genirq: Do not copy affinity before set
While rumaging through arch code I found that there are a few
workarounds which deal with the fact that the initial affinity setting
from request_irq() copies the mask into irq_data->affinity before the
chip code is called. In the normal path we unconditionally copy the
mask when the chip code returns 0.
Copy after the code is called and add a return code
IRQ_SET_MASK_OK_NOCOPY for the chip functions, which prevents the
copy. That way we see the real mask when the chip function decided to
truncate it further as some arches do. IRQ_SET_MASK_OK is 0, which is
the current behaviour.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index ade65bf..dc95d53d 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -148,9 +148,12 @@
if (irq_can_move_pcntxt(desc)) {
ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
- if (!ret) {
+ switch (ret) {
+ case IRQ_SET_MASK_OK:
cpumask_copy(desc->irq_data.affinity, mask);
+ case IRQ_SET_MASK_OK_NOCOPY:
irq_set_thread_affinity(desc);
+ ret = 0;
}
} else {
desc->status |= IRQ_MOVE_PENDING;
@@ -254,9 +257,12 @@
/*
* Generic version of the affinity autoselector.
*/
-static int setup_affinity(unsigned int irq, struct irq_desc *desc)
+static int
+setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
{
+ struct irq_chip *chip = get_irq_desc_chip(desc);
struct cpumask *set = irq_default_affinity;
+ int ret;
/* Excludes PER_CPU and NO_BALANCE interrupts */
if (!irq_can_set_affinity(irq))
@@ -273,13 +279,20 @@
else
desc->status &= ~IRQ_AFFINITY_SET;
}
- cpumask_and(desc->irq_data.affinity, cpu_online_mask, set);
- desc->irq_data.chip->irq_set_affinity(&desc->irq_data, desc->irq_data.affinity, false);
+ cpumask_and(mask, cpu_online_mask, set);
+ ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
+ switch (ret) {
+ case IRQ_SET_MASK_OK:
+ cpumask_copy(desc->irq_data.affinity, mask);
+ case IRQ_SET_MASK_OK_NOCOPY:
+ irq_set_thread_affinity(desc);
+ }
return 0;
}
#else
-static inline int setup_affinity(unsigned int irq, struct irq_desc *d)
+static inline int
+setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
{
return irq_select_affinity(irq);
}
@@ -288,23 +301,23 @@
/*
* Called when affinity is set via /proc/irq
*/
-int irq_select_affinity_usr(unsigned int irq)
+int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
int ret;
raw_spin_lock_irqsave(&desc->lock, flags);
- ret = setup_affinity(irq, desc);
+ ret = setup_affinity(irq, desc, mask);
if (!ret)
irq_set_thread_affinity(desc);
raw_spin_unlock_irqrestore(&desc->lock, flags);
-
return ret;
}
#else
-static inline int setup_affinity(unsigned int irq, struct irq_desc *desc)
+static inline int
+setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
{
return 0;
}
@@ -765,8 +778,8 @@
struct irqaction *old, **old_ptr;
const char *old_name = NULL;
unsigned long flags;
- int nested, shared = 0;
- int ret;
+ int ret, nested, shared = 0;
+ cpumask_var_t mask;
if (!desc)
return -EINVAL;
@@ -831,6 +844,11 @@
new->thread = t;
}
+ if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
+ ret = -ENOMEM;
+ goto out_thread;
+ }
+
/*
* The following block of code has to be executed atomically
*/
@@ -876,7 +894,7 @@
new->flags & IRQF_TRIGGER_MASK);
if (ret)
- goto out_thread;
+ goto out_mask;
} else
compat_irq_chip_set_default_handler(desc);
#if defined(CONFIG_IRQ_PER_CPU)
@@ -903,7 +921,7 @@
desc->status |= IRQ_NO_BALANCING;
/* Set default affinity mask once everything is setup */
- setup_affinity(irq, desc);
+ setup_affinity(irq, desc, mask);
} else if ((new->flags & IRQF_TRIGGER_MASK)
&& (new->flags & IRQF_TRIGGER_MASK)
@@ -956,6 +974,9 @@
#endif
ret = -EBUSY;
+out_mask:
+ free_cpumask_var(mask);
+
out_thread:
raw_spin_unlock_irqrestore(&desc->lock, flags);
if (new->thread) {