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-rw-r--r--arch/powerpc/kernel/exceptions-64s.S186
1 files changed, 86 insertions, 100 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 6353019966e6..ae418b85c17c 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -116,9 +116,11 @@ EXC_VIRT_NONE(0x4000, 0x100)
EXC_REAL_BEGIN(system_reset, 0x100, 0x100)
SET_SCRATCH0(r13)
- GET_PACA(r13)
- clrrdi r13,r13,1 /* Last bit of HSPRG0 is set if waking from winkle */
- EXCEPTION_PROLOG_PSERIES_PACA(PACA_EXGEN, system_reset_common, EXC_STD,
+ /*
+ * MSR_RI is not enabled, because PACA_EXNMI and nmi stack is
+ * being used, so a nested NMI exception would corrupt it.
+ */
+ EXCEPTION_PROLOG_PSERIES_NORI(PACA_EXNMI, system_reset_common, EXC_STD,
IDLETEST, 0x100)
EXC_REAL_END(system_reset, 0x100, 0x100)
@@ -126,34 +128,37 @@ EXC_VIRT_NONE(0x4100, 0x100)
#ifdef CONFIG_PPC_P7_NAP
EXC_COMMON_BEGIN(system_reset_idle_common)
-BEGIN_FTR_SECTION
- GET_PACA(r13) /* Restore HSPRG0 to get the winkle bit in r13 */
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
- bl pnv_restore_hyp_resource
+ b pnv_powersave_wakeup
+#endif
- li r0,PNV_THREAD_RUNNING
- stb r0,PACA_THREAD_IDLE_STATE(r13) /* Clear thread state */
+EXC_COMMON_BEGIN(system_reset_common)
+ /*
+ * Increment paca->in_nmi then enable MSR_RI. SLB or MCE will be able
+ * to recover, but nested NMI will notice in_nmi and not recover
+ * because of the use of the NMI stack. in_nmi reentrancy is tested in
+ * system_reset_exception.
+ */
+ lhz r10,PACA_IN_NMI(r13)
+ addi r10,r10,1
+ sth r10,PACA_IN_NMI(r13)
+ li r10,MSR_RI
+ mtmsrd r10,1
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
- li r0,KVM_HWTHREAD_IN_KERNEL
- stb r0,HSTATE_HWTHREAD_STATE(r13)
- /* Order setting hwthread_state vs. testing hwthread_req */
- sync
- lbz r0,HSTATE_HWTHREAD_REQ(r13)
- cmpwi r0,0
- beq 1f
- BRANCH_TO_KVM(r10, kvm_start_guest)
-1:
-#endif
+ mr r10,r1
+ ld r1,PACA_NMI_EMERG_SP(r13)
+ subi r1,r1,INT_FRAME_SIZE
+ EXCEPTION_COMMON_NORET_STACK(PACA_EXNMI, 0x100,
+ system_reset, system_reset_exception,
+ ADD_NVGPRS;ADD_RECONCILE)
- /* Return SRR1 from power7_nap() */
- mfspr r3,SPRN_SRR1
- blt cr3,2f
- b pnv_wakeup_loss
-2: b pnv_wakeup_noloss
-#endif
+ /*
+ * The stack is no longer in use, decrement in_nmi.
+ */
+ lhz r10,PACA_IN_NMI(r13)
+ subi r10,r10,1
+ sth r10,PACA_IN_NMI(r13)
-EXC_COMMON(system_reset_common, 0x100, system_reset_exception)
+ b ret_from_except
#ifdef CONFIG_PPC_PSERIES
/*
@@ -161,8 +166,9 @@ EXC_COMMON(system_reset_common, 0x100, system_reset_exception)
*/
TRAMP_REAL_BEGIN(system_reset_fwnmi)
SET_SCRATCH0(r13) /* save r13 */
- EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD,
- NOTEST, 0x100)
+ /* See comment at system_reset exception */
+ EXCEPTION_PROLOG_PSERIES_NORI(PACA_EXNMI, system_reset_common,
+ EXC_STD, NOTEST, 0x100)
#endif /* CONFIG_PPC_PSERIES */
@@ -172,14 +178,6 @@ EXC_REAL_BEGIN(machine_check, 0x200, 0x100)
* vector
*/
SET_SCRATCH0(r13) /* save r13 */
- /*
- * Running native on arch 2.06 or later, we may wakeup from winkle
- * inside machine check. If yes, then last bit of HSPRG0 would be set
- * to 1. Hence clear it unconditionally.
- */
- GET_PACA(r13)
- clrrdi r13,r13,1
- SET_PACA(r13)
EXCEPTION_PROLOG_0(PACA_EXMC)
BEGIN_FTR_SECTION
b machine_check_powernv_early
@@ -212,6 +210,12 @@ BEGIN_FTR_SECTION
* NOTE: We are here with MSR_ME=0 (off), which means we risk a
* checkstop if we get another machine check exception before we do
* rfid with MSR_ME=1.
+ *
+ * This interrupt can wake directly from idle. If that is the case,
+ * the machine check is handled then the idle wakeup code is called
+ * to restore state. In that case, the POWER9 DD1 idle PACA workaround
+ * is not applied in the early machine check code, which will cause
+ * bugs.
*/
mr r11,r1 /* Save r1 */
lhz r10,PACA_IN_MCE(r13)
@@ -268,20 +272,11 @@ machine_check_fwnmi:
machine_check_pSeries_0:
EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST_PR, 0x200)
/*
- * The following is essentially EXCEPTION_PROLOG_PSERIES_1 with the
- * difference that MSR_RI is not enabled, because PACA_EXMC is being
- * used, so nested machine check corrupts it. machine_check_common
- * enables MSR_RI.
+ * MSR_RI is not enabled, because PACA_EXMC is being used, so a
+ * nested machine check corrupts it. machine_check_common enables
+ * MSR_RI.
*/
- ld r10,PACAKMSR(r13)
- xori r10,r10,MSR_RI
- mfspr r11,SPRN_SRR0
- LOAD_HANDLER(r12, machine_check_common)
- mtspr SPRN_SRR0,r12
- mfspr r12,SPRN_SRR1
- mtspr SPRN_SRR1,r10
- rfid
- b . /* prevent speculative execution */
+ EXCEPTION_PROLOG_PSERIES_1_NORI(machine_check_common, EXC_STD)
TRAMP_KVM_SKIP(PACA_EXMC, 0x200)
@@ -340,6 +335,37 @@ EXC_COMMON_BEGIN(machine_check_common)
/* restore original r1. */ \
ld r1,GPR1(r1)
+#ifdef CONFIG_PPC_P7_NAP
+/*
+ * This is an idle wakeup. Low level machine check has already been
+ * done. Queue the event then call the idle code to do the wake up.
+ */
+EXC_COMMON_BEGIN(machine_check_idle_common)
+ bl machine_check_queue_event
+
+ /*
+ * We have not used any non-volatile GPRs here, and as a rule
+ * most exception code including machine check does not.
+ * Therefore PACA_NAPSTATELOST does not need to be set. Idle
+ * wakeup will restore volatile registers.
+ *
+ * Load the original SRR1 into r3 for pnv_powersave_wakeup_mce.
+ *
+ * Then decrement MCE nesting after finishing with the stack.
+ */
+ ld r3,_MSR(r1)
+
+ lhz r11,PACA_IN_MCE(r13)
+ subi r11,r11,1
+ sth r11,PACA_IN_MCE(r13)
+
+ /* Turn off the RI bit because SRR1 is used by idle wakeup code. */
+ /* Recoverability could be improved by reducing the use of SRR1. */
+ li r11,0
+ mtmsrd r11,1
+
+ b pnv_powersave_wakeup_mce
+#endif
/*
* Handle machine check early in real mode. We come here with
* ME=1, MMU (IR=0 and DR=0) off and using MC emergency stack.
@@ -352,6 +378,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early)
bl machine_check_early
std r3,RESULT(r1) /* Save result */
ld r12,_MSR(r1)
+
#ifdef CONFIG_PPC_P7_NAP
/*
* Check if thread was in power saving mode. We come here when any
@@ -362,48 +389,12 @@ EXC_COMMON_BEGIN(machine_check_handle_early)
*
* Go back to nap/sleep/winkle mode 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
- blt 3f
- /* Supervisor/Hypervisor state loss */
- li r0,1
- stb r0,PACA_NAPSTATELOST(r13)
-3: bl machine_check_queue_event
- MACHINE_CHECK_HANDLER_WINDUP
- GET_PACA(r13)
- ld r1,PACAR1(r13)
- /*
- * Check what idle state this CPU was in and go back to same mode
- * again.
- */
- lbz r3,PACA_THREAD_IDLE_STATE(r13)
- cmpwi r3,PNV_THREAD_NAP
- bgt 10f
- IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP)
- /* No return */
-10:
- cmpwi r3,PNV_THREAD_SLEEP
- bgt 2f
- IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP)
- /* No return */
-
-2:
- /*
- * Go back to winkle. Please note that this thread was woken up in
- * machine check from winkle and have not restored the per-subcore
- * state. Hence before going back to winkle, set last bit of HSPRG0
- * to 1. This will make sure that if this thread gets woken up
- * again at reset vector 0x100 then it will get chance to restore
- * the subcore state.
- */
- ori r13,r13,1
- SET_PACA(r13)
- IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE)
- /* No return */
-4:
+ BEGIN_FTR_SECTION
+ rlwinm. r11,r12,47-31,30,31
+ bne machine_check_idle_common
+ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
#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.
@@ -968,17 +959,12 @@ EXC_VIRT_NONE(0x4e60, 0x20)
TRAMP_KVM_HV(PACA_EXGEN, 0xe60)
TRAMP_REAL_BEGIN(hmi_exception_early)
EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_HV, 0xe60)
- mr r10,r1 /* Save r1 */
- ld r1,PACAEMERGSP(r13) /* Use emergency stack */
+ mr r10,r1 /* Save r1 */
+ ld r1,PACAEMERGSP(r13) /* Use emergency stack for realmode */
subi r1,r1,INT_FRAME_SIZE /* alloc stack frame */
- std r9,_CCR(r1) /* save CR in stackframe */
mfspr r11,SPRN_HSRR0 /* Save HSRR0 */
- std r11,_NIP(r1) /* save HSRR0 in stackframe */
- mfspr r12,SPRN_HSRR1 /* Save SRR1 */
- std r12,_MSR(r1) /* save SRR1 in stackframe */
- std r10,0(r1) /* make stack chain pointer */
- std r0,GPR0(r1) /* save r0 in stackframe */
- std r10,GPR1(r1) /* save r1 in stackframe */
+ mfspr r12,SPRN_HSRR1 /* Save HSRR1 */
+ EXCEPTION_PROLOG_COMMON_1()
EXCEPTION_PROLOG_COMMON_2(PACA_EXGEN)
EXCEPTION_PROLOG_COMMON_3(0xe60)
addi r3,r1,STACK_FRAME_OVERHEAD