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PCI: Use cached MSI cap while enabling MSI interrupts

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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>
This commit is contained in:
Gavin Shan 2013-04-04 16:54:32 +00:00 committed by Bjorn Helgaas
parent cdf1fd4d90
commit f465136d72
1 changed files with 11 additions and 13 deletions
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24
drivers/pci/msi.c
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@ -546,14 +546,13 @@ static int populate_msi_sysfs(struct pci_dev *pdev)
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 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
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 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
*/
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 @@ EXPORT_SYMBOL(pci_enable_msi_block);
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)