[PATCH 2/2] x86: gart: fix breakage due to IOMMU initialization cleanup

From: FUJITA Tomonori
Date: Tue Dec 08 2009 - 06:08:16 EST


From: Yinghai Lu <yinghai@xxxxxxxxxx>

This fixes the following breakage of the commit
75f1cdf1dda92cae037ec848ae63690d91913eac:

- GART systems that don't AGP with broken BIOS and more than 4GB
memory are forced to use swiotlb. They can allocate aperture by hand
and use GART.

- GART systems without GAP must disable GART on shutdown.

- swiotlb usage is forced by the boot option, gart_iommu_hole_init()
is not called. so we disable GART early_gart_iommu_check().

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
---
arch/x86/kernel/aperture_64.c | 11 ++++++-----
arch/x86/kernel/pci-gart_64.c | 3 ++-
2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index e0dfb68..3704997 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -280,7 +280,8 @@ void __init early_gart_iommu_check(void)
* or BIOS forget to put that in reserved.
* try to update e820 to make that region as reserved.
*/
- int i, fix, slot;
+ u32 agp_aper_base = 0, agp_aper_order = 0;
+ int i, fix, slot, valid_agp = 0;
u32 ctl;
u32 aper_size = 0, aper_order = 0, last_aper_order = 0;
u64 aper_base = 0, last_aper_base = 0;
@@ -290,6 +291,8 @@ void __init early_gart_iommu_check(void)
return;

/* This is mostly duplicate of iommu_hole_init */
+ agp_aper_base = search_agp_bridge(&agp_aper_order, &valid_agp);
+
fix = 0;
for (i = 0; i < ARRAY_SIZE(bus_dev_ranges); i++) {
int bus;
@@ -342,10 +345,10 @@ void __init early_gart_iommu_check(void)
}
}

- if (!fix)
+ if (valid_agp)
return;

- /* different nodes have different setting, disable them all at first*/
+ /* disable them all at first */
for (i = 0; i < ARRAY_SIZE(bus_dev_ranges); i++) {
int bus;
int dev_base, dev_limit;
@@ -458,8 +461,6 @@ out:

if (aper_alloc) {
/* Got the aperture from the AGP bridge */
- } else if (!valid_agp) {
- /* Do nothing */
} else if ((!no_iommu && max_pfn > MAX_DMA32_PFN) ||
force_iommu ||
valid_agp ||
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index e6a0d40..56c0e73 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -710,7 +710,8 @@ static void gart_iommu_shutdown(void)
struct pci_dev *dev;
int i;

- if (no_agp)
+ /* don't shutdown it if there is AGP installed */
+ if (!no_agp)
return;

for (i = 0; i < num_k8_northbridges; i++) {
--
1.5.6.5

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