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genirq: Do not copy affinity before set

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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>
This commit is contained in:
Thomas Gleixner 2011-02-07 16:02:20 +01:00
parent 569bda8df1
commit 3b8249e759
4 changed files with 47 additions and 15 deletions
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11
include/linux/irq.h
View File

@ -85,6 +85,17 @@ typedef void (*irq_flow_handler_t)(unsigned int irq,
# define IRQ_NO_BALANCING_MASK IRQ_NO_BALANCING
#endif
/*
* Return value for chip->irq_set_affinity()
*
* IRQ_SET_MASK_OK - OK, core updates irq_data.affinity
* IRQ_SET_MASK_NOCPY - OK, chip did update irq_data.affinity
*/
enum {
IRQ_SET_MASK_OK = 0,
IRQ_SET_MASK_OK_NOCOPY,
};
struct msi_desc;
/**

2
kernel/irq/internals.h
View File

@ -43,7 +43,7 @@ static inline void unregister_handler_proc(unsigned int irq,
struct irqaction *action) { }
#endif
extern int irq_select_affinity_usr(unsigned int irq);
extern int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask);
extern void irq_set_thread_affinity(struct irq_desc *desc);

47
kernel/irq/manage.c
View File

@ -148,9 +148,12 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
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 @@ EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
/*
* 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 @@ static int setup_affinity(unsigned int irq, struct irq_desc *desc)
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 @@ static inline int setup_affinity(unsigned int irq, struct irq_desc *d)
/*
* 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 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
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 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
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 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
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 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
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 @@ mismatch:
#endif
ret = -EBUSY;
out_mask:
free_cpumask_var(mask);
out_thread:
raw_spin_unlock_irqrestore(&desc->lock, flags);
if (new->thread) {

2
kernel/irq/proc.c
View File

@ -89,7 +89,7 @@ static ssize_t irq_affinity_proc_write(struct file *file,
if (!cpumask_intersects(new_value, cpu_online_mask)) {
/* Special case for empty set - allow the architecture
code to set default SMP affinity. */
err = irq_select_affinity_usr(irq) ? -EINVAL : count;
err = irq_select_affinity_usr(irq, new_value) ? -EINVAL : count;
} else {
irq_set_affinity(irq, new_value);
err = count;