iommu/arm-smmu-v3: disable stall for quiet_cd

In the stall model, invalid transactions were expected to be
stalled and aborted by the IOPF handler.

However, when killing a test case with a huge amount of data, the
accelerator streamline can not stop until all data is consumed
even if the page fault handler reports errors. As a result, the
kill may take a long time, about 10 seconds with numerous iopf
interrupts.

So disable stall for quiet_cd in the non-force stall model, since
force stall model (STALL_MODEL==0b10) requires CD.S must be 1.

Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Signed-off-by: Wenkai Lin <linwenkai6@hisilicon.com>
Suggested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20231206005727.46150-1-zhangfei.gao@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 7445454c2af244f03b9274db12e3e4dd325e31ab..7086e5fa41ff6bc8415e9e3525dbec829f70f75d 100644 (file)
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1063,6 +1063,7 @@ int arm_smmu_write_ctx_desc(struct arm_smmu_master *master, int ssid,
        bool cd_live;
        __le64 *cdptr;
        struct arm_smmu_ctx_desc_cfg *cd_table = &master->cd_table;
+       struct arm_smmu_device *smmu = master->smmu;
 
        if (WARN_ON(ssid >= (1 << cd_table->s1cdmax)))
                return -E2BIG;
@@ -1077,6 +1078,8 @@ int arm_smmu_write_ctx_desc(struct arm_smmu_master *master, int ssid,
        if (!cd) { /* (5) */
                val = 0;
        } else if (cd == &quiet_cd) { /* (4) */
+               if (!(smmu->features & ARM_SMMU_FEAT_STALL_FORCE))
+                       val &= ~(CTXDESC_CD_0_S | CTXDESC_CD_0_R);
                val |= CTXDESC_CD_0_TCR_EPD0;
        } else if (cd_live) { /* (3) */
                val &= ~CTXDESC_CD_0_ASID;