[tip: irq/msi] PCI/MSI: Provide MSI_FLAG_MSIX_CONTIGUOUS

tip-bot2 for Thomas Gleixner
2021-12-16T21:42:11Z

The following commit has been merged into the irq/msi branch of tip:

Commit-ID: 7a823443e9b4ed1ff4a3026d184f09d23fd6d9c9
Gitweb: https://git.kernel.org/tip/7a823443e9b4ed1ff4a3026d184f09d23fd6d9c9
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Fri, 10 Dec 2021 23:19:20 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 16 Dec 2021 22:16:40 +01:00

PCI/MSI: Provide MSI_FLAG_MSIX_CONTIGUOUS

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 <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20211210221814.662401116@linutronix.de

---
drivers/pci/msi/irqdomain.c | 16 ++++++++++++++--
include/linux/msi.h | 2 ++
2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
index 4224202..180b2a1 100644
--- a/drivers/pci/msi/irqdomain.c
+++ b/drivers/pci/msi/irqdomain.c
@@ -89,9 +89,21 @@ static int pci_msi_domain_check_cap(struct irq_domain *domain,
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;
}

diff --git a/include/linux/msi.h b/include/linux/msi.h
index b3d3b0b..d206239 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -362,6 +362,8 @@ 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,