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| author | Max Filippov <jcmvbkbc@gmail.com> | 2015-07-16 10:37:31 +0300 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2015-08-17 07:33:39 +0300 |
| commit | 38fef73c21d117cf992fb5ec6e30630e54e13f4f (patch) | |
| tree | ca3aae4c2e29ee81c66dcc16eb835e0b8c4e631f /arch/xtensa/kernel/traps.c | |
| parent | 98e298329e7b391293da5097817437292c842dc9 (diff) | |
| download | talos-obmc-linux-38fef73c21d117cf992fb5ec6e30630e54e13f4f.tar.gz talos-obmc-linux-38fef73c21d117cf992fb5ec6e30630e54e13f4f.zip | |
xtensa: implement fake NMI
In case perf IRQ is the highest of the medium-level IRQs, and is alone
on its level, it may be treated as NMI:
- LOCKLEVEL is defined to be one level less than EXCM level,
- IRQ masking never lowers current IRQ level,
- new fake exception cause code, EXCCAUSE_MAPPED_NMI is assigned to that
IRQ; new second level exception handler, do_nmi, assigned to it
handles it as NMI,
- atomic operations in configurations without s32c1i still need to mask
all interrupts.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/kernel/traps.c')
| -rw-r--r-- | arch/xtensa/kernel/traps.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c index a1b5bd237c71..42d441f7898b 100644 --- a/arch/xtensa/kernel/traps.c +++ b/arch/xtensa/kernel/traps.c @@ -62,6 +62,7 @@ extern void fast_coprocessor(void); extern void do_illegal_instruction (struct pt_regs*); extern void do_interrupt (struct pt_regs*); +extern void do_nmi(struct pt_regs *); extern void do_unaligned_user (struct pt_regs*); extern void do_multihit (struct pt_regs*, unsigned long); extern void do_page_fault (struct pt_regs*, unsigned long); @@ -146,6 +147,9 @@ COPROCESSOR(6), #if XTENSA_HAVE_COPROCESSOR(7) COPROCESSOR(7), #endif +#if XTENSA_FAKE_NMI +{ EXCCAUSE_MAPPED_NMI, 0, do_nmi }, +#endif { EXCCAUSE_MAPPED_DEBUG, 0, do_debug }, { -1, -1, 0 } @@ -199,6 +203,28 @@ void do_multihit(struct pt_regs *regs, unsigned long exccause) extern void do_IRQ(int, struct pt_regs *); +#if XTENSA_FAKE_NMI + +irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id); + +DEFINE_PER_CPU(unsigned long, nmi_count); + +void do_nmi(struct pt_regs *regs) +{ + struct pt_regs *old_regs; + + if ((regs->ps & PS_INTLEVEL_MASK) < LOCKLEVEL) + trace_hardirqs_off(); + + old_regs = set_irq_regs(regs); + nmi_enter(); + ++*this_cpu_ptr(&nmi_count); + xtensa_pmu_irq_handler(0, NULL); + nmi_exit(); + set_irq_regs(old_regs); +} +#endif + void do_interrupt(struct pt_regs *regs) { static const unsigned int_level_mask[] = { |
