6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jernej Skrabec jernej.skrabec@gmail.com
[ 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@gmail.com Signed-off-by: Andre Przywara andre.przywara@arm.com Reviewed-by: Chen-Yu Tsai wens@csie.org Link: https://lore.kernel.org/r/20240616224056.29159-2-andre.przywara@arm.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/sun50i-iommu.c | 1 + 1 file changed, 1 insertion(+)
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) |