cpumask: make irq_set_affinity() take a const struct cpumask

Impact: change existing irq_chip API

Not much point with gentle transition here: the struct irq_chip's
setaffinity method signature needs to change.

Fortunately, not widely used code, but hits a few architectures.

Note: In irq_select_affinity() I save a temporary in by mangling
irq_desc[irq].affinity directly.  Ingo, does this break anything?

(Folded in fix from KOSAKI Motohiro)

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Acked-by: Ingo Molnar <mingo@redhat.com>
Cc: ralf@linux-mips.org
Cc: grundler@parisc-linux.org
Cc: jeremy@xensource.com
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>

4 files changed, 37 insertions, 30 deletions

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 10b5092e9bfe..58d8e31daa49 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -45,7 +45,7 @@ void dynamic_irq_init(unsigned int irq)
         desc->irq_count = 0;
         desc->irqs_unhandled = 0;
 #ifdef CONFIG_SMP
-        cpus_setall(desc->affinity);
+        cpumask_setall(&desc->affinity);
 #endif
         spin_unlock_irqrestore(&desc->lock, flags);
 }
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 801addda3c43..10ad2f87ed9a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -79,7 +79,7 @@ int irq_can_set_affinity(unsigned int irq)
  *      @cpumask:       cpumask
  *
  */
-int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
+int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 {
         struct irq_desc *desc = irq_to_desc(irq);
         unsigned long flags;
@@ -91,14 +91,14 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
         if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
-                desc->affinity = cpumask;
+                cpumask_copy(&desc->affinity, cpumask);
                 desc->chip->set_affinity(irq, cpumask);
         } else {
                 desc->status |= IRQ_MOVE_PENDING;
-                desc->pending_mask = cpumask;
+                cpumask_copy(&desc->pending_mask, cpumask);
         }
 #else
-        desc->affinity = cpumask;
+        cpumask_copy(&desc->affinity, cpumask);
         desc->chip->set_affinity(irq, cpumask);
 #endif
         desc->status |= IRQ_AFFINITY_SET;
@@ -112,26 +112,24 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
  */
 int do_irq_select_affinity(unsigned int irq, struct irq_desc *desc)
 {
-        cpumask_t mask;
-
         if (!irq_can_set_affinity(irq))
                 return 0;
 
-        cpus_and(mask, cpu_online_map, irq_default_affinity);
-
         /*
          * Preserve an userspace affinity setup, but make sure that
          * one of the targets is online.
          */
         if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) {
-                if (cpus_intersects(desc->affinity, cpu_online_map))
-                        mask = desc->affinity;
+                if (cpumask_any_and(&desc->affinity, cpu_online_mask)
+                    < nr_cpu_ids)
+                        goto set_affinity;
                 else
                         desc->status &= ~IRQ_AFFINITY_SET;
         }
 
-        desc->affinity = mask;
-        desc->chip->set_affinity(irq, mask);
+        cpumask_and(&desc->affinity, cpu_online_mask, &irq_default_affinity);
+set_affinity:
+        desc->chip->set_affinity(irq, &desc->affinity);
 
         return 0;
 }
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index 9db681d95814..bd72329e630c 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -4,7 +4,6 @@
 void move_masked_irq(int irq)
 {
         struct irq_desc *desc = irq_to_desc(irq);
-        cpumask_t tmp;
 
         if (likely(!(desc->status & IRQ_MOVE_PENDING)))
                 return;
@@ -19,7 +18,7 @@ void move_masked_irq(int irq)
 
         desc->status &= ~IRQ_MOVE_PENDING;
 
-        if (unlikely(cpus_empty(desc->pending_mask)))
+        if (unlikely(cpumask_empty(&desc->pending_mask)))
                 return;
 
         if (!desc->chip->set_affinity)
@@ -27,8 +26,6 @@ void move_masked_irq(int irq)
 
         assert_spin_locked(&desc->lock);
 
-        cpus_and(tmp, desc->pending_mask, cpu_online_map);
-
         /*
          * If there was a valid mask to work with, please
          * do the disable, re-program, enable sequence.
@@ -41,10 +38,13 @@ void move_masked_irq(int irq)
          * For correct operation this depends on the caller
          * masking the irqs.
          */
-        if (likely(!cpus_empty(tmp))) {
-                desc->chip->set_affinity(irq,tmp);
+        if (likely(cpumask_any_and(&desc->pending_mask, cpu_online_mask)
+                   < nr_cpu_ids)) {
+                cpumask_and(&desc->affinity,
+                            &desc->pending_mask, cpu_online_mask);
+                desc->chip->set_affinity(irq, &desc->affinity);
         }
-        cpus_clear(desc->pending_mask);
+        cpumask_clear(&desc->pending_mask);
 }
 
 void move_native_irq(int irq)
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index f293349d49d0..8e91c9762520 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -40,33 +40,42 @@ static ssize_t irq_affinity_proc_write(struct file *file,
                 const char __user *buffer, size_t count, loff_t *pos)
 {
         unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data;
-        cpumask_t new_value;
+        cpumask_var_t new_value;
         int err;
 
         if (!irq_to_desc(irq)->chip->set_affinity || no_irq_affinity ||
             irq_balancing_disabled(irq))
                 return -EIO;
 
-        err = cpumask_parse_user(buffer, count, &new_value);
+        if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
+                return -ENOMEM;
+
+        err = cpumask_parse_user(buffer, count, new_value);
         if (err)
-                return err;
+                goto free_cpumask;
 
-        if (!is_affinity_mask_valid(new_value))
-                return -EINVAL;
+        if (!is_affinity_mask_valid(*new_value)) {
+                err = -EINVAL;
+                goto free_cpumask;
+        }
 
         /*
          * Do not allow disabling IRQs completely - it's a too easy
          * way to make the system unusable accidentally :-) At least
          * one online CPU still has to be targeted.
          */
-        if (!cpus_intersects(new_value, cpu_online_map))
+        if (!cpumask_intersects(new_value, cpu_online_mask)) {
                 /* Special case for empty set - allow the architecture
                    code to set default SMP affinity. */
-                return irq_select_affinity_usr(irq) ? -EINVAL : count;
-
-        irq_set_affinity(irq, new_value);
+                err = irq_select_affinity_usr(irq) ? -EINVAL : count;
+        } else {
+                irq_set_affinity(irq, new_value);
+                err = count;
+        }
 
-        return count;
+free_cpumask:
+        free_cpumask_var(new_value);
+        return err;
 }
 
 static int irq_affinity_proc_open(struct inode *inode, struct file *file)