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authorJon Mason <jdmason@us.ibm.com>2006-06-26 13:58:05 +0200
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 10:48:18 -0700
commit8d4f6b93a4aaa6b56b600cd1165c971f4395e4b3 (patch)
tree23955634ded577e53c46390714a6f069b4587c86 /arch/x86_64/kernel
parent2bbc419f9d51b44f3fdeea12c5b786bdace82b8e (diff)
downloadlinux-8d4f6b93a4aaa6b56b600cd1165c971f4395e4b3.tar.bz2
[PATCH] x86_64: Calgary IOMMU - introduce iommu_detected
swiotlb relies on the gart specific iommu_aperture variable to know if we discovered a hardware IOMMU before swiotlb initialization. Introduce iommu_detected to do the same thing, but in a HW IOMMU neutral manner, in preparation for adding the Calgary HW IOMMU. Signed-Off-By: Muli Ben-Yehuda <muli@il.ibm.com> Signed-Off-By: Jon Mason <jdmason@us.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64/kernel')
-rw-r--r--arch/x86_64/kernel/aperture.c1
-rw-r--r--arch/x86_64/kernel/pci-dma.c3
-rw-r--r--arch/x86_64/kernel/pci-gart.c4
-rw-r--r--arch/x86_64/kernel/pci-swiotlb.c2
4 files changed, 9 insertions, 1 deletions
diff --git a/arch/x86_64/kernel/aperture.c b/arch/x86_64/kernel/aperture.c
index 9ea723bab16c..a195ef06ec55 100644
--- a/arch/x86_64/kernel/aperture.c
+++ b/arch/x86_64/kernel/aperture.c
@@ -209,6 +209,7 @@ void __init iommu_hole_init(void)
if (!early_is_k8_nb(read_pci_config(0, num, 3, 0x00)))
continue;
+ iommu_detected = 1;
iommu_aperture = 1;
aper_order = (read_pci_config(0, num, 3, 0x90) >> 1) & 7;
diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c
index 33926c367250..7edd1a40fab3 100644
--- a/arch/x86_64/kernel/pci-dma.c
+++ b/arch/x86_64/kernel/pci-dma.c
@@ -33,6 +33,9 @@ int panic_on_overflow __read_mostly = 0;
int force_iommu __read_mostly= 0;
#endif
+/* Set this to 1 if there is a HW IOMMU in the system */
+int iommu_detected __read_mostly = 0;
+
/* Dummy device used for NULL arguments (normally ISA). Better would
be probably a smaller DMA mask, but this is bug-to-bug compatible
to i386. */
diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c
index 82a346e6e2e4..4f67957d2b42 100644
--- a/arch/x86_64/kernel/pci-gart.c
+++ b/arch/x86_64/kernel/pci-gart.c
@@ -597,6 +597,10 @@ static int __init pci_iommu_init(void)
if (swiotlb)
return -ENODEV;
+ /* Did we detect a different HW IOMMU? */
+ if (iommu_detected && !iommu_aperture)
+ return -1;
+
if (no_iommu ||
(!force_iommu && end_pfn <= MAX_DMA32_PFN) ||
!iommu_aperture ||
diff --git a/arch/x86_64/kernel/pci-swiotlb.c b/arch/x86_64/kernel/pci-swiotlb.c
index 990ed67896f2..ebdb77fe2057 100644
--- a/arch/x86_64/kernel/pci-swiotlb.c
+++ b/arch/x86_64/kernel/pci-swiotlb.c
@@ -31,7 +31,7 @@ struct dma_mapping_ops swiotlb_dma_ops = {
void pci_swiotlb_init(void)
{
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
- if (!iommu_aperture && !no_iommu &&
+ if (!iommu_detected && !no_iommu &&
(end_pfn > MAX_DMA32_PFN || force_iommu))
swiotlb = 1;
if (swiotlb) {