[PATCH 08/13] pci: spread interrupt vectors in pci_alloc_irq_vectors

[Christoph Hellwig]

Set the affinity_mask before allocating vectors.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 drivers/pci/msi.c   | 26 ++++++++++++++++++++++++--
 include/linux/pci.h |  1 +
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index a33adec..50d694c 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -568,6 +568,7 @@ static struct msi_desc *msi_setup_entry(struct pci_dev 
*dev, int nvec)
        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;
@@ -679,10 +680,18 @@ 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)
 {
+       const struct cpumask *mask = NULL;
        struct msi_desc *entry;
-       int i;
+       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);
+               }
+
                entry = alloc_msi_entry(&dev->dev);
                if (!entry) {
                        if (!i)
@@ -699,6 +708,7 @@ static int msix_setup_entries(struct pci_dev *dev, void 
__iomem *base,
                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));
        }
@@ -1176,12 +1186,20 @@ int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned 
int min_vecs,
 {
        unsigned int vecs, i;
        u32 *irqs;
+       int ret;
 
        max_vecs = min(max_vecs, pci_nr_irq_vectors(dev));
 
+       ret = irq_create_affinity_mask(&dev->irq_affinity, &max_vecs);
+       if (ret)
+               return ret;
+       if (max_vecs < min_vecs)
+               return -ENOSPC;
+
+       ret = -ENOMEM;
        irqs = kcalloc(max_vecs, sizeof(u32), GFP_KERNEL);
        if (!irqs)
-               return -ENOMEM;
+               goto out_free_affinity;
 
        if (!(flags & PCI_IRQ_NOMSIX)) {
                vecs = pci_enable_msix_range_wrapper(dev, irqs, min_vecs,
@@ -1208,6 +1226,10 @@ int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned 
int min_vecs,
 done:
        dev->irqs = irqs;
        return vecs;
+out_free_affinity:
+       kfree(dev->irq_affinity);
+       dev->irq_affinity = NULL;
+       return ret;
 }
 EXPORT_SYMBOL(pci_alloc_irq_vectors);
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 84a20fc..f474611 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -321,6 +321,7 @@ struct pci_dev {
         */
        unsigned int    irq;
        unsigned int    *irqs;
+       struct cpumask  *irq_affinity;
        struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory 
regions + expansion ROMs */
 
        bool match_driver;              /* Skip attaching driver */
-- 
2.1.4