lkml.org 
[lkml]   [2019]   [Jun]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3/8] iommu/arm-smmu-v3: Support platform SSID
Date
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.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
---
drivers/iommu/arm-smmu-v3.c | 11 +++++++++++
drivers/iommu/of_iommu.c | 6 +++++-
include/linux/iommu.h | 1 +
3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 4d5a694f02c2..3254f473e681 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -604,6 +604,7 @@ struct arm_smmu_master {
struct list_head domain_head;
u32 *sids;
unsigned int num_sids;
+ unsigned int ssid_bits;
bool ats_enabled :1;
};

@@ -2097,6 +2098,16 @@ static int arm_smmu_add_device(struct device *dev)
}
}

+ master->ssid_bits = min(smmu->ssid_bits, fwspec->num_pasid_bits);
+
+ /*
+ * If the SMMU doesn't support 2-stage CD, limit the linear
+ * tables to a reasonable number of contexts, let's say
+ * 64kB / sizeof(ctx_desc) = 1024 = 2^10
+ */
+ if (!(smmu->features & ARM_SMMU_FEAT_2_LVL_CDTAB))
+ master->ssid_bits = min(master->ssid_bits, 10U);
+
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 f04a6df65eb8..04f4f6b95d82 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -206,8 +206,12 @@ 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 519e40fb23ce..b91df613385f 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -536,6 +536,7 @@ struct iommu_fwspec {
struct fwnode_handle *iommu_fwnode;
void *iommu_priv;
u32 flags;
+ u32 num_pasid_bits;
unsigned int num_ids;
u32 ids[1];
};
--
2.21.0
\
 
 \ /
  Last update: 2019-06-10 20:53    [W:0.110 / U:0.344 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site