[patch 55/75] genirq: Mirror IRQ_PER_CPU and IRQ_NO_BALANCING inirq_data.state

From: Thomas Gleixner
Date: Thu Feb 10 2011 - 18:42:43 EST


That's the right data structure to look at for arch code.

Accessor functions are provided.

irqd_is_per_cpu(irqdata);
irqd_can_balance(irqdata);

Coders who access them directly will be tracked down and slapped with
stinking trouts.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
include/linux/irq.h | 16 +++++++++++++++-
kernel/irq/chip.c | 15 +++++++++------
kernel/irq/internals.h | 11 +++++++++++
kernel/irq/manage.c | 16 ++++++++++------
kernel/irq/migration.c | 2 +-
kernel/irq/settings.h | 36 ++++++++++++++++++++++++++++++++++++
kernel/irq/spurious.c | 3 ++-
7 files changed, 84 insertions(+), 15 deletions(-)

Index: linux-2.6-tip/include/linux/irq.h
===================================================================
--- linux-2.6-tip.orig/include/linux/irq.h
+++ linux-2.6-tip/include/linux/irq.h
@@ -130,10 +130,14 @@ struct irq_data {
* Bit masks for irq_data.state
*
* IRQD_SETAFFINITY_PENDING - Affinity setting is pending
+ * IRQD_NO_BALANCING - Balancing disabled for this IRQ
+ * IRQD_PER_CPU - Interrupt is per cpu
*/
enum {
/* Bit 0 - 7 reserved for TYPE will use later */
- IRQD_SETAFFINITY_PENDING = (1 << 8),
+ IRQD_SETAFFINITY_PENDING = (1 << 8),
+ IRQD_NO_BALANCING = (1 << 10),
+ IRQD_PER_CPU = (1 << 11),
};

static inline bool irqd_is_setaffinity_pending(struct irq_data *d)
@@ -141,6 +145,16 @@ static inline bool irqd_is_setaffinity_p
return d->state_use_accessors & IRQD_SETAFFINITY_PENDING;
}

+static inline bool irqd_is_per_cpu(struct irq_data *d)
+{
+ return d->state_use_accessors & IRQD_PER_CPU;
+}
+
+static inline bool irqd_can_balance(struct irq_data *d)
+{
+ return !(d->state_use_accessors & (IRQD_PER_CPU | IRQD_NO_BALANCING));
+}
+
/**
* struct irq_chip - hardware interrupt chip descriptor
*
Index: linux-2.6-tip/kernel/irq/chip.c
===================================================================
--- linux-2.6-tip.orig/kernel/irq/chip.c
+++ linux-2.6-tip/kernel/irq/chip.c
@@ -732,12 +732,15 @@ void irq_modify_status(unsigned int irq,
if (!desc)
return;

- /* Sanitize flags */
- set &= IRQF_MODIFY_MASK;
- clr &= IRQF_MODIFY_MASK;
-
raw_spin_lock_irqsave(&desc->lock, flags);
- desc->status &= ~clr;
- desc->status |= set;
+
+ irq_settings_clr_and_set(desc, clr, set);
+
+ irqd_clear(&desc->irq_data, IRQD_NO_BALANCING | IRQD_PER_CPU);
+ if (irq_settings_has_no_balance_set(desc))
+ irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
+ if (irq_settings_is_per_cpu(desc))
+ irqd_set(&desc->irq_data, IRQD_PER_CPU);
+
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
Index: linux-2.6-tip/kernel/irq/internals.h
===================================================================
--- linux-2.6-tip.orig/kernel/irq/internals.h
+++ linux-2.6-tip/kernel/irq/internals.h
@@ -137,3 +137,14 @@ static inline void irqd_clr_move_pending
d->state_use_accessors &= ~IRQD_SETAFFINITY_PENDING;
irq_compat_clr_move_pending(irq_data_to_desc(d));
}
+
+static inline void irqd_clear(struct irq_data *d, unsigned int mask)
+{
+ d->state_use_accessors &= ~mask;
+}
+
+static inline void irqd_set(struct irq_data *d, unsigned int mask)
+{
+ d->state_use_accessors |= mask;
+}
+
Index: linux-2.6-tip/kernel/irq/manage.c
===================================================================
--- linux-2.6-tip.orig/kernel/irq/manage.c
+++ linux-2.6-tip/kernel/irq/manage.c
@@ -73,8 +73,8 @@ int irq_can_set_affinity(unsigned int ir
{
struct irq_desc *desc = irq_to_desc(irq);

- if ((desc->status & (IRQ_PER_CPU | IRQ_NO_BALANCING)) ||
- !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
+ if (!irqd_can_balance(&desc->irq_data) || !desc->irq_data.chip ||
+ !desc->irq_data.chip->irq_set_affinity)
return 0;

return 1;
@@ -903,8 +903,10 @@ __setup_irq(unsigned int irq, struct irq
IRQS_INPROGRESS | IRQS_ONESHOT | \
IRQS_WAITING);

- if (new->flags & IRQF_PERCPU)
- desc->status |= IRQ_PER_CPU;
+ if (new->flags & IRQF_PERCPU) {
+ irqd_set(&desc->irq_data, IRQD_PER_CPU);
+ irq_settings_set_per_cpu(desc);
+ }

if (new->flags & IRQF_ONESHOT)
desc->istate |= IRQS_ONESHOT;
@@ -916,8 +918,10 @@ __setup_irq(unsigned int irq, struct irq
desc->depth = 1;

/* Exclude IRQ from balancing if requested */
- if (new->flags & IRQF_NOBALANCING)
- desc->status |= IRQ_NO_BALANCING;
+ if (new->flags & IRQF_NOBALANCING) {
+ irq_settings_set_no_balancing(desc);
+ irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
+ }

/* Set default affinity mask once everything is setup */
setup_affinity(irq, desc, mask);
Index: linux-2.6-tip/kernel/irq/migration.c
===================================================================
--- linux-2.6-tip.orig/kernel/irq/migration.c
+++ linux-2.6-tip/kernel/irq/migration.c
@@ -15,7 +15,7 @@ void move_masked_irq(int irq)
/*
* Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
*/
- if (desc->status & (IRQ_PER_CPU | IRQ_NO_BALANCING)) {
+ if (!irqd_can_balance(&desc->irq_data)) {
WARN_ON(1);
return;
}
Index: linux-2.6-tip/kernel/irq/settings.h
===================================================================
--- linux-2.6-tip.orig/kernel/irq/settings.h
+++ linux-2.6-tip/kernel/irq/settings.h
@@ -4,6 +4,9 @@
*/
enum {
_IRQ_DEFAULT_INIT_FLAGS = IRQ_DEFAULT_INIT_FLAGS,
+ _IRQ_PER_CPU = IRQ_PER_CPU,
+ _IRQ_NO_BALANCING = IRQ_NO_BALANCING,
+ _IRQF_MODIFY_MASK = IRQF_MODIFY_MASK,
};

#undef IRQ_INPROGRESS
@@ -22,3 +25,36 @@ enum {
#define IRQ_WAKEUP GOT_YOU_MORON
#undef IRQ_MOVE_PENDING
#define IRQ_MOVE_PENDING GOT_YOU_MORON
+#undef IRQ_PER_CPU
+#define IRQ_PER_CPU GOT_YOU_MORON
+#undef IRQ_NO_BALANCING
+#define IRQ_NO_BALANCING GOT_YOU_MORON
+#undef IRQF_MODIFY_MASK
+#define IRQF_MODIFY_MASK GOT_YOU_MORON
+
+static inline void
+irq_settings_clr_and_set(struct irq_desc *desc, u32 clr, u32 set)
+{
+ desc->status &= ~(clr & _IRQF_MODIFY_MASK);
+ desc->status |= (set & _IRQF_MODIFY_MASK);
+}
+
+static inline bool irq_settings_is_per_cpu(struct irq_desc *desc)
+{
+ return desc->status & _IRQ_PER_CPU;
+}
+
+static inline void irq_settings_set_per_cpu(struct irq_desc *desc)
+{
+ desc->status |= _IRQ_PER_CPU;
+}
+
+static inline void irq_settings_set_no_balancing(struct irq_desc *desc)
+{
+ desc->status |= _IRQ_NO_BALANCING;
+}
+
+static inline bool irq_settings_has_no_balance_set(struct irq_desc *desc)
+{
+ return desc->status & _IRQ_NO_BALANCING;
+}
Index: linux-2.6-tip/kernel/irq/spurious.c
===================================================================
--- linux-2.6-tip.orig/kernel/irq/spurious.c
+++ linux-2.6-tip/kernel/irq/spurious.c
@@ -68,7 +68,8 @@ static int try_one_irq(int irq, struct i
raw_spin_lock(&desc->lock);

/* PER_CPU and nested thread interrupts are never polled */
- if ((desc->status & IRQ_PER_CPU) || (desc->istate & IRQS_NESTED_THREAD))
+ if (irq_settings_is_per_cpu(desc) ||
+ (desc->istate & IRQS_NESTED_THREAD))
goto out;

/*


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/