[PATCH v2 05/11] powerpc/64e/interrupt: NMI save irq soft-mask state in C
Nicholas Piggin
npiggin at gmail.com
Tue Mar 16 21:41:59 AEDT 2021
64e non-maskable interrupts save the state of the irq soft-mask in
asm. This can be done in C in interrupt wrappers as 64s does.
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
I haven't been able to test this with qemu because it doesn't seem
to cause FSL bookE WDT interrupts.
This makes WatchdogException an NMI interrupt, which affects 32-bit
as well (okay, or create a new handler?)
---
arch/powerpc/include/asm/interrupt.h | 32 +++++++++++++++++--------
arch/powerpc/kernel/exceptions-64e.S | 36 ++++------------------------
arch/powerpc/kernel/traps.c | 13 +++++++++-
3 files changed, 38 insertions(+), 43 deletions(-)
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 7c633896d758..305d7c17a4cf 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -130,18 +130,32 @@ static inline void interrupt_async_exit_prepare(struct pt_regs *regs, struct int
struct interrupt_nmi_state {
#ifdef CONFIG_PPC64
-#ifdef CONFIG_PPC_BOOK3S_64
u8 irq_soft_mask;
u8 irq_happened;
-#endif
u8 ftrace_enabled;
#endif
};
+static inline bool nmi_disables_ftrace(struct pt_regs *regs)
+{
+ /* Allow DEC and PMI to be traced when they are soft-NMI */
+ if (IS_ENABLED(CONFIG_PPC_BOOK3S_64)) {
+ if (TRAP(regs) == 0x900)
+ return false;
+ if (TRAP(regs) == 0xf00)
+ return false;
+ }
+ if (IS_ENABLED(CONFIG_PPC_BOOK3E)) {
+ if (TRAP(regs) == 0x260)
+ return false;
+ }
+
+ return true;
+}
+
static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct interrupt_nmi_state *state)
{
#ifdef CONFIG_PPC64
-#ifdef CONFIG_PPC_BOOK3S_64
state->irq_soft_mask = local_paca->irq_soft_mask;
state->irq_happened = local_paca->irq_happened;
@@ -154,9 +168,8 @@ static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct inte
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
/* Don't do any per-CPU operations until interrupt state is fixed */
-#endif
- /* Allow DEC and PMI to be traced when they are soft-NMI */
- if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260) {
+
+ if (nmi_disables_ftrace(regs)) {
state->ftrace_enabled = this_cpu_get_ftrace_enabled();
this_cpu_set_ftrace_enabled(0);
}
@@ -180,16 +193,14 @@ static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct inter
nmi_exit();
#ifdef CONFIG_PPC64
- if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260)
+ if (nmi_disables_ftrace(regs))
this_cpu_set_ftrace_enabled(state->ftrace_enabled);
-#ifdef CONFIG_PPC_BOOK3S_64
/* Check we didn't change the pending interrupt mask. */
WARN_ON_ONCE((state->irq_happened | PACA_IRQ_HARD_DIS) != local_paca->irq_happened);
local_paca->irq_happened = state->irq_happened;
local_paca->irq_soft_mask = state->irq_soft_mask;
#endif
-#endif
}
/*
@@ -402,6 +413,7 @@ DECLARE_INTERRUPT_HANDLER(SMIException);
DECLARE_INTERRUPT_HANDLER(handle_hmi_exception);
DECLARE_INTERRUPT_HANDLER(unknown_exception);
DECLARE_INTERRUPT_HANDLER_ASYNC(unknown_async_exception);
+DECLARE_INTERRUPT_HANDLER_NMI(unknown_nmi_exception);
DECLARE_INTERRUPT_HANDLER(instruction_breakpoint_exception);
DECLARE_INTERRUPT_HANDLER(RunModeException);
DECLARE_INTERRUPT_HANDLER(single_step_exception);
@@ -425,7 +437,7 @@ DECLARE_INTERRUPT_HANDLER(altivec_assist_exception);
DECLARE_INTERRUPT_HANDLER(CacheLockingException);
DECLARE_INTERRUPT_HANDLER(SPEFloatingPointException);
DECLARE_INTERRUPT_HANDLER(SPEFloatingPointRoundException);
-DECLARE_INTERRUPT_HANDLER(WatchdogException);
+DECLARE_INTERRUPT_HANDLER_NMI(WatchdogException);
DECLARE_INTERRUPT_HANDLER(kernel_bad_stack);
/* slb.c */
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 7a2e7be33092..18be576fc0b3 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -63,9 +63,6 @@
ld reg, (SPECIAL_EXC_##name * 8 + SPECIAL_EXC_FRAME_OFFS)(r1)
special_reg_save:
- lbz r9,PACAIRQHAPPENED(r13)
- RECONCILE_IRQ_STATE(r3,r4)
-
/*
* We only need (or have stack space) to save this stuff if
* we interrupted the kernel.
@@ -119,15 +116,11 @@ BEGIN_FTR_SECTION
mtspr SPRN_MAS5,r10
mtspr SPRN_MAS8,r10
END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
- SPECIAL_EXC_STORE(r9,IRQHAPPENED)
-
mfspr r10,SPRN_DEAR
SPECIAL_EXC_STORE(r10,DEAR)
mfspr r10,SPRN_ESR
SPECIAL_EXC_STORE(r10,ESR)
- lbz r10,PACAIRQSOFTMASK(r13)
- SPECIAL_EXC_STORE(r10,SOFTE)
ld r10,_NIP(r1)
SPECIAL_EXC_STORE(r10,CSRR0)
ld r10,_MSR(r1)
@@ -194,27 +187,6 @@ BEGIN_FTR_SECTION
mtspr SPRN_MAS8,r10
END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
- lbz r6,PACAIRQSOFTMASK(r13)
- ld r5,SOFTE(r1)
-
- /* Interrupts had better not already be enabled... */
- tweqi r6,IRQS_ENABLED
-
- andi. r6,r5,IRQS_DISABLED
- bne 1f
-
- TRACE_ENABLE_INTS
- stb r5,PACAIRQSOFTMASK(r13)
-1:
- /*
- * Restore PACAIRQHAPPENED rather than setting it based on
- * the return MSR[EE], since we could have interrupted
- * interrupt replay or other inconsistent transitory
- * states that must remain that way.
- */
- SPECIAL_EXC_LOAD(r10,IRQHAPPENED)
- stb r10,PACAIRQHAPPENED(r13)
-
SPECIAL_EXC_LOAD(r10,DEAR)
mtspr SPRN_DEAR,r10
SPECIAL_EXC_LOAD(r10,ESR)
@@ -566,7 +538,7 @@ __end_interrupts:
bl special_reg_save
CHECK_NAPPING();
addi r3,r1,STACK_FRAME_OVERHEAD
- bl unknown_exception
+ bl unknown_nmi_exception
b ret_from_crit_except
/* Machine Check Interrupt */
@@ -702,7 +674,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#ifdef CONFIG_BOOKE_WDT
bl WatchdogException
#else
- bl unknown_exception
+ bl unknown_nmi_exception
#endif
b ret_from_crit_except
@@ -886,7 +858,7 @@ kernel_dbg_exc:
bl special_reg_save
CHECK_NAPPING();
addi r3,r1,STACK_FRAME_OVERHEAD
- bl unknown_exception
+ bl unknown_nmi_exception
b ret_from_crit_except
/*
@@ -910,7 +882,7 @@ kernel_dbg_exc:
bl special_reg_save
CHECK_NAPPING();
addi r3,r1,STACK_FRAME_OVERHEAD
- bl unknown_exception
+ bl unknown_nmi_exception
b ret_from_crit_except
/* Hypervisor call */
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index c74e7727860a..97b5f3d83ff7 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1079,6 +1079,16 @@ DEFINE_INTERRUPT_HANDLER_ASYNC(unknown_async_exception)
_exception(SIGTRAP, regs, TRAP_UNK, 0);
}
+DEFINE_INTERRUPT_HANDLER_NMI(unknown_nmi_exception)
+{
+ printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
+ regs->nip, regs->msr, regs->trap);
+
+ _exception(SIGTRAP, regs, TRAP_UNK, 0);
+
+ return 0;
+}
+
DEFINE_INTERRUPT_HANDLER(instruction_breakpoint_exception)
{
if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
@@ -2183,10 +2193,11 @@ void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
return;
}
-DEFINE_INTERRUPT_HANDLER(WatchdogException) /* XXX NMI? async? */
+DEFINE_INTERRUPT_HANDLER_NMI(WatchdogException)
{
printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
WatchdogHandler(regs);
+ return 0;
}
#endif
--
2.23.0
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