[PATCH 11/18] iommu/omap: Add IOMMU_DOMAIN_DMA support

Robin Murphy
2020-08-20T15:11:55Z

Now that arch/arm is wired up for default domains and iommu-dma,
implement the corresponding driver-side support for DMA domains.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
drivers/iommu/omap-iommu.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 71f29c0927fc..ea25c2fe0418 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -9,6 +9,7 @@
* Paul Mundt and Toshihiro Kobayashi
*/

+#include <linux/dma-iommu.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/slab.h>
@@ -1574,13 +1575,19 @@ static struct iommu_domain *omap_iommu_domain_alloc(unsigned type)
{
struct omap_iommu_domain *omap_domain;

- if (type != IOMMU_DOMAIN_UNMANAGED)
+ if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
return NULL;

omap_domain = kzalloc(sizeof(*omap_domain), GFP_KERNEL);
if (!omap_domain)
return NULL;

+ if (type == IOMMU_DOMAIN_DMA &&
+ iommu_get_dma_cookie(&omap_domain->domain)) {
+ kfree(omap_domain);
+ return NULL;
+ }
+
spin_lock_init(&omap_domain->lock);

omap_domain->domain.geometry.aperture_start = 0;
@@ -1601,6 +1608,7 @@ static void omap_iommu_domain_free(struct iommu_domain *domain)
if (omap_domain->dev)
_omap_iommu_detach_dev(omap_domain, omap_domain->dev);

+ iommu_put_dma_cookie(&omap_domain->domain);
kfree(omap_domain);
}

@@ -1736,6 +1744,17 @@ static struct iommu_group *omap_iommu_device_group(struct device *dev)
return group;
}

+static int omap_iommu_of_xlate(struct device *dev,
+ struct of_phandle_args *args)
+{
+ /*
+ * Logically, some of the housekeeping from _omap_iommu_add_device()
+ * should probably move here, but the minimum we *need* is simply to
+ * cooperate with of_iommu at all to let iommu-dma work.
+ */
+ return 0;
+}
+
static const struct iommu_ops omap_iommu_ops = {
.domain_alloc = omap_iommu_domain_alloc,
.domain_free = omap_iommu_domain_free,
@@ -1747,6 +1766,7 @@ static const struct iommu_ops omap_iommu_ops = {
.probe_device = omap_iommu_probe_device,
.release_device = omap_iommu_release_device,
.device_group = omap_iommu_device_group,
+ .of_xlate = omap_iommu_of_xlate,
.pgsize_bitmap = OMAP_IOMMU_PGSIZES,
};

--
2.28.0.dirty