powerpc/tm: Clear MSR RI in non-recoverable TM code

[platform/kernel/linux-starfive.git] / arch / powerpc / kernel / tm.S

diff --git a/arch/powerpc/kernel/tm.S b/arch/powerpc/kernel/tm.S
index 2da67e7..51be8fb 100644 (file)
--- a/arch/powerpc/kernel/tm.S
+++ b/arch/powerpc/kernel/tm.S
@@ -112,9 +112,18 @@ _GLOBAL(tm_reclaim)
        std     r3, STACK_PARAM(0)(r1)
        SAVE_NVGPRS(r1)
 
+       /* We need to setup MSR for VSX register save instructions.  Here we
+        * also clear the MSR RI since when we do the treclaim, we won't have a
+        * valid kernel pointer for a while.  We clear RI here as it avoids
+        * adding another mtmsr closer to the treclaim.  This makes the region
+        * maked as non-recoverable wider than it needs to be but it saves on
+        * inserting another mtmsrd later.
+        */
        mfmsr   r14
        mr      r15, r14
        ori     r15, r15, MSR_FP
+       li      r16, MSR_RI
+       andc    r15, r15, r16
        oris    r15, r15, MSR_VEC@h
 #ifdef CONFIG_VSX
        BEGIN_FTR_SECTION
@@ -349,9 +358,10 @@ restore_gprs:
        mtcr    r5
        mtxer   r6
 
-       /* MSR and flags:  We don't change CRs, and we don't need to alter
-        * MSR.
+       /* Clear the MSR RI since we are about to change R1.  EE is already off
         */
+       li      r4, 0
+       mtmsrd  r4, 1
 
        REST_4GPRS(0, r7)                       /* GPR0-3 */
        REST_GPR(4, r7)                         /* GPR4-6 */
@@ -377,6 +387,10 @@ restore_gprs:
        GET_PACA(r13)
        GET_SCRATCH0(r1)
 
+       /* R1 is restored, so we are recoverable again.  EE is still off */
+       li      r4, MSR_RI
+       mtmsrd  r4, 1
+
        REST_NVGPRS(r1)
 
        addi    r1, r1, TM_FRAME_SIZE