[RFC PATCH 09/12] powerpc: move NMI entry/exit code into wrapper
Nicholas Piggin
npiggin at gmail.com
Sun Sep 6 03:43:32 AEST 2020
This moves the common NMI entry and exit code into the interrupt handler
wrappers.
This changes the behaviour of soft-NMI (watchdog) and HMI interrupts, and
also MCE interrupts on 64e, by adding missing parts of the NMI entry to
them.
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
arch/powerpc/include/asm/interrupt.h | 26 +++++++++++++++++++
arch/powerpc/kernel/mce.c | 12 ---------
arch/powerpc/kernel/traps.c | 38 +++++-----------------------
arch/powerpc/kernel/watchdog.c | 10 +++-----
4 files changed, 37 insertions(+), 49 deletions(-)
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 83fe1d64cf23..69eb8a432984 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -31,6 +31,27 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs)
}
#endif /* CONFIG_PPC_BOOK3S_64 */
+struct interrupt_nmi_state {
+#ifdef CONFIG_PPC64
+ u8 ftrace_enabled;
+#endif
+};
+
+static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct interrupt_nmi_state *state)
+{
+ this_cpu_set_ftrace_enabled(0);
+
+ nmi_enter();
+}
+
+static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct interrupt_nmi_state *state)
+{
+ nmi_exit();
+
+ this_cpu_set_ftrace_enabled(state->ftrace_enabled);
+}
+
+
/**
* DECLARE_INTERRUPT_HANDLER_RAW - Declare raw interrupt handler function
* @func: Function name of the entry point
@@ -177,10 +198,15 @@ static __always_inline long ___##func(struct pt_regs *regs); \
\
__visible noinstr long func(struct pt_regs *regs) \
{ \
+ struct interrupt_nmi_state state; \
long ret; \
\
+ interrupt_nmi_enter_prepare(regs, &state); \
+ \
ret = ___##func (regs); \
\
+ interrupt_nmi_exit_prepare(regs, &state); \
+ \
return ret; \
} \
\
diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index d0bbcc4fe13c..9f39deed4fca 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -592,13 +592,6 @@ EXPORT_SYMBOL_GPL(machine_check_print_event_info);
DEFINE_INTERRUPT_HANDLER_NMI(machine_check_early)
{
long handled = 0;
- bool nested = in_nmi();
- u8 ftrace_enabled = this_cpu_get_ftrace_enabled();
-
- this_cpu_set_ftrace_enabled(0);
-
- if (!nested)
- nmi_enter();
hv_nmi_check_nonrecoverable(regs);
@@ -608,11 +601,6 @@ DEFINE_INTERRUPT_HANDLER_NMI(machine_check_early)
if (ppc_md.machine_check_early)
handled = ppc_md.machine_check_early(regs);
- if (!nested)
- nmi_exit();
-
- this_cpu_set_ftrace_enabled(ftrace_enabled);
-
return handled;
}
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 3784578db630..01ddbe5ed5a4 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -443,11 +443,6 @@ DEFINE_INTERRUPT_HANDLER_NMI(system_reset_exception)
{
unsigned long hsrr0, hsrr1;
bool saved_hsrrs = false;
- u8 ftrace_enabled = this_cpu_get_ftrace_enabled();
-
- this_cpu_set_ftrace_enabled(0);
-
- nmi_enter();
/*
* System reset can interrupt code where HSRRs are live and MSR[RI]=1.
@@ -519,10 +514,6 @@ DEFINE_INTERRUPT_HANDLER_NMI(system_reset_exception)
mtspr(SPRN_HSRR1, hsrr1);
}
- nmi_exit();
-
- this_cpu_set_ftrace_enabled(ftrace_enabled);
-
/* What should we do here? We could issue a shutdown or hard reset. */
return 0;
@@ -828,6 +819,12 @@ int machine_check_generic(struct pt_regs *regs)
#endif /* everything else */
+/*
+ * BOOK3S_64 does not call this handler as a non-maskable interrupt
+ * (it uses its own early real-mode handler to handle the MCE proper
+ * and then raises irq_work to call this handler when interrupts are
+ * enabled).
+ */
#ifdef CONFIG_PPC_BOOK3S_64
DEFINE_INTERRUPT_HANDLER_ASYNC(machine_check_exception)
#else
@@ -836,20 +833,6 @@ DEFINE_INTERRUPT_HANDLER_NMI(machine_check_exception)
{
int recover = 0;
- /*
- * BOOK3S_64 does not call this handler as a non-maskable interrupt
- * (it uses its own early real-mode handler to handle the MCE proper
- * and then raises irq_work to call this handler when interrupts are
- * enabled).
- *
- * This is silly. The BOOK3S_64 should just call a different function
- * rather than expecting semantics to magically change. Something
- * like 'non_nmi_machine_check_exception()', perhaps?
- */
- const bool nmi = !IS_ENABLED(CONFIG_PPC_BOOK3S_64);
-
- if (nmi) nmi_enter();
-
__this_cpu_inc(irq_stat.mce_exceptions);
add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
@@ -874,24 +857,17 @@ DEFINE_INTERRUPT_HANDLER_NMI(machine_check_exception)
if (check_io_access(regs))
goto bail;
- if (nmi) nmi_exit();
-
die("Machine check", regs, SIGBUS);
/* Must die if the interrupt is not recoverable */
if (!(regs->msr & MSR_RI))
die("Unrecoverable Machine check", regs, SIGBUS);
-#ifdef CONFIG_PPC_BOOK3S_64
bail:
+#ifdef CONFIG_PPC_BOOK3S_64
return;
#else
return 0;
-
-bail:
- if (nmi) nmi_exit();
-
- return 0;
#endif
}
diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c
index 824b9376ac35..dc39534836a3 100644
--- a/arch/powerpc/kernel/watchdog.c
+++ b/arch/powerpc/kernel/watchdog.c
@@ -254,11 +254,12 @@ DEFINE_INTERRUPT_HANDLER_NMI(soft_nmi_interrupt)
int cpu = raw_smp_processor_id();
u64 tb;
+ /* should only arrive from kernel, with irqs disabled */
+ WARN_ON_ONCE(!arch_irq_disabled_regs(regs));
+
if (!cpumask_test_cpu(cpu, &wd_cpus_enabled))
return 0;
- nmi_enter();
-
__this_cpu_inc(irq_stat.soft_nmi_irqs);
tb = get_tb();
@@ -266,7 +267,7 @@ DEFINE_INTERRUPT_HANDLER_NMI(soft_nmi_interrupt)
wd_smp_lock(&flags);
if (cpumask_test_cpu(cpu, &wd_smp_cpus_stuck)) {
wd_smp_unlock(&flags);
- goto out;
+ return 0;
}
set_cpu_stuck(cpu, tb);
@@ -290,9 +291,6 @@ DEFINE_INTERRUPT_HANDLER_NMI(soft_nmi_interrupt)
if (wd_panic_timeout_tb < 0x7fffffff)
mtspr(SPRN_DEC, wd_panic_timeout_tb);
-out:
- nmi_exit();
-
return 0;
}
--
2.23.0
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