On 2023/8/3 8:07, Jason Gunthorpe wrote:
Except for dart every driver returns 0 or IDENTITY from def_domain_type().
The drivers that return IDENTITY have some kind of good reason, typically
that quirky hardware really can't support anything other than IDENTITY.
Arrange things so that if the driver says it needs IDENTITY then
iommu_get_default_domain_type() either fails or returns IDENTITY. It will
never reject the driver's override to IDENTITY.
The only real functional difference is that the PCI untrusted flag is now
ignored for quirky HW instead of overriding the IOMMU driver.
This makes the next patch cleaner that wants to force IDENTITY always for
ARM_IOMMU because there is no support for DMA.
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>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/iommu/iommu.c | 66 +++++++++++++++++++++----------------------
1 file changed, 33 insertions(+), 33 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index c64365169b678d..53174179102d17 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1669,19 +1669,6 @@ struct iommu_group *fsl_mc_device_group(struct device *dev)
}
EXPORT_SYMBOL_GPL(fsl_mc_device_group);
-static int iommu_get_def_domain_type(struct device *dev)
-{
- const struct iommu_ops *ops = dev_iommu_ops(dev);
-
- if (dev_is_pci(dev) && to_pci_dev(dev)->untrusted)
- return IOMMU_DOMAIN_DMA;
-
- if (ops->def_domain_type)
- return ops->def_domain_type(dev);
-
- return 0;
-}
-
static struct iommu_domain *
__iommu_group_alloc_default_domain(const struct bus_type *bus,
struct iommu_group *group, int req_type)
@@ -1775,36 +1762,49 @@ static int iommu_bus_notifier(struct notifier_block *nb,
static int iommu_get_default_domain_type(struct iommu_group *group,
int target_type)
{
+ const struct iommu_ops *ops = dev_iommu_ops(
+ list_first_entry(&group->devices, struct group_device, list)
+ ->dev);
How about consolidating above into a single helper?
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1787,6 +1787,21 @@ __iommu_group_alloc_default_domain(struct
iommu_group *group, int req_type)
return __iommu_group_domain_alloc(group, req_type);
}
+/*
+ * Returns the iommu_ops for the devices in an iommu group.
+ *
+ * It is assumed that all devices in an iommu group are managed by a single
+ * IOMMU unit. Therefore, this returns the dev_iommu_ops of the first
device
+ * in the group.
+ */
+static const struct iommu_ops *group_iommu_ops(struct iommu_group *group)
+{
+ struct group_device *device;
+
+ device = list_first_entry(&group->devices, struct group_device, list);
+ return dev_iommu_ops(device->dev);
+}
+
/*
* req_type of 0 means "auto" which means to select a domain based on
* iommu_def_domain_type or what the driver actually supports.
@@ -1794,10 +1809,7 @@ __iommu_group_alloc_default_domain(struct
iommu_group *group, int req_type)
static struct iommu_domain *
iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
{
- struct device *dev =
- list_first_entry(&group->devices, struct group_device, list)
- ->dev;
- const struct iommu_ops *ops = dev_iommu_ops(dev);
+ const struct iommu_ops *ops = group_iommu_ops(group);
struct iommu_domain *dom;
lockdep_assert_held(&group->mutex);
@@ -1888,9 +1900,7 @@ static int iommu_bus_notifier(struct
notifier_block *nb,
static int iommu_get_default_domain_type(struct iommu_group *group,
int target_type)
{
- const struct iommu_ops *ops = dev_iommu_ops(
- list_first_entry(&group->devices, struct group_device, list)
- ->dev);
+ const struct iommu_ops *ops = group_iommu_ops(group);
int best_type = target_type;
struct group_device *gdev;
struct device *last_dev;
@@ -2124,13 +2134,9 @@ static struct iommu_domain
*__iommu_domain_alloc(const struct iommu_ops *ops,
static struct iommu_domain *
__iommu_group_domain_alloc(struct iommu_group *group, unsigned int type)
{
- struct device *dev =
- list_first_entry(&group->devices, struct group_device, list)
- ->dev;
-
lockdep_assert_held(&group->mutex);
- return __iommu_domain_alloc(dev_iommu_ops(dev), dev, type);
+ return __iommu_domain_alloc(group_iommu_ops(group), dev, type);
}
struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus)
int best_type = target_type;
struct group_device *gdev;
struct device *last_dev;
+ int type;
lockdep_assert_held(&group->mutex);
-
for_each_group_device(group, gdev) {
- unsigned int type = iommu_get_def_domain_type(gdev->dev);
-
- if (best_type && type && best_type != type) {
- if (target_type) {
- dev_err_ratelimited(
- gdev->dev,
- "Device cannot be in %s domain\n",
- iommu_domain_type_str(target_type));
- return -1;
- }
-
- dev_warn(
- gdev->dev,
- "Device needs domain type %s, but device %s in the same iommu group requires type %s - using default\n",
- iommu_domain_type_str(type), dev_name(last_dev),
- iommu_domain_type_str(best_type));
- return 0;
+ type = best_type;
+ if (ops->def_domain_type) {
+ type = ops->def_domain_type(gdev->dev);
+ if (best_type && type && best_type != type)
+ goto err;
}
- if (!best_type)
- best_type = type;
+
+ if (dev_is_pci(gdev->dev) && to_pci_dev(gdev->dev)->untrusted) {
+ type = IOMMU_DOMAIN_DMA;
+ if (best_type && type && best_type != type)
+ goto err;
+ }
+ best_type = type;
last_dev = gdev->dev;
}
return best_type;
+
+err:
+ if (target_type) {
+ dev_err_ratelimited(
+ gdev->dev,
+ "Device cannot be in %s domain - it is forcing %s\n",
+ iommu_domain_type_str(target_type),
+ iommu_domain_type_str(type));
+ return -1;
+ }
+
+ dev_warn(
+ gdev->dev,
+ "Device needs domain type %s, but device %s in the same iommu group requires type %s - using default\n",
+ iommu_domain_type_str(type), dev_name(last_dev),
+ iommu_domain_type_str(best_type));
+ return 0;
This doesn't match the commit message, where it states:
"Arrange things so that if the driver says it needs IDENTITY then
iommu_get_default_domain_type() either fails or returns IDENTITY.
"
I saw that this change was made in the sequential patch. It is probably
better to put that here?
}
static void iommu_group_do_probe_finalize(struct device *dev)
Best regards,
baolu
