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amd64_edac: Remove polling mechanism
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Switch to reusing the mcheck core's machine check polling mechanism
instead of duplicating functionality by using the EDAC polling routine.

Correct formatting while at it.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Acked-by: Doug Thompson <dougthompson@xmission.com>
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Borislav Petkov committed Aug 3, 2010
1 parent 98a5ae2 commit f434755
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Showing 2 changed files with 8 additions and 126 deletions.
118 changes: 0 additions & 118 deletions drivers/edac/amd64_edac.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1978,107 +1978,6 @@ static int get_channel_from_ecc_syndrome(struct mem_ctl_info *mci, u16 syndrome)
return map_err_sym_to_channel(err_sym, pvt->syn_type);
}

/*
* Check for valid error in the NB Status High register. If so, proceed to read
* NB Status Low, NB Address Low and NB Address High registers and store data
* into error structure.
*
* Returns:
* - 1: if hardware regs contains valid error info
* - 0: if no valid error is indicated
*/
static int amd64_get_error_info_regs(struct mem_ctl_info *mci,
struct err_regs *regs)
{
struct amd64_pvt *pvt;
struct pci_dev *misc_f3_ctl;

pvt = mci->pvt_info;
misc_f3_ctl = pvt->misc_f3_ctl;

if (amd64_read_pci_cfg(misc_f3_ctl, K8_NBSH, &regs->nbsh))
return 0;

if (!(regs->nbsh & K8_NBSH_VALID_BIT))
return 0;

/* valid error, read remaining error information registers */
if (amd64_read_pci_cfg(misc_f3_ctl, K8_NBSL, &regs->nbsl) ||
amd64_read_pci_cfg(misc_f3_ctl, K8_NBEAL, &regs->nbeal) ||
amd64_read_pci_cfg(misc_f3_ctl, K8_NBEAH, &regs->nbeah) ||
amd64_read_pci_cfg(misc_f3_ctl, K8_NBCFG, &regs->nbcfg))
return 0;

return 1;
}

/*
* This function is called to retrieve the error data from hardware and store it
* in the info structure.
*
* Returns:
* - 1: if a valid error is found
* - 0: if no error is found
*/
static int amd64_get_error_info(struct mem_ctl_info *mci,
struct err_regs *info)
{
struct amd64_pvt *pvt;
struct err_regs regs;

pvt = mci->pvt_info;

if (!amd64_get_error_info_regs(mci, info))
return 0;

/*
* Here's the problem with the K8's EDAC reporting: There are four
* registers which report pieces of error information. They are shared
* between CEs and UEs. Furthermore, contrary to what is stated in the
* BKDG, the overflow bit is never used! Every error always updates the
* reporting registers.
*
* Can you see the race condition? All four error reporting registers
* must be read before a new error updates them! There is no way to read
* all four registers atomically. The best than can be done is to detect
* that a race has occured and then report the error without any kind of
* precision.
*
* What is still positive is that errors are still reported and thus
* problems can still be detected - just not localized because the
* syndrome and address are spread out across registers.
*
* Grrrrr!!!!! Here's hoping that AMD fixes this in some future K8 rev.
* UEs and CEs should have separate register sets with proper overflow
* bits that are used! At very least the problem can be fixed by
* honoring the ErrValid bit in 'nbsh' and not updating registers - just
* set the overflow bit - unless the current error is CE and the new
* error is UE which would be the only situation for overwriting the
* current values.
*/

regs = *info;

/* Use info from the second read - most current */
if (unlikely(!amd64_get_error_info_regs(mci, info)))
return 0;

/* clear the error bits in hardware */
pci_write_bits32(pvt->misc_f3_ctl, K8_NBSH, 0, K8_NBSH_VALID_BIT);

/* Check for the possible race condition */
if ((regs.nbsh != info->nbsh) ||
(regs.nbsl != info->nbsl) ||
(regs.nbeah != info->nbeah) ||
(regs.nbeal != info->nbeal)) {
amd64_mc_printk(mci, KERN_WARNING,
"hardware STATUS read access race condition "
"detected!\n");
return 0;
}
return 1;
}

/*
* Handle any Correctable Errors (CEs) that have occurred. Check for valid ERROR
* ADDRESS and process.
Expand Down Expand Up @@ -2202,20 +2101,6 @@ void amd64_decode_bus_error(int node_id, struct err_regs *regs)

}

/*
* The main polling 'check' function, called FROM the edac core to perform the
* error checking and if an error is encountered, error processing.
*/
static void amd64_check(struct mem_ctl_info *mci)
{
struct err_regs regs;

if (amd64_get_error_info(mci, &regs)) {
struct amd64_pvt *pvt = mci->pvt_info;
amd_decode_nb_mce(pvt->mc_node_id, &regs, 1);
}
}

/*
* Input:
* 1) struct amd64_pvt which contains pvt->dram_f2_ctl pointer
Expand Down Expand Up @@ -2756,9 +2641,6 @@ static void amd64_setup_mci_misc_attributes(struct mem_ctl_info *mci)
mci->dev_name = pci_name(pvt->dram_f2_ctl);
mci->ctl_page_to_phys = NULL;

/* IMPORTANT: Set the polling 'check' function in this module */
mci->edac_check = amd64_check;

/* memory scrubber interface */
mci->set_sdram_scrub_rate = amd64_set_scrub_rate;
mci->get_sdram_scrub_rate = amd64_get_scrub_rate;
Expand Down
16 changes: 8 additions & 8 deletions drivers/edac/edac_mce_amd.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -133,7 +133,7 @@ static void amd_decode_dc_mce(u64 mc0_status)
u32 ec = mc0_status & 0xffff;
u32 xec = (mc0_status >> 16) & 0xf;

pr_emerg(" Data Cache Error");
pr_emerg("Data Cache Error");

if (xec == 1 && TLB_ERROR(ec))
pr_cont(": %s TLB multimatch.\n", LL_MSG(ec));
Expand Down Expand Up @@ -176,7 +176,7 @@ static void amd_decode_ic_mce(u64 mc1_status)
u32 ec = mc1_status & 0xffff;
u32 xec = (mc1_status >> 16) & 0xf;

pr_emerg(" Instruction Cache Error");
pr_emerg("Instruction Cache Error");

if (xec == 1 && TLB_ERROR(ec))
pr_cont(": %s TLB multimatch.\n", LL_MSG(ec));
Expand Down Expand Up @@ -233,7 +233,7 @@ static void amd_decode_bu_mce(u64 mc2_status)
u32 ec = mc2_status & 0xffff;
u32 xec = (mc2_status >> 16) & 0xf;

pr_emerg(" Bus Unit Error");
pr_emerg("Bus Unit Error");

if (xec == 0x1)
pr_cont(" in the write data buffers.\n");
Expand Down Expand Up @@ -275,7 +275,7 @@ static void amd_decode_ls_mce(u64 mc3_status)
u32 ec = mc3_status & 0xffff;
u32 xec = (mc3_status >> 16) & 0xf;

pr_emerg(" Load Store Error");
pr_emerg("Load Store Error");

if (xec == 0x0) {
u8 rrrr = (ec >> 4) & 0xf;
Expand Down Expand Up @@ -304,7 +304,7 @@ void amd_decode_nb_mce(int node_id, struct err_regs *regs, int handle_errors)
if (TLB_ERROR(ec) && !report_gart_errors)
return;

pr_emerg(" Northbridge Error, node %d", node_id);
pr_emerg("Northbridge Error, node %d", node_id);

/*
* F10h, revD can disable ErrCpu[3:0] so check that first and also the
Expand Down Expand Up @@ -342,13 +342,13 @@ static void amd_decode_fr_mce(u64 mc5_status)
static inline void amd_decode_err_code(unsigned int ec)
{
if (TLB_ERROR(ec)) {
pr_emerg(" Transaction: %s, Cache Level %s\n",
pr_emerg("Transaction: %s, Cache Level %s\n",
TT_MSG(ec), LL_MSG(ec));
} else if (MEM_ERROR(ec)) {
pr_emerg(" Transaction: %s, Type: %s, Cache Level: %s",
pr_emerg("Transaction: %s, Type: %s, Cache Level: %s",
RRRR_MSG(ec), TT_MSG(ec), LL_MSG(ec));
} else if (BUS_ERROR(ec)) {
pr_emerg(" Transaction type: %s(%s), %s, Cache Level: %s, "
pr_emerg("Transaction type: %s(%s), %s, Cache Level: %s, "
"Participating Processor: %s\n",
RRRR_MSG(ec), II_MSG(ec), TO_MSG(ec), LL_MSG(ec),
PP_MSG(ec));
Expand Down

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