PCI/MSI: Sanitize MSI-X checks

There is no point in doing the same sanity checks over and over in a loop
during MSI-X enablement. Put them in front of the loop and return early
when they fail.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20221111122015.516946468@linutronix.de
This commit is contained in:
Thomas Gleixner 2022-11-11 14:55:07 +01:00
parent 12910ffd18
commit bab65e48cb

View File

@ -721,47 +721,31 @@ out_disable:
return ret;
}
static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
int nvec, struct irq_affinity *affd, int flags)
static bool pci_msix_validate_entries(struct msix_entry *entries, int nvec, int hwsize)
{
int nr_entries;
int i, j;
if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
return -EINVAL;
if (!entries)
return true;
nr_entries = pci_msix_vec_count(dev);
if (nr_entries < 0)
return nr_entries;
if (nvec > nr_entries && !(flags & PCI_IRQ_VIRTUAL))
return nr_entries;
if (entries) {
/* Check for any invalid entries */
for (i = 0; i < nvec; i++) {
if (entries[i].entry >= nr_entries)
return -EINVAL; /* invalid entry */
/* Entry within hardware limit? */
if (entries[i].entry >= hwsize)
return false;
/* Check for duplicate entries */
for (j = i + 1; j < nvec; j++) {
if (entries[i].entry == entries[j].entry)
return -EINVAL; /* duplicate entry */
return false;
}
}
return true;
}
/* Check whether driver already requested for MSI IRQ */
if (dev->msi_enabled) {
pci_info(dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
return -EINVAL;
}
return msix_capability_init(dev, entries, nvec, affd);
}
int __pci_enable_msix_range(struct pci_dev *dev,
struct msix_entry *entries, int minvec,
int maxvec, struct irq_affinity *affd,
int flags)
int __pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, int minvec,
int maxvec, struct irq_affinity *affd, int flags)
{
int rc, nvec = maxvec;
int hwsize, rc, nvec = maxvec;
if (maxvec < minvec)
return -ERANGE;
@ -774,6 +758,23 @@ int __pci_enable_msix_range(struct pci_dev *dev,
if (WARN_ON_ONCE(dev->msix_enabled))
return -EINVAL;
if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
return -EINVAL;
hwsize = pci_msix_vec_count(dev);
if (hwsize < 0)
return hwsize;
if (!pci_msix_validate_entries(entries, nvec, hwsize))
return -EINVAL;
/* PCI_IRQ_VIRTUAL is a horrible hack! */
if (nvec > hwsize && !(flags & PCI_IRQ_VIRTUAL))
nvec = hwsize;
if (nvec < minvec)
return -ENOSPC;
rc = pci_setup_msi_context(dev);
if (rc)
return rc;
@ -785,7 +786,7 @@ int __pci_enable_msix_range(struct pci_dev *dev,
return -ENOSPC;
}
rc = __pci_enable_msix(dev, entries, nvec, affd, flags);
rc = msix_capability_init(dev, entries, nvec, affd);
if (rc == 0)
return nvec;