On 2022-01-24 07:11, Lu Baolu wrote:
The common iommu_ops is hooked to both device and domain. When a helper
has both device and domain pointer, the way to get the iommu_ops looks
messy in iommu core. This sorts out the way to get iommu_ops. The device
related helpers go through device pointer, while the domain related ones
go through domain pointer.
Signed-off-by: Lu Baolu <[email protected]>
---
include/linux/iommu.h | 8 ++++++++
drivers/iommu/iommu.c | 25 ++++++++++++++-----------
2 files changed, 22 insertions(+), 11 deletions(-)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index aa5486243892..111b3e9c79bb 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -385,6 +385,14 @@ static inline void iommu_iotlb_gather_init(struct
iommu_iotlb_gather *gather)
};
}
+static inline const struct iommu_ops *dev_iommu_ops_get(struct device *dev)
+{
+ if (dev && dev->iommu && dev->iommu->iommu_dev)
+ return dev->iommu->iommu_dev->ops;
+
+ return NULL;
This probably warrants at least a WARN, but it's arguable to just assume
that valid ops must be installed if iommu_probe_device() has succeeded.
The device ops are essentially for internal use within the IOMMU
subsystem itself, so we should be able to trust ourselves not to misuse
the helper.
+}
+
#define IOMMU_BUS_NOTIFY_PRIORITY 0
#define IOMMU_GROUP_NOTIFY_ADD_DEVICE 1 /* Device added */
#define IOMMU_GROUP_NOTIFY_DEL_DEVICE 2 /* Pre Device removed */
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5230c6d90ece..6631e2ea44df 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -764,6 +764,7 @@ EXPORT_SYMBOL_GPL(iommu_group_set_name);
static int iommu_create_device_direct_mappings(struct iommu_group *group,
struct device *dev)
{
+ const struct iommu_ops *ops = dev_iommu_ops_get(dev);
struct iommu_domain *domain = group->default_domain;
struct iommu_resv_region *entry;
struct list_head mappings;
@@ -785,8 +786,8 @@ static int iommu_create_device_direct_mappings(struct
iommu_group *group,
dma_addr_t start, end, addr;
size_t map_size = 0;
- if (domain->ops->apply_resv_region)
- domain->ops->apply_resv_region(dev, domain, entry);
+ if (ops->apply_resv_region)
+ ops->apply_resv_region(dev, domain, entry);
Strictly I think this was a domain op, as it was about reserving the
IOVA range in the given DMA domain. Also taking the domain as an
argument is a bit of a giveaway. However it's now just dead code either
way since there are no remaining implementations, and no reason for any
new ones.
start = ALIGN(entry->start, pg_size);
end = ALIGN(entry->start + entry->length, pg_size);
@@ -831,8 +832,10 @@ static int iommu_create_device_direct_mappings(struct
iommu_group *group,
static bool iommu_is_attach_deferred(struct iommu_domain *domain,
struct device *dev)
{
- if (domain->ops->is_attach_deferred)
- return domain->ops->is_attach_deferred(domain, dev);
+ const struct iommu_ops *ops = dev_iommu_ops_get(dev);
+
+ if (ops->is_attach_deferred)
+ return ops->is_attach_deferred(domain, dev);
Similarly if this takes a domain as its first argument then it's de
facto a domain method. However, I'd concur that logically it *is* a
device op, so let's drop that (unused) domain argument if we're cleaning up.
Maybe there's even an argument for factoring this out to a standard flag
in dev_iommu rather than an op at all?
The others covered here look OK - we can blame PCI for page response
being weirdly device-centric - however could we also convert all the
feasible instances of dev->bus->iommu_ops to dev_iommu_ops() as well?
(Subtly implying that I'm also not a fan of having "_get" in the name
for a non-refcounted lookup...) Obviously iommu_probe_device() and
iommmu_domain_alloc() still need bus ops at this point, but I'm working
on that... :)
Thanks,
Robin.
return false;
}
@@ -1251,10 +1254,10 @@ int iommu_page_response(struct device *dev,
struct iommu_fault_event *evt;
struct iommu_fault_page_request *prm;
struct dev_iommu *param = dev->iommu;
+ const struct iommu_ops *ops = dev_iommu_ops_get(dev);
bool has_pasid = msg->flags & IOMMU_PAGE_RESP_PASID_VALID;
- struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
- if (!domain || !domain->ops->page_response)
+ if (!ops || !ops->page_response)
return -ENODEV;
if (!param || !param->fault_param)
@@ -1295,7 +1298,7 @@ int iommu_page_response(struct device *dev,
msg->pasid = 0;
}
- ret = domain->ops->page_response(dev, evt, msg);
+ ret = ops->page_response(dev, evt, msg);
list_del(&evt->list);
kfree(evt);
break;
@@ -1758,10 +1761,10 @@ static int __iommu_group_dma_attach(struct iommu_group
*group)
static int iommu_group_do_probe_finalize(struct device *dev, void *data)
{
- struct iommu_domain *domain = data;
+ const struct iommu_ops *ops = dev_iommu_ops_get(dev);
- if (domain->ops->probe_finalize)
- domain->ops->probe_finalize(dev);
+ if (ops->probe_finalize)
+ ops->probe_finalize(dev);
return 0;
}
@@ -2020,7 +2023,7 @@ EXPORT_SYMBOL_GPL(iommu_attach_device);
int iommu_deferred_attach(struct device *dev, struct iommu_domain *domain)
{
- const struct iommu_ops *ops = domain->ops;
+ const struct iommu_ops *ops = dev_iommu_ops_get(dev);
if (ops->is_attach_deferred && ops->is_attach_deferred(domain, dev))
return __iommu_attach_device(domain, dev);
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