diff options
| -rw-r--r-- | Documentation/PCI/MSI-HOWTO.txt | 4 | ||||
| -rw-r--r-- | drivers/pci/msi.c | 134 | ||||
| -rw-r--r-- | include/linux/pci.h | 2 |
3 files changed, 95 insertions, 45 deletions
diff --git a/Documentation/PCI/MSI-HOWTO.txt b/Documentation/PCI/MSI-HOWTO.txt index 0ac612b8c3fb..c55df2911136 100644 --- a/Documentation/PCI/MSI-HOWTO.txt +++ b/Documentation/PCI/MSI-HOWTO.txt @@ -99,6 +99,10 @@ PCI_IRQ_NOMSI and PCI_IRQ_NOMSIX flag in case a device claims to support MSI or MSI-X, but the support is broken, or to pass PCI_IRQ_NOLEGACY in case the device does not support legacy interrupt lines. +By default this function will spread the interrupts around the available +CPUs, but this feature can be disabled by passing the PCI_IRQ_NOAFFINITY +flag. + To get the Linux IRQ numbers passed to request_irq() and free_irq() and the vectors, use the following function: diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 5e5ab478ea7d..a02981efdad5 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -569,6 +569,7 @@ 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; @@ -680,10 +681,18 @@ 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) @@ -703,6 +712,7 @@ 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)); } @@ -1028,19 +1038,8 @@ int pci_msi_enabled(void) } EXPORT_SYMBOL(pci_msi_enabled); -/** - * pci_enable_msi_range - configure device's MSI capability structure - * @dev: device to configure - * @minvec: minimal number of interrupts to configure - * @maxvec: maximum number of interrupts to configure - * - * This function tries to allocate a maximum possible number of interrupts in a - * range between @minvec and @maxvec. It returns a negative errno if an error - * occurs. If it succeeds, it returns the actual number of interrupts allocated - * and updates the @dev's irq member to the lowest new interrupt number; - * the other interrupt numbers allocated to this device are consecutive. - **/ -int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec) +static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec, + unsigned int flags) { int nvec; int rc; @@ -1063,25 +1062,85 @@ int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec) nvec = pci_msi_vec_count(dev); if (nvec < 0) return nvec; - else if (nvec < minvec) + if (nvec < minvec) return -EINVAL; - else if (nvec > maxvec) + + if (nvec > maxvec) nvec = maxvec; - do { + for (;;) { + if (!(flags & PCI_IRQ_NOAFFINITY)) { + dev->irq_affinity = irq_create_affinity_mask(&nvec); + if (nvec < minvec) + return -ENOSPC; + } + rc = msi_capability_init(dev, nvec); - if (rc < 0) { + if (rc == 0) + return nvec; + + kfree(dev->irq_affinity); + dev->irq_affinity = NULL; + + if (rc < 0) return rc; - } else if (rc > 0) { - if (rc < minvec) + if (rc < minvec) + return -ENOSPC; + + nvec = rc; + } +} + +/** + * pci_enable_msi_range - configure device's MSI capability structure + * @dev: device to configure + * @minvec: minimal number of interrupts to configure + * @maxvec: maximum number of interrupts to configure + * + * This function tries to allocate a maximum possible number of interrupts in a + * range between @minvec and @maxvec. It returns a negative errno if an error + * occurs. If it succeeds, it returns the actual number of interrupts allocated + * and updates the @dev's irq member to the lowest new interrupt number; + * the other interrupt numbers allocated to this device are consecutive. + **/ +int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec) +{ + return __pci_enable_msi_range(dev, minvec, maxvec, PCI_IRQ_NOAFFINITY); +} +EXPORT_SYMBOL(pci_enable_msi_range); + +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; + + if (maxvec < minvec) + return -ERANGE; + + for (;;) { + if (!(flags & PCI_IRQ_NOAFFINITY)) { + dev->irq_affinity = irq_create_affinity_mask(&nvec); + if (nvec < minvec) return -ENOSPC; - nvec = rc; } - } while (rc); - return nvec; + rc = pci_enable_msix(dev, entries, nvec); + if (rc == 0) + return nvec; + + kfree(dev->irq_affinity); + dev->irq_affinity = NULL; + + if (rc < 0) + return rc; + if (rc < minvec) + return -ENOSPC; + + nvec = rc; + } } -EXPORT_SYMBOL(pci_enable_msi_range); /** * pci_enable_msix_range - configure device's MSI-X capability structure @@ -1099,26 +1158,10 @@ EXPORT_SYMBOL(pci_enable_msi_range); * with new allocated MSI-X interrupts. **/ int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, - int minvec, int maxvec) + int minvec, int maxvec) { - int nvec = maxvec; - int rc; - - if (maxvec < minvec) - return -ERANGE; - - do { - rc = pci_enable_msix(dev, entries, nvec); - if (rc < 0) { - return rc; - } else if (rc > 0) { - if (rc < minvec) - return -ENOSPC; - nvec = rc; - } - } while (rc); - - return nvec; + return __pci_enable_msix_range(dev, entries, minvec, maxvec, + PCI_IRQ_NOAFFINITY); } EXPORT_SYMBOL(pci_enable_msix_range); @@ -1145,13 +1188,14 @@ int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs, int vecs = -ENOSPC; if (!(flags & PCI_IRQ_NOMSIX)) { - vecs = pci_enable_msix_range(dev, NULL, min_vecs, max_vecs); + vecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs, + flags); if (vecs > 0) return vecs; } if (!(flags & PCI_IRQ_NOMSI)) { - vecs = pci_enable_msi_range(dev, min_vecs, max_vecs); + vecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, flags); if (vecs > 0) return vecs; } diff --git a/include/linux/pci.h b/include/linux/pci.h index 52ecd49e8049..f1406619f868 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -320,6 +320,7 @@ struct pci_dev { * directly, use the values stored here. They might be different! */ unsigned int irq; + struct cpumask *irq_affinity; struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory regions + expansion ROMs */ bool match_driver; /* Skip attaching driver */ @@ -1240,6 +1241,7 @@ int pci_set_vga_state(struct pci_dev *pdev, bool decode, #define PCI_IRQ_NOLEGACY (1 << 0) /* don't use legacy interrupts */ #define PCI_IRQ_NOMSI (1 << 1) /* don't use MSI interrupts */ #define PCI_IRQ_NOMSIX (1 << 2) /* don't use MSI-X interrupts */ +#define PCI_IRQ_NOAFFINITY (1 << 3) /* don't auto-assign affinity */ /* kmem_cache style wrapper around pci_alloc_consistent() */ |