x86_64: add pseudo-features for 32-bit compat syscall
Add pseudo-feature bits to describe whether the CPU supports sysenter
and/or syscall from ia32-compat userspace. This removes a hardcoded
test in vdso32-setup.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/cpu/centaur_64.c b/arch/x86/kernel/cpu/centaur_64.c
index 13526fd..2026d21 100644
--- a/arch/x86/kernel/cpu/centaur_64.c
+++ b/arch/x86/kernel/cpu/centaur_64.c
@@ -10,6 +10,8 @@
{
if (c->x86 == 0x6 && c->x86_model >= 0xf)
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
+
+ set_cpu_cap(c, X86_FEATURE_SYSENTER32);
}
static void __cpuinit init_centaur(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kernel/cpu/common_64.c b/arch/x86/kernel/cpu/common_64.c
index 7518502..36537ab 100644
--- a/arch/x86/kernel/cpu/common_64.c
+++ b/arch/x86/kernel/cpu/common_64.c
@@ -314,6 +314,9 @@
if (c->extended_cpuid_level >= 0x80000007)
c->x86_power = cpuid_edx(0x80000007);
+ /* Assume all 64-bit CPUs support 32-bit syscall */
+ set_cpu_cap(c, X86_FEATURE_SYSCALL32);
+
if (c->x86_vendor != X86_VENDOR_UNKNOWN &&
cpu_devs[c->x86_vendor]->c_early_init)
cpu_devs[c->x86_vendor]->c_early_init(c);
diff --git a/arch/x86/kernel/cpu/intel_64.c b/arch/x86/kernel/cpu/intel_64.c
index fcb1cc9..02f7733 100644
--- a/arch/x86/kernel/cpu/intel_64.c
+++ b/arch/x86/kernel/cpu/intel_64.c
@@ -12,6 +12,8 @@
if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
(c->x86 == 0x6 && c->x86_model >= 0x0e))
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
+
+ set_cpu_cap(c, X86_FEATURE_SYSENTER32);
}
/*
diff --git a/include/asm-x86/cpufeature.h b/include/asm-x86/cpufeature.h
index 84a56da..75ef959 100644
--- a/include/asm-x86/cpufeature.h
+++ b/include/asm-x86/cpufeature.h
@@ -74,8 +74,8 @@
#define X86_FEATURE_ARCH_PERFMON (3*32+11) /* Intel Architectural PerfMon */
#define X86_FEATURE_PEBS (3*32+12) /* Precise-Event Based Sampling */
#define X86_FEATURE_BTS (3*32+13) /* Branch Trace Store */
-/* 14 free */
-/* 15 free */
+#define X86_FEATURE_SYSCALL32 (3*32+14) /* syscall in ia32 userspace */
+#define X86_FEATURE_SYSENTER32 (3*32+15) /* sysenter in ia32 userspace */
#define X86_FEATURE_REP_GOOD (3*32+16) /* rep microcode works well on this CPU */
#define X86_FEATURE_MFENCE_RDTSC (3*32+17) /* Mfence synchronizes RDTSC */
#define X86_FEATURE_LFENCE_RDTSC (3*32+18) /* Lfence synchronizes RDTSC */