genirq/msi: Switch to new irq spreading infrastructure

Switch MSI over to the new spreading code. If a pci device contains a valid
pointer to a cpumask, then this mask is used for spreading otherwise the
online cpu mask is used. This allows a driver to restrict the spread to a
subset of CPUs, e.g. cpus on a particular node.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: axboe@fb.com
Cc: keith.busch@intel.com
Cc: agordeev@redhat.com
Cc: linux-block@vger.kernel.org
Link: http://lkml.kernel.org/r/1473862739-15032-4-git-send-email-hch@lst.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 15 insertions, 16 deletions

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index a623b44f2d4b..5a5a685aba33 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -236,25 +236,24 @@ static int alloc_descs(unsigned int start, unsigned int cnt, int node,
         const struct cpumask *mask = NULL;
         struct irq_desc *desc;
         unsigned int flags;
-        int i, cpu = -1;
+        int i;
 
-        if (affinity && cpumask_empty(affinity))
-                return -EINVAL;
+        /* Validate affinity mask(s) */
+        if (affinity) {
+                for (i = 0, mask = affinity; i < cnt; i++, mask++) {
+                        if (cpumask_empty(mask))
+                                return -EINVAL;
+                }
+        }
 
         flags = affinity ? IRQD_AFFINITY_MANAGED : 0;
+        mask = NULL;
 
         for (i = 0; i < cnt; i++) {
                 if (affinity) {
-                        cpu = cpumask_next(cpu, affinity);
-                        if (cpu >= nr_cpu_ids)
-                                cpu = cpumask_first(affinity);
-                        node = cpu_to_node(cpu);
-
-                        /*
-                         * For single allocations we use the caller provided
-                         * mask otherwise we use the mask of the target cpu
-                         */
-                        mask = cnt == 1 ? affinity : cpumask_of(cpu);
+                        node = cpu_to_node(cpumask_first(affinity));
+                        mask = affinity;
+                        affinity++;
                 }
                 desc = alloc_desc(start + i, node, flags, mask, owner);
                 if (!desc)
@@ -481,9 +480,9 @@ EXPORT_SYMBOL_GPL(irq_free_descs);
  * @cnt:        Number of consecutive irqs to allocate.
  * @node:       Preferred node on which the irq descriptor should be allocated
  * @owner:      Owning module (can be NULL)
- * @affinity:   Optional pointer to an affinity mask which hints where the
- *              irq descriptors should be allocated and which default
- *              affinities to use
+ * @affinity:   Optional pointer to an affinity mask array of size @cnt which
+ *              hints where the irq descriptors should be allocated and which
+ *              default affinities to use
  *
  * Returns the first irq number or error code
  */