Commit-ID:  108fab4b5c8f12064ef86e02cb0459992affb30f
Gitweb:     https://git.kernel.org/tip/108fab4b5c8f12064ef86e02cb0459992affb30f
Author:     Konrad Rzeszutek Wilk <[email protected]>
AuthorDate: Fri, 1 Jun 2018 10:59:21 -0400
Committer:  Thomas Gleixner <[email protected]>
CommitDate: Wed, 6 Jun 2018 14:13:17 +0200

x86/bugs: Switch the selection of mitigation from CPU vendor to CPU features

Both AMD and Intel can have SPEC_CTRL_MSR for SSBD.

However AMD also has two more other ways of doing it - which
are !SPEC_CTRL MSR ways.

Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: [email protected]
Cc: KarimAllah Ahmed <[email protected]>
Cc: [email protected]
Cc: "H. Peter Anvin" <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: David Woodhouse <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

---
 arch/x86/kernel/cpu/bugs.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 6bea81855cdd..cd0fda1fff6d 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -532,17 +532,12 @@ static enum ssb_mitigation __init 
__ssb_select_mitigation(void)
                 * Intel uses the SPEC CTRL MSR Bit(2) for this, while AMD may
                 * use a completely different MSR and bit dependent on family.
                 */
-               switch (boot_cpu_data.x86_vendor) {
-               case X86_VENDOR_INTEL:
-               case X86_VENDOR_AMD:
-                       if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL)) {
-                               x86_amd_ssb_disable();
-                               break;
-                       }
+               if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
+                       x86_amd_ssb_disable();
+               else {
                        x86_spec_ctrl_base |= SPEC_CTRL_SSBD;
                        x86_spec_ctrl_mask |= SPEC_CTRL_SSBD;
                        wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
-                       break;
                }
        }
 

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