The patch adjusts function msi_capability_init() and pci_enable_msi_block()
so that we needn't figure out the address of MSI capability structure
for multiple time in one function call path while enabling MSI.
Signed-off-by: Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx>
---
drivers/pci/msi.c | 19 ++++++++-----------
1 files changed, 8 insertions(+), 11 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index a20cb0a..f6fa697 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -542,6 +542,7 @@ out_unroll:
* msi_capability_init - configure device's MSI capability structure
* @dev: pointer to the pci_dev data structure of MSI device function
* @nvec: number of interrupts to allocate
+ * @pos: address of MSI capability structure
*
* Setup the MSI capability structure of the device with the requested
* number of interrupts. A return value of zero indicates the successful
@@ -549,14 +550,13 @@ out_unroll:
* an error, and a positive return value indicates the number of interrupts
* which could have been allocated.
*/
-static int msi_capability_init(struct pci_dev *dev, int nvec)
+static int msi_capability_init(struct pci_dev *dev, int nvec, int pos)
{
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, pos, 0); /* Disable MSI during set up */
pci_read_config_word(dev, msi_control_reg(pos), &control);
@@ -823,18 +823,15 @@ int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
int pos, status, maxvec;
u16 msgctl;
- pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
- if (!pos)
- return -EINVAL;
+ status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI, &pos);
+ if (status)
+ return status;
+
pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
maxvec = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
if (nvec > maxvec)
return maxvec;
- status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI, &pos);
- if (status)
- return status;
-
WARN_ON(!!dev->msi_enabled);
/* Check whether driver already requested MSI-X irqs */
@@ -844,7 +841,7 @@ int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
return -EINVAL;
}
- status = msi_capability_init(dev, nvec);
+ status = msi_capability_init(dev, nvec, pos);
return status;
}
EXPORT_SYMBOL(pci_enable_msi_block);
--
1.7.5.4
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