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iommu/vt-d: Remove INTEL_IOMMU_BROKEN_GFX_WA

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Commit 62edf5dc4a ("intel-iommu: Restore DMAR_BROKEN_GFX_WA option for
broken graphics drivers") was introduced 24 years ago as a temporary
workaround for graphics drivers that used physical addresses for DMA and
avoided DMA APIs. This workaround was disabled by default.

As 24 years have passed, it is expected that graphics driver developers
have migrated their drivers to use kernel DMA APIs. Therefore, this
workaround is no longer required and could been removed.

The Intel iommu driver also provides a "igfx_off" option to turn off
the DMA translation for the graphic dedicated IOMMU. Hence, there is
really no good reason to keep this config option.

Suggested-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20240130060823.57990-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Lu Baolu 2024-02-27 10:14:34 +08:00 committed by Joerg Roedel
parent 54be6c6c5a
commit 4b8d18c0c9
2 changed files with 0 additions and 15 deletions
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11
drivers/iommu/intel/Kconfig
View File

@ -64,17 +64,6 @@ config INTEL_IOMMU_DEFAULT_ON
one is found. If this option is not selected, DMAR support can
be enabled by passing intel_iommu=on to the kernel.
config INTEL_IOMMU_BROKEN_GFX_WA
bool "Workaround broken graphics drivers (going away soon)"
depends on BROKEN && X86
help
Current Graphics drivers tend to use physical address
for DMA and avoid using DMA APIs. Setting this config
option permits the IOMMU driver to set a unity map for
all the OS-visible memory. Hence the driver can continue
to use physical addresses for DMA, at least until this
option is removed in the 2.6.32 kernel.
config INTEL_IOMMU_FLOPPY_WA
def_bool y
depends on X86

4
drivers/iommu/intel/iommu.c
View File

@ -2660,10 +2660,6 @@ static int __init init_dmars(void)
iommu_set_root_entry(iommu);
}
#ifdef CONFIG_INTEL_IOMMU_BROKEN_GFX_WA
dmar_map_gfx = 0;
#endif
if (!dmar_map_gfx)
iommu_identity_mapping |= IDENTMAP_GFX;