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Date: Mon, 18 Aug 2008 12:33:21 +0200
From: Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>
To: mingo@...e.hu
Cc: linux-kernel@...r.kernel.org, linux-embedded@...r.kernel.org,
tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
michael@...e-electrons.com, thomas.petazzoni@...e-electrons.com
Subject: [PATCH] [x86] Move cmpxchg fallbacks to a generic place
arch/x86/kernel/cpu/intel.c defines a few fallback functions
(cmpxchg_*()) that are used when the CPU doesn't support cmpxchg
and/or cmpxchg64 natively. However, while defined in an Intel-specific
file, these functions are also used for CPUs from other vendors when
they don't support cmpxchg and/or cmpxchg64. This breaks the
compilation when support for Intel CPUs is disabled.
This patch moves these functions to a new
arch/x86/kernel/cpu/cmpxchg.c file, unconditionally compiled when
X86_32 is enabled.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>
---
arch/x86/kernel/cpu/Makefile | 2 +-
arch/x86/kernel/cpu/cmpxchg.c | 72 +++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/cpu/intel.c | 64 ------------------------------------
3 files changed, 73 insertions(+), 65 deletions(-)
create mode 100644 arch/x86/kernel/cpu/cmpxchg.c
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index a35ee92..a0fc6c1 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -5,7 +5,7 @@
obj-y := intel_cacheinfo.o addon_cpuid_features.o
obj-y += proc.o feature_names.o
-obj-$(CONFIG_X86_32) += common.o bugs.o
+obj-$(CONFIG_X86_32) += common.o bugs.o cmpxchg.o
obj-$(CONFIG_X86_64) += common_64.o bugs_64.o
obj-$(CONFIG_CPU_SUP_AMD_32) += amd.o
diff --git a/arch/x86/kernel/cpu/cmpxchg.c b/arch/x86/kernel/cpu/cmpxchg.c
new file mode 100644
index 0000000..2056ccf
--- /dev/null
+++ b/arch/x86/kernel/cpu/cmpxchg.c
@@ -0,0 +1,72 @@
+/*
+ * cmpxchg*() fallbacks for CPU not supporting these instructions
+ */
+
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/module.h>
+
+#ifndef CONFIG_X86_CMPXCHG
+unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
+{
+ u8 prev;
+ unsigned long flags;
+
+ /* Poor man's cmpxchg for 386. Unsuitable for SMP */
+ local_irq_save(flags);
+ prev = *(u8 *)ptr;
+ if (prev == old)
+ *(u8 *)ptr = new;
+ local_irq_restore(flags);
+ return prev;
+}
+EXPORT_SYMBOL(cmpxchg_386_u8);
+
+unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
+{
+ u16 prev;
+ unsigned long flags;
+
+ /* Poor man's cmpxchg for 386. Unsuitable for SMP */
+ local_irq_save(flags);
+ prev = *(u16 *)ptr;
+ if (prev == old)
+ *(u16 *)ptr = new;
+ local_irq_restore(flags);
+ return prev;
+}
+EXPORT_SYMBOL(cmpxchg_386_u16);
+
+unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
+{
+ u32 prev;
+ unsigned long flags;
+
+ /* Poor man's cmpxchg for 386. Unsuitable for SMP */
+ local_irq_save(flags);
+ prev = *(u32 *)ptr;
+ if (prev == old)
+ *(u32 *)ptr = new;
+ local_irq_restore(flags);
+ return prev;
+}
+EXPORT_SYMBOL(cmpxchg_386_u32);
+#endif
+
+#ifndef CONFIG_X86_CMPXCHG64
+unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
+{
+ u64 prev;
+ unsigned long flags;
+
+ /* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
+ local_irq_save(flags);
+ prev = *(u64 *)ptr;
+ if (prev == old)
+ *(u64 *)ptr = new;
+ local_irq_restore(flags);
+ return prev;
+}
+EXPORT_SYMBOL(cmpxchg_486_u64);
+#endif
+
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 5c8959b..77618c7 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -307,69 +307,5 @@ static struct cpu_dev intel_cpu_dev __cpuinitdata = {
cpu_vendor_dev_register(X86_VENDOR_INTEL, &intel_cpu_dev);
-#ifndef CONFIG_X86_CMPXCHG
-unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
-{
- u8 prev;
- unsigned long flags;
-
- /* Poor man's cmpxchg for 386. Unsuitable for SMP */
- local_irq_save(flags);
- prev = *(u8 *)ptr;
- if (prev == old)
- *(u8 *)ptr = new;
- local_irq_restore(flags);
- return prev;
-}
-EXPORT_SYMBOL(cmpxchg_386_u8);
-
-unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
-{
- u16 prev;
- unsigned long flags;
-
- /* Poor man's cmpxchg for 386. Unsuitable for SMP */
- local_irq_save(flags);
- prev = *(u16 *)ptr;
- if (prev == old)
- *(u16 *)ptr = new;
- local_irq_restore(flags);
- return prev;
-}
-EXPORT_SYMBOL(cmpxchg_386_u16);
-
-unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
-{
- u32 prev;
- unsigned long flags;
-
- /* Poor man's cmpxchg for 386. Unsuitable for SMP */
- local_irq_save(flags);
- prev = *(u32 *)ptr;
- if (prev == old)
- *(u32 *)ptr = new;
- local_irq_restore(flags);
- return prev;
-}
-EXPORT_SYMBOL(cmpxchg_386_u32);
-#endif
-
-#ifndef CONFIG_X86_CMPXCHG64
-unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
-{
- u64 prev;
- unsigned long flags;
-
- /* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
- local_irq_save(flags);
- prev = *(u64 *)ptr;
- if (prev == old)
- *(u64 *)ptr = new;
- local_irq_restore(flags);
- return prev;
-}
-EXPORT_SYMBOL(cmpxchg_486_u64);
-#endif
-
/* arch_initcall(intel_cpu_init); */
--
1.5.4.3
--
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