PCI: Use cached MSI cap while enabling MSI interrupts
The patch uses the cached MSI capability offset in pci_dev instead
of reading it from config space when enabling MSI interrupts.
[bhelgaas: removed unrelated msi_control_reg() changes]
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 60a4b10..0138550 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -546,14 +546,13 @@
static int msi_capability_init(struct pci_dev *dev, int nvec)
{
struct msi_desc *entry;
- int pos, ret;
+ int ret;
u16 control;
unsigned mask;
- pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
msi_set_enable(dev, 0); /* Disable MSI during set up */
- pci_read_config_word(dev, msi_control_reg(pos), &control);
+ pci_read_config_word(dev, msi_control_reg(dev->msi_cap), &control);
/* MSI Entry Initialization */
entry = alloc_msi_entry(dev);
if (!entry)
@@ -564,9 +563,9 @@
entry->msi_attrib.entry_nr = 0;
entry->msi_attrib.maskbit = is_mask_bit_support(control);
entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */
- entry->msi_attrib.pos = pos;
+ entry->msi_attrib.pos = dev->msi_cap;
- entry->mask_pos = msi_mask_reg(pos, entry->msi_attrib.is_64);
+ entry->mask_pos = msi_mask_reg(dev->msi_cap, entry->msi_attrib.is_64);
/* All MSIs are unmasked by default, Mask them all */
if (entry->msi_attrib.maskbit)
pci_read_config_dword(dev, entry->mask_pos, &entry->masked);
@@ -807,13 +806,13 @@
*/
int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
{
- int status, pos, maxvec;
+ int status, maxvec;
u16 msgctl;
- pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
- if (!pos)
+ if (!dev->msi_cap)
return -EINVAL;
- pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
+
+ pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
maxvec = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
if (nvec > maxvec)
return maxvec;
@@ -838,14 +837,13 @@
int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec)
{
- int ret, pos, nvec;
+ int ret, nvec;
u16 msgctl;
- pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
- if (!pos)
+ if (!dev->msi_cap)
return -EINVAL;
- pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
+ pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
if (maxvec)
