[PATCH 5/7] x86/mce: Carve out bank scanning code

Borislav Petkov
2018-06-22T09:54:42Z

From: Borislav Petkov <bp@suse.de>

Carve out the scan loop into a separate function.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/cpu/mcheck/mce.c | 134 ++++++++++++++++---------------
1 file changed, 71 insertions(+), 63 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 05d2d15a95bd..5e834bad4eaf 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -1130,6 +1130,76 @@ static bool __mc_check_crashing_cpu(int cpu)
return false;
}

+static void __mc_scan_banks(struct mce *m, struct mce *final,
+ unsigned long *toclear, unsigned long *valid_banks,
+ int no_way_out, int *worst)
+{
+ struct mca_config *cfg = &mca_cfg;
+ int severity, i;
+
+ for (i = 0; i < cfg->banks; i++) {
+ __clear_bit(i, toclear);
+ if (!test_bit(i, valid_banks))
+ continue;
+ if (!mce_banks[i].ctl)
+ continue;
+
+ m->misc = 0;
+ m->addr = 0;
+ m->bank = i;
+
+ m->status = mce_rdmsrl(msr_ops.status(i));
+ if ((m->status & MCI_STATUS_VAL) == 0)
+ continue;
+
+ /*
+ * Non uncorrected or non signaled errors are handled by
+ * machine_check_poll. Leave them alone, unless this panics.
+ */
+ if (!(m->status & (cfg->ser ? MCI_STATUS_S : MCI_STATUS_UC)) &&
+ !no_way_out)
+ continue;
+
+ /*
+ * Set taint even when machine check was not enabled.
+ */
+ add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
+
+ severity = mce_severity(m, cfg->tolerant, NULL, true);
+
+ /*
+ * When machine check was for corrected/deferred handler don't
+ * touch, unless we're panicing.
+ */
+ if ((severity == MCE_KEEP_SEVERITY ||
+ severity == MCE_UCNA_SEVERITY) && !no_way_out)
+ continue;
+ __set_bit(i, toclear);
+ if (severity == MCE_NO_SEVERITY) {
+ /*
+ * Machine check event was not enabled. Clear, but
+ * ignore.
+ */
+ continue;
+ }
+
+ mce_read_aux(m, i);
+
+ /* assuming valid severity level != 0 */
+ m->severity = severity;
+
+ mce_log(m);
+
+ if (severity > *worst) {
+ *final = *m;
+ *worst = severity;
+ }
+ }
+
+ /* mce_clear_state will clear *final, save locally for use later */
+ *m = *final;
+}
+
/*
* The actual machine check handler. This only handles real
* exceptions when something got corrupted coming in through int 18.
@@ -1151,8 +1221,6 @@ void do_machine_check(struct pt_regs *regs, long error_code)
char *msg = "Unknown";
struct mce m, *final;
int worst = 0;
- int severity;
- int i;

/*
* Establish sequential order between the CPUs entering the machine
@@ -1225,67 +1293,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
order = mce_start(&no_way_out);
}

- for (i = 0; i < cfg->banks; i++) {
- __clear_bit(i, toclear);
- if (!test_bit(i, valid_banks))
- continue;
- if (!mce_banks[i].ctl)
- continue;
-
- m.misc = 0;
- m.addr = 0;
- m.bank = i;
-
- m.status = mce_rdmsrl(msr_ops.status(i));
- if ((m.status & MCI_STATUS_VAL) == 0)
- continue;
-
- /*
- * Non uncorrected or non signaled errors are handled by
- * machine_check_poll. Leave them alone, unless this panics.
- */
- if (!(m.status & (cfg->ser ? MCI_STATUS_S : MCI_STATUS_UC)) &&
- !no_way_out)
- continue;
-
- /*
- * Set taint even when machine check was not enabled.
- */
- add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
-
- severity = mce_severity(&m, cfg->tolerant, NULL, true);
-
- /*
- * When machine check was for corrected/deferred handler don't
- * touch, unless we're panicing.
- */
- if ((severity == MCE_KEEP_SEVERITY ||
- severity == MCE_UCNA_SEVERITY) && !no_way_out)
- continue;
- __set_bit(i, toclear);
- if (severity == MCE_NO_SEVERITY) {
- /*
- * Machine check event was not enabled. Clear, but
- * ignore.
- */
- continue;
- }
-
- mce_read_aux(&m, i);
-
- /* assuming valid severity level != 0 */
- m.severity = severity;
-
- mce_log(&m);
-
- if (severity > worst) {
- *final = m;
- worst = severity;
- }
- }
-
- /* mce_clear_state will clear *final, save locally for use later */
- m = *final;
+ __mc_scan_banks(&m, final, toclear, valid_banks, no_way_out, &worst);

if (!no_way_out)
mce_clear_state(toclear);
--
2.17.0.582.gccdcbd54c