[PATCH 13/16] amd64_edac: Check ECC capabilities initially

From: Borislav Petkov
Date: Fri Nov 26 2010 - 14:06:24 EST


From: Borislav Petkov <borislav.petkov@xxxxxxx>

Rework the code to check the hardware ECC capabilities at PCI probing
time. We do all further initialization only if we actually can/have ECC
enabled.

While at it:
0. Fix function naming.
1. Simplify/clarify debug output.
2. Remove amd64_ prefix from the static functions
3. Reorganize code.

Signed-off-by: Borislav Petkov <borislav.petkov@xxxxxxx>
---
drivers/edac/amd64_edac.c | 141 ++++++++++++++++++++++++---------------------
1 files changed, 75 insertions(+), 66 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 2388bb9..2fe7725 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -2188,18 +2188,19 @@ static u32 amd64_csrow_nr_pages(int csrow_nr, struct amd64_pvt *pvt)
static int amd64_init_csrows(struct mem_ctl_info *mci)
{
struct csrow_info *csrow;
- struct amd64_pvt *pvt;
+ struct amd64_pvt *pvt = mci->pvt_info;
u64 input_addr_min, input_addr_max, sys_addr;
+ u32 val;
int i, empty = 1;

- pvt = mci->pvt_info;
+ amd64_read_pci_cfg(pvt->F3, K8_NBCFG, &val);

- amd64_read_pci_cfg(pvt->F3, K8_NBCFG, &pvt->nbcfg);
+ pvt->nbcfg = val;
+ pvt->ctl_error_info.nbcfg = val;

- debugf0("NBCFG= 0x%x CHIPKILL= %s DRAM ECC= %s\n", pvt->nbcfg,
- (pvt->nbcfg & K8_NBCFG_CHIPKILL) ? "Enabled" : "Disabled",
- (pvt->nbcfg & K8_NBCFG_ECC_ENABLE) ? "Enabled" : "Disabled"
- );
+ debugf0("node %d, NBCFG=0x%08x[ChipKillEccCap: %d|DramEccEn: %d]\n",
+ pvt->mc_node_id, val,
+ !!(val & K8_NBCFG_CHIPKILL), !!(val & K8_NBCFG_ECC_ENABLE));

for (i = 0; i < pvt->cs_count; i++) {
csrow = &mci->csrows[i];
@@ -2294,7 +2295,7 @@ out:
return ret;
}

-static int amd64_toggle_ecc_err_reporting(struct ecc_settings *s, u8 nid, bool on)
+static int toggle_ecc_err_reporting(struct ecc_settings *s, u8 nid, bool on)
{
cpumask_var_t cmask;
int cpu;
@@ -2332,30 +2333,31 @@ static int amd64_toggle_ecc_err_reporting(struct ecc_settings *s, u8 nid, bool o
return 0;
}

-static void amd64_enable_ecc_error_reporting(struct mem_ctl_info *mci)
+static bool enable_ecc_error_reporting(struct ecc_settings *s, u8 nid,
+ struct pci_dev *F3)
{
- struct amd64_pvt *pvt = mci->pvt_info;
- u8 nid = pvt->mc_node_id;
- struct ecc_settings *s = ecc_stngs[nid];
+ bool ret = true;
u32 value, mask = K8_NBCTL_CECCEn | K8_NBCTL_UECCEn;

- amd64_read_pci_cfg(pvt->F3, K8_NBCTL, &value);
+ if (toggle_ecc_err_reporting(s, nid, ON)) {
+ amd64_warn("Error enabling ECC reporting over MCGCTL!\n");
+ return false;
+ }
+
+ amd64_read_pci_cfg(F3, K8_NBCTL, &value);

/* turn on UECCEn and CECCEn bits */
s->old_nbctl = value & mask;
s->nbctl_valid = true;

value |= mask;
- pci_write_config_dword(pvt->F3, K8_NBCTL, value);
+ pci_write_config_dword(F3, K8_NBCTL, value);

- if (amd64_toggle_ecc_err_reporting(s, nid, ON))
- amd64_warn("Error enabling ECC reporting over MCGCTL!\n");
+ amd64_read_pci_cfg(F3, K8_NBCFG, &value);

- amd64_read_pci_cfg(pvt->F3, K8_NBCFG, &value);
-
- debugf0("NBCFG(1)= 0x%x CHIPKILL= %s ECC_ENABLE= %s\n", value,
- (value & K8_NBCFG_CHIPKILL) ? "Enabled" : "Disabled",
- (value & K8_NBCFG_ECC_ENABLE) ? "Enabled" : "Disabled");
+ debugf0("1: node %d, NBCFG=0x%08x[ChipKillEccCap: %d|DramEccEn: %d]\n",
+ nid, value,
+ !!(value & K8_NBCFG_CHIPKILL), !!(value & K8_NBCFG_ECC_ENABLE));

if (!(value & K8_NBCFG_ECC_ENABLE)) {
amd64_warn("DRAM ECC disabled on this node, enabling...\n");
@@ -2364,13 +2366,14 @@ static void amd64_enable_ecc_error_reporting(struct mem_ctl_info *mci)

/* Attempt to turn on DRAM ECC Enable */
value |= K8_NBCFG_ECC_ENABLE;
- pci_write_config_dword(pvt->F3, K8_NBCFG, value);
+ pci_write_config_dword(F3, K8_NBCFG, value);

- amd64_read_pci_cfg(pvt->F3, K8_NBCFG, &value);
+ amd64_read_pci_cfg(F3, K8_NBCFG, &value);

if (!(value & K8_NBCFG_ECC_ENABLE)) {
amd64_warn("Hardware rejected DRAM ECC enable,"
"check memory DIMM configuration.\n");
+ ret = false;
} else {
amd64_info("Hardware accepted DRAM ECC Enable\n");
}
@@ -2378,11 +2381,11 @@ static void amd64_enable_ecc_error_reporting(struct mem_ctl_info *mci)
s->flags.nb_ecc_prev = 1;
}

- debugf0("NBCFG(2)= 0x%x CHIPKILL= %s ECC_ENABLE= %s\n", value,
- (value & K8_NBCFG_CHIPKILL) ? "Enabled" : "Disabled",
- (value & K8_NBCFG_ECC_ENABLE) ? "Enabled" : "Disabled");
+ debugf0("2: node %d, NBCFG=0x%08x[ChipKillEccCap: %d|DramEccEn: %d]\n",
+ nid, value,
+ !!(value & K8_NBCFG_CHIPKILL), !!(value & K8_NBCFG_ECC_ENABLE));

- pvt->ctl_error_info.nbcfg = value;
+ return ret;
}

static void amd64_restore_ecc_error_reporting(struct amd64_pvt *pvt)
@@ -2408,15 +2411,15 @@ static void amd64_restore_ecc_error_reporting(struct amd64_pvt *pvt)
}

/* restore the NB Enable MCGCTL bit */
- if (amd64_toggle_ecc_err_reporting(s, nid, OFF))
+ if (toggle_ecc_err_reporting(s, nid, OFF))
amd64_warn("Error restoring NB MCGCTL settings!\n");
}

/*
- * EDAC requires that the BIOS have ECC enabled before taking over the
- * processing of ECC errors. This is because the BIOS can properly initialize
- * the memory system completely. A command line option allows to force-enable
- * hardware ECC later in amd64_enable_ecc_error_reporting().
+ * EDAC requires that the BIOS have ECC enabled before
+ * taking over the processing of ECC errors. A command line
+ * option allows to force-enable hardware ECC later in
+ * enable_ecc_error_reporting().
*/
static const char *ecc_msg =
"ECC disabled in the BIOS or no ECC capability, module will not load.\n"
@@ -2424,33 +2427,28 @@ static const char *ecc_msg =
"'ecc_enable_override'.\n"
" (Note that use of the override may cause unknown side effects.)\n";

-static int amd64_check_ecc_enabled(struct amd64_pvt *pvt)
+static bool ecc_enabled(struct pci_dev *F3, u8 nid)
{
u32 value;
- u8 ecc_enabled = 0;
+ u8 ecc_en = 0;
bool nb_mce_en = false;

- amd64_read_pci_cfg(pvt->F3, K8_NBCFG, &value);
+ amd64_read_pci_cfg(F3, K8_NBCFG, &value);

- ecc_enabled = !!(value & K8_NBCFG_ECC_ENABLE);
- amd64_info("DRAM ECC %s.\n", (ecc_enabled ? "enabled" : "disabled"));
+ ecc_en = !!(value & K8_NBCFG_ECC_ENABLE);
+ amd64_info("DRAM ECC %s.\n", (ecc_en ? "enabled" : "disabled"));

- nb_mce_en = amd64_nb_mce_bank_enabled_on_node(pvt->mc_node_id);
+ nb_mce_en = amd64_nb_mce_bank_enabled_on_node(nid);
if (!nb_mce_en)
- amd64_notice("NB MCE bank disabled, "
- "set MSR 0x%08x[4] on node %d to enable.\n",
- MSR_IA32_MCG_CTL, pvt->mc_node_id);
-
- if (!ecc_enabled || !nb_mce_en) {
- if (!ecc_enable_override) {
- amd64_notice("%s", ecc_msg);
- return -ENODEV;
- } else {
- amd64_warn("Forcing ECC on!\n");
- }
- }
+ amd64_notice("NB MCE bank disabled, set MSR "
+ "0x%08x[4] on node %d to enable.\n",
+ MSR_IA32_MCG_CTL, nid);

- return 0;
+ if (!ecc_en || !nb_mce_en) {
+ amd64_notice("%s", ecc_msg);
+ return false;
+ }
+ return true;
}

struct mcidev_sysfs_attribute sysfs_attrs[ARRAY_SIZE(amd64_dbg_attrs) +
@@ -2536,7 +2534,7 @@ static struct amd64_family_type *amd64_per_family_init(struct amd64_pvt *pvt)
return fam_type;
}

-static int amd64_probe_one_instance(struct pci_dev *F2)
+static int amd64_init_one_instance(struct pci_dev *F2)
{
struct amd64_pvt *pvt = NULL;
struct amd64_family_type *fam_type = NULL;
@@ -2561,11 +2559,6 @@ static int amd64_probe_one_instance(struct pci_dev *F2)
if (err)
goto err_free;

- ret = -EINVAL;
- err = amd64_check_ecc_enabled(pvt);
- if (err)
- goto err_put;
-
/*
* Save the pointer to the private data for use in 2nd initialization
* stage
@@ -2574,9 +2567,6 @@ static int amd64_probe_one_instance(struct pci_dev *F2)

return 0;

-err_put:
- amd64_free_mc_sibling_devices(pvt);
-
err_free:
kfree(pvt);

@@ -2618,7 +2608,6 @@ static int amd64_init_2nd_stage(struct amd64_pvt *pvt)
if (amd64_init_csrows(mci))
mci->edac_cap = EDAC_FLAG_NONE;

- amd64_enable_ecc_error_reporting(mci);
amd64_set_mc_sysfs_attributes(mci);

ret = -ENODEV;
@@ -2655,12 +2644,13 @@ err_exit:
}


-static int __devinit amd64_init_one_instance(struct pci_dev *pdev,
+static int __devinit amd64_probe_one_instance(struct pci_dev *pdev,
const struct pci_device_id *mc_type)
{
- int ret = 0;
u8 nid = get_node_id(pdev);
+ struct pci_dev *F3 = node_to_amd_nb(nid)->misc;
struct ecc_settings *s;
+ int ret = 0;

ret = pci_enable_device(pdev);
if (ret < 0) {
@@ -2671,15 +2661,34 @@ static int __devinit amd64_init_one_instance(struct pci_dev *pdev,
ret = -ENOMEM;
s = kzalloc(sizeof(struct ecc_settings), GFP_KERNEL);
if (!s)
- return ret;
+ goto err_out;

ecc_stngs[nid] = s;

- ret = amd64_probe_one_instance(pdev);
+ if (!ecc_enabled(F3, nid)) {
+ ret = -ENODEV;
+
+ if (!ecc_enable_override)
+ goto err_enable;
+
+ amd64_warn("Forcing ECC on!\n");
+
+ if (!enable_ecc_error_reporting(s, nid, F3))
+ goto err_enable;
+ }
+
+ ret = amd64_init_one_instance(pdev);
if (ret < 0)
amd64_err("Error probing instance: %d\n", nid);

return ret;
+
+err_enable:
+ kfree(s);
+ ecc_stngs[nid] = NULL;
+
+err_out:
+ return ret;
}

static void __devexit amd64_remove_one_instance(struct pci_dev *pdev)
@@ -2741,7 +2750,7 @@ MODULE_DEVICE_TABLE(pci, amd64_pci_table);

static struct pci_driver amd64_pci_driver = {
.name = EDAC_MOD_STR,
- .probe = amd64_init_one_instance,
+ .probe = amd64_probe_one_instance,
.remove = __devexit_p(amd64_remove_one_instance),
.id_table = amd64_pci_table,
};
--
1.7.3.1.50.g1e633

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