This is a note to let you know that I've just added the patch titled
iommu: Add iommu_ops->identity_domain
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-add-iommu_ops-identity_domain.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b0a7b2647cf144cc009330beba9e75dbc2249a91
Author: Jason Gunthorpe <jgg@xxxxxxxx>
Date: Wed Sep 13 10:43:34 2023 -0300
iommu: Add iommu_ops->identity_domain
[ Upstream commit df31b298477e65a01deff0af352be3a61524d930 ]
This allows a driver to set a global static to an IDENTITY domain and
the core code will automatically use it whenever an IDENTITY domain
is requested.
By making it always available it means the IDENTITY can be used in error
handling paths to force the iommu driver into a known state. Devices
implementing global static identity domains should avoid failing their
attach_dev ops.
To make global static domains simpler allow drivers to omit their free
function and update the iommufd selftest.
Convert rockchip to use the new mechanism.
Tested-by: Steven Price <steven.price@xxxxxxx>
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Tested-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Link: https://lore.kernel.org/r/1-v8-81230027b2fa+9d-iommu_all_defdom_jgg@xxxxxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Stable-dep-of: 229e6ee43d2a ("iommu/arm-smmu: Defer probe of clients after smmu device bound")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 3f1029c0825e9..e97299987d43f 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1979,6 +1979,9 @@ static struct iommu_domain *__iommu_domain_alloc(const struct bus_type *bus,
if (bus == NULL || bus->iommu_ops == NULL)
return NULL;
+ if (alloc_type == IOMMU_DOMAIN_IDENTITY && bus->iommu_ops->identity_domain)
+ return bus->iommu_ops->identity_domain;
+
domain = bus->iommu_ops->domain_alloc(alloc_type);
if (!domain)
return NULL;
@@ -2012,7 +2015,8 @@ void iommu_domain_free(struct iommu_domain *domain)
if (domain->type == IOMMU_DOMAIN_SVA)
mmdrop(domain->mm);
iommu_put_dma_cookie(domain);
- domain->ops->free(domain);
+ if (domain->ops->free)
+ domain->ops->free(domain);
}
EXPORT_SYMBOL_GPL(iommu_domain_free);
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 00b794d74e03b..d29e438377405 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -126,10 +126,6 @@ struct selftest_obj {
};
};
-static void mock_domain_blocking_free(struct iommu_domain *domain)
-{
-}
-
static int mock_domain_nop_attach(struct iommu_domain *domain,
struct device *dev)
{
@@ -137,7 +133,6 @@ static int mock_domain_nop_attach(struct iommu_domain *domain,
}
static const struct iommu_domain_ops mock_blocking_ops = {
- .free = mock_domain_blocking_free,
.attach_dev = mock_domain_nop_attach,
};
diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 8ff69fbf9f65d..033678f2f8b3a 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -989,13 +989,8 @@ static int rk_iommu_identity_attach(struct iommu_domain *identity_domain,
return 0;
}
-static void rk_iommu_identity_free(struct iommu_domain *domain)
-{
-}
-
static struct iommu_domain_ops rk_identity_ops = {
.attach_dev = rk_iommu_identity_attach,
- .free = rk_iommu_identity_free,
};
static struct iommu_domain rk_identity_domain = {
@@ -1059,9 +1054,6 @@ static struct iommu_domain *rk_iommu_domain_alloc(unsigned type)
{
struct rk_iommu_domain *rk_domain;
- if (type == IOMMU_DOMAIN_IDENTITY)
- return &rk_identity_domain;
-
if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
return NULL;
@@ -1186,6 +1178,7 @@ static int rk_iommu_of_xlate(struct device *dev,
}
static const struct iommu_ops rk_iommu_ops = {
+ .identity_domain = &rk_identity_domain,
.domain_alloc = rk_iommu_domain_alloc,
.probe_device = rk_iommu_probe_device,
.release_device = rk_iommu_release_device,
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index b6ef263e85c06..0274d12a48e1b 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -260,6 +260,8 @@ struct iommu_iotlb_gather {
* will be blocked by the hardware.
* @pgsize_bitmap: bitmap of all possible supported page sizes
* @owner: Driver module providing these ops
+ * @identity_domain: An always available, always attachable identity
+ * translation.
*/
struct iommu_ops {
bool (*capable)(struct device *dev, enum iommu_cap);
@@ -294,6 +296,7 @@ struct iommu_ops {
const struct iommu_domain_ops *default_domain_ops;
unsigned long pgsize_bitmap;
struct module *owner;
+ struct iommu_domain *identity_domain;
};
/**
