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Date: Mon, 13 Oct 2014 09:32:22 +0200
From: Ingo Molnar <mingo@...nel.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, "H. Peter Anvin" <hpa@...or.com>,
Thomas Gleixner <tglx@...utronix.de>,
Andrew Morton <akpm@...ux-foundation.org>
Subject: [GIT PULL] x86/cpufeature tree changes for v3.18
Linus,
Please pull the latest x86-cpufeature-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-cpufeature-for-linus
# HEAD: 9298b815efe500b272e4084ed05eeae7a92b5340 x86: Add more disabled features
This tree includes the following changes:
- Introduce DISABLED_MASK to list disabled CPU features, to
simplify CPU feature handling and avoid excessive #ifdefs
- Remove the lightly used cpu_has_pae() primitive
Thanks,
Ingo
------------------>
Dave Hansen (3):
x86: Axe the lightly-used cpu_has_pae
x86: Introduce disabled-features
x86: Add more disabled features
arch/x86/boot/mkcpustr.c | 1 +
arch/x86/include/asm/cpufeature.h | 52 +++++++++++++++++---------------
arch/x86/include/asm/disabled-features.h | 39 ++++++++++++++++++++++++
arch/x86/kernel/cpu/common.c | 2 +-
arch/x86/kernel/cpu/mtrr/main.c | 6 ++--
arch/x86/kernel/machine_kexec_32.c | 3 +-
6 files changed, 74 insertions(+), 29 deletions(-)
create mode 100644 arch/x86/include/asm/disabled-features.h
diff --git a/arch/x86/boot/mkcpustr.c b/arch/x86/boot/mkcpustr.c
index 4579eff0ef4d..637097e66a62 100644
--- a/arch/x86/boot/mkcpustr.c
+++ b/arch/x86/boot/mkcpustr.c
@@ -16,6 +16,7 @@
#include <stdio.h>
#include "../include/asm/required-features.h"
+#include "../include/asm/disabled-features.h"
#include "../include/asm/cpufeature.h"
#include "../kernel/cpu/capflags.c"
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index bb9b258d60e7..42db503b61fb 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -8,6 +8,10 @@
#include <asm/required-features.h>
#endif
+#ifndef _ASM_X86_DISABLED_FEATURES_H
+#include <asm/disabled-features.h>
+#endif
+
#define NCAPINTS 11 /* N 32-bit words worth of info */
#define NBUGINTS 1 /* N 32-bit bug flags */
@@ -274,6 +278,18 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
(((bit)>>5)==8 && (1UL<<((bit)&31) & REQUIRED_MASK8)) || \
(((bit)>>5)==9 && (1UL<<((bit)&31) & REQUIRED_MASK9)) )
+#define DISABLED_MASK_BIT_SET(bit) \
+ ( (((bit)>>5)==0 && (1UL<<((bit)&31) & DISABLED_MASK0)) || \
+ (((bit)>>5)==1 && (1UL<<((bit)&31) & DISABLED_MASK1)) || \
+ (((bit)>>5)==2 && (1UL<<((bit)&31) & DISABLED_MASK2)) || \
+ (((bit)>>5)==3 && (1UL<<((bit)&31) & DISABLED_MASK3)) || \
+ (((bit)>>5)==4 && (1UL<<((bit)&31) & DISABLED_MASK4)) || \
+ (((bit)>>5)==5 && (1UL<<((bit)&31) & DISABLED_MASK5)) || \
+ (((bit)>>5)==6 && (1UL<<((bit)&31) & DISABLED_MASK6)) || \
+ (((bit)>>5)==7 && (1UL<<((bit)&31) & DISABLED_MASK7)) || \
+ (((bit)>>5)==8 && (1UL<<((bit)&31) & DISABLED_MASK8)) || \
+ (((bit)>>5)==9 && (1UL<<((bit)&31) & DISABLED_MASK9)) )
+
#define cpu_has(c, bit) \
(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
test_cpu_cap(c, bit))
@@ -282,6 +298,18 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
x86_this_cpu_test_bit(bit, (unsigned long *)&cpu_info.x86_capability))
+/*
+ * This macro is for detection of features which need kernel
+ * infrastructure to be used. It may *not* directly test the CPU
+ * itself. Use the cpu_has() family if you want true runtime
+ * testing of CPU features, like in hypervisor code where you are
+ * supporting a possible guest feature where host support for it
+ * is not relevant.
+ */
+#define cpu_feature_enabled(bit) \
+ (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : \
+ cpu_has(&boot_cpu_data, bit))
+
#define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit)
#define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability))
@@ -296,11 +324,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
} while (0)
#define cpu_has_fpu boot_cpu_has(X86_FEATURE_FPU)
-#define cpu_has_vme boot_cpu_has(X86_FEATURE_VME)
#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)
@@ -316,9 +342,6 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
#define cpu_has_avx2 boot_cpu_has(X86_FEATURE_AVX2)
#define cpu_has_ht boot_cpu_has(X86_FEATURE_HT)
#define cpu_has_nx boot_cpu_has(X86_FEATURE_NX)
-#define cpu_has_k6_mtrr boot_cpu_has(X86_FEATURE_K6_MTRR)
-#define cpu_has_cyrix_arr boot_cpu_has(X86_FEATURE_CYRIX_ARR)
-#define cpu_has_centaur_mcr boot_cpu_has(X86_FEATURE_CENTAUR_MCR)
#define cpu_has_xstore boot_cpu_has(X86_FEATURE_XSTORE)
#define cpu_has_xstore_enabled boot_cpu_has(X86_FEATURE_XSTORE_EN)
#define cpu_has_xcrypt boot_cpu_has(X86_FEATURE_XCRYPT)
@@ -353,25 +376,6 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
#define cpu_has_eager_fpu boot_cpu_has(X86_FEATURE_EAGER_FPU)
#define cpu_has_topoext boot_cpu_has(X86_FEATURE_TOPOEXT)
-#ifdef CONFIG_X86_64
-
-#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
-
-#undef cpu_has_cyrix_arr
-#define cpu_has_cyrix_arr 0
-
-#undef cpu_has_centaur_mcr
-#define cpu_has_centaur_mcr 0
-
-#endif /* CONFIG_X86_64 */
-
#if __GNUC__ >= 4
extern void warn_pre_alternatives(void);
extern bool __static_cpu_has_safe(u16 bit);
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
new file mode 100644
index 000000000000..97534a7d38e3
--- /dev/null
+++ b/arch/x86/include/asm/disabled-features.h
@@ -0,0 +1,39 @@
+#ifndef _ASM_X86_DISABLED_FEATURES_H
+#define _ASM_X86_DISABLED_FEATURES_H
+
+/* These features, although they might be available in a CPU
+ * will not be used because the compile options to support
+ * them are not present.
+ *
+ * This code allows them to be checked and disabled at
+ * compile time without an explicit #ifdef. Use
+ * cpu_feature_enabled().
+ */
+
+#ifdef CONFIG_X86_64
+# define DISABLE_VME (1<<(X86_FEATURE_VME & 31))
+# define DISABLE_K6_MTRR (1<<(X86_FEATURE_K6_MTRR & 31))
+# define DISABLE_CYRIX_ARR (1<<(X86_FEATURE_CYRIX_ARR & 31))
+# define DISABLE_CENTAUR_MCR (1<<(X86_FEATURE_CENTAUR_MCR & 31))
+#else
+# define DISABLE_VME 0
+# define DISABLE_K6_MTRR 0
+# define DISABLE_CYRIX_ARR 0
+# define DISABLE_CENTAUR_MCR 0
+#endif /* CONFIG_X86_64 */
+
+/*
+ * Make sure to add features to the correct mask
+ */
+#define DISABLED_MASK0 (DISABLE_VME)
+#define DISABLED_MASK1 0
+#define DISABLED_MASK2 0
+#define DISABLED_MASK3 (DISABLE_CYRIX_ARR|DISABLE_CENTAUR_MCR|DISABLE_K6_MTRR)
+#define DISABLED_MASK4 0
+#define DISABLED_MASK5 0
+#define DISABLED_MASK6 0
+#define DISABLED_MASK7 0
+#define DISABLED_MASK8 0
+#define DISABLED_MASK9 0
+
+#endif /* _ASM_X86_DISABLED_FEATURES_H */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index e4ab2b42bd6f..724d221107eb 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1391,7 +1391,7 @@ void cpu_init(void)
printk(KERN_INFO "Initializing CPU#%d\n", cpu);
- if (cpu_has_vme || cpu_has_tsc || cpu_has_de)
+ if (cpu_feature_enabled(X86_FEATURE_VME) || cpu_has_tsc || cpu_has_de)
clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
load_current_idt();
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index f961de9964c7..ea5f363a1948 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -707,7 +707,7 @@ void __init mtrr_bp_init(void)
} else {
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
- if (cpu_has_k6_mtrr) {
+ if (cpu_feature_enabled(X86_FEATURE_K6_MTRR)) {
/* Pre-Athlon (K6) AMD CPU MTRRs */
mtrr_if = mtrr_ops[X86_VENDOR_AMD];
size_or_mask = SIZE_OR_MASK_BITS(32);
@@ -715,14 +715,14 @@ void __init mtrr_bp_init(void)
}
break;
case X86_VENDOR_CENTAUR:
- if (cpu_has_centaur_mcr) {
+ if (cpu_feature_enabled(X86_FEATURE_CENTAUR_MCR)) {
mtrr_if = mtrr_ops[X86_VENDOR_CENTAUR];
size_or_mask = SIZE_OR_MASK_BITS(32);
size_and_mask = 0;
}
break;
case X86_VENDOR_CYRIX:
- if (cpu_has_cyrix_arr) {
+ if (cpu_feature_enabled(X86_FEATURE_CYRIX_ARR)) {
mtrr_if = mtrr_ops[X86_VENDOR_CYRIX];
size_or_mask = SIZE_OR_MASK_BITS(32);
size_and_mask = 0;
diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c
index 1667b1de8d5d..72e8e310258d 100644
--- a/arch/x86/kernel/machine_kexec_32.c
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -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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