[PATCH 13/26] x86: detect 5-level paging support
From: Kirill A. Shutemov <hidden>
Date: 2017-03-13 05:52:01
Also in:
linux-mm, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
5-level paging support is required from hardware when compiled with CONFIG_X86_5LEVEL=y. We may implement runtime switch support later. Signed-off-by: Kirill A. Shutemov <redacted> --- arch/x86/boot/cpucheck.c | 9 +++++++++ arch/x86/boot/cpuflags.c | 12 ++++++++++-- arch/x86/include/asm/disabled-features.h | 8 +++++++- arch/x86/include/asm/required-features.h | 8 +++++++- 4 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/arch/x86/boot/cpucheck.c b/arch/x86/boot/cpucheck.c
index 4ad7d70e8739..8f0c4c9fc904 100644
--- a/arch/x86/boot/cpucheck.c
+++ b/arch/x86/boot/cpucheck.c@@ -44,6 +44,15 @@ static const u32 req_flags[NCAPINTS] = 0, /* REQUIRED_MASK5 not implemented in this file */ REQUIRED_MASK6, 0, /* REQUIRED_MASK7 not implemented in this file */ + 0, /* REQUIRED_MASK8 not implemented in this file */ + 0, /* REQUIRED_MASK9 not implemented in this file */ + 0, /* REQUIRED_MASK10 not implemented in this file */ + 0, /* REQUIRED_MASK11 not implemented in this file */ + 0, /* REQUIRED_MASK12 not implemented in this file */ + 0, /* REQUIRED_MASK13 not implemented in this file */ + 0, /* REQUIRED_MASK14 not implemented in this file */ + 0, /* REQUIRED_MASK15 not implemented in this file */ + REQUIRED_MASK16, }; #define A32(a, b, c, d) (((d) << 24)+((c) << 16)+((b) << 8)+(a))
diff --git a/arch/x86/boot/cpuflags.c b/arch/x86/boot/cpuflags.c
index 6687ab953257..9e77c23c2422 100644
--- a/arch/x86/boot/cpuflags.c
+++ b/arch/x86/boot/cpuflags.c@@ -70,16 +70,19 @@ int has_eflag(unsigned long mask) # define EBX_REG "=b" #endif -static inline void cpuid(u32 id, u32 *a, u32 *b, u32 *c, u32 *d) +static inline void cpuid_count(u32 id, u32 count, + u32 *a, u32 *b, u32 *c, u32 *d) { asm volatile(".ifnc %%ebx,%3 ; movl %%ebx,%3 ; .endif \n\t" "cpuid \n\t" ".ifnc %%ebx,%3 ; xchgl %%ebx,%3 ; .endif \n\t" : "=a" (*a), "=c" (*c), "=d" (*d), EBX_REG (*b) - : "a" (id) + : "a" (id), "c" (count) ); } +#define cpuid(id, a, b, c, d) cpuid_count(id, 0, a, b, c, d) + void get_cpuflags(void) { u32 max_intel_level, max_amd_level;
@@ -108,6 +111,11 @@ void get_cpuflags(void) cpu.model += ((tfms >> 16) & 0xf) << 4; } + if (max_intel_level >= 0x00000007) { + cpuid_count(0x00000007, 0, &ignored, &ignored, + &cpu.flags[16], &ignored); + } + cpuid(0x80000000, &max_amd_level, &ignored, &ignored, &ignored);
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index 85599ad4d024..fc0960236fc3 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h@@ -36,6 +36,12 @@ # define DISABLE_OSPKE (1<<(X86_FEATURE_OSPKE & 31)) #endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */ +#ifdef CONFIG_X86_5LEVEL +#define DISABLE_LA57 0 +#else +#define DISABLE_LA57 (1<<(X86_FEATURE_LA57 & 31)) +#endif + /* * Make sure to add features to the correct mask */
@@ -55,7 +61,7 @@ #define DISABLED_MASK13 0 #define DISABLED_MASK14 0 #define DISABLED_MASK15 0 -#define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE) +#define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57) #define DISABLED_MASK17 0 #define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 18)
diff --git a/arch/x86/include/asm/required-features.h b/arch/x86/include/asm/required-features.h
index fac9a5c0abe9..d91ba04dd007 100644
--- a/arch/x86/include/asm/required-features.h
+++ b/arch/x86/include/asm/required-features.h@@ -53,6 +53,12 @@ # define NEED_MOVBE 0 #endif +#ifdef CONFIG_X86_5LEVEL +# define NEED_LA57 (1<<(X86_FEATURE_LA57 & 31)) +#else +# define NEED_LA57 0 +#endif + #ifdef CONFIG_X86_64 #ifdef CONFIG_PARAVIRT /* Paravirtualized systems may not have PSE or PGE available */
@@ -98,7 +104,7 @@ #define REQUIRED_MASK13 0 #define REQUIRED_MASK14 0 #define REQUIRED_MASK15 0 -#define REQUIRED_MASK16 0 +#define REQUIRED_MASK16 (NEED_LA57) #define REQUIRED_MASK17 0 #define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 18)
--
2.11.0
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