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powerpc: move NMI entry/exit code into wrapper

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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@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-40-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2021-01-30 23:08:49 +10:00 committed by Michael Ellerman
parent 74c3354bc1
commit 118178e62e
4 changed files with 38 additions and 46 deletions
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28
arch/powerpc/include/asm/interrupt.h
View File

@ -94,14 +94,42 @@ static inline void interrupt_async_exit_prepare(struct pt_regs *regs, struct int
}
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)
{
#ifdef CONFIG_PPC64
/* Allow DEC and PMI to be traced when they are soft-NMI */
if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260) {
state->ftrace_enabled = this_cpu_get_ftrace_enabled();
this_cpu_set_ftrace_enabled(0);
}
#endif
/*
* Do not use nmi_enter() for pseries hash guest taking a real-mode
* NMI because not everything it touches is within the RMA limit.
*/
if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64) ||
!firmware_has_feature(FW_FEATURE_LPAR) ||
radix_enabled() || (mfmsr() & MSR_DR))
nmi_enter();
}
static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct interrupt_nmi_state *state)
{
if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64) ||
!firmware_has_feature(FW_FEATURE_LPAR) ||
radix_enabled() || (mfmsr() & MSR_DR))
nmi_exit();
#ifdef CONFIG_PPC64
if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260)
this_cpu_set_ftrace_enabled(state->ftrace_enabled);
#endif
}
/**

11
arch/powerpc/kernel/mce.c
View File

@ -587,12 +587,6 @@ EXPORT_SYMBOL_GPL(machine_check_print_event_info);
DEFINE_INTERRUPT_HANDLER_NMI(machine_check_early)
{
long handled = 0;
u8 ftrace_enabled = this_cpu_get_ftrace_enabled();
this_cpu_set_ftrace_enabled(0);
/* Do not use nmi_enter/exit for pseries hpte guest */
if (radix_enabled() || !firmware_has_feature(FW_FEATURE_LPAR))
nmi_enter();
hv_nmi_check_nonrecoverable(regs);
@ -602,11 +596,6 @@ DEFINE_INTERRUPT_HANDLER_NMI(machine_check_early)
if (ppc_md.machine_check_early)
handled = ppc_md.machine_check_early(regs);
if (radix_enabled() || !firmware_has_feature(FW_FEATURE_LPAR))
nmi_exit();
this_cpu_set_ftrace_enabled(ftrace_enabled);
return handled;
}

35
arch/powerpc/kernel/traps.c
View File

@ -435,11 +435,6 @@ 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.
@ -514,10 +509,6 @@ out:
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;
@ -809,6 +800,12 @@ void die_mce(const char *str, struct pt_regs *regs, long err)
}
NOKPROBE_SYMBOL(die_mce);
/*
* 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
@ -817,20 +814,6 @@ 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);
@ -862,8 +845,6 @@ bail:
if (!(regs->msr & MSR_RI))
die_mce("Unrecoverable Machine check", regs, SIGBUS);
if (nmi) nmi_exit();
#ifdef CONFIG_PPC_BOOK3S_64
return;
#else
@ -1892,14 +1873,10 @@ DEFINE_INTERRUPT_HANDLER(vsx_unavailable_tm)
DECLARE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi);
DEFINE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi)
{
nmi_enter();
__this_cpu_inc(irq_stat.pmu_irqs);
perf_irq(regs);
nmi_exit();
return 0;
}
#endif

10
arch/powerpc/kernel/watchdog.c
View File

@ -255,11 +255,12 @@ 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();
@ -267,7 +268,7 @@ 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);
@ -291,9 +292,6 @@ 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;
}