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>

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 0db72ba..06100dd 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -549,15 +549,23 @@ 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, nvec, NULL);
+       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);
 
@@ -568,7 +576,6 @@ 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->affinity                 = dev->irq_affinity;
 
        if (control & PCI_MSI_FLAGS_64BIT)
                entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
@@ -579,6 +586,8 @@ 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;
 }
 
@@ -607,7 +616,7 @@ 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;
@@ -615,7 +624,7 @@ 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;
 
@@ -678,28 +687,29 @@ 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;
 
-               entry = alloc_msi_entry(&dev->dev, 1, NULL);
+       if (affinity) {
+               masks = irq_create_affinity_masks(dev->irq_affinity, nvec);
+               if (!masks)
+                       pr_err("Unable to allocate affinity masks, ignoring\n");
+       }
+
+       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;
@@ -710,11 +720,14 @@ 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->affinity                 = mask;
 
                list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
+               if (masks)
+                       curmsk++;
        }
-
+       ret = 0;
+out:
+       kfree(masks);
        return 0;
 }
 
@@ -743,8 +756,8 @@ 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;
@@ -759,7 +772,7 @@ 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;
 
@@ -939,22 +952,8 @@ 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;
@@ -986,7 +985,27 @@ 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);
 
@@ -1039,6 +1058,7 @@ 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;
 
@@ -1067,19 +1087,17 @@ 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)
@@ -1111,26 +1129,24 @@ 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)

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index a623b44..5a5a685 100644 (file)
--- 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
  */