From 1bc98de26d3f270e004421685a8e698e91cf95ca Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Thu, 20 Jun 2013 18:13:22 +0800 Subject: [PATCH] powernv/opal: Notifier for OPAL events This patch implements a notifier to receive a notification on OPAL event mask changes. The notifier is only called as a result of an OPAL interrupt, which will happen upon reception of FSP messages or PCI errors. Any event mask change detected as a result of opal_poll_events() will not result in a notifier call. [benh: changelog] Signed-off-by: Gavin Shan Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/opal.h | 5 ++ arch/powerpc/platforms/powernv/opal.c | 69 ++++++++++++++++++++++++++- 2 files changed, 73 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h index 28807978bb46..029fe85722aa 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -644,6 +644,11 @@ extern void hvc_opal_init_early(void); extern int early_init_dt_scan_opal(unsigned long node, const char *uname, int depth, void *data); +extern int opal_notifier_register(struct notifier_block *nb); +extern void opal_notifier_enable(void); +extern void opal_notifier_disable(void); +extern void opal_notifier_update_evt(uint64_t evt_mask, uint64_t evt_val); + extern int opal_get_chars(uint32_t vtermno, char *buf, int count); extern int opal_put_chars(uint32_t vtermno, const char *buf, int total_len); diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index 628c564ceadb..106301fd2fa5 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -31,6 +32,10 @@ static DEFINE_SPINLOCK(opal_write_lock); extern u64 opal_mc_secondary_handler[]; static unsigned int *opal_irqs; static unsigned int opal_irq_count; +static ATOMIC_NOTIFIER_HEAD(opal_notifier_head); +static DEFINE_SPINLOCK(opal_notifier_lock); +static uint64_t last_notified_mask = 0x0ul; +static atomic_t opal_notifier_hold = ATOMIC_INIT(0); int __init early_init_dt_scan_opal(unsigned long node, const char *uname, int depth, void *data) @@ -95,6 +100,68 @@ static int __init opal_register_exception_handlers(void) early_initcall(opal_register_exception_handlers); +int opal_notifier_register(struct notifier_block *nb) +{ + if (!nb) { + pr_warning("%s: Invalid argument (%p)\n", + __func__, nb); + return -EINVAL; + } + + atomic_notifier_chain_register(&opal_notifier_head, nb); + return 0; +} + +static void opal_do_notifier(uint64_t events) +{ + unsigned long flags; + uint64_t changed_mask; + + if (atomic_read(&opal_notifier_hold)) + return; + + spin_lock_irqsave(&opal_notifier_lock, flags); + changed_mask = last_notified_mask ^ events; + last_notified_mask = events; + spin_unlock_irqrestore(&opal_notifier_lock, flags); + + /* + * We feed with the event bits and changed bits for + * enough information to the callback. + */ + atomic_notifier_call_chain(&opal_notifier_head, + events, (void *)changed_mask); +} + +void opal_notifier_update_evt(uint64_t evt_mask, + uint64_t evt_val) +{ + unsigned long flags; + + spin_lock_irqsave(&opal_notifier_lock, flags); + last_notified_mask &= ~evt_mask; + last_notified_mask |= evt_val; + spin_unlock_irqrestore(&opal_notifier_lock, flags); +} + +void opal_notifier_enable(void) +{ + int64_t rc; + uint64_t evt = 0; + + atomic_set(&opal_notifier_hold, 0); + + /* Process pending events */ + rc = opal_poll_events(&evt); + if (rc == OPAL_SUCCESS && evt) + opal_do_notifier(evt); +} + +void opal_notifier_disable(void) +{ + atomic_set(&opal_notifier_hold, 1); +} + int opal_get_chars(uint32_t vtermno, char *buf, int count) { s64 len, rc; @@ -297,7 +364,7 @@ static irqreturn_t opal_interrupt(int irq, void *data) opal_handle_interrupt(virq_to_hw(irq), &events); - /* XXX TODO: Do something with the events */ + opal_do_notifier(events); return IRQ_HANDLED; } -- 2.39.2