x86/irq: Get rid of code duplication
Reusing an existing vector and assigning a new vector has duplicated
code. Consolidate it.
This is also a preparatory patch for finally plugging the cleanup race.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Borislav Petkov <bp@alien8.de>
Tested-by: Joe Lawrence <joe.lawrence@stratus.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jeremiah Mahler <jmmahler@gmail.com>
Cc: andy.shevchenko@gmail.com
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: stable@vger.kernel.org #4.3+
Link: http://lkml.kernel.org/r/20151231160106.721599216@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 1bd29c6..fccfa3f 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -118,7 +118,7 @@
*/
static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START;
static int current_offset = VECTOR_OFFSET_START % 16;
- int cpu;
+ int cpu, vector;
if (d->move_in_progress)
return -EBUSY;
@@ -128,7 +128,7 @@
cpumask_clear(searched_cpumask);
cpu = cpumask_first_and(mask, cpu_online_mask);
while (cpu < nr_cpu_ids) {
- int new_cpu, vector, offset;
+ int new_cpu, offset;
/* Get the possible target cpus for @mask/@cpu from the apic */
apic->vector_allocation_domain(cpu, vector_cpumask, mask);
@@ -148,16 +148,12 @@
if (cpumask_equal(vector_cpumask, d->domain))
goto success;
/*
- * New cpumask using the vector is a proper subset of
- * the current in use mask. So cleanup the vector
- * allocation for the members that are not used anymore.
+ * Mark the cpus which are not longer in the mask for
+ * cleanup.
*/
- cpumask_andnot(d->old_domain, d->domain,
- vector_cpumask);
- d->move_in_progress =
- cpumask_intersects(d->old_domain, cpu_online_mask);
- cpumask_copy(d->domain, vector_cpumask);
- goto success;
+ cpumask_andnot(d->old_domain, d->domain, vector_cpumask);
+ vector = d->cfg.vector;
+ goto update;
}
vector = current_vector;
@@ -183,16 +179,12 @@
/* Found one! */
current_vector = vector;
current_offset = offset;
- if (d->cfg.vector) {
+ /* Schedule the old vector for cleanup on all cpus */
+ if (d->cfg.vector)
cpumask_copy(d->old_domain, d->domain);
- d->move_in_progress =
- cpumask_intersects(d->old_domain, cpu_online_mask);
- }
for_each_cpu(new_cpu, vector_searchmask)
per_cpu(vector_irq, new_cpu)[vector] = irq_to_desc(irq);
- d->cfg.vector = vector;
- cpumask_copy(d->domain, vector_cpumask);
- goto success;
+ goto update;
next_cpu:
/*
@@ -209,6 +201,11 @@
}
return -ENOSPC;
+update:
+ /* Cleanup required ? */
+ d->move_in_progress = cpumask_intersects(d->old_domain, cpu_online_mask);
+ d->cfg.vector = vector;
+ cpumask_copy(d->domain, vector_cpumask);
success:
/*
* Cache destination APIC IDs into cfg->dest_apicid. This cannot fail