Re: [patch V2 25/36] PCI/MSI: Provide MSI_FLAG_MSIX_CONTIGUOUS
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2021-12-07 21:05:49
Also in:
linux-arm-kernel, linux-iommu, linux-pci, lkml, xen-devel
On Mon, Dec 06, 2021 at 11:39:36PM +0100, Thomas Gleixner wrote:
Provide a domain info flag which makes the core code check for a contiguous MSI-X index on allocation. That's simpler than checking it at some other domain callback in architecture code. Signed-off-by: Thomas Gleixner <redacted> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
quoted hunk ↗ jump to hunk
--- drivers/pci/msi/irqdomain.c | 16 ++++++++++++++-- include/linux/msi.h | 2 ++ 2 files changed, 16 insertions(+), 2 deletions(-)--- a/drivers/pci/msi/irqdomain.c +++ b/drivers/pci/msi/irqdomain.c@@ -89,9 +89,21 @@ static int pci_msi_domain_check_cap(stru if (pci_msi_desc_is_multi_msi(desc) && !(info->flags & MSI_FLAG_MULTI_PCI_MSI)) return 1; - else if (desc->pci.msi_attrib.is_msix && !(info->flags & MSI_FLAG_PCI_MSIX)) - return -ENOTSUPP; + if (desc->pci.msi_attrib.is_msix) { + if (!(info->flags & MSI_FLAG_PCI_MSIX)) + return -ENOTSUPP; + + if (info->flags & MSI_FLAG_MSIX_CONTIGUOUS) { + unsigned int idx = 0; + + /* Check for gaps in the entry indices */ + for_each_msi_entry(desc, dev) { + if (desc->msi_index != idx++) + return -ENOTSUPP; + } + } + } return 0; } --- a/include/linux/msi.h +++ b/include/linux/msi.h@@ -376,6 +376,8 @@ enum { MSI_FLAG_LEVEL_CAPABLE = (1 << 6), /* Populate sysfs on alloc() and destroy it on free() */ MSI_FLAG_DEV_SYSFS = (1 << 7), + /* MSI-X entries must be contiguous */ + MSI_FLAG_MSIX_CONTIGUOUS = (1 << 8), }; int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask,