[PATCH v6 13/25] iommu/omap: Implement an IDENTITY domain

Jason Gunthorpe
2023-08-03T00:10:00Z

What omap does during omap_iommu_set_platform_dma() is actually putting
the iommu into identity mode.

Move to the new core support for ARM_DMA_USE_IOMMU by defining
ops->identity_domain.

This driver does not support IOMMU_DOMAIN_DMA, however it cannot be
compiled on ARM64 either. Most likely it is fine to support dma-iommu.c

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/iommu/omap-iommu.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 537e402f9bba97..34340ef15241bc 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -1555,16 +1555,31 @@ static void _omap_iommu_detach_dev(struct omap_iommu_domain *omap_domain,
omap_domain->dev = NULL;
}

-static void omap_iommu_set_platform_dma(struct device *dev)
+static int omap_iommu_identity_attach(struct iommu_domain *identity_domain,
+ struct device *dev)
{
struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
- struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
+ struct omap_iommu_domain *omap_domain;

+ if (domain == identity_domain || !domain)
+ return 0;
+
+ omap_domain = to_omap_domain(domain);
spin_lock(&omap_domain->lock);
_omap_iommu_detach_dev(omap_domain, dev);
spin_unlock(&omap_domain->lock);
+ return 0;
}

+static struct iommu_domain_ops omap_iommu_identity_ops = {
+ .attach_dev = omap_iommu_identity_attach,
+};
+
+static struct iommu_domain omap_iommu_identity_domain = {
+ .type = IOMMU_DOMAIN_IDENTITY,
+ .ops = &omap_iommu_identity_ops,
+};
+
static struct iommu_domain *omap_iommu_domain_alloc(unsigned type)
{
struct omap_iommu_domain *omap_domain;
@@ -1732,11 +1747,11 @@ static struct iommu_group *omap_iommu_device_group(struct device *dev)
}

static const struct iommu_ops omap_iommu_ops = {
+ .identity_domain = &omap_iommu_identity_domain,
.domain_alloc = omap_iommu_domain_alloc,
.probe_device = omap_iommu_probe_device,
.release_device = omap_iommu_release_device,
.device_group = omap_iommu_device_group,
- .set_platform_dma_ops = omap_iommu_set_platform_dma,
.pgsize_bitmap = OMAP_IOMMU_PGSIZES,
.default_domain_ops = &(const struct iommu_domain_ops) {
.attach_dev = omap_iommu_attach_dev,
--
2.41.0