This is a note to let you know that I've just added the patch titled
iommu: sun50i: clear bypass register
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-sun50i-clear-bypass-register.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e76ca1b7590f636ca053a0af61ae1a8994aca3e2
Author: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
Date: Sun Jun 16 23:40:52 2024 +0100
iommu: sun50i: clear bypass register
[ Upstream commit 927c70c93d929f4c2dcaf72f51b31bb7d118a51a ]
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: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
Reviewed-by: Chen-Yu Tsai <wens@xxxxxxxx>
Link: https://lore.kernel.org/r/20240616224056.29159-2-andre.przywara@xxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c
index 74c5cb93e900..94bd7f25f6f2 100644
--- a/drivers/iommu/sun50i-iommu.c
+++ b/drivers/iommu/sun50i-iommu.c
@@ -449,6 +449,7 @@ 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) |
