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 <sha...@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/opal.h | 4 ++
arch/powerpc/platforms/powernv/opal.c | 74 ++++++++++++++++++++++++++++++++-
2 files changed, 77 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 2880797..c5803c0 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -644,6 +644,10 @@ 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(uint64_t mask, void (*cb)(uint64_t));
+extern void opal_notifier_disable(void);
+extern void opal_notifier_enable(void);
+
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 628c564..9e4c9e9 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -26,11 +26,21 @@ struct opal {
u64 entry;
} opal;
+struct opal_cb {
+ struct list_head list;
+ uint64_t mask;
+ void (*cb)(uint64_t);
+};
+
static struct device_node *opal_node;
static DEFINE_SPINLOCK(opal_write_lock);
extern u64 opal_mc_secondary_handler[];
static unsigned int *opal_irqs;
static unsigned int opal_irq_count;
+static LIST_HEAD(opal_notifier);
+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 +105,68 @@ static int __init opal_register_exception_handlers(void)
early_initcall(opal_register_exception_handlers);
+int opal_notifier_register(uint64_t mask, void (*cb)(uint64_t))
+{
+ unsigned long flags;
+ struct opal_cb *p;
+
+ if (!mask || !cb) {
+ pr_warning("%s: Invalid argument (%llx, %p)!\n",
+ __func__, mask, cb);
+ return -EINVAL;
+ }
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p) {
+ pr_warning("%s: Out of memory (%llx, %p)!\n",
+ __func__, mask, cb);
+ return -ENOMEM;
+ }
+ p->mask = mask;
+ p->cb = cb;
+
+ spin_lock_irqsave(&opal_notifier_lock, flags);
+ list_add_tail(&p->list, &opal_notifier);
+ spin_unlock_irqrestore(&opal_notifier_lock, flags);
+
+ return 0;
+}
+
+static void opal_do_notifier(uint64_t events)
+{
+ struct opal_cb *p;
+ uint64_t changed_mask;
+
+ if (atomic_read(&opal_notifier_hold))
+ return;
+
+ changed_mask = last_notified_mask ^ events;
+ last_notified_mask = events;
+
+ list_for_each_entry(p, &opal_notifier, list) {
+ if (changed_mask & p->mask)
+ p->cb(events);
+ }
+}
+
+void opal_notifier_disable(void)
+{
+ atomic_set(&opal_notifier_hold, 1);
+}
+
+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);
+}
+
int opal_get_chars(uint32_t vtermno, char *buf, int count)
{
s64 len, rc;
@@ -297,7 +369,7 @@ 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;
}
--
1.7.5.4
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