[PATCH] x86_64: Use function pointers to call DMA mapping functions
AK: I hacked Muli's original patch a lot and there were a lot
of changes - all bugs are probably to blame on me now.
There were also some changes in the fall back behaviour
for swiotlb - in particular it doesn't try to use GFP_DMA
now anymore. Also all DMA mapping operations use the
same core dma_alloc_coherent code with proper fallbacks now.
And various other changes and cleanups.
Known problems: iommu=force swiotlb=force together breaks
needs more testing.
This patch cleans up x86_64's DMA mapping dispatching code. Right now
we have three possible IOMMU types: AGP GART, swiotlb and nommu, and
in the future we will also have Xen's x86_64 swiotlb and other HW
IOMMUs for x86_64. In order to support all of them cleanly, this
patch:
- introduces a struct dma_mapping_ops with function pointers for each
of the DMA mapping operations of gart (AMD HW IOMMU), swiotlb
(software IOMMU) and nommu (no IOMMU).
- gets rid of:
if (swiotlb)
return swiotlb_xxx();
- PCI_DMA_BUS_IS_PHYS is now checked against the dma_ops being set
This makes swiotlb faster by avoiding double copying in some cases.
Signed-Off-By: Muli Ben-Yehuda <mulix@mulix.org>
Signed-Off-By: Jon D. Mason <jdmason@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 150e1ac..ee053e3 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -351,32 +351,24 @@
depends on HPET_TIMER && RTC=y
config GART_IOMMU
- bool "IOMMU support"
+ bool "K8 GART IOMMU support"
default y
+ select SWIOTLB
depends on PCI
help
Support the IOMMU. Needed to run systems with more than 3GB of memory
properly with 32-bit PCI devices that do not support DAC (Double Address
Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter.
Normally the kernel will take the right choice by itself.
- This option includes a driver for the AMD Opteron/Athlon64 IOMMU
- and a software emulation used on some other systems.
+ This option includes a driver for the AMD Opteron/Athlon64 northbridge IOMMU
+ and a software emulation used on other systems.
If unsure, say Y.
# need this always enabled with GART_IOMMU for the VIA workaround
config SWIOTLB
- bool
- depends on GART_IOMMU
- default y
-
-config DUMMY_IOMMU
bool
- depends on !GART_IOMMU && !SWIOTLB
default y
- help
- Don't use IOMMU code. This will cause problems when you have more than 4GB
- of memory and any 32-bit devices. Don't turn on unless you know what you
- are doing.
+ depends on GART_IOMMU
config X86_MCE
bool "Machine check support" if EMBEDDED