[PATCH 4/4] x86/mce: Get rid of the ->quirk_no_way_out() indirect call

From: Borislav Petkov
Date: Fri Sep 17 2021 - 06:54:20 EST


From: Borislav Petkov <bp@xxxxxxx>

Use a flag setting to call the only quirk function for that.

No functional changes.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
arch/x86/kernel/cpu/mce/core.c | 64 +++++++++++++++---------------
arch/x86/kernel/cpu/mce/internal.h | 5 ++-
2 files changed, 35 insertions(+), 34 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index ee4f534424b8..e0cef8781c6f 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -121,8 +121,6 @@ mce_banks_t mce_banks_ce_disabled;
static struct work_struct mce_work;
static struct irq_work mce_irq_work;

-static void (*quirk_no_way_out)(int bank, struct mce *m, struct pt_regs *regs);
-
/*
* CPU/chipset specific EDAC code can register a notifier call here to print
* MCE errors in a human-readable form.
@@ -818,6 +816,34 @@ bool machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
}
EXPORT_SYMBOL_GPL(machine_check_poll);

+/*
+ * During IFU recovery Sandy Bridge -EP4S processors set the RIPV and
+ * EIPV bits in MCG_STATUS to zero on the affected logical processor (SDM
+ * Vol 3B Table 15-20). But this confuses both the code that determines
+ * whether the machine check occurred in kernel or user mode, and also
+ * the severity assessment code. Pretend that EIPV was set, and take the
+ * ip/cs values from the pt_regs that mce_gather_info() ignored earlier.
+ */
+static void quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
+{
+ if (bank != 0)
+ return;
+ if ((m->mcgstatus & (MCG_STATUS_EIPV|MCG_STATUS_RIPV)) != 0)
+ return;
+ if ((m->status & (MCI_STATUS_OVER|MCI_STATUS_UC|
+ MCI_STATUS_EN|MCI_STATUS_MISCV|MCI_STATUS_ADDRV|
+ MCI_STATUS_PCC|MCI_STATUS_S|MCI_STATUS_AR|
+ MCACOD)) !=
+ (MCI_STATUS_UC|MCI_STATUS_EN|
+ MCI_STATUS_MISCV|MCI_STATUS_ADDRV|MCI_STATUS_S|
+ MCI_STATUS_AR|MCACOD_INSTR))
+ return;
+
+ m->mcgstatus |= MCG_STATUS_EIPV;
+ m->ip = regs->ip;
+ m->cs = regs->cs;
+}
+
/*
* Do a quick check if any of the events requires a panic.
* This decides if we keep the events around or clear them.
@@ -834,8 +860,8 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
continue;

__set_bit(i, validp);
- if (quirk_no_way_out)
- quirk_no_way_out(i, m, regs);
+ if (mce_flags.snb_ifu_quirk)
+ quirk_sandybridge_ifu(i, m, regs);

m->bank = i;
if (mce_severity(m, regs, mca_cfg.tolerant, &tmp, true) >= MCE_PANIC_SEVERITY) {
@@ -1692,34 +1718,6 @@ static void __mcheck_cpu_check_banks(void)
}
}

-/*
- * During IFU recovery Sandy Bridge -EP4S processors set the RIPV and
- * EIPV bits in MCG_STATUS to zero on the affected logical processor (SDM
- * Vol 3B Table 15-20). But this confuses both the code that determines
- * whether the machine check occurred in kernel or user mode, and also
- * the severity assessment code. Pretend that EIPV was set, and take the
- * ip/cs values from the pt_regs that mce_gather_info() ignored earlier.
- */
-static void quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
-{
- if (bank != 0)
- return;
- if ((m->mcgstatus & (MCG_STATUS_EIPV|MCG_STATUS_RIPV)) != 0)
- return;
- if ((m->status & (MCI_STATUS_OVER|MCI_STATUS_UC|
- MCI_STATUS_EN|MCI_STATUS_MISCV|MCI_STATUS_ADDRV|
- MCI_STATUS_PCC|MCI_STATUS_S|MCI_STATUS_AR|
- MCACOD)) !=
- (MCI_STATUS_UC|MCI_STATUS_EN|
- MCI_STATUS_MISCV|MCI_STATUS_ADDRV|MCI_STATUS_S|
- MCI_STATUS_AR|MCACOD_INSTR))
- return;
-
- m->mcgstatus |= MCG_STATUS_EIPV;
- m->ip = regs->ip;
- m->cs = regs->cs;
-}
-
/* Add per CPU specific workarounds here */
static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
{
@@ -1793,7 +1791,7 @@ static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
cfg->bootlog = 0;

if (c->x86 == 6 && c->x86_model == 45)
- quirk_no_way_out = quirk_sandybridge_ifu;
+ mce_flags.snb_ifu_quirk = 1;
}

if (c->x86_vendor == X86_VENDOR_ZHAOXIN) {
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 1ad7b4bf5423..21865545cd3b 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -167,7 +167,10 @@ struct mce_vendor_flags {
/* Centaur Winchip C6-style MCA */
winchip : 1,

- __reserved_0 : 58;
+ /* SandyBridge IFU quirk */
+ snb_ifu_quirk : 1,
+
+ __reserved_0 : 57;
};

extern struct mce_vendor_flags mce_flags;
--
2.29.2