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iommu: Flow ERR_PTR out from __iommu_domain_alloc()

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Most of the calling code now has error handling that can carry an error
code further up the call chain. Keep the exported interface
iommu_domain_alloc() returning NULL and reflow the internal code to use
ERR_PTR not NULL for domain allocation failure.

Optionally allow drivers to return ERR_PTR from any of the alloc ops. Many
of the new ops (user, sva, etc) already return ERR_PTR, so having two
rules is confusing and hard on drivers. This fixes a bug in DART that was
returning ERR_PTR.

Fixes: 482feb5c64 ("iommu/dart: Call apple_dart_finalize_domain() as part of alloc_paging()")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/linux-iommu/b85e0715-3224-4f45-ad6b-ebb9f08c015d@moroto.mountain/
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/0-v2-55ae413017b8+97-domain_alloc_err_ptr_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Jason Gunthorpe 2023-11-01 20:28:11 -03:00 committed by Joerg Roedel
parent 2cc14f52ae
commit 34e2dccbb3
1 changed files with 39 additions and 20 deletions
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59
drivers/iommu/iommu.c
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@ -1788,7 +1788,7 @@ iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
*/
if (ops->default_domain) {
if (req_type)
return NULL;
return ERR_PTR(-EINVAL);
return ops->default_domain;
}
@ -1797,15 +1797,15 @@ iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
/* The driver gave no guidance on what type to use, try the default */
dom = __iommu_group_alloc_default_domain(group, iommu_def_domain_type);
if (dom)
if (!IS_ERR(dom))
return dom;
/* Otherwise IDENTITY and DMA_FQ defaults will try DMA */
if (iommu_def_domain_type == IOMMU_DOMAIN_DMA)
return NULL;
return ERR_PTR(-EINVAL);
dom = __iommu_group_alloc_default_domain(group, IOMMU_DOMAIN_DMA);
if (!dom)
return NULL;
if (IS_ERR(dom))
return dom;
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);
@ -2094,10 +2094,17 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops,
else if (ops->domain_alloc)
domain = ops->domain_alloc(alloc_type);
else
return NULL;
return ERR_PTR(-EOPNOTSUPP);
/*
* Many domain_alloc ops now return ERR_PTR, make things easier for the
* driver by accepting ERR_PTR from all domain_alloc ops instead of
* having two rules.
*/
if (IS_ERR(domain))
return domain;
if (!domain)
return NULL;
return ERR_PTR(-ENOMEM);
domain->type = type;
/*
@ -2110,9 +2117,14 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops,
if (!domain->ops)
domain->ops = ops->default_domain_ops;
if (iommu_is_dma_domain(domain) && iommu_get_dma_cookie(domain)) {
iommu_domain_free(domain);
domain = NULL;
if (iommu_is_dma_domain(domain)) {
int rc;
rc = iommu_get_dma_cookie(domain);
if (rc) {
iommu_domain_free(domain);
return ERR_PTR(rc);
}
}
return domain;
}
@ -2129,10 +2141,15 @@ __iommu_group_domain_alloc(struct iommu_group *group, unsigned int type)
struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus)
{
struct iommu_domain *domain;
if (bus == NULL || bus->iommu_ops == NULL)
return NULL;
return __iommu_domain_alloc(bus->iommu_ops, NULL,
domain = __iommu_domain_alloc(bus->iommu_ops, NULL,
IOMMU_DOMAIN_UNMANAGED);
if (IS_ERR(domain))
return NULL;
return domain;
}
EXPORT_SYMBOL_GPL(iommu_domain_alloc);
@ -3041,8 +3058,8 @@ static int iommu_setup_default_domain(struct iommu_group *group,
return -EINVAL;
dom = iommu_group_alloc_default_domain(group, req_type);
if (!dom)
return -ENODEV;
if (IS_ERR(dom))
return PTR_ERR(dom);
if (group->default_domain == dom)
return 0;
@ -3243,21 +3260,23 @@ void iommu_device_unuse_default_domain(struct device *dev)
static int __iommu_group_alloc_blocking_domain(struct iommu_group *group)
{
struct iommu_domain *domain;
if (group->blocking_domain)
return 0;
group->blocking_domain =
__iommu_group_domain_alloc(group, IOMMU_DOMAIN_BLOCKED);
if (!group->blocking_domain) {
domain = __iommu_group_domain_alloc(group, IOMMU_DOMAIN_BLOCKED);
if (IS_ERR(domain)) {
/*
* For drivers that do not yet understand IOMMU_DOMAIN_BLOCKED
* create an empty domain instead.
*/
group->blocking_domain = __iommu_group_domain_alloc(
group, IOMMU_DOMAIN_UNMANAGED);
if (!group->blocking_domain)
return -EINVAL;
domain = __iommu_group_domain_alloc(group,
IOMMU_DOMAIN_UNMANAGED);
if (IS_ERR(domain))
return PTR_ERR(domain);
}
group->blocking_domain = domain;
return 0;
}