[PATCH v4 4/6] iommu: Regulate EINVAL in ->attach_dev callback functions

From: Nicolin Chen
Date: Wed Sep 21 2022 - 04:24:27 EST


Following the new rules in include/linux/iommu.h kdocs, EINVAL now can be
used to indicate that domain and device are incompatible by a caller that
treats it as a soft failure and tries attaching to another domain.

On the other hand, there are ->attach_dev callback functions returning it
for obvious device-specific errors. They will result in some inefficiency
in the caller handling routine.

Update these places to corresponding errnos following the new rules.

Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
drivers/iommu/fsl_pamu.c | 2 +-
drivers/iommu/fsl_pamu_domain.c | 4 ++--
drivers/iommu/intel/pasid.c | 6 ++++--
drivers/iommu/mtk_iommu.c | 2 +-
drivers/iommu/omap-iommu.c | 4 ++--
drivers/iommu/virtio-iommu.c | 2 +-
6 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/fsl_pamu.c b/drivers/iommu/fsl_pamu.c
index 0d03f837a5d4..2eb3211c8167 100644
--- a/drivers/iommu/fsl_pamu.c
+++ b/drivers/iommu/fsl_pamu.c
@@ -211,7 +211,7 @@ int pamu_config_ppaace(int liodn, u32 omi, u32 stashid, int prot)
ppaace->op_encode.index_ot.omi = omi;
} else if (~omi != 0) {
pr_debug("bad operation mapping index: %d\n", omi);
- return -EINVAL;
+ return -ENODEV;
}

/* configure stash id */
diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
index 011f9ab7f743..b4a1c0f79c3e 100644
--- a/drivers/iommu/fsl_pamu_domain.c
+++ b/drivers/iommu/fsl_pamu_domain.c
@@ -258,7 +258,7 @@ static int fsl_pamu_attach_device(struct iommu_domain *domain,
liodn = of_get_property(dev->of_node, "fsl,liodn", &len);
if (!liodn) {
pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node);
- return -EINVAL;
+ return -ENODEV;
}

spin_lock_irqsave(&dma_domain->domain_lock, flags);
@@ -267,7 +267,7 @@ static int fsl_pamu_attach_device(struct iommu_domain *domain,
if (liodn[i] >= PAACE_NUMBER_ENTRIES) {
pr_debug("Invalid liodn %d, attach device failed for %pOF\n",
liodn[i], dev->of_node);
- ret = -EINVAL;
+ ret = -ENODEV;
break;
}

diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index c5e7e8b020a5..aff1a9caa496 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -101,8 +101,10 @@ int intel_pasid_alloc_table(struct device *dev)

might_sleep();
info = dev_iommu_priv_get(dev);
- if (WARN_ON(!info || !dev_is_pci(dev) || info->pasid_table))
- return -EINVAL;
+ if (WARN_ON(!info || !dev_is_pci(dev)))
+ return -ENODEV;
+ if (WARN_ON(info->pasid_table))
+ return -EEXIST;

pasid_table = kzalloc(sizeof(*pasid_table), GFP_KERNEL);
if (!pasid_table)
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 7e363b1f24df..be1a7d1cc630 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -607,7 +607,7 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom,
dom->iop = alloc_io_pgtable_ops(ARM_V7S, &dom->cfg, data);
if (!dom->iop) {
dev_err(data->dev, "Failed to alloc io pgtable\n");
- return -EINVAL;
+ return -ENOMEM;
}

/* Update our support page sizes bitmap */
diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index d9cf2820c02e..447e40d55918 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -1414,7 +1414,7 @@ static int omap_iommu_attach_init(struct device *dev,

odomain->num_iommus = omap_iommu_count(dev);
if (!odomain->num_iommus)
- return -EINVAL;
+ return -ENODEV;

odomain->iommus = kcalloc(odomain->num_iommus, sizeof(*iommu),
GFP_ATOMIC);
@@ -1464,7 +1464,7 @@ omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)

if (!arch_data || !arch_data->iommu_dev) {
dev_err(dev, "device doesn't have an associated iommu\n");
- return -EINVAL;
+ return -ENODEV;
}

spin_lock(&omap_domain->lock);
diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index 80151176ba12..4c652773fd6c 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -669,7 +669,7 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev,
dev_err(vdev->dev,
"granule 0x%lx larger than system page size 0x%lx\n",
viommu_page_size, PAGE_SIZE);
- return -EINVAL;
+ return -ENODEV;
}

ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain,
--
2.17.1