[PATCH 3/5] x86/speculation: Introduce SPEC_CTRL_MSR bit for PSFD

From: Ramakrishna Saripalli
Date: Tue Apr 06 2021 - 11:50:48 EST


From: Ramakrishna Saripalli <rk.saripalli@xxxxxxx>

All AMD processors that support PSF implement a bit in
SPEC_CTRL MSR (0x48) to disable or enable Predictive Store
Forwarding.

Signed-off-by: Ramakrishna Saripalli<rk.saripalli@xxxxxxx>
---
arch/x86/include/asm/msr-index.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 546d6ecf0a35..f569918c8754 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -51,6 +51,8 @@
#define SPEC_CTRL_STIBP BIT(SPEC_CTRL_STIBP_SHIFT) /* STIBP mask */
#define SPEC_CTRL_SSBD_SHIFT 2 /* Speculative Store Bypass Disable bit */
#define SPEC_CTRL_SSBD BIT(SPEC_CTRL_SSBD_SHIFT) /* Speculative Store Bypass Disable */
+#define SPEC_CTRL_PSFD_SHIFT 7
+#define SPEC_CTRL_PSFD BIT(SPEC_CTRL_PSFD_SHIFT) /* Predictive Store Forwarding Disable */

#define MSR_IA32_PRED_CMD 0x00000049 /* Prediction Command */
#define PRED_CMD_IBPB BIT(0) /* Indirect Branch Prediction Barrier */
--
2.25.1