From e75eafb9b0395c338230b0eef2cc92ca8d20dee2 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 14 Sep 2016 16:18:49 +0200 Subject: [PATCH] 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 Cc: Christoph Hellwig 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 --- drivers/pci/msi.c | 128 ++++++++++++++++++++++++------------------- kernel/irq/irqdesc.c | 31 +++++------ 2 files changed, 87 insertions(+), 72 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 0db72ba24003..06100dde0e86 100644 --- 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 a623b44f2d4b..5a5a685aba33 100644 --- 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 */ -- 2.20.1