[ 77/82] iommu/amd: Cache pdev pointer to root-bridge

Ben Hutchings
2012-06-08T05:21:49Z

From: Joerg Roedel <joerg.roedel@amd.com>

commit c1bf94ec1e12d76838ad485158aecf208ebd8fb9 upstream.

At some point pci_get_bus_and_slot started to enable
interrupts. Since this function is used in the
amd_iommu_resume path it will enable interrupts on resume
which causes a warning. The fix will use a cached pointer
to the root-bridge to re-enable the IOMMU in case the BIOS
is broken.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/iommu/amd_iommu_init.c | 13 +++++--------
drivers/iommu/amd_iommu_types.h | 3 +++
2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index c567903..542024b 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1029,6 +1029,9 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
if (!iommu->dev)
return 1;

+ iommu->root_pdev = pci_get_bus_and_slot(iommu->dev->bus->number,
+ PCI_DEVFN(0, 0));
+
iommu->cap_ptr = h->cap_ptr;
iommu->pci_seg = h->pci_seg;
iommu->mmio_phys = h->mmio_phys;
@@ -1323,20 +1326,16 @@ static void iommu_apply_resume_quirks(struct amd_iommu *iommu)
{
int i, j;
u32 ioc_feature_control;
- struct pci_dev *pdev = NULL;
+ struct pci_dev *pdev = iommu->root_pdev;

/* RD890 BIOSes may not have completely reconfigured the iommu */
- if (!is_rd890_iommu(iommu->dev))
+ if (!is_rd890_iommu(iommu->dev) || !pdev)
return;

/*
* First, we need to ensure that the iommu is enabled. This is
* controlled by a register in the northbridge
*/
- pdev = pci_get_bus_and_slot(iommu->dev->bus->number, PCI_DEVFN(0, 0));
-
- if (!pdev)
- return;

/* Select Northbridge indirect register 0x75 and enable writing */
pci_write_config_dword(pdev, 0x60, 0x75 | (1 << 7));
@@ -1346,8 +1345,6 @@ static void iommu_apply_resume_quirks(struct amd_iommu *iommu)
if (!(ioc_feature_control & 0x1))
pci_write_config_dword(pdev, 0x64, ioc_feature_control | 1);

- pci_dev_put(pdev);
-
/* Restore the iommu BAR */
pci_write_config_dword(iommu->dev, iommu->cap_ptr + 4,
iommu->stored_addr_lo);
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index 2452f3b..2435555 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -481,6 +481,9 @@ struct amd_iommu {
/* Pointer to PCI device of this IOMMU */
struct pci_dev *dev;

+ /* Cache pdev to root device for resume quirks */
+ struct pci_dev *root_pdev;
+
/* physical address of MMIO space */
u64 mmio_phys;
/* virtual address of MMIO space */