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| author | Ralf Baechle <ralf@linux-mips.org> | 2007-01-20 00:18:01 +0000 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2007-01-23 18:26:47 +0000 |
| commit | ac8be955049dab828a68b9c68a75144832f8289f (patch) | |
| tree | c9992cccbc6bcb2f099395ef614ebc96b91a2598 /include | |
| parent | 9ee79a3d372fcb6729893437f4923c5efd1f85db (diff) | |
| download | op-kernel-dev-ac8be955049dab828a68b9c68a75144832f8289f.zip op-kernel-dev-ac8be955049dab828a68b9c68a75144832f8289f.tar.gz | |
[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 <ralf@linux-mips.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-mips/irqflags.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/include/asm-mips/irqflags.h b/include/asm-mips/irqflags.h index 46bf5de..af3b07d 100644 --- a/include/asm-mips/irqflags.h +++ b/include/asm-mips/irqflags.h @@ -15,6 +15,27 @@ #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" @@ -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) |
