From 89535821c04256964e266bf585cf224f65e08983 Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Wed, 15 Jan 2020 13:52:29 +0100 Subject: [PATCH] iommu/arm-smmu-v3: Parse PASID devicetree property of platform devices For platform devices that support SubstreamID (SSID), firmware provides the number of supported SSID bits. Restrict it to what the SMMU supports and cache it into master->ssid_bits, which will also be used for PCI PASID. Reviewed-by: Eric Auger Reviewed-by: Jonathan Cameron Signed-off-by: Jean-Philippe Brucker Signed-off-by: Will Deacon --- drivers/iommu/arm-smmu-v3.c | 13 +++++++++++++ drivers/iommu/of_iommu.c | 6 +++++- include/linux/iommu.h | 2 ++ 3 files changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 4a9442f004ca..2717c2b211d2 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -289,6 +289,12 @@ #define CTXDESC_CD_1_TTB0_MASK GENMASK_ULL(51, 4) +/* + * When the SMMU only supports linear context descriptor tables, pick a + * reasonable size limit (64kB). + */ +#define CTXDESC_LINEAR_CDMAX ilog2(SZ_64K / (CTXDESC_CD_DWORDS << 3)) + /* Command queue */ #define CMDQ_ENT_SZ_SHIFT 4 #define CMDQ_ENT_DWORDS ((1 << CMDQ_ENT_SZ_SHIFT) >> 3) @@ -627,6 +633,7 @@ struct arm_smmu_master { u32 *sids; unsigned int num_sids; bool ats_enabled; + unsigned int ssid_bits; }; /* SMMU private data for an IOMMU domain */ @@ -2559,6 +2566,12 @@ static int arm_smmu_add_device(struct device *dev) } } + master->ssid_bits = min(smmu->ssid_bits, fwspec->num_pasid_bits); + + if (!(smmu->features & ARM_SMMU_FEAT_2_LVL_CDTAB)) + master->ssid_bits = min_t(u8, master->ssid_bits, + CTXDESC_LINEAR_CDMAX); + group = iommu_group_get_for_dev(dev); if (!IS_ERR(group)) { iommu_group_put(group); diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index e7bc8b721947..20738aacac89 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -203,8 +203,12 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, if (err) break; } - } + fwspec = dev_iommu_fwspec_get(dev); + if (!err && fwspec) + of_property_read_u32(master_np, "pasid-num-bits", + &fwspec->num_pasid_bits); + } /* * Two success conditions can be represented by non-negative err here: diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 90007c92ad2d..c1ad15228447 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -579,6 +579,7 @@ struct iommu_group *fsl_mc_device_group(struct device *dev); * @ops: ops for this device's IOMMU * @iommu_fwnode: firmware handle for this device's IOMMU * @iommu_priv: IOMMU driver private data for this device + * @num_pasid_bits: number of PASID bits supported by this device * @num_ids: number of associated device IDs * @ids: IDs which this device may present to the IOMMU */ @@ -587,6 +588,7 @@ struct iommu_fwspec { struct fwnode_handle *iommu_fwnode; void *iommu_priv; u32 flags; + u32 num_pasid_bits; unsigned int num_ids; u32 ids[1]; };