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authorMax Filippov <jcmvbkbc@gmail.com>2015-11-27 16:26:41 +0300
committerMax Filippov <jcmvbkbc@gmail.com>2016-01-11 17:31:55 +0300
commite462919413547dcfe84e785380d0f47f1359878a (patch)
tree4c80bbd286f9c106d243149ec14634c2e9811a6f /arch/xtensa/kernel
parentafd2ff9b7e1b367172f18ba7f693dfb62bdcb2dc (diff)
xtensa: make fake NMI configurable
Do not always use fake NMI when safe, provide Kconfig option instead. Print a warning if fake NMI is chosen in unsafe configuration, but allow it, because it may work if the user knows that interrupts with priorities at or above PMM IRQ are not used. Add a check to NMI handler that BUGs if any of these IRQs fire. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/kernel')
-rw-r--r--arch/xtensa/kernel/traps.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 42d441f7898b..be0cae8082c7 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -205,6 +205,32 @@ extern void do_IRQ(int, struct pt_regs *);
#if XTENSA_FAKE_NMI
+#define IS_POW2(v) (((v) & ((v) - 1)) == 0)
+
+#if !(PROFILING_INTLEVEL == XCHAL_EXCM_LEVEL && \
+ IS_POW2(XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL)))
+#warning "Fake NMI is requested for PMM, but there are other IRQs at or above its level."
+#warning "Fake NMI will be used, but there will be a bugcheck if one of those IRQs fire."
+
+static inline void check_valid_nmi(void)
+{
+ unsigned intread = get_sr(interrupt);
+ unsigned intenable = get_sr(intenable);
+
+ BUG_ON(intread & intenable &
+ ~(XTENSA_INTLEVEL_ANDBELOW_MASK(PROFILING_INTLEVEL) ^
+ XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL) ^
+ BIT(XCHAL_PROFILING_INTERRUPT)));
+}
+
+#else
+
+static inline void check_valid_nmi(void)
+{
+}
+
+#endif
+
irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id);
DEFINE_PER_CPU(unsigned long, nmi_count);
@@ -219,6 +245,7 @@ void do_nmi(struct pt_regs *regs)
old_regs = set_irq_regs(regs);
nmi_enter();
++*this_cpu_ptr(&nmi_count);
+ check_valid_nmi();
xtensa_pmu_irq_handler(0, NULL);
nmi_exit();
set_irq_regs(old_regs);