[tip:x86/mtrr] x86: fix get_mtrr() warning about smp_processor_id() with CONFIG_PREEMPT=y

Yinghai Lu
2009-03-14T11:41:21Z

Commit-ID: 63516ef6d6a8379ee5c32463efc6a75f9da8a309
Gitweb: http://git.kernel.org/tip/63516ef6d6a8379ee5c32463efc6a75f9da8a309
Author: Yinghai Lu <yinghai@kernel.org>
AuthorDate: Fri, 13 Mar 2009 12:46:07 -0700
Commit: Ingo Molnar <mingo@elte.hu>
CommitDate: Sat, 14 Mar 2009 12:27:06 +0100

x86: fix get_mtrr() warning about smp_processor_id() with CONFIG_PREEMPT=y

Impact: fix debug warning

Jaswinder noticed that there is a warning about smp_processor_id()
in get_mtrr().

Fix it by wrapping the printout into a get/put_cpu() pair.

Reported-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <49BAB7FF.4030107@kernel.org>
[ changed to get/put_cpu(), cleaned up surrounding code a it. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
arch/x86/kernel/cpu/mtrr/generic.c | 20 ++++++++++++++------
1 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index 950c434..641ee35 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -381,11 +381,14 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base,
{
unsigned int mask_lo, mask_hi, base_lo, base_hi;
unsigned int tmp, hi;
+ int cpu;

/*
* get_mtrr doesn't need to update mtrr_state, also it could be called
* from any cpu, so try to print it out directly.
*/
+ cpu = get_cpu();
+
rdmsr(MTRRphysMask_MSR(reg), mask_lo, mask_hi);

if ((mask_lo & 0x800) == 0) {
@@ -393,15 +396,16 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base,
*base = 0;
*size = 0;
*type = 0;
- return;
+ goto out_put_cpu;
}

rdmsr(MTRRphysBase_MSR(reg), base_lo, base_hi);

- /* Work out the shifted address mask. */
+ /* Work out the shifted address mask: */
tmp = mask_hi << (32 - PAGE_SHIFT) | mask_lo >> PAGE_SHIFT;
mask_lo = size_or_mask | tmp;
- /* Expand tmp with high bits to all 1s*/
+
+ /* Expand tmp with high bits to all 1s: */
hi = fls(tmp);
if (hi > 0) {
tmp |= ~((1<<(hi - 1)) - 1);
@@ -412,15 +416,19 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base,
}
}

- /* This works correctly if size is a power of two, i.e. a
- contiguous range. */
+ /*
+ * This works correctly if size is a power of two, i.e. a
+ * contiguous range:
+ */
*size = -mask_lo;
*base = base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT;
*type = base_lo & 0xff;

printk(KERN_DEBUG " get_mtrr: cpu%d reg%02d base=%010lx size=%010lx %s\n",
- smp_processor_id(), reg, *base, *size,
+ cpu, reg, *base, *size,
mtrr_attrib_to_str(*type & 0xff));
+out_put_cpu:
+ put_cpu();
}

/**