[PATCH 3/6] x86/mce: Create helper function to save addr/misc when needed

From: Tony Luck
Date: Tue Jan 03 2012 - 15:21:48 EST


The MCI_STATUS_MISCV and MCI_STATUS_ADDRV bits in the bank status
registers define whether the MISC and ADDR registers respectively
contain valid data - provide a helper function to check these bits
and read the registers when needed.

In addition, processors that support software error recovery (as
indicated by the MCG_SER_P bit in the MCG_CAP register) may include
some undefined bits in the ADDR register - mask these out.

Acked-by: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
arch/x86/kernel/cpu/mcheck/mce.c | 31 +++++++++++++++++++++++--------
1 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 1a08ce5..2f1c200 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -492,6 +492,27 @@ static void mce_report_event(struct pt_regs *regs)
irq_work_queue(&__get_cpu_var(mce_irq_work));
}

+/*
+ * Read ADDR and MISC registers.
+ */
+static void mce_read_aux(struct mce *m, int i)
+{
+ if (m->status & MCI_STATUS_MISCV)
+ m->misc = mce_rdmsrl(MSR_IA32_MCx_MISC(i));
+ if (m->status & MCI_STATUS_ADDRV) {
+ m->addr = mce_rdmsrl(MSR_IA32_MCx_ADDR(i));
+
+ /*
+ * Mask the reported address by the reported granularity.
+ */
+ if (mce_ser && (m->status & MCI_STATUS_MISCV)) {
+ u8 shift = MCI_MISC_ADDR_LSB(m->misc);
+ m->addr >>= shift;
+ m->addr <<= shift;
+ }
+ }
+}
+
DEFINE_PER_CPU(unsigned, mce_poll_count);

/*
@@ -542,10 +563,7 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
(m.status & (mce_ser ? MCI_STATUS_S : MCI_STATUS_UC)))
continue;

- if (m.status & MCI_STATUS_MISCV)
- m.misc = mce_rdmsrl(MSR_IA32_MCx_MISC(i));
- if (m.status & MCI_STATUS_ADDRV)
- m.addr = mce_rdmsrl(MSR_IA32_MCx_ADDR(i));
+ mce_read_aux(&m, i);

if (!(flags & MCP_TIMESTAMP))
m.tsc = 0;
@@ -981,10 +999,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
if (severity == MCE_AR_SEVERITY)
kill_it = 1;

- if (m.status & MCI_STATUS_MISCV)
- m.misc = mce_rdmsrl(MSR_IA32_MCx_MISC(i));
- if (m.status & MCI_STATUS_ADDRV)
- m.addr = mce_rdmsrl(MSR_IA32_MCx_ADDR(i));
+ mce_read_aux(&m, i);

/*
* Action optional error. Queue address for later processing.
--
1.7.3.1

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