This is used when the iommu driver is taking control of the dma_ops,
currently only on S390 and power spapr. It is designed to preserve the
original ops->detach_dev() semantic that these S390 was built around.
Provide an opaque domain type and a 'default_domain' ops value that allows
the driver to trivially force any single domain as the default domain.
Update iommufd selftest to use this instead of set_platform_dma_ops
Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/iommu/iommu.c | 13 +++++++++++++
drivers/iommu/iommufd/selftest.c | 14 +++++---------
include/linux/iommu.h | 8 ++++++++
3 files changed, 26 insertions(+), 9 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 33bd1107090720..0e13e566581c21 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -184,6 +184,8 @@ static const char *iommu_domain_type_str(unsigned int t)
case IOMMU_DOMAIN_DMA:
case IOMMU_DOMAIN_DMA_FQ:
return "Translated";
+ case IOMMU_DOMAIN_PLATFORM:
+ return "Platform";
default:
return "Unknown";
}
@@ -1752,6 +1754,17 @@ iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
lockdep_assert_held(&group->mutex);
+ /*
+ * Allow legacy drivers to specify the domain that will be the default
+ * domain. This should always be either an IDENTITY/BLOCKED/PLATFORM
+ * domain. Do not use in new drivers.
+ */
+ if (bus->iommu_ops->default_domain) {
+ if (req_type)
+ return ERR_PTR(-EINVAL);
+ return bus->iommu_ops->default_domain;
+ }
+
if (req_type)
return __iommu_group_alloc_default_domain(bus, group, req_type);
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index d48a202a7c3b81..fb981ba97c4e87 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -281,14 +281,6 @@ static bool mock_domain_capable(struct device *dev, enum iommu_cap cap)
return cap == IOMMU_CAP_CACHE_COHERENCY;
}
-static void mock_domain_set_plaform_dma_ops(struct device *dev)
-{
- /*
- * mock doesn't setup default domains because we can't hook into the
- * normal probe path
- */
-}
-
static struct iommu_device mock_iommu_device = {
};
@@ -298,12 +290,16 @@ static struct iommu_device *mock_probe_device(struct device *dev)
}
static const struct iommu_ops mock_ops = {
+ /*
+ * IOMMU_DOMAIN_BLOCKED cannot be returned from def_domain_type()
+ * because it is zero.
+ */
+ .default_domain = &mock_blocking_domain,
.owner = THIS_MODULE,
.pgsize_bitmap = MOCK_IO_PAGE_SIZE,
.hw_info = mock_domain_hw_info,
.domain_alloc = mock_domain_alloc,
.capable = mock_domain_capable,
- .set_platform_dma_ops = mock_domain_set_plaform_dma_ops,
.device_group = generic_device_group,
.probe_device = mock_probe_device,
.default_domain_ops =
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index d0920b2a9f1c0e..a05480be05fd08 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -64,6 +64,7 @@ struct iommu_domain_geometry {
#define __IOMMU_DOMAIN_DMA_FQ (1U << 3) /* DMA-API uses flush queue */
#define __IOMMU_DOMAIN_SVA (1U << 4) /* Shared process address space */
+#define __IOMMU_DOMAIN_PLATFORM (1U << 5)
#define IOMMU_DOMAIN_ALLOC_FLAGS ~__IOMMU_DOMAIN_DMA_FQ
/*
@@ -81,6 +82,8 @@ struct iommu_domain_geometry {
* invalidation.
* IOMMU_DOMAIN_SVA - DMA addresses are shared process addresses
* represented by mm_struct's.
+ * IOMMU_DOMAIN_PLATFORM - Legacy domain for drivers that do their own
+ * dma_api stuff. Do not use in new drivers.
*/
#define IOMMU_DOMAIN_BLOCKED (0U)
#define IOMMU_DOMAIN_IDENTITY (__IOMMU_DOMAIN_PT)
@@ -91,6 +94,7 @@ struct iommu_domain_geometry {
__IOMMU_DOMAIN_DMA_API | \
__IOMMU_DOMAIN_DMA_FQ)
#define IOMMU_DOMAIN_SVA (__IOMMU_DOMAIN_SVA)
+#define IOMMU_DOMAIN_PLATFORM (__IOMMU_DOMAIN_PLATFORM)
struct iommu_domain {
unsigned type;
@@ -262,6 +266,9 @@ struct iommu_iotlb_gather {
* @owner: Driver module providing these ops
* @identity_domain: An always available, always attachable identity
* translation.
+ * @default_domain: If not NULL this will always be set as the default domain.
+ * This should be an IDENTITY/BLOCKED/PLATFORM domain.
+ * Do not use in new drivers.
*/
struct iommu_ops {
bool (*capable)(struct device *dev, enum iommu_cap);
@@ -297,6 +304,7 @@ struct iommu_ops {
unsigned long pgsize_bitmap;
struct module *owner;
struct iommu_domain *identity_domain;
+ struct iommu_domain *default_domain;
};
/**
--
2.42.0
