Merge branch 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpufeature updates from Ingo Molnar:
 "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"

* 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Add more disabled features
  x86: Introduce disabled-features
  x86: Axe the lightly-used cpu_has_pae

6 files changed, 74 insertions, 29 deletions

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 094292a63e74..0bb1335313b2 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 */
 
@@ -282,6 +286,18 @@ 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))
@@ -290,6 +306,18 @@ 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))
@@ -304,11 +332,9 @@ 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)
@@ -324,9 +350,6 @@ 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)
@@ -361,25 +384,6 @@ 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 d8b1166c7888..ef58886ba61c 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1398,7 +1398,7 @@ 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