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authorPawan Gupta <pawan.kumar.gupta@linux.intel.com>2019-10-23 10:52:35 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-11-16 10:27:50 +0100
commit725afc0d60cf8b9e3bf023920c881f4a4261dc49 (patch)
treedb1dac504258489227bd40fd674fa26488af643f /arch/x86/kernel/cpu/common.c
parent124635392ef394772850172bd5370e62cfe781b4 (diff)
x86/cpu: Add a helper function x86_read_arch_cap_msr()
commit 286836a70433fb64131d2590f4bf512097c255e1 upstream. Add a helper function to read the IA32_ARCH_CAPABILITIES MSR. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Neelima Krishnan <neelima.krishnan@intel.com> Reviewed-by: Mark Gross <mgross@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
-rw-r--r--arch/x86/kernel/cpu/common.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 3965235973c8..ef8c98bc775c 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -918,19 +918,26 @@ static bool __init cpu_matches(unsigned long which)
return m && !!(m->driver_data & which);
}
-static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
+u64 x86_read_arch_cap_msr(void)
{
u64 ia32_cap = 0;
+ if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES))
+ rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
+
+ return ia32_cap;
+}
+
+static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
+{
+ u64 ia32_cap = x86_read_arch_cap_msr();
+
if (cpu_matches(NO_SPECULATION))
return;
setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
- if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
- rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
-
if (!cpu_matches(NO_SSB) && !(ia32_cap & ARCH_CAP_SSB_NO) &&
!cpu_has(c, X86_FEATURE_AMD_SSB_NO))
setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);