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authorJason Gunthorpe <jgg@nvidia.com>2023-05-11 06:42:11 +0200
committerJoerg Roedel <jroedel@suse.de>2023-05-23 08:15:56 +0200
commitfcbb0a4d738ce3ccc06d2c73ba227cce5094d885 (patch)
tree52e67d0f4c116c0771fab2b57175c8761c7cc848 /drivers/iommu
parentiommu: Consolidate the code to calculate the target default domain type (diff)
downloadlinux-fcbb0a4d738ce3ccc06d2c73ba227cce5094d885.tar.xz
linux-fcbb0a4d738ce3ccc06d2c73ba227cce5094d885.zip
iommu: Revise iommu_group_alloc_default_domain()
Robin points out that the fallback to guessing what domains the driver supports should only happen if the driver doesn't return a preference from its ops->def_domain_type(). Re-organize iommu_group_alloc_default_domain() so it internally uses iommu_def_domain_type only during the fallback and makes it clearer how the fallback sequence works. Make iommu_group_alloc_default_domain() return the domain so the return based logic is cleaner and to prepare for the next patch. Remove the iommu_alloc_default_domain() function as it is now trivially just calling iommu_group_alloc_default_domain(). Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Tested-by: Heiko Stuebner <heiko@sntech.de> Tested-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/13-v5-1b99ae392328+44574-iommu_err_unwind_jgg@nvidia.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/iommu.c71
1 files changed, 37 insertions, 34 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 9e661cbd3d42..7120f57c8028 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -93,8 +93,9 @@ static const char * const iommu_group_resv_type_string[] = {
static int iommu_bus_notifier(struct notifier_block *nb,
unsigned long action, void *data);
static void iommu_release_device(struct device *dev);
-static int iommu_alloc_default_domain(struct iommu_group *group,
- struct device *dev);
+static struct iommu_domain *
+iommu_group_alloc_default_domain(struct iommu_group *group, int req_type);
+static int iommu_get_def_domain_type(struct device *dev);
static struct iommu_domain *__iommu_domain_alloc(const struct bus_type *bus,
unsigned type);
static int __iommu_attach_device(struct iommu_domain *domain,
@@ -434,7 +435,8 @@ int iommu_probe_device(struct device *dev)
* support default domains, so the return value is not yet
* checked.
*/
- iommu_alloc_default_domain(group, dev);
+ group->default_domain = iommu_group_alloc_default_domain(
+ group, iommu_get_def_domain_type(dev));
if (group->default_domain) {
iommu_create_device_direct_mappings(group, dev);
ret = __iommu_group_set_domain(group,
@@ -1645,35 +1647,38 @@ static int iommu_get_def_domain_type(struct device *dev)
return 0;
}
-static int iommu_group_alloc_default_domain(const struct bus_type *bus,
- struct iommu_group *group,
- unsigned int type)
+/*
+ * req_type of 0 means "auto" which means to select a domain based on
+ * iommu_def_domain_type or what the driver actually supports.
+ */
+static struct iommu_domain *
+iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
{
+ const struct bus_type *bus =
+ list_first_entry(&group->devices, struct group_device, list)
+ ->dev->bus;
struct iommu_domain *dom;
- dom = __iommu_domain_alloc(bus, type);
- if (!dom && type != IOMMU_DOMAIN_DMA) {
- dom = __iommu_domain_alloc(bus, IOMMU_DOMAIN_DMA);
- if (dom)
- pr_warn("Failed to allocate default IOMMU domain of type %u for group %s - Falling back to IOMMU_DOMAIN_DMA",
- type, group->name);
- }
-
- if (!dom)
- return -ENOMEM;
+ lockdep_assert_held(&group->mutex);
- group->default_domain = dom;
- return 0;
-}
+ if (req_type)
+ return __iommu_domain_alloc(bus, req_type);
-static int iommu_alloc_default_domain(struct iommu_group *group,
- struct device *dev)
-{
- unsigned int type;
+ /* The driver gave no guidance on what type to use, try the default */
+ dom = __iommu_domain_alloc(bus, iommu_def_domain_type);
+ if (dom)
+ return dom;
- type = iommu_get_def_domain_type(dev) ? : iommu_def_domain_type;
+ /* Otherwise IDENTITY and DMA_FQ defaults will try DMA */
+ if (iommu_def_domain_type == IOMMU_DOMAIN_DMA)
+ return NULL;
+ dom = __iommu_domain_alloc(bus, IOMMU_DOMAIN_DMA);
+ if (!dom)
+ return NULL;
- return iommu_group_alloc_default_domain(dev->bus, group, type);
+ pr_warn("Failed to allocate default IOMMU domain of type %u for group %s - Falling back to IOMMU_DOMAIN_DMA",
+ iommu_def_domain_type, group->name);
+ return dom;
}
/**
@@ -1785,15 +1790,12 @@ static int iommu_get_default_domain_type(struct iommu_group *group,
"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 iommu_def_domain_type;
+ return 0;
}
if (!best_type)
best_type = type;
last_dev = gdev->dev;
}
-
- if (!best_type)
- return iommu_def_domain_type;
return best_type;
}
@@ -1850,9 +1852,8 @@ int bus_iommu_probe(const struct bus_type *bus)
list_del_init(&group->entry);
/* Try to allocate default domain */
- iommu_group_alloc_default_domain(
- bus, group, iommu_get_default_domain_type(group, 0));
-
+ group->default_domain = iommu_group_alloc_default_domain(
+ group, iommu_get_default_domain_type(group, 0));
if (!group->default_domain) {
mutex_unlock(&group->mutex);
continue;
@@ -2897,9 +2898,11 @@ static int iommu_change_dev_def_domain(struct iommu_group *group,
group->domain = NULL;
/* Sets group->default_domain to the newly allocated domain */
- ret = iommu_group_alloc_default_domain(dev->bus, group, type);
- if (ret)
+ group->default_domain = iommu_group_alloc_default_domain(group, type);
+ if (!group->default_domain) {
+ ret = -EINVAL;
goto restore_old_domain;
+ }
group->domain = prev_dom;
ret = iommu_create_device_direct_mappings(group, dev);