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Message-Id: <20161208162150.148763-17-kirill.shutemov@linux.intel.com>
Date: Thu, 8 Dec 2016 19:21:37 +0300
From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To: Linus Torvalds <torvalds@...ux-foundation.org>,
Andrew Morton <akpm@...ux-foundation.org>, x86@...nel.org,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Arnd Bergmann <arnd@...db.de>,
"H. Peter Anvin" <hpa@...or.com>
Cc: Andi Kleen <ak@...ux.intel.com>,
Dave Hansen <dave.hansen@...el.com>,
Andy Lutomirski <luto@...capital.net>,
linux-arch@...r.kernel.org, linux-mm@...ck.org,
linux-kernel@...r.kernel.org,
"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [RFC, PATCHv1 15/28] x86: detect 5-level paging support
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 <kirill.shutemov@...ux.intel.com>
---
arch/x86/boot/cpucheck.c | 9 +++++++++
arch/x86/boot/cpuflags.c | 16 ++++++++++++++++
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/disabled-features.h | 8 +++++++-
arch/x86/include/asm/required-features.h | 8 +++++++-
5 files changed, 40 insertions(+), 2 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..26e9a287805f 100644
--- a/arch/x86/boot/cpuflags.c
+++ b/arch/x86/boot/cpuflags.c
@@ -80,6 +80,17 @@ 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), "c" (count)
+ );
+}
+
void get_cpuflags(void)
{
u32 max_intel_level, max_amd_level;
@@ -108,6 +119,11 @@ 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/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 92a8308b96f6..388f1277880f 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -280,6 +280,7 @@
/* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx), word 16 */
#define X86_FEATURE_PKU (16*32+ 3) /* Protection Keys for Userspace */
#define X86_FEATURE_OSPKE (16*32+ 4) /* OS Protection Keys Enable */
+#define X86_FEATURE_LA57 (16*32+16) /* 5-level page tables */
/* AMD-defined CPU features, CPUID level 0x80000007 (ebx), word 17 */
#define X86_FEATURE_OVERFLOW_RECOV (17*32+0) /* MCA overflow recovery support */
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)
--
2.10.2
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