[PATCH v2 02/05] iommu/ipmmu-vmsa: Consistent ->of_xlate() handling

From: Magnus Damm
Date: Mon Jul 17 2017 - 09:08:49 EST


From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>

The 32-bit ARM code gets updated to make use of ->of_xlate() and the
code is shared between 64-bit and 32-bit ARM. The of_device_is_available()
check gets dropped since it is included in of_iommu_xlate().

Suggested-by: Robin Murphy <robin.murphy@xxxxxxx>
Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
---

Changes since V1:
- Moved "Initialize once" check to ipmmu_of_xlate() - thanks Geert!

drivers/iommu/ipmmu-vmsa.c | 51 ++++++++++++++------------------------------
1 file changed, 17 insertions(+), 34 deletions(-)

--- 0002/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c 2017-07-17 21:03:38.340607110 +0900
@@ -734,6 +734,16 @@ error:
return ret;
}

+static int ipmmu_of_xlate(struct device *dev,
+ struct of_phandle_args *spec)
+{
+ /* Initialize once - xlate() will call multiple times */
+ if (to_priv(dev))
+ return 0;
+
+ return ipmmu_init_platform_device(dev);
+}
+
#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)

static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
@@ -750,11 +760,11 @@ static int ipmmu_add_device(struct devic
struct iommu_group *group;
int ret;

- if (to_priv(dev)) {
- dev_warn(dev, "IOMMU driver already assigned to device %s\n",
- dev_name(dev));
- return -EINVAL;
- }
+ /*
+ * Only let through devices that have been verified in xlate()
+ */
+ if (!to_priv(dev))
+ return -ENODEV;

/* Create a device group and add the device to it. */
group = iommu_group_alloc();
@@ -773,10 +783,6 @@ static int ipmmu_add_device(struct devic
goto error;
}

- ret = ipmmu_init_platform_device(dev);
- if (ret < 0)
- goto error;
-
/*
* Create the ARM mapping, used by the ARM DMA mapping core to allocate
* VAs. This will allocate a corresponding IOMMU domain.
@@ -817,24 +823,13 @@ error:
if (!IS_ERR_OR_NULL(group))
iommu_group_remove_device(dev);

- kfree(to_priv(dev)->utlbs);
- kfree(to_priv(dev));
- set_priv(dev, NULL);
-
return ret;
}

static void ipmmu_remove_device(struct device *dev)
{
- struct ipmmu_vmsa_iommu_priv *priv = to_priv(dev);
-
arm_iommu_detach_device(dev);
iommu_group_remove_device(dev);
-
- kfree(priv->utlbs);
- kfree(priv);
-
- set_priv(dev, NULL);
}

static const struct iommu_ops ipmmu_ops = {
@@ -849,6 +844,7 @@ static const struct iommu_ops ipmmu_ops
.add_device = ipmmu_add_device,
.remove_device = ipmmu_remove_device,
.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
+ .of_xlate = ipmmu_of_xlate,
};

#endif /* !CONFIG_ARM && CONFIG_IOMMU_DMA */
@@ -958,19 +954,6 @@ static struct iommu_group *ipmmu_find_gr
return group;
}

-static int ipmmu_of_xlate_dma(struct device *dev,
- struct of_phandle_args *spec)
-{
- /* If the IPMMU device is disabled in DT then return error
- * to make sure the of_iommu code does not install ops
- * even though the iommu device is disabled
- */
- if (!of_device_is_available(spec->np))
- return -ENODEV;
-
- return ipmmu_init_platform_device(dev);
-}
-
static const struct iommu_ops ipmmu_ops = {
.domain_alloc = ipmmu_domain_alloc_dma,
.domain_free = ipmmu_domain_free_dma,
@@ -984,7 +967,7 @@ static const struct iommu_ops ipmmu_ops
.remove_device = ipmmu_remove_device_dma,
.device_group = ipmmu_find_group_dma,
.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
- .of_xlate = ipmmu_of_xlate_dma,
+ .of_xlate = ipmmu_of_xlate,
};

#endif /* CONFIG_IOMMU_DMA */