: Borislav Petkov --- drivers/edac/amd64_edac.c | 130 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) create mode 100644 drivers/edac/amd64_edac.c (limited to 'drivers/edac/amd64_edac.c') diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c new file mode 100644 index 00000000000..6876d435979 --- /dev/null +++ b/drivers/edac/amd64_edac.c @@ -0,0 +1,130 @@ +#include "amd64_edac.h" + +static struct edac_pci_ctl_info *amd64_ctl_pci; + +static int report_gart_errors; +module_param(report_gart_errors, int, 0644); + +/* + * Set by command line parameter. If BIOS has enabled the ECC, this override is + * cleared to prevent re-enabling the hardware by this driver. + */ +static int ecc_enable_override; +module_param(ecc_enable_override, int, 0644); + +/* Lookup table for all possible MC control instances */ +struct amd64_pvt; +static struct mem_ctl_info *mci_lookup[MAX_NUMNODES]; +static struct amd64_pvt *pvt_lookup[MAX_NUMNODES]; + +/* + * Memory scrubber control interface. For K8, memory scrubbing is handled by + * hardware and can involve L2 cache, dcache as well as the main memory. With + * F10, this is extended to L3 cache scrubbing on CPU models sporting that + * functionality. + * + * This causes the "units" for the scrubbing speed to vary from 64 byte blocks + * (dram) over to cache lines. This is nasty, so we will use bandwidth in + * bytes/sec for the setting. + * + * Currently, we only do dram scrubbing. If the scrubbing is done in software on + * other archs, we might not have access to the caches directly. + */ + +/* + * scan the scrub rate mapping table for a close or matching bandwidth value to + * issue. If requested is too big, then use last maximum value found. + */ +static int amd64_search_set_scrub_rate(struct pci_dev *ctl, u32 new_bw, + u32 min_scrubrate) +{ + u32 scrubval; + int i; + + /* + * map the configured rate (new_bw) to a value specific to the AMD64 + * memory controller and apply to register. Search for the first + * bandwidth entry that is greater or equal than the setting requested + * and program that. If at last entry, turn off DRAM scrubbing. + */ + for (i = 0; i < ARRAY_SIZE(scrubrates); i++) { + /* + * skip scrub rates which aren't recommended + * (see F10 BKDG, F3x58) + */ + if (scrubrates[i].scrubval < min_scrubrate) + continue; + + if (scrubrates[i].bandwidth <= new_bw) + break; + + /* + * if no suitable bandwidth found, turn off DRAM scrubbing + * entirely by falling back to the last element in the + * scrubrates array. + */ + } + + scrubval = scrubrates[i].scrubval; + if (scrubval) + edac_printk(KERN_DEBUG, EDAC_MC, + "Setting scrub rate bandwidth: %u\n", + scrubrates[i].bandwidth); + else + edac_printk(KERN_DEBUG, EDAC_MC, "Turning scrubbing off.\n"); + + pci_write_bits32(ctl, K8_SCRCTRL, scrubval, 0x001F); + + return 0; +} + +static int amd64_set_scrub_rate(struct mem_ctl_info *mci, u32 *bandwidth) +{ + struct amd64_pvt *pvt = mci->pvt_info; + u32 min_scrubrate = 0x0; + + switch (boot_cpu_data.x86) { + case 0xf: + min_scrubrate = K8_MIN_SCRUB_RATE_BITS; + break; + case 0x10: + min_scrubrate = F10_MIN_SCRUB_RATE_BITS; + break; + case 0x11: + min_scrubrate = F11_MIN_SCRUB_RATE_BITS; + break; + + default: + amd64_printk(KERN_ERR, "Unsupported family!\n"); + break; + } + return amd64_search_set_scrub_rate(pvt->misc_f3_ctl, *bandwidth, + min_scrubrate); +} + +static int amd64_get_scrub_rate(struct mem_ctl_info *mci, u32 *bw) +{ + struct amd64_pvt *pvt = mci->pvt_info; + u32 scrubval = 0; + int status = -1, i, ret = 0; + + ret = pci_read_config_dword(pvt->misc_f3_ctl, K8_SCRCTRL, &scrubval); + if (ret) + debugf0("Reading K8_SCRCTRL failed\n"); + + scrubval = scrubval & 0x001F; + + edac_printk(KERN_DEBUG, EDAC_MC, + "pci-read, sdram scrub control value: %d \n", scrubval); + + for (i = 0; ARRAY_SIZE(scrubrates); i++) { + if (scrubrates[i].scrubval == scrubval) { + *bw = scrubrates[i].bandwidth; + status = 0; + break; + } + } + + return status; +} + -- cgit v1.2.3