[23/26] powerpc/ps3: Fix lost SMP IPIs

Greg KH
2011-11-19T00:08:54Z

From: Geoff Levand <geoff@infradead.org>

commit 72f3bea075287785ed32b777b6dd2636aa7002e8 upstream.

Fixes the PS3 bootup hang introduced in 3.0-rc1 by:

commit 317f394160e9beb97d19a84c39b7e5eb3d7815a
sched: Move the second half of ttwu() to the remote cpu

Move the PS3's LV1 EOI call lv1_end_of_interrupt_ext() from ps3_chip_eoi()
to ps3_get_irq() for IPI messages.

If lv1_send_event_locally() is called between a previous call to
lv1_send_event_locally() and the coresponding call to
lv1_end_of_interrupt_ext() the second event will not be delivered to the
target cpu.

The PS3's SMP IPIs are implemented using lv1_send_event_locally(), so if two
IPI messages of the same type are sent to the same target in a relatively
short period of time the second IPI event can become lost when
lv1_end_of_interrupt_ext() is called from ps3_chip_eoi().

Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/powerpc/platforms/ps3/interrupt.c | 23 ++++++++++++++++++++++-
arch/powerpc/platforms/ps3/platform.h | 1 +
arch/powerpc/platforms/ps3/smp.c | 2 ++
3 files changed, 25 insertions(+), 1 deletion(-)

--- a/arch/powerpc/platforms/ps3/interrupt.c
+++ b/arch/powerpc/platforms/ps3/interrupt.c
@@ -88,6 +88,7 @@ struct ps3_private {
struct ps3_bmp bmp __attribute__ ((aligned (PS3_BMP_MINALIGN)));
u64 ppe_id;
u64 thread_id;
+ unsigned long ipi_mask;
};

static DEFINE_PER_CPU(struct ps3_private, ps3_private);
@@ -144,7 +145,11 @@ static void ps3_chip_unmask(struct irq_d
static void ps3_chip_eoi(struct irq_data *d)
{
const struct ps3_private *pd = irq_data_get_irq_chip_data(d);
- lv1_end_of_interrupt_ext(pd->ppe_id, pd->thread_id, d->irq);
+
+ /* non-IPIs are EOIed here. */
+
+ if (!test_bit(63 - d->irq, &pd->ipi_mask))
+ lv1_end_of_interrupt_ext(pd->ppe_id, pd->thread_id, d->irq);
}

/**
@@ -691,6 +696,16 @@ void __init ps3_register_ipi_debug_brk(u
cpu, virq, pd->bmp.ipi_debug_brk_mask);
}

+void __init ps3_register_ipi_irq(unsigned int cpu, unsigned int virq)
+{
+ struct ps3_private *pd = &per_cpu(ps3_private, cpu);
+
+ set_bit(63 - virq, &pd->ipi_mask);
+
+ DBG("%s:%d: cpu %u, virq %u, ipi_mask %lxh\n", __func__, __LINE__,
+ cpu, virq, pd->ipi_mask);
+}
+
static unsigned int ps3_get_irq(void)
{
struct ps3_private *pd = &__get_cpu_var(ps3_private);
@@ -720,6 +735,12 @@ static unsigned int ps3_get_irq(void)
BUG();
}
#endif
+
+ /* IPIs are EOIed here. */
+
+ if (test_bit(63 - plug, &pd->ipi_mask))
+ lv1_end_of_interrupt_ext(pd->ppe_id, pd->thread_id, plug);
+
return plug;
}

--- a/arch/powerpc/platforms/ps3/platform.h
+++ b/arch/powerpc/platforms/ps3/platform.h
@@ -43,6 +43,7 @@ void ps3_mm_shutdown(void);
void ps3_init_IRQ(void);
void ps3_shutdown_IRQ(int cpu);
void __init ps3_register_ipi_debug_brk(unsigned int cpu, unsigned int virq);
+void __init ps3_register_ipi_irq(unsigned int cpu, unsigned int virq);

/* smp */

--- a/arch/powerpc/platforms/ps3/smp.c
+++ b/arch/powerpc/platforms/ps3/smp.c
@@ -94,6 +94,8 @@ static void __init ps3_smp_setup_cpu(int

if (result)
virqs[i] = NO_IRQ;
+ else
+ ps3_register_ipi_irq(cpu, virqs[i]);
}

ps3_register_ipi_debug_brk(cpu, virqs[PPC_MSG_DEBUGGER_BREAK]);