[PATCH] [14/28] x86: MCE: Add MSR read wrappers for easier error injection

From: Andi Kleen
Date: Tue Apr 07 2009 - 11:14:10 EST



This will be used by future patches to allow machine check error injection.
Right now it's a nop, except for adding some wrappers around the MSR reads.

This is early in the sequence to avoid too many conflicts.

Andi Kleen <ak@xxxxxxxxxxxxxxx>


Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

---
arch/x86/kernel/cpu/mcheck/mce_64.c | 37 ++++++++++++++++++++++++------------
1 file changed, 25 insertions(+), 12 deletions(-)

Index: linux/arch/x86/kernel/cpu/mcheck/mce_64.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/mcheck/mce_64.c 2009-04-07 16:09:59.000000000 +0200
+++ linux/arch/x86/kernel/cpu/mcheck/mce_64.c 2009-04-07 16:43:12.000000000 +0200
@@ -171,6 +171,19 @@
panic(msg);
}

+/* MSR access wrappers used for error injection */
+static u64 mce_rdmsrl(u32 msr)
+{
+ u64 v;
+ rdmsrl(msr, v);
+ return v;
+}
+
+static void mce_wrmsrl(u32 msr, u64 v)
+{
+ wrmsrl(msr, v);
+}
+
int mce_available(struct cpuinfo_x86 *c)
{
if (mce_dont_init)
@@ -188,7 +201,7 @@
m->cs = 0;
}
if (rip_msr)
- rdmsrl(rip_msr, m->ip);
+ m->ip = mce_rdmsrl(rip_msr);
}

/*
@@ -250,7 +263,7 @@

mce_setup(&m);

- rdmsrl(MSR_IA32_MCG_STATUS, m.mcgstatus);
+ m.mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS);
for (i = 0; i < banks; i++) {
if (!bank[i] || !test_bit(i, *b))
continue;
@@ -261,7 +274,7 @@
m.tsc = 0;

barrier();
- rdmsrl(MSR_IA32_MC0_STATUS + i*4, m.status);
+ m.status = mce_rdmsrl(MSR_IA32_MC0_STATUS + i*4);
if (!(m.status & MCI_STATUS_VAL))
continue;

@@ -276,9 +289,9 @@
continue;

if (m.status & MCI_STATUS_MISCV)
- rdmsrl(MSR_IA32_MC0_MISC + i*4, m.misc);
+ m.misc = mce_rdmsrl(MSR_IA32_MC0_MISC + i*4);
if (m.status & MCI_STATUS_ADDRV)
- rdmsrl(MSR_IA32_MC0_ADDR + i*4, m.addr);
+ m.addr = mce_rdmsrl(MSR_IA32_MC0_ADDR + i*4);

if (!(flags & MCP_TIMESTAMP))
m.tsc = 0;
@@ -294,7 +307,7 @@
/*
* Clear state for this bank.
*/
- wrmsrl(MSR_IA32_MC0_STATUS+4*i, 0);
+ mce_wrmsrl(MSR_IA32_MC0_STATUS+4*i, 0);
}

/*
@@ -342,8 +355,8 @@
goto out;

mce_setup(&m);
+ m.mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS);

- rdmsrl(MSR_IA32_MCG_STATUS, m.mcgstatus);
/* if the restart IP is not valid, we're done for */
if (!(m.mcgstatus & MCG_STATUS_RIPV))
no_way_out = 1;
@@ -360,7 +373,7 @@
m.addr = 0;
m.bank = i;

- rdmsrl(MSR_IA32_MC0_STATUS + i*4, m.status);
+ m.status = mce_rdmsrl(MSR_IA32_MC0_STATUS + i*4);
if ((m.status & MCI_STATUS_VAL) == 0)
continue;

@@ -400,9 +413,9 @@
}

if (m.status & MCI_STATUS_MISCV)
- rdmsrl(MSR_IA32_MC0_MISC + i*4, m.misc);
+ m.misc = mce_rdmsrl(MSR_IA32_MC0_MISC + i*4);
if (m.status & MCI_STATUS_ADDRV)
- rdmsrl(MSR_IA32_MC0_ADDR + i*4, m.addr);
+ m.addr = mce_rdmsrl(MSR_IA32_MC0_ADDR + i*4);

mce_get_rip(&m, regs);
mce_log(&m);
@@ -467,9 +480,9 @@
/* the last thing we do is clear state */
for (i = 0; i < banks; i++) {
if (test_bit(i, toclear))
- wrmsrl(MSR_IA32_MC0_STATUS+4*i, 0);
+ mce_wrmsrl(MSR_IA32_MC0_STATUS+4*i, 0);
}
- wrmsrl(MSR_IA32_MCG_STATUS, 0);
+ mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);
out:
atomic_dec(&mce_entry);
sync_core();
--
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