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-rw-r--r--arch/powerpc/kernel/exceptions-64s.S82
-rw-r--r--arch/powerpc/kernel/idle_power7.S1
2 files changed, 83 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 4034dfb2a530..1aec3025eeee 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -155,6 +155,24 @@ machine_check_pSeries_1:
*/
HMT_MEDIUM_PPR_DISCARD
SET_SCRATCH0(r13) /* save r13 */
+#ifdef CONFIG_PPC_P7_NAP
+BEGIN_FTR_SECTION
+ /* Running native on arch 2.06 or later, check if we are
+ * waking up from nap. We only handle no state loss and
+ * supervisor state loss. We do -not- handle hypervisor
+ * state loss at this time.
+ */
+ mfspr r13,SPRN_SRR1
+ rlwinm. r13,r13,47-31,30,31
+ beq 9f
+
+ /* waking up from powersave (nap) state */
+ cmpwi cr1,r13,2
+ /* Total loss of HV state is fatal. let's just stay stuck here */
+ bgt cr1,.
+9:
+END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
+#endif /* CONFIG_PPC_P7_NAP */
EXCEPTION_PROLOG_0(PACA_EXMC)
BEGIN_FTR_SECTION
b machine_check_pSeries_early
@@ -818,6 +836,70 @@ BEGIN_FTR_SECTION
bl .save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl .machine_check_early
+ ld r12,_MSR(r1)
+#ifdef CONFIG_PPC_P7_NAP
+ /*
+ * Check if thread was in power saving mode. We come here when any
+ * of the following is true:
+ * a. thread wasn't in power saving mode
+ * b. thread was in power saving mode with no state loss or
+ * supervisor state loss
+ *
+ * Go back to nap again if (b) is true.
+ */
+ rlwinm. r11,r12,47-31,30,31 /* Was it in power saving mode? */
+ beq 4f /* No, it wasn;t */
+ /* Thread was in power saving mode. Go back to nap again. */
+ cmpwi r11,2
+ bne 3f
+ /* Supervisor state loss */
+ li r0,1
+ stb r0,PACA_NAPSTATELOST(r13)
+3: MACHINE_CHECK_HANDLER_WINDUP
+ GET_PACA(r13)
+ ld r1,PACAR1(r13)
+ b .power7_enter_nap_mode
+4:
+#endif
+ /*
+ * Check if we are coming from hypervisor userspace. If yes then we
+ * continue in host kernel in V mode to deliver the MC event.
+ */
+ rldicl. r11,r12,4,63 /* See if MC hit while in HV mode. */
+ beq 5f
+ andi. r11,r12,MSR_PR /* See if coming from user. */
+ bne 9f /* continue in V mode if we are. */
+
+5:
+#ifdef CONFIG_KVM_BOOK3S_64_HV
+ /*
+ * We are coming from kernel context. Check if we are coming from
+ * guest. if yes, then we can continue. We will fall through
+ * do_kvm_200->kvmppc_interrupt to deliver the MC event to guest.
+ */
+ lbz r11,HSTATE_IN_GUEST(r13)
+ cmpwi r11,0 /* Check if coming from guest */
+ bne 9f /* continue if we are. */
+#endif
+ /*
+ * At this point we are not sure about what context we come from.
+ * Queue up the MCE event and return from the interrupt.
+ * But before that, check if this is an un-recoverable exception.
+ * If yes, then stay on emergency stack and panic.
+ */
+ andi. r11,r12,MSR_RI
+ bne 2f
+1: addi r3,r1,STACK_FRAME_OVERHEAD
+ bl .unrecoverable_exception
+ b 1b
+2:
+ /*
+ * Return from MC interrupt.
+ * TODO: Queue up the MCE event so that we can log it later.
+ */
+ MACHINE_CHECK_HANDLER_WINDUP
+ rfid
+9:
/* Deliver the machine check to host kernel in V mode. */
MACHINE_CHECK_HANDLER_WINDUP
b machine_check_pSeries
diff --git a/arch/powerpc/kernel/idle_power7.S b/arch/powerpc/kernel/idle_power7.S
index 847e40e62fce..3fdef0f0c67f 100644
--- a/arch/powerpc/kernel/idle_power7.S
+++ b/arch/powerpc/kernel/idle_power7.S
@@ -84,6 +84,7 @@ _GLOBAL(power7_nap)
std r9,_MSR(r1)
std r1,PACAR1(r13)
+_GLOBAL(power7_enter_nap_mode)
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
/* Tell KVM we're napping */
li r4,KVM_HWTHREAD_IN_NAP