[MIPS] SMTC: Fix recursion in instant IPI replay code.
local_irq_restore -> raw_local_irq_restore -> irq_restore_epilog ->
smtc_ipi_replay -> smtc_ipi_dq -> spin_unlock_irqrestore ->
_spin_unlock_irqrestore -> local_irq_restore
The recursion does abort when there is no more IPI queued for a CPU, so
this isn't usually fatal which is why we got away with this for so long
until this was discovered by code inspection.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/irqflags.h b/include/asm-mips/irqflags.h
index af3b07d..e459fa0 100644
--- a/include/asm-mips/irqflags.h
+++ b/include/asm-mips/irqflags.h
@@ -13,29 +13,9 @@
#ifndef __ASSEMBLY__
+#include <linux/compiler.h>
#include <asm/hazards.h>
-/*
- * CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY does prompt replay of deferred IPIs,
- * at the cost of branch and call overhead on each local_irq_restore()
- */
-
-#ifdef CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY
-
-extern void smtc_ipi_replay(void);
-
-#define irq_restore_epilog(flags) \
-do { \
- if (!(flags & 0x0400)) \
- smtc_ipi_replay(); \
-} while (0)
-
-#else
-
-#define irq_restore_epilog(ignore) do { } while (0)
-
-#endif /* CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY */
-
__asm__ (
" .macro raw_local_irq_enable \n"
" .set push \n"
@@ -205,17 +185,28 @@
" .set pop \n"
" .endm \n");
-#define raw_local_irq_restore(flags) \
-do { \
- unsigned long __tmp1; \
- \
- __asm__ __volatile__( \
- "raw_local_irq_restore\t%0" \
- : "=r" (__tmp1) \
- : "0" (flags) \
- : "memory"); \
- irq_restore_epilog(flags); \
-} while(0)
+extern void smtc_ipi_replay(void);
+
+static inline void raw_local_irq_restore(unsigned long flags)
+{
+ unsigned long __tmp1;
+
+#ifdef CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY
+ /*
+ * CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY does prompt replay of deferred
+ * IPIs, at the cost of branch and call overhead on each
+ * local_irq_restore()
+ */
+ if (unlikely(!(flags & 0x0400)))
+ smtc_ipi_replay();
+#endif
+
+ __asm__ __volatile__(
+ "raw_local_irq_restore\t%0"
+ : "=r" (__tmp1)
+ : "0" (flags)
+ : "memory");
+}
static inline int raw_irqs_disabled_flags(unsigned long flags)
{