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authorChristoph Hellwig <hch@lst.de>2016-07-12 12:20:16 +0300
committerBjorn Helgaas <bhelgaas@google.com>2016-07-21 23:49:43 +0300
commit3ac020e0ca8beff9b695f9866a06d50c09c602d6 (patch)
treedf850544e807b5e90021fc55045871e3f2387d53 /drivers/pci/msi.c
parent12eb21de1f26233ad195ffe991697d61790f4193 (diff)
downloadlinux-3ac020e0ca8beff9b695f9866a06d50c09c602d6.tar.xz
PCI: Make the "entries" argument to pci_enable_msix() optional
The "entries" argument isn't needed if the list of entries does not contain any holes. Make it optional so that we can avoid the need to allocate a msix_entry structure for this (common) case. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Alexander Gordeev <agordeev@redhat.com>
Diffstat (limited to 'drivers/pci/msi.c')
-rw-r--r--drivers/pci/msi.c30
1 files changed, 16 insertions, 14 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index a385f39be6f7..98ace67c5f4d 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -695,7 +695,10 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
entry->msi_attrib.is_msix = 1;
entry->msi_attrib.is_64 = 1;
- entry->msi_attrib.entry_nr = entries[i].entry;
+ if (entries)
+ entry->msi_attrib.entry_nr = entries[i].entry;
+ else
+ entry->msi_attrib.entry_nr = i;
entry->msi_attrib.default_irq = dev->irq;
entry->mask_base = base;
entry->nvec_used = 1;
@@ -713,11 +716,11 @@ static void msix_program_entries(struct pci_dev *dev,
int i = 0;
for_each_pci_msi_entry(entry, dev) {
- entries[i].vector = entry->irq;
+ if (entries)
+ entries[i++].vector = entry->irq;
entry->masked = readl(pci_msix_desc_addr(entry) +
PCI_MSIX_ENTRY_VECTOR_CTRL);
msix_mask_irq(entry, 1);
- i++;
}
}
@@ -930,7 +933,7 @@ EXPORT_SYMBOL(pci_msix_vec_count);
/**
* pci_enable_msix - configure device's MSI-X capability structure
* @dev: pointer to the pci_dev data structure of MSI-X device function
- * @entries: pointer to an array of MSI-X entries
+ * @entries: pointer to an array of MSI-X entries (optional)
* @nvec: number of MSI-X irqs requested for allocation by device driver
*
* Setup the MSI-X capability structure of device function with the number
@@ -950,22 +953,21 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
if (!pci_msi_supported(dev, nvec))
return -EINVAL;
- if (!entries)
- return -EINVAL;
-
nr_entries = pci_msix_vec_count(dev);
if (nr_entries < 0)
return nr_entries;
if (nvec > nr_entries)
return nr_entries;
- /* Check for any invalid entries */
- for (i = 0; i < nvec; i++) {
- if (entries[i].entry >= nr_entries)
- return -EINVAL; /* invalid entry */
- for (j = i + 1; j < nvec; j++) {
- if (entries[i].entry == entries[j].entry)
- return -EINVAL; /* duplicate entry */
+ if (entries) {
+ /* Check for any invalid entries */
+ for (i = 0; i < nvec; i++) {
+ if (entries[i].entry >= nr_entries)
+ return -EINVAL; /* invalid entry */
+ for (j = i + 1; j < nvec; j++) {
+ if (entries[i].entry == entries[j].entry)
+ return -EINVAL; /* duplicate entry */
+ }
}
}
WARN_ON(!!dev->msix_enabled);