From ac8be955049dab828a68b9c68a75144832f8289f Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Sat, 20 Jan 2007 00:18:01 +0000 Subject: [MIPS] SMTC: Instant IPI replay. SMTC pseudo-interrupts between TCs are deferred and queued if the target TC is interrupt-inhibited (IXMT). In the first SMTC prototypes, these queued IPIs were serviced on return to user mode, or on entry into the kernel idle loop. The INSTANT_REPLAY option dispatches them as part of local_irq_restore() processing, which adds runtime overhead (hence the option to turn it off), but ensures that IPIs are handled promptly even under heavy I/O interrupt load. Signed-off-by: Ralf Baechle --- include/asm-mips/irqflags.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'include') diff --git a/include/asm-mips/irqflags.h b/include/asm-mips/irqflags.h index 46bf5de5ac72..af3b07dfad4b 100644 --- a/include/asm-mips/irqflags.h +++ b/include/asm-mips/irqflags.h @@ -15,6 +15,27 @@ #include +/* + * 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" @@ -193,6 +214,7 @@ do { \ : "=r" (__tmp1) \ : "0" (flags) \ : "memory"); \ + irq_restore_epilog(flags); \ } while(0) static inline int raw_irqs_disabled_flags(unsigned long flags) -- cgit v1.2.3