x86: Add more disabled features

The original motivation for these patches was for an Intel CPU
feature called MPX.  The patch to add a disabled feature for it
will go in with the other parts of the support.

But, in the meantime, there are a few other features than MPX
that we can make assumptions about at compile-time based on
compile options.  Add them to disabled-features.h and check them
with cpu_feature_enabled().

Note that this gets rid of the last things that needed an #ifdef
CONFIG_X86_64 in cpufeature.h.  Yay!

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: http://lkml.kernel.org/r/20140911211524.C0EC332A@viggo.jf.intel.com
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 1492041..42db503 100644 (file)
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -324,7 +324,6 @@ 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)
@@ -343,9 +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)
@@ -380,22 +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_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
index 1a9955d..97534a7 100644 (file)
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -10,13 +10,25 @@
  * 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 0
+#define DISABLED_MASK0 (DISABLE_VME)
 #define DISABLED_MASK1 0
 #define DISABLED_MASK2 0
-#define DISABLED_MASK3 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

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index e4ab2b4..724d221 100644 (file)
--- 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 f961de9..ea5f363 100644 (file)
--- 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;