Commit 927c70c9 authored by Jernej Skrabec's avatar Jernej Skrabec Committed by Joerg Roedel
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iommu: sun50i: clear bypass register 



The Allwinner H6 IOMMU has a bypass register, which allows to circumvent
the page tables for each possible master. The reset value for this
register is 0, which disables the bypass.
The Allwinner H616 IOMMU resets this register to 0x7f, which activates
the bypass for all masters, which is not what we want.

Always clear this register to 0, to enforce the usage of page tables,
and make this driver compatible with the H616 in this respect.

Signed-off-by: default avatarJernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: default avatarAndre Przywara <andre.przywara@arm.com>
Reviewed-by: default avatarChen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20240616224056.29159-2-andre.przywara@arm.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 83a7eefe

drivers/iommu/sun50i-iommu.c

+1 −0
Original line number Diff line number Diff line
@@ -452,6 +452,7 @@ static int sun50i_iommu_enable(struct sun50i_iommu *iommu) 
		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(3) |

		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(4) |

		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(5));

	iommu_write(iommu, IOMMU_BYPASS_REG, 0);

	iommu_write(iommu, IOMMU_INT_ENABLE_REG, IOMMU_INT_MASK);

	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_NONE),

		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 0) |