diff options
Diffstat (limited to 'bsp/meta-arm/meta-arm-bsp/recipes-kernel/linux/linux-linaro-arm-5.4/n1sdp/0001-TMP-iommu-arm-smmu-v3-Ignore-IOPF-capabilities.patch')
| -rw-r--r-- | bsp/meta-arm/meta-arm-bsp/recipes-kernel/linux/linux-linaro-arm-5.4/n1sdp/0001-TMP-iommu-arm-smmu-v3-Ignore-IOPF-capabilities.patch | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/bsp/meta-arm/meta-arm-bsp/recipes-kernel/linux/linux-linaro-arm-5.4/n1sdp/0001-TMP-iommu-arm-smmu-v3-Ignore-IOPF-capabilities.patch b/bsp/meta-arm/meta-arm-bsp/recipes-kernel/linux/linux-linaro-arm-5.4/n1sdp/0001-TMP-iommu-arm-smmu-v3-Ignore-IOPF-capabilities.patch new file mode 100644 index 00000000..e1ff4a55 --- /dev/null +++ b/bsp/meta-arm/meta-arm-bsp/recipes-kernel/linux/linux-linaro-arm-5.4/n1sdp/0001-TMP-iommu-arm-smmu-v3-Ignore-IOPF-capabilities.patch @@ -0,0 +1,46 @@ +From 4ebcbe09471d6b6b18fce42993489bed3801f10c Mon Sep 17 00:00:00 2001 +From: Jean-Philippe Brucker <jean-philippe@linaro.org> +Date: Fri, 24 Jan 2020 10:17:14 +0100 +Subject: [PATCH 1/4] TMP: iommu/arm-smmu-v3: Ignore IOPF capabilities + +Don't mandate PRI or stall to enable SVA. Some devices have their own +method for managing I/O page faults when they notice a translation +request that fails. + +Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> +--- + drivers/iommu/arm-smmu-v3.c | 18 +++++++++++++++++- + 1 file changed, 17 insertions(+), 1 deletion(-) + +diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c +index fed6a9d5867e..a8d7d6ccbb21 100644 +--- a/drivers/iommu/arm-smmu-v3.c ++++ b/drivers/iommu/arm-smmu-v3.c +@@ -3276,7 +3276,23 @@ static bool arm_smmu_ats_supported(struct arm_smmu_master *master) + + static bool arm_smmu_iopf_supported(struct arm_smmu_master *master) + { +- return master->stall_enabled || master->pri_supported; ++ /* return master->stall_enabled || master->pri_supported; */ ++ ++ /* ++ * FIXME: this temporary hack allows enabling SVA for any endpoint even ++ * when they don't have PRI/stall. ++ * ++ * To implement this more cleanly, we need a third method, complementing ++ * stall_enabled and pri_supported, to enable IOPF. A bit that says ++ * "this device's page faults are handled out of band", called for ++ * example master->oob_iopf. How to set it? It can easily be a firmware ++ * quirk, but that does not suffice in my opinion. We need to know that ++ * there is software ready to handle these page faults. The device ++ * driver owning this endpoint could for example call ++ * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_OOB_IOPF), before ++ * enabling IOMMU_DEV_FEAT_SVA. ++ */ ++ return true; + } + + static void arm_smmu_enable_ats(struct arm_smmu_master *master) +-- +2.25.0 + |