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-rw-r--r--arch/powerpc/kernel/entry_64.S24
-rw-r--r--arch/powerpc/kernel/rtas.c9
2 files changed, 21 insertions, 12 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 9581906b5ee9..da18f83ef883 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -330,22 +330,22 @@ _GLOBAL(enter_rtas)
clrldi r4,r4,2 /* convert to realmode address */
mtlr r4
- li r0,0
- ori r0,r0,MSR_EE|MSR_SE|MSR_BE|MSR_RI
- andc r0,r6,r0
-
- li r9,1
- rldicr r9,r9,MSR_SF_LG,(63-MSR_SF_LG)
- ori r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP|MSR_RI|MSR_LE
- andc r6,r0,r9
-
__enter_rtas:
- sync /* disable interrupts so SRR0/1 */
- mtmsrd r0 /* don't get trashed */
-
LOAD_REG_ADDR(r4, rtas)
ld r5,RTASENTRY(r4) /* get the rtas->entry value */
ld r4,RTASBASE(r4) /* get the rtas->base value */
+
+ /*
+ * RTAS runs in 32-bit big endian real mode, but leave MSR[RI] on as we
+ * may hit NMI (SRESET or MCE) while in RTAS. RTAS should disable RI in
+ * its critical regions (as specified in PAPR+ section 7.2.1). MSR[S]
+ * is not impacted by RFI_TO_KERNEL (only urfid can unset it). So if
+ * MSR[S] is set, it will remain when entering RTAS.
+ */
+ LOAD_REG_IMMEDIATE(r6, MSR_ME | MSR_RI)
+
+ li r0,0
+ mtmsrd r0,1 /* disable RI before using SRR0/1 */
mtspr SPRN_SRR0,r5
mtspr SPRN_SRR1,r6
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index a6bbce998ddf..03d173b1e599 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -50,6 +50,15 @@ void enter_rtas(unsigned long);
static inline void do_enter_rtas(unsigned long args)
{
+ unsigned long msr;
+
+ /*
+ * Make sure MSR[RI] is currently enabled as it will be forced later
+ * in enter_rtas.
+ */
+ msr = mfmsr();
+ BUG_ON(!(msr & MSR_RI));
+
enter_rtas(args);
srr_regs_clobbered(); /* rtas uses SRRs, invalidate */