A driver may have a need to allocate multiple sets of MSI/MSI-X
interrupts, and have them appropriately affinitized. Add support for
defining a number of sets in the irq_affinity structure, of varying
sizes, and get each set affinitized correctly across the machine.
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
include/linux/interrupt.h | 4 ++++
kernel/irq/affinity.c | 40 ++++++++++++++++++++++++++++++---------
2 files changed, 35 insertions(+), 9 deletions(-)
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 1d6711c28271..ca397ff40836 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -247,10 +247,14 @@ struct irq_affinity_notify {
* the MSI(-X) vector space
* @post_vectors: Don't apply affinity to @post_vectors at end of
* the MSI(-X) vector space
+ * @nr_sets: Length of passed in *sets array
+ * @sets: Number of affinitized sets
*/
struct irq_affinity {
int pre_vectors;
int post_vectors;
+ int nr_sets;
+ int *sets;
};
#if defined(CONFIG_SMP)
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index f4f29b9d90ee..2046a0f0f0f1 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -180,6 +180,7 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
int curvec, usedvecs;
cpumask_var_t nmsk, npresmsk, *node_to_cpumask;
struct cpumask *masks = NULL;
+ int i, nr_sets;
/*
* If there aren't any vectors left after applying the pre/post
@@ -210,10 +211,23 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
get_online_cpus();
build_node_to_cpumask(node_to_cpumask);
- /* Spread on present CPUs starting from affd->pre_vectors */
- usedvecs = irq_build_affinity_masks(affd, curvec, affvecs,
- node_to_cpumask, cpu_present_mask,
- nmsk, masks);
+ /*
+ * Spread on present CPUs starting from affd->pre_vectors. If we
+ * have multiple sets, build each sets affinity mask separately.
+ */
+ nr_sets = affd->nr_sets;
+ if (!nr_sets)
+ nr_sets = 1;
+
+ for (i = 0, usedvecs = 0; i < nr_sets; i++) {
+ int this_vecs = affd->sets ? affd->sets[i] : affvecs;
+ int nr;
+
+ nr = irq_build_affinity_masks(affd, curvec, this_vecs,
+ node_to_cpumask, cpu_present_mask,
+ nmsk, masks + usedvecs);
+ usedvecs += nr;
+ }
/*
* Spread on non present CPUs starting from the next vector to be
@@ -258,13 +272,21 @@ int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity
{
int resv = affd->pre_vectors + affd->post_vectors;
int vecs = maxvec - resv;
- int ret;
+ int set_vecs;
if (resv > minvec)
return 0;
- get_online_cpus();
- ret = min_t(int, cpumask_weight(cpu_possible_mask), vecs) + resv;
- put_online_cpus();
- return ret;
+ if (affd->nr_sets) {
+ int i;
+
+ for (i = 0, set_vecs = 0; i < affd->nr_sets; i++)
+ set_vecs += affd->sets[i];
+ } else {
+ get_online_cpus();
+ set_vecs = cpumask_weight(cpu_possible_mask);
+ put_online_cpus();
+ }
+
+ return resv + min(set_vecs, vecs);
}
--
2.17.1
