[+cc Alexander] Sorry to be a pedant, but can you please edit the subject to be:
PCI: Provide sensible IRQ vector alloc/free routines so it matches the drivers/pci convention? I like this idea a lot. The MSI-X/MSI interfaces are much better than they used to be, and I think this would be another significant improvement. What do you think, Alexander? Here's the whole series in case you don't have it handy: http://lkml.kernel.org/r/1460770552-31260-1-git-send-email-...@lst.de On Fri, Apr 15, 2016 at 06:35:50PM -0700, Christoph Hellwig wrote: > Hide all the MSI-X vs MSI vs legacy bullshit, and provide an array of > interrupt vectors in the pci_dev structure, and ensure we get proper > interrupt affinity by default. This patch doesn't do anything for affinity by itself. > Signed-off-by: Christoph Hellwig <h...@lst.de> > --- > drivers/pci/irq.c | 89 > ++++++++++++++++++++++++++++++++++++++++++++++++++++- > drivers/pci/msi.c | 2 +- > drivers/pci/pci.h | 5 +++ > include/linux/pci.h | 5 +++ > 4 files changed, 99 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/irq.c b/drivers/pci/irq.c > index 6684f15..b683465 100644 > --- a/drivers/pci/irq.c > +++ b/drivers/pci/irq.c > @@ -1,7 +1,8 @@ > /* > - * PCI IRQ failure handing code > + * PCI IRQ handing code s/handing/handling/ :) > * > * Copyright (c) 2008 James Bottomley <james.bottom...@hansenpartnership.com> > + * Copyright (c) 2016 Christoph Hellwig. > */ > > #include <linux/acpi.h> > @@ -9,6 +10,92 @@ > #include <linux/kernel.h> > #include <linux/export.h> > #include <linux/pci.h> > +#include <linux/interrupt.h> > +#include "pci.h" > + > +static int pci_nr_irq_vectors(struct pci_dev *pdev) > +{ > + int nr_entries; > + > + nr_entries = pci_msix_vec_count(pdev); > + if (nr_entries <= 0 && pci_msi_supported(pdev, 1)) > + nr_entries = pci_msi_vec_count(pdev); > + if (nr_entries <= 0) > + nr_entries = 1; > + return nr_entries; > +} > + > +static int pci_enable_msix_range_wrapper(struct pci_dev *pdev, u32 *irqs, > + int nr_vecs) > +{ > + struct msix_entry *msix_entries; > + int vecs, i; > + > + msix_entries = kcalloc(nr_vecs, sizeof(struct msix_entry), GFP_KERNEL); > + if (!msix_entries) > + return -ENOMEM; > + > + for (i = 0; i < nr_vecs; i++) > + msix_entries[i].entry = i; > + > + vecs = pci_enable_msix_range(pdev, msix_entries, 1, nr_vecs); > + if (vecs > 0) { > + for (i = 0; i < vecs; i++) > + irqs[i] = msix_entries[i].vector; > + } > + > + kfree(msix_entries); > + return vecs; > +} > + > +int pci_alloc_irq_vectors(struct pci_dev *pdev, int nr_vecs) > +{ > + int vecs, ret, i; > + u32 *irqs; > + > + nr_vecs = min(nr_vecs, pci_nr_irq_vectors(pdev)); > + > + irqs = kcalloc(nr_vecs, sizeof(u32), GFP_KERNEL); > + if (!irqs) > + return -ENOMEM; > + > + vecs = pci_enable_msix_range_wrapper(pdev, irqs, nr_vecs); > + if (vecs <= 0) { > + vecs = pci_enable_msi_range(pdev, 1, min(nr_vecs, 32)); I don't see one, but seems like we should have a #define for this "32". I guess pci_enable_msi_range() already protects itself, so this min() is probably not strictly necessary anyway. > + if (vecs <= 0) { > + ret = -EIO; > + if (!pdev->irq) > + goto out_free_irqs; > + > + /* use legacy irq */ > + vecs = 1; > + } > + > + for (i = 0; i < vecs; i++) > + irqs[i] = pdev->irq + i; > + } > + > + pdev->irqs = irqs; > + return vecs; > + > +out_free_irqs: > + kfree(irqs); > + return ret; return -EIO; and remove "ret". > +} > +EXPORT_SYMBOL(pci_alloc_irq_vectors); > + > +void pci_free_irq_vectors(struct pci_dev *pdev) > +{ > + if (pdev->msi_enabled) > + pci_disable_msi(pdev); > + else if (pdev->msix_enabled) > + pci_disable_msix(pdev); > + > + kfree(pdev->dev.irq_affinity); > + pdev->dev.irq_affinity = NULL; These two lines belong in a different patch. > + kfree(pdev->irqs); > +} > +EXPORT_SYMBOL(pci_free_irq_vectors); > > static void pci_note_irq_problem(struct pci_dev *pdev, const char *reason) > { > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c > index a080f44..544d306 100644 > --- a/drivers/pci/msi.c > +++ b/drivers/pci/msi.c > @@ -815,7 +815,7 @@ out_free: > * to determine if MSI/-X are supported for the device. If MSI/-X is > * supported return 1, else return 0. > **/ > -static int pci_msi_supported(struct pci_dev *dev, int nvec) > +int pci_msi_supported(struct pci_dev *dev, int nvec) > { > struct pci_bus *bus; > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index d0fb934..263422c 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -144,8 +144,13 @@ extern unsigned int pci_pm_d3_delay; > > #ifdef CONFIG_PCI_MSI > void pci_no_msi(void); > +int pci_msi_supported(struct pci_dev *dev, int nvec); > #else > static inline void pci_no_msi(void) { } > +static int pci_msi_supported(struct pci_dev *dev, int nvec) > +{ > + return 0; > +} > #endif > > static inline void pci_msi_set_enable(struct pci_dev *dev, int enable) > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 004b813..4fbc14f 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -322,6 +322,7 @@ struct pci_dev { > * directly, use the values stored here. They might be different! > */ > unsigned int irq; > + unsigned int *irqs; > struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory > regions + expansion ROMs */ > > bool match_driver; /* Skip attaching driver */ > @@ -1235,6 +1236,9 @@ resource_size_t pcibios_iov_resource_alignment(struct > pci_dev *dev, int resno); > int pci_set_vga_state(struct pci_dev *pdev, bool decode, > unsigned int command_bits, u32 flags); > > +int pci_alloc_irq_vectors(struct pci_dev *dev, int nr_vecs); > +void pci_free_irq_vectors(struct pci_dev *pdev); > + > /* kmem_cache style wrapper around pci_alloc_consistent() */ > > #include <linux/pci-dma.h> > @@ -1282,6 +1286,7 @@ static inline int pci_enable_msix_exact(struct pci_dev > *dev, > return rc; > return 0; > } > + > #else > static inline int pci_msi_vec_count(struct pci_dev *dev) { return -ENOSYS; } > static inline void pci_msi_shutdown(struct pci_dev *dev) { } > -- > 2.1.4 >
