linux/drivers/edac/amd64_edac.c
Doug Thompson 2bc6541872 amd64_edac: add memory scrubber interface
Borislav:
- fix/cleanup comments
- fix function return value patterns
- cleanup debug calls

Reviewed-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
2009-06-10 12:18:49 +02:00

131 lines
3.5 KiB
C

#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;
}