This is a note to let you know that I've just added the patch titled
iommu/qcom: Disable and reset context bank before programming
to the 5.15-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-qcom-disable-and-reset-context-bank-before-pro.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2f5b1abcd1edbd28b6b748cb79137843ae34787b
Author: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Date: Thu Jun 22 11:27:39 2023 +0200
iommu/qcom: Disable and reset context bank before programming
[ Upstream commit 9f3fef23d9b5a858a6e6d5f478bb1b6b76265e76 ]
Writing the new TTBRs, TCRs and MAIRs on a previously enabled
context bank may trigger a context fault, resulting in firmware
driven AP resets: change the domain initialization programming
sequence to disable the context bank(s) and to also clear the
related fault address (CB_FAR) and fault status (CB_FSR)
registers before writing new values to TTBR0/1, TCR/TCR2, MAIR0/1.
Fixes: 0ae349a0f33f ("iommu/qcom: Add qcom_iommu")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230622092742.74819-4-angelogioacchino.delregno@xxxxxxxxxxxxx
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
index a47cb654b7048..9438203f08de7 100644
--- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c
+++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
@@ -273,6 +273,13 @@ static int qcom_iommu_init_domain(struct iommu_domain *domain,
ctx->secure_init = true;
}
+ /* Disable context bank before programming */
+ iommu_writel(ctx, ARM_SMMU_CB_SCTLR, 0);
+
+ /* Clear context bank fault address fault status registers */
+ iommu_writel(ctx, ARM_SMMU_CB_FAR, 0);
+ iommu_writel(ctx, ARM_SMMU_CB_FSR, ARM_SMMU_FSR_FAULT);
+
/* TTBRs */
iommu_writeq(ctx, ARM_SMMU_CB_TTBR0,
pgtbl_cfg.arm_lpae_s1_cfg.ttbr |
