[PATCH 1/3] x86: axe the lightly-used cpu_has_pae

From: Dave Hansen
Date: Thu Sep 11 2014 - 17:15:33 EST



From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>

cpu_has_pae is only referenced in one place: the X86_32 kexec
code (in a file not even built on 64-bit). It hardly warrants
its own macro, or the trouble we go to ensuring that it can't
be called in X86_64 code.

Axe the macro and replace it with a direct cpu feature check.

Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Acked-by: Borislav Petkov <bp@xxxxxxx>
---

b/arch/x86/include/asm/cpufeature.h | 4 ----
b/arch/x86/kernel/machine_kexec_32.c | 3 ++-
2 files changed, 2 insertions(+), 5 deletions(-)

diff -puN arch/x86/include/asm/cpufeature.h~x86-axe-cpu_has_pae arch/x86/include/asm/cpufeature.h
--- a/arch/x86/include/asm/cpufeature.h~x86-axe-cpu_has_pae 2014-08-13 13:39:06.903716185 -0700
+++ b/arch/x86/include/asm/cpufeature.h 2014-08-13 13:39:19.610291207 -0700
@@ -300,7 +300,6 @@ extern const char * const x86_bug_flags[
#define cpu_has_de boot_cpu_has(X86_FEATURE_DE)
#define cpu_has_pse boot_cpu_has(X86_FEATURE_PSE)
#define cpu_has_tsc boot_cpu_has(X86_FEATURE_TSC)
-#define cpu_has_pae boot_cpu_has(X86_FEATURE_PAE)
#define cpu_has_pge boot_cpu_has(X86_FEATURE_PGE)
#define cpu_has_apic boot_cpu_has(X86_FEATURE_APIC)
#define cpu_has_sep boot_cpu_has(X86_FEATURE_SEP)
@@ -358,9 +357,6 @@ extern const char * const x86_bug_flags[
#undef cpu_has_vme
#define cpu_has_vme 0

-#undef cpu_has_pae
-#define cpu_has_pae ___BUG___
-
#undef cpu_has_k6_mtrr
#define cpu_has_k6_mtrr 0

diff -puN arch/x86/kernel/machine_kexec_32.c~x86-axe-cpu_has_pae arch/x86/kernel/machine_kexec_32.c
--- a/arch/x86/kernel/machine_kexec_32.c~x86-axe-cpu_has_pae 2014-08-13 13:39:06.905716275 -0700
+++ b/arch/x86/kernel/machine_kexec_32.c 2014-08-13 13:39:06.937717723 -0700
@@ -247,7 +247,8 @@ void machine_kexec(struct kimage *image)
/* now call it */
image->start = relocate_kernel_ptr((unsigned long)image->head,
(unsigned long)page_list,
- image->start, cpu_has_pae,
+ image->start,
+ boot_cpu_has(X86_FEATURE_PAE),
image->preserve_context);

#ifdef CONFIG_KEXEC_JUMP
_
--
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