x86/cpufeature: Make sure DISABLED/REQUIRED macros are updated

x86 has two macros which allow us to evaluate some CPUID-based
features at compile time:

	REQUIRED_MASK_BIT_SET()
	DISABLED_MASK_BIT_SET()

They're both defined by having the compiler check the bit
argument against some constant masks of features.

But, when adding new CPUID leaves, we need to check new words
for these macros.  So make sure that those macros and the
REQUIRED_MASK* and DISABLED_MASK* get updated when necessary.

This looks kinda silly to have an open-coded value ("18" in
this case) open-coded in 5 places in the code.  But, we really do
need 5 places updated when NCAPINTS gets bumped, so now we just
force the issue.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160629200108.92466F6F@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index ec8100459afe7727c16497fba9811e08a647635e..7b20720db3fa5e3e7be3f7b08bd5638033bd3751 100644 (file)
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -67,7 +67,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
           (((bit)>>5)==14 && (1UL<<((bit)&31) & REQUIRED_MASK14)) ||   \
           (((bit)>>5)==15 && (1UL<<((bit)&31) & REQUIRED_MASK15)) ||   \
           (((bit)>>5)==16 && (1UL<<((bit)&31) & REQUIRED_MASK16)) ||   \
-          (((bit)>>5)==17 && (1UL<<((bit)&31) & REQUIRED_MASK17)))
+          (((bit)>>5)==17 && (1UL<<((bit)&31) & REQUIRED_MASK17)) ||   \
+          REQUIRED_MASK_CHECK                                     ||   \
+          BUILD_BUG_ON_ZERO(NCAPINTS != 18))
 
 #define DISABLED_MASK_BIT_SET(bit)                                     \
         ( (((bit)>>5)==0  && (1UL<<((bit)&31) & DISABLED_MASK0 )) ||   \
@@ -87,7 +89,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
           (((bit)>>5)==14 && (1UL<<((bit)&31) & DISABLED_MASK14)) ||   \
           (((bit)>>5)==15 && (1UL<<((bit)&31) & DISABLED_MASK15)) ||   \
           (((bit)>>5)==16 && (1UL<<((bit)&31) & DISABLED_MASK16)) ||   \
-          (((bit)>>5)==17 && (1UL<<((bit)&31) & DISABLED_MASK17)))
+          (((bit)>>5)==17 && (1UL<<((bit)&31) & DISABLED_MASK17)) ||   \
+          DISABLED_MASK_CHECK                                     ||   \
+          BUILD_BUG_ON_ZERO(NCAPINTS != 18))
 
 #define cpu_has(c, bit)                                                        \
        (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :  \

diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index 5627f8cb9706911622642983c5c4767f5a775713..85599ad4d0247863cef655d02b9a4b3f83c77fb7 100644 (file)
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -57,5 +57,6 @@
 #define DISABLED_MASK15        0
 #define DISABLED_MASK16        (DISABLE_PKU|DISABLE_OSPKE)
 #define DISABLED_MASK17        0
+#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 18)
 
 #endif /* _ASM_X86_DISABLED_FEATURES_H */

diff --git a/arch/x86/include/asm/required-features.h b/arch/x86/include/asm/required-features.h
index fad4277d582e90014f7a8249e228c49b751689f6..fac9a5c0abe94b233b72b35bca8c7a665847b694 100644 (file)
--- a/arch/x86/include/asm/required-features.h
+++ b/arch/x86/include/asm/required-features.h
@@ -100,5 +100,6 @@
 #define REQUIRED_MASK15        0
 #define REQUIRED_MASK16        0
 #define REQUIRED_MASK17        0
+#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 18)
 
 #endif /* _ASM_X86_REQUIRED_FEATURES_H */