[patch 26/37] PCI/MSI: Provide MSI_FLAG_MSIX_CONTIGUOUS

Thomas Gleixner
2021-11-27T01:27:47Z

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>
---
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
@@ -378,6 +378,8 @@ 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,