2013-08-08 13:12:59

by Yijing Wang

Subject: [PATCH 14/16] amd_iommu: clean up unnecessary MSI/MSI-X capability find

PCI core will initialize device MSI/MSI-X capability in
pci_msi_init_pci_dev(). So device driver should use
pci_dev->msi_cap/msix_cap to determine whether the device
support MSI/MSI-X instead of using
pci_find_capability(pci_dev, PCI_CAP_ID_MSI/MSIX).
Access to PCIe device config space again will consume more time.

Signed-off-by: Yijing Wang <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
drivers/iommu/amd_iommu_init.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 7acbf35..8f798be 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1384,7 +1384,7 @@ static int iommu_init_msi(struct amd_iommu *iommu)
if (iommu->int_enabled)
goto enable_faults;

- if (pci_find_capability(iommu->dev, PCI_CAP_ID_MSI))
+ if (iommu->dev->msi_cap)
ret = iommu_setup_msi(iommu);
else
ret = -ENODEV;
--
1.7.1

2013-08-14 10:20:17

by Joerg Roedel

Subject: Re: [PATCH 14/16] amd_iommu: clean up unnecessary MSI/MSI-X capability find

On Thu, Aug 08, 2013 at 09:12:36PM +0800, Yijing Wang wrote:
> PCI core will initialize device MSI/MSI-X capability in
> pci_msi_init_pci_dev(). So device driver should use
> pci_dev->msi_cap/msix_cap to determine whether the device
> support MSI/MSI-X instead of using
> pci_find_capability(pci_dev, PCI_CAP_ID_MSI/MSIX).
> Access to PCIe device config space again will consume more time.
>
> Signed-off-by: Yijing Wang <[email protected]>
> Cc: Joerg Roedel <[email protected]>
> Cc: [email protected]
> Cc: [email protected]

Applied to x86/amd, thanks.