diff options
author | James Hogan | 2015-01-19 15:38:24 +0000 |
---|---|---|
committer | Ralf Baechle | 2015-02-05 14:37:35 +0100 |
commit | 1b6af71a8f50f59a96f65ad90e4d20612d2a2526 (patch) | |
tree | f13a4bc3c18ef198249c9deb79bbd90561801c07 /drivers/irqchip | |
parent | c2d9f17757310484ab4fd65954f5f9850f6a1349 (diff) |
IRQCHIP: mips-gic: Avoid rerouting timer IRQs for smp-cmp
Commit e9de688dac65 ("irqchip: mips-gic: Support local interrupts")
changed the GIC irqchip driver so that all local interrupts were routed
to the same CPU pin used for external interrupts. Unfortunately this
causes a regression when smp-cmp is used. The CPUs are started by the
bootloader and put in a timer based waiting poll loop, but when their
timer interrupts are rerouted to a different IRQ pin which is not
unmasked they never wake up.
Since smp-cmp support is deprecated and everybody who was using it
should be switching to smp-cps which brings up the secondary CPUs
without bootloader assistance, I've gone for the simple fix which can be
easily removed once smp-cmp is removed, rather than a fully generic fix.
In __gic_init() the local GIC_VPE_TIMER_MAP register is read to find the
boot-time routing of the local timer interrupt, and a chained handler is
added to that CPU pin as well as the normal one.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Fixes: e9de688dac65 ("irqchip: mips-gic: Support local interrupts")
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Reviewed-by: Andrew Bresticker <abrestic@chromium.org>
Patchwork: https://patchwork.linux-mips.org/patch/9081/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'drivers/irqchip')
-rw-r--r-- | drivers/irqchip/irq-mips-gic.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c index 2b0468e3df6a..56b96c63dc4b 100644 --- a/drivers/irqchip/irq-mips-gic.c +++ b/drivers/irqchip/irq-mips-gic.c @@ -37,6 +37,7 @@ static struct irq_domain *gic_irq_domain; static int gic_shared_intrs; static int gic_vpes; static unsigned int gic_cpu_pin; +static unsigned int timer_cpu_pin; static struct irq_chip gic_level_irq_controller, gic_edge_irq_controller; static void __gic_irq_dispatch(void); @@ -616,6 +617,8 @@ static int gic_local_irq_domain_map(struct irq_domain *d, unsigned int virq, gic_write(GIC_REG(VPE_OTHER, GIC_VPE_COMPARE_MAP), val); break; case GIC_LOCAL_INT_TIMER: + /* CONFIG_MIPS_CMP workaround (see __gic_init) */ + val = GIC_MAP_TO_PIN_MSK | timer_cpu_pin; gic_write(GIC_REG(VPE_OTHER, GIC_VPE_TIMER_MAP), val); break; case GIC_LOCAL_INT_PERFCTR: @@ -713,12 +716,36 @@ static void __init __gic_init(unsigned long gic_base_addr, if (cpu_has_veic) { /* Always use vector 1 in EIC mode */ gic_cpu_pin = 0; + timer_cpu_pin = gic_cpu_pin; set_vi_handler(gic_cpu_pin + GIC_PIN_TO_VEC_OFFSET, __gic_irq_dispatch); } else { gic_cpu_pin = cpu_vec - GIC_CPU_PIN_OFFSET; irq_set_chained_handler(MIPS_CPU_IRQ_BASE + cpu_vec, gic_irq_dispatch); + /* + * With the CMP implementation of SMP (deprecated), other CPUs + * are started by the bootloader and put into a timer based + * waiting poll loop. We must not re-route those CPU's local + * timer interrupts as the wait instruction will never finish, + * so just handle whatever CPU interrupt it is routed to by + * default. + * + * This workaround should be removed when CMP support is + * dropped. + */ + if (IS_ENABLED(CONFIG_MIPS_CMP) && + gic_local_irq_is_routable(GIC_LOCAL_INT_TIMER)) { + timer_cpu_pin = gic_read(GIC_REG(VPE_LOCAL, + GIC_VPE_TIMER_MAP)) & + GIC_MAP_MSK; + irq_set_chained_handler(MIPS_CPU_IRQ_BASE + + GIC_CPU_PIN_OFFSET + + timer_cpu_pin, + gic_irq_dispatch); + } else { + timer_cpu_pin = gic_cpu_pin; + } } gic_irq_domain = irq_domain_add_simple(node, GIC_NUM_LOCAL_INTRS + |