Merge branch 'irq/for-block' into irq/core

Add the new irq spreading infrastructure.

9 files changed, 293 insertions, 123 deletions

diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
index 279e53989374..be6a599bc0c1 100644
--- a/drivers/base/platform-msi.c
+++ b/drivers/base/platform-msi.c
@@ -142,13 +142,12 @@ static int platform_msi_alloc_descs_with_irq(struct device *dev, int virq,
         }
 
         for (i = 0; i < nvec; i++) {
-                desc = alloc_msi_entry(dev);
+                desc = alloc_msi_entry(dev, 1, NULL);
                 if (!desc)
                         break;
 
                 desc->platform.msi_priv_data = data;
                 desc->platform.msi_index = base + i;
-                desc->nvec_used = 1;
                 desc->irq = virq ? virq + i : 0;
 
                 list_add_tail(&desc->list, dev_to_msi_list(dev));
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 137b4c5fb638..bfdd0744b686 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -550,15 +550,23 @@ error_attrs:
         return ret;
 }
 
-static struct msi_desc *msi_setup_entry(struct pci_dev *dev, int nvec)
+static struct msi_desc *
+msi_setup_entry(struct pci_dev *dev, int nvec, bool affinity)
 {
-        u16 control;
+        struct cpumask *masks = NULL;
         struct msi_desc *entry;
+        u16 control;
+
+        if (affinity) {
+                masks = irq_create_affinity_masks(dev->irq_affinity, nvec);
+                if (!masks)
+                        pr_err("Unable to allocate affinity masks, ignoring\n");
+        }
 
         /* MSI Entry Initialization */
-        entry = alloc_msi_entry(&dev->dev);
+        entry = alloc_msi_entry(&dev->dev, nvec, masks);
         if (!entry)
-                return NULL;
+                goto out;
 
         pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
 
@@ -569,8 +577,6 @@ static struct msi_desc *msi_setup_entry(struct pci_dev *dev, int nvec)
         entry->msi_attrib.default_irq   = dev->irq;     /* Save IOAPIC IRQ */
         entry->msi_attrib.multi_cap     = (control & PCI_MSI_FLAGS_QMASK) >> 1;
         entry->msi_attrib.multiple      = ilog2(__roundup_pow_of_two(nvec));
-        entry->nvec_used                = nvec;
-        entry->affinity                 = dev->irq_affinity;
 
         if (control & PCI_MSI_FLAGS_64BIT)
                 entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
@@ -581,6 +587,8 @@ static struct msi_desc *msi_setup_entry(struct pci_dev *dev, int nvec)
         if (entry->msi_attrib.maskbit)
                 pci_read_config_dword(dev, entry->mask_pos, &entry->masked);
 
+out:
+        kfree(masks);
         return entry;
 }
 
@@ -609,7 +617,7 @@ static int msi_verify_entries(struct pci_dev *dev)
  * an error, and a positive return value indicates the number of interrupts
  * which could have been allocated.
  */
-static int msi_capability_init(struct pci_dev *dev, int nvec)
+static int msi_capability_init(struct pci_dev *dev, int nvec, bool affinity)
 {
         struct msi_desc *entry;
         int ret;
@@ -617,7 +625,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
 
         pci_msi_set_enable(dev, 0);     /* Disable MSI during set up */
 
-        entry = msi_setup_entry(dev, nvec);
+        entry = msi_setup_entry(dev, nvec, affinity);
         if (!entry)
                 return -ENOMEM;
 
@@ -680,28 +688,29 @@ static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
 }
 
 static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
-                              struct msix_entry *entries, int nvec)
+                              struct msix_entry *entries, int nvec,
+                              bool affinity)
 {
-        const struct cpumask *mask = NULL;
+        struct cpumask *curmsk, *masks = NULL;
         struct msi_desc *entry;
-        int cpu = -1, i;
-
-        for (i = 0; i < nvec; i++) {
-                if (dev->irq_affinity) {
-                        cpu = cpumask_next(cpu, dev->irq_affinity);
-                        if (cpu >= nr_cpu_ids)
-                                cpu = cpumask_first(dev->irq_affinity);
-                        mask = cpumask_of(cpu);
-                }
+        int ret, i;
+
+        if (affinity) {
+                masks = irq_create_affinity_masks(dev->irq_affinity, nvec);
+                if (!masks)
+                        pr_err("Unable to allocate affinity masks, ignoring\n");
+        }
 
-                entry = alloc_msi_entry(&dev->dev);
+        for (i = 0, curmsk = masks; i < nvec; i++) {
+                entry = alloc_msi_entry(&dev->dev, 1, curmsk);
                 if (!entry) {
                         if (!i)
                                 iounmap(base);
                         else
                                 free_msi_irqs(dev);
                         /* No enough memory. Don't try again */
-                        return -ENOMEM;
+                        ret = -ENOMEM;
+                        goto out;
                 }
 
                 entry->msi_attrib.is_msix       = 1;
@@ -712,12 +721,14 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
                         entry->msi_attrib.entry_nr = i;
                 entry->msi_attrib.default_irq   = dev->irq;
                 entry->mask_base                = base;
-                entry->nvec_used                = 1;
-                entry->affinity                 = mask;
 
                 list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
+                if (masks)
+                        curmsk++;
         }
-
+        ret = 0;
+out:
+        kfree(masks);
         return 0;
 }
 
@@ -746,8 +757,8 @@ static void msix_program_entries(struct pci_dev *dev,
  * single MSI-X irq. A return of zero indicates the successful setup of
  * requested MSI-X entries with allocated irqs or non-zero for otherwise.
  **/
-static int msix_capability_init(struct pci_dev *dev,
-                                struct msix_entry *entries, int nvec)
+static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
+                                int nvec, bool affinity)
 {
         int ret;
         u16 control;
@@ -762,7 +773,7 @@ static int msix_capability_init(struct pci_dev *dev,
         if (!base)
                 return -ENOMEM;
 
-        ret = msix_setup_entries(dev, base, entries, nvec);
+        ret = msix_setup_entries(dev, base, entries, nvec, affinity);
         if (ret)
                 return ret;
 
@@ -942,22 +953,8 @@ int pci_msix_vec_count(struct pci_dev *dev)
 }
 EXPORT_SYMBOL(pci_msix_vec_count);
 
-/**
- * pci_enable_msix - configure device's MSI-X capability structure
- * @dev: pointer to the pci_dev data structure of MSI-X device function
- * @entries: pointer to an array of MSI-X entries (optional)
- * @nvec: number of MSI-X irqs requested for allocation by device driver
- *
- * Setup the MSI-X capability structure of device function with the number
- * of requested irqs upon its software driver call to request for
- * MSI-X mode enabled on its hardware device function. A return of zero
- * indicates the successful configuration of MSI-X capability structure
- * with new allocated MSI-X irqs. A return of < 0 indicates a failure.
- * Or a return of > 0 indicates that driver request is exceeding the number
- * of irqs or MSI-X vectors available. Driver should use the returned value to
- * re-send its request.
- **/
-int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
+static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
+                             int nvec, bool affinity)
 {
         int nr_entries;
         int i, j;
@@ -989,7 +986,27 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
                 dev_info(&dev->dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
                 return -EINVAL;
         }
-        return msix_capability_init(dev, entries, nvec);
+        return msix_capability_init(dev, entries, nvec, affinity);
+}
+
+/**
+ * pci_enable_msix - configure device's MSI-X capability structure
+ * @dev: pointer to the pci_dev data structure of MSI-X device function
+ * @entries: pointer to an array of MSI-X entries (optional)
+ * @nvec: number of MSI-X irqs requested for allocation by device driver
+ *
+ * Setup the MSI-X capability structure of device function with the number
+ * of requested irqs upon its software driver call to request for
+ * MSI-X mode enabled on its hardware device function. A return of zero
+ * indicates the successful configuration of MSI-X capability structure
+ * with new allocated MSI-X irqs. A return of < 0 indicates a failure.
+ * Or a return of > 0 indicates that driver request is exceeding the number
+ * of irqs or MSI-X vectors available. Driver should use the returned value to
+ * re-send its request.
+ **/
+int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
+{
+        return __pci_enable_msix(dev, entries, nvec, false);
 }
 EXPORT_SYMBOL(pci_enable_msix);
 
@@ -1042,6 +1059,7 @@ EXPORT_SYMBOL(pci_msi_enabled);
 static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
                 unsigned int flags)
 {
+        bool affinity = flags & PCI_IRQ_AFFINITY;
         int nvec;
         int rc;
 
@@ -1070,19 +1088,17 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
                 nvec = maxvec;
 
         for (;;) {
-                if (flags & PCI_IRQ_AFFINITY) {
-                        dev->irq_affinity = irq_create_affinity_mask(&nvec);
+                if (affinity) {
+                        nvec = irq_calc_affinity_vectors(dev->irq_affinity,
+                                        nvec);
                         if (nvec < minvec)
                                 return -ENOSPC;
                 }
 
-                rc = msi_capability_init(dev, nvec);
+                rc = msi_capability_init(dev, nvec, affinity);
                 if (rc == 0)
                         return nvec;
 
-                kfree(dev->irq_affinity);
-                dev->irq_affinity = NULL;
-
                 if (rc < 0)
                         return rc;
                 if (rc < minvec)
@@ -1114,26 +1130,24 @@ static int __pci_enable_msix_range(struct pci_dev *dev,
                 struct msix_entry *entries, int minvec, int maxvec,
                 unsigned int flags)
 {
-        int nvec = maxvec;
-        int rc;
+        bool affinity = flags & PCI_IRQ_AFFINITY;
+        int rc, nvec = maxvec;
 
         if (maxvec < minvec)
                 return -ERANGE;
 
         for (;;) {
-                if (flags & PCI_IRQ_AFFINITY) {
-                        dev->irq_affinity = irq_create_affinity_mask(&nvec);
+                if (affinity) {
+                        nvec = irq_calc_affinity_vectors(dev->irq_affinity,
+                                        nvec);
                         if (nvec < minvec)
                                 return -ENOSPC;
                 }
 
-                rc = pci_enable_msix(dev, entries, nvec);
+                rc = __pci_enable_msix(dev, entries, nvec, affinity);
                 if (rc == 0)
                         return nvec;
 
-                kfree(dev->irq_affinity);
-                dev->irq_affinity = NULL;
-
                 if (rc < 0)
                         return rc;
                 if (rc < minvec)
@@ -1257,6 +1271,37 @@ int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
 }
 EXPORT_SYMBOL(pci_irq_vector);
 
+/**
+ * pci_irq_get_affinity - return the affinity of a particular msi vector
+ * @dev:        PCI device to operate on
+ * @nr:         device-relative interrupt vector index (0-based).
+ */
+const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
+{
+        if (dev->msix_enabled) {
+                struct msi_desc *entry;
+                int i = 0;
+
+                for_each_pci_msi_entry(entry, dev) {
+                        if (i == nr)
+                                return entry->affinity;
+                        i++;
+                }
+                WARN_ON_ONCE(1);
+                return NULL;
+        } else if (dev->msi_enabled) {
+                struct msi_desc *entry = first_pci_msi_entry(dev);
+
+                if (WARN_ON_ONCE(!entry || nr >= entry->nvec_used))
+                        return NULL;
+
+                return &entry->affinity[nr];
+        } else {
+                return cpu_possible_mask;
+        }
+}
+EXPORT_SYMBOL(pci_irq_get_affinity);
+
 struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc)
 {
         return to_pci_dev(desc->dev);
diff --git a/drivers/staging/fsl-mc/bus/mc-msi.c b/drivers/staging/fsl-mc/bus/mc-msi.c
index c7be156ae5e0..4fd8e41ef468 100644
--- a/drivers/staging/fsl-mc/bus/mc-msi.c
+++ b/drivers/staging/fsl-mc/bus/mc-msi.c
@@ -213,7 +213,7 @@ static int fsl_mc_msi_alloc_descs(struct device *dev, unsigned int irq_count)
         struct msi_desc *msi_desc;
 
         for (i = 0; i < irq_count; i++) {
-                msi_desc = alloc_msi_entry(dev);
+                msi_desc = alloc_msi_entry(dev, 1, NULL);
                 if (!msi_desc) {
                         dev_err(dev, "Failed to allocate msi entry\n");
                         error = -ENOMEM;
@@ -221,7 +221,6 @@ static int fsl_mc_msi_alloc_descs(struct device *dev, unsigned int irq_count)
                 }
 
                 msi_desc->fsl_mc.msi_index = i;
-                msi_desc->nvec_used = 1;
                 INIT_LIST_HEAD(&msi_desc->list);
                 list_add_tail(&msi_desc->list, dev_to_msi_list(dev));
         }
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index b6683f0ffc9f..72f0721f75e7 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -278,7 +278,8 @@ extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
 extern int
 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
 
-struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs);
+struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity, int nvec);
+int irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec);
 
 #else /* CONFIG_SMP */
 
@@ -311,11 +312,18 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
         return 0;
 }
 
-static inline struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs)
+static inline struct cpumask *
+irq_create_affinity_masks(const struct cpumask *affinity, int nvec)
 {
-        *nr_vecs = 1;
         return NULL;
 }
+
+static inline int
+irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec)
+{
+        return maxvec;
+}
+
 #endif /* CONFIG_SMP */
 
 /*
diff --git a/include/linux/msi.h b/include/linux/msi.h
index e8c81fbd5f9c..0db320b7bb15 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -68,7 +68,7 @@ struct msi_desc {
         unsigned int                    nvec_used;
         struct device                   *dev;
         struct msi_msg                  msg;
-        const struct cpumask            *affinity;
+        struct cpumask                  *affinity;
 
         union {
                 /* PCI MSI/X specific data */
@@ -123,7 +123,8 @@ static inline void *msi_desc_to_pci_sysdata(struct msi_desc *desc)
 }
 #endif /* CONFIG_PCI_MSI */
 
-struct msi_desc *alloc_msi_entry(struct device *dev);
+struct msi_desc *alloc_msi_entry(struct device *dev, int nvec,
+                                 const struct cpumask *affinity);
 void free_msi_entry(struct msi_desc *entry);
 void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg);
 void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0ab835965669..3b0a8004f313 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1300,6 +1300,7 @@ int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
                 unsigned int max_vecs, unsigned int flags);
 void pci_free_irq_vectors(struct pci_dev *dev);
 int pci_irq_vector(struct pci_dev *dev, unsigned int nr);
+const struct cpumask *pci_irq_get_affinity(struct pci_dev *pdev, int vec);
 
 #else
 static inline int pci_msi_vec_count(struct pci_dev *dev) { return -ENOSYS; }
@@ -1342,6 +1343,11 @@ static inline int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
                 return -EINVAL;
         return dev->irq;
 }
+static inline const struct cpumask *pci_irq_get_affinity(struct pci_dev *pdev,
+                int vec)
+{
+        return cpu_possible_mask;
+}
 #endif
 
 #ifdef CONFIG_PCIEPORTBUS
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index 32f6cfcff212..17f51d63da56 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -4,60 +4,151 @@
 #include <linux/slab.h>
 #include <linux/cpu.h>
 
-static int get_first_sibling(unsigned int cpu)
+static void irq_spread_init_one(struct cpumask *irqmsk, struct cpumask *nmsk,
+                                int cpus_per_vec)
 {
-        unsigned int ret;
+        const struct cpumask *siblmsk;
+        int cpu, sibl;
 
-        ret = cpumask_first(topology_sibling_cpumask(cpu));
-        if (ret < nr_cpu_ids)
-                return ret;
-        return cpu;
+        for ( ; cpus_per_vec > 0; ) {
+                cpu = cpumask_first(nmsk);
+
+                /* Should not happen, but I'm too lazy to think about it */
+                if (cpu >= nr_cpu_ids)
+                        return;
+
+                cpumask_clear_cpu(cpu, nmsk);
+                cpumask_set_cpu(cpu, irqmsk);
+                cpus_per_vec--;
+
+                /* If the cpu has siblings, use them first */
+                siblmsk = topology_sibling_cpumask(cpu);
+                for (sibl = -1; cpus_per_vec > 0; ) {
+                        sibl = cpumask_next(sibl, siblmsk);
+                        if (sibl >= nr_cpu_ids)
+                                break;
+                        if (!cpumask_test_and_clear_cpu(sibl, nmsk))
+                                continue;
+                        cpumask_set_cpu(sibl, irqmsk);
+                        cpus_per_vec--;
+                }
+        }
+}
+
+static int get_nodes_in_cpumask(const struct cpumask *mask, nodemask_t *nodemsk)
+{
+        int n, nodes;
+
+        /* Calculate the number of nodes in the supplied affinity mask */
+        for (n = 0, nodes = 0; n < num_online_nodes(); n++) {
+                if (cpumask_intersects(mask, cpumask_of_node(n))) {
+                        node_set(n, *nodemsk);
+                        nodes++;
+                }
+        }
+        return nodes;
 }
 
-/*
- * Take a map of online CPUs and the number of available interrupt vectors
- * and generate an output cpumask suitable for spreading MSI/MSI-X vectors
- * so that they are distributed as good as possible around the CPUs.  If
- * more vectors than CPUs are available we'll map one to each CPU,
- * otherwise we map one to the first sibling of each socket.
+/**
+ * irq_create_affinity_masks - Create affinity masks for multiqueue spreading
+ * @affinity:           The affinity mask to spread. If NULL cpu_online_mask
+ *                      is used
+ * @nvecs:              The number of vectors
  *
- * If there are more vectors than CPUs we will still only have one bit
- * set per CPU, but interrupt code will keep on assigning the vectors from
- * the start of the bitmap until we run out of vectors.
+ * Returns the masks pointer or NULL if allocation failed.
  */
-struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs)
+struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity,
+                                          int nvec)
 {
-        struct cpumask *affinity_mask;
-        unsigned int max_vecs = *nr_vecs;
+        int n, nodes, vecs_per_node, cpus_per_vec, extra_vecs, curvec = 0;
+        nodemask_t nodemsk = NODE_MASK_NONE;
+        struct cpumask *masks;
+        cpumask_var_t nmsk;
 
-        if (max_vecs == 1)
+        if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
                 return NULL;
 
-        affinity_mask = kzalloc(cpumask_size(), GFP_KERNEL);
-        if (!affinity_mask) {
-                *nr_vecs = 1;
-                return NULL;
-        }
+        masks = kzalloc(nvec * sizeof(*masks), GFP_KERNEL);
+        if (!masks)
+                goto out;
 
+        /* Stabilize the cpumasks */
         get_online_cpus();
-        if (max_vecs >= num_online_cpus()) {
-                cpumask_copy(affinity_mask, cpu_online_mask);
-                *nr_vecs = num_online_cpus();
-        } else {
-                unsigned int vecs = 0, cpu;
-
-                for_each_online_cpu(cpu) {
-                        if (cpu == get_first_sibling(cpu)) {
-                                cpumask_set_cpu(cpu, affinity_mask);
-                                vecs++;
-                        }
+        /* If the supplied affinity mask is NULL, use cpu online mask */
+        if (!affinity)
+                affinity = cpu_online_mask;
+
+        nodes = get_nodes_in_cpumask(affinity, &nodemsk);
 
-                        if (--max_vecs == 0)
+        /*
+         * If the number of nodes in the mask is less than or equal the
+         * number of vectors we just spread the vectors across the nodes.
+         */
+        if (nvec <= nodes) {
+                for_each_node_mask(n, nodemsk) {
+                        cpumask_copy(masks + curvec, cpumask_of_node(n));
+                        if (++curvec == nvec)
                                 break;
                 }
-                *nr_vecs = vecs;
+                goto outonl;
         }
+
+        /* Spread the vectors per node */
+        vecs_per_node = nvec / nodes;
+        /* Account for rounding errors */
+        extra_vecs = nvec - (nodes * vecs_per_node);
+
+        for_each_node_mask(n, nodemsk) {
+                int ncpus, v, vecs_to_assign = vecs_per_node;
+
+                /* Get the cpus on this node which are in the mask */
+                cpumask_and(nmsk, affinity, cpumask_of_node(n));
+
+                /* Calculate the number of cpus per vector */
+                ncpus = cpumask_weight(nmsk);
+
+                for (v = 0; curvec < nvec && v < vecs_to_assign; curvec++, v++) {
+                        cpus_per_vec = ncpus / vecs_to_assign;
+
+                        /* Account for extra vectors to compensate rounding errors */
+                        if (extra_vecs) {
+                                cpus_per_vec++;
+                                if (!--extra_vecs)
+                                        vecs_per_node++;
+                        }
+                        irq_spread_init_one(masks + curvec, nmsk, cpus_per_vec);
+                }
+
+                if (curvec >= nvec)
+                        break;
+        }
+
+outonl:
         put_online_cpus();
+out:
+        free_cpumask_var(nmsk);
+        return masks;
+}
+
+/**
+ * irq_calc_affinity_vectors - Calculate to optimal number of vectors for a given affinity mask
+ * @affinity:           The affinity mask to spread. If NULL cpu_online_mask
+ *                      is used
+ * @maxvec:             The maximum number of vectors available
+ */
+int irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec)
+{
+        int cpus, ret;
 
-        return affinity_mask;
+        /* Stabilize the cpumasks */
+        get_online_cpus();
+        /* If the supplied affinity mask is NULL, use cpu online mask */
+        if (!affinity)
+                affinity = cpu_online_mask;
+
+        cpus = cpumask_weight(affinity);
+        ret = (cpus < maxvec) ? cpus : maxvec;
+
+        put_online_cpus();
+        return ret;
 }
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 93b51727abaa..00bb0aeea1d0 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -424,25 +424,24 @@ 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)
@@ -670,9 +669,9 @@ 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
  */
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 19e9dfbe97fa..8a3e872798f3 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -18,20 +18,42 @@
 /* Temparory solution for building, will be removed later */
 #include <linux/pci.h>
 
-struct msi_desc *alloc_msi_entry(struct device *dev)
+/**
+ * alloc_msi_entry - Allocate an initialize msi_entry
+ * @dev:        Pointer to the device for which this is allocated
+ * @nvec:       The number of vectors used in this entry
+ * @affinity:   Optional pointer to an affinity mask array size of @nvec
+ *
+ * If @affinity is not NULL then a an affinity array[@nvec] is allocated
+ * and the affinity masks from @affinity are copied.
+ */
+struct msi_desc *
+alloc_msi_entry(struct device *dev, int nvec, const struct cpumask *affinity)
 {
-        struct msi_desc *desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+        struct msi_desc *desc;
+
+        desc = kzalloc(sizeof(*desc), GFP_KERNEL);
         if (!desc)
                 return NULL;
 
         INIT_LIST_HEAD(&desc->list);
         desc->dev = dev;
+        desc->nvec_used = nvec;
+        if (affinity) {
+                desc->affinity = kmemdup(affinity,
+                        nvec * sizeof(*desc->affinity), GFP_KERNEL);
+                if (!desc->affinity) {
+                        kfree(desc);
+                        return NULL;
+                }
+        }
 
         return desc;
 }
 
 void free_msi_entry(struct msi_desc *entry)
 {
+        kfree(entry->affinity);
         kfree(entry);
 }