genirq/affinity: Add support for allocating interrupt sets

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.

[ tglx: Minor changelog tweaks ]

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Cc: linux-block@vger.kernel.org
Link: https://lkml.kernel.org/r/20181102145951.31979-5-ming.lei@redhat.com

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index af24ed50a2452008e32dc837834682a506739fd9..265ed3e4c920762f9a4ee57dc3fdde3f9858d7d2 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1036,6 +1036,13 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
        if (maxvec < minvec)
                return -ERANGE;
 
+       /*
+        * If the caller is passing in sets, we can't support a range of
+        * vectors. The caller needs to handle that.
+        */
+       if (affd && affd->nr_sets && minvec != maxvec)
+               return -EINVAL;
+
        if (WARN_ON_ONCE(dev->msi_enabled))
                return -EINVAL;
 
@@ -1087,6 +1094,13 @@ static int __pci_enable_msix_range(struct pci_dev *dev,
        if (maxvec < minvec)
                return -ERANGE;
 
+       /*
+        * If the caller is passing in sets, we can't support a range of
+        * supported vectors. The caller needs to handle that.
+        */
+       if (affd && affd->nr_sets && minvec != maxvec)
+               return -EINVAL;
+
        if (WARN_ON_ONCE(dev->msix_enabled))
                return -EINVAL;
 

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 1d6711c282715a59d6b34ef3954a109ba953aa9d..ca397ff40836ad7e2b02c24b7a21f281a0596f83 100644 (file)
--- 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 e028b773e38aaec86cad5b62e9dd6b1257a2fa5b..08c904eb727982647993c3518ede965121061d7c 100644 (file)
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -171,28 +171,29 @@ out:
  *     2) spread other possible CPUs on these vectors
  */
 static int irq_build_affinity_masks(const struct irq_affinity *affd,
-                                   int startvec, int numvecs,
+                                   int startvec, int numvecs, int firstvec,
                                    cpumask_var_t *node_to_cpumask,
                                    struct cpumask *masks)
 {
-       int curvec = startvec, usedvecs = -1;
+       int curvec = startvec, nr_present, nr_others;
+       int ret = -ENOMEM;
        cpumask_var_t nmsk, npresmsk;
 
        if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
-                       return usedvecs;
+                       return ret;
 
        if (!zalloc_cpumask_var(&npresmsk, GFP_KERNEL))
                        goto fail;
 
+       ret = 0;
        /* Stabilize the cpumasks */
        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, numvecs,
-                                             affd->pre_vectors,
-                                             node_to_cpumask,
-                                             cpu_present_mask, nmsk, masks);
+       nr_present = __irq_build_affinity_masks(affd, curvec, numvecs,
+                                               firstvec, node_to_cpumask,
+                                               cpu_present_mask, nmsk, masks);
 
        /*
         * Spread on non present CPUs starting from the next vector to be
@@ -200,23 +201,24 @@ static int irq_build_affinity_masks(const struct irq_affinity *affd,
         * vector space, assign the non present CPUs to the already spread
         * out vectors.
         */
-       if (usedvecs >= numvecs)
-               curvec = affd->pre_vectors;
+       if (nr_present >= numvecs)
+               curvec = firstvec;
        else
-               curvec = affd->pre_vectors + usedvecs;
+               curvec = firstvec + nr_present;
        cpumask_andnot(npresmsk, cpu_possible_mask, cpu_present_mask);
-       usedvecs += __irq_build_affinity_masks(affd, curvec, numvecs,
-                                              affd->pre_vectors,
-                                              node_to_cpumask, npresmsk,
-                                              nmsk, masks);
+       nr_others = __irq_build_affinity_masks(affd, curvec, numvecs,
+                                              firstvec, node_to_cpumask,
+                                              npresmsk, nmsk, masks);
        put_online_cpus();
 
+       if (nr_present < numvecs)
+                       WARN_ON(nr_present + nr_others < numvecs);
+
        free_cpumask_var(npresmsk);
 
  fail:
        free_cpumask_var(nmsk);
-
-       return usedvecs;
+       return ret;
 }
 
 /**
@@ -233,6 +235,7 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
        int curvec, usedvecs;
        cpumask_var_t *node_to_cpumask;
        struct cpumask *masks = NULL;
+       int i, nr_sets;
 
        /*
         * If there aren't any vectors left after applying the pre/post
@@ -253,8 +256,28 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
        for (curvec = 0; curvec < affd->pre_vectors; curvec++)
                cpumask_copy(masks + curvec, irq_default_affinity);
 
-       usedvecs = irq_build_affinity_masks(affd, curvec, affvecs,
-                                           node_to_cpumask, 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 ret;
+
+               ret = irq_build_affinity_masks(affd, curvec, this_vecs,
+                                               curvec, node_to_cpumask, masks);
+               if (ret) {
+                               kfree(masks);
+                               masks = NULL;
+                               goto outnodemsk;
+               }
+               curvec += this_vecs;
+               usedvecs += this_vecs;
+       }
 
        /* Fill out vectors at the end that don't need affinity */
        if (usedvecs >= affvecs)
@@ -279,13 +302,21 @@ 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);
 }