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author | Jason Gunthorpe <jgg@nvidia.com> | 2023-05-11 06:42:11 +0200 |
---|---|---|
committer | Joerg Roedel <jroedel@suse.de> | 2023-05-23 08:15:56 +0200 |
commit | fcbb0a4d738ce3ccc06d2c73ba227cce5094d885 (patch) | |
tree | 52e67d0f4c116c0771fab2b57175c8761c7cc848 /drivers/iommu | |
parent | iommu: Consolidate the code to calculate the target default domain type (diff) | |
download | linux-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.c | 71 |
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); |