Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] Vr41xx: Fix after GENERIC_HARDIRQS_NO__DO_IRQ change
  [MIPS] SMTC: Instant IPI replay.
This commit is contained in:
Linus Torvalds 2007-01-23 11:19:32 -08:00
commit d227e87e6c
5 changed files with 130 additions and 86 deletions

View file

@ -1568,6 +1568,20 @@ config MIPS_MT_FPAFF
depends on MIPS_MT
default y
config MIPS_MT_SMTC_INSTANT_REPLAY
bool "Low-latency Dispatch of Deferred SMTC IPIs"
depends on MIPS_MT_SMTC
default y
help
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.
config MIPS_VPE_LOADER_TOM
bool "Load VPE program into memory hidden from linux"
depends on MIPS_VPE_LOADER

View file

@ -1017,6 +1017,33 @@ void setup_cross_vpe_interrupts(void)
* SMTC-specific hacks invoked from elsewhere in the kernel.
*/
void smtc_ipi_replay(void)
{
/*
* To the extent that we've ever turned interrupts off,
* we may have accumulated deferred IPIs. This is subtle.
* If we use the smtc_ipi_qdepth() macro, we'll get an
* exact number - but we'll also disable interrupts
* and create a window of failure where a new IPI gets
* queued after we test the depth but before we re-enable
* interrupts. So long as IXMT never gets set, however,
* we should be OK: If we pick up something and dispatch
* it here, that's great. If we see nothing, but concurrent
* with this operation, another TC sends us an IPI, IXMT
* is clear, and we'll handle it as a real pseudo-interrupt
* and not a pseudo-pseudo interrupt.
*/
if (IPIQ[smp_processor_id()].depth > 0) {
struct smtc_ipi *pipi;
extern void self_ipi(struct smtc_ipi *);
while ((pipi = smtc_ipi_dq(&IPIQ[smp_processor_id()]))) {
self_ipi(pipi);
smtc_cpu_stats[smp_processor_id()].selfipis++;
}
}
}
void smtc_idle_loop_hook(void)
{
#ifdef SMTC_IDLE_HOOK_DEBUG
@ -1113,29 +1140,14 @@ void smtc_idle_loop_hook(void)
if (pdb_msg != &id_ho_db_msg[0])
printk("CPU%d: %s", smp_processor_id(), id_ho_db_msg);
#endif /* SMTC_IDLE_HOOK_DEBUG */
/*
* To the extent that we've ever turned interrupts off,
* we may have accumulated deferred IPIs. This is subtle.
* If we use the smtc_ipi_qdepth() macro, we'll get an
* exact number - but we'll also disable interrupts
* and create a window of failure where a new IPI gets
* queued after we test the depth but before we re-enable
* interrupts. So long as IXMT never gets set, however,
* we should be OK: If we pick up something and dispatch
* it here, that's great. If we see nothing, but concurrent
* with this operation, another TC sends us an IPI, IXMT
* is clear, and we'll handle it as a real pseudo-interrupt
* and not a pseudo-pseudo interrupt.
*/
if (IPIQ[smp_processor_id()].depth > 0) {
struct smtc_ipi *pipi;
extern void self_ipi(struct smtc_ipi *);
if ((pipi = smtc_ipi_dq(&IPIQ[smp_processor_id()])) != NULL) {
self_ipi(pipi);
smtc_cpu_stats[smp_processor_id()].selfipis++;
}
}
/*
* Replay any accumulated deferred IPIs. If "Instant Replay"
* is in use, there should never be any.
*/
#ifndef CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY
smtc_ipi_replay();
#endif /* CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY */
}
void smtc_soft_dump(void)

View file

@ -1,7 +1,7 @@
/*
* Interrupt handing routines for NEC VR4100 series.
*
* Copyright (C) 2005 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
* Copyright (C) 2005-2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@ -73,13 +73,19 @@ static void irq_dispatch(unsigned int irq)
if (cascade->get_irq != NULL) {
unsigned int source_irq = irq;
desc = irq_desc + source_irq;
desc->chip->ack(source_irq);
if (desc->chip->mask_ack)
desc->chip->mask_ack(source_irq);
else {
desc->chip->mask(source_irq);
desc->chip->ack(source_irq);
}
irq = cascade->get_irq(irq);
if (irq < 0)
atomic_inc(&irq_err_count);
else
irq_dispatch(irq);
desc->chip->end(source_irq);
if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
desc->chip->unmask(source_irq);
} else
do_IRQ(irq);
}