| Message ID | 1461084994-2355-6-git-send-email-eric.auger@linaro.org |
|---|---|
| State | New |
| Headers | show |
Robin, On 04/20/2016 03:12 PM, Robin Murphy wrote: > On 19/04/16 17:56, Eric Auger wrote: >> we will need to track which host physical addresses are mapped to >> reserved IOVA. In that prospect we introduce a new RB tree indexed >> by physical address. This RB tree only is used for reserved IOVA >> bindings. >> >> It is expected this RB tree will contain very few bindings. > > Sounds like a good reason in favour of using a list, and thus having > rather less code here ;) OK will move to a simple list. > >> Those >> generally correspond to single page mapping one MSI frame (GICv2m >> frame or ITS GITS_TRANSLATER frame). >> >> Signed-off-by: Eric Auger <eric.auger@linaro.org> >> >> --- >> v5 -> v6: >> - add comment about @d->reserved_lock to be held >> >> v3 -> v4: >> - that code was formerly in "iommu/arm-smmu: add a reserved binding RB >> tree" >> --- >> drivers/iommu/dma-reserved-iommu.c | 63 >> ++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 63 insertions(+) >> >> diff --git a/drivers/iommu/dma-reserved-iommu.c >> b/drivers/iommu/dma-reserved-iommu.c >> index 2562af0..f6fa18e 100644 >> --- a/drivers/iommu/dma-reserved-iommu.c >> +++ b/drivers/iommu/dma-reserved-iommu.c >> @@ -23,6 +23,69 @@ struct reserved_iova_domain { >> int prot; /* iommu protection attributes to be obeyed */ >> }; >> >> +struct iommu_reserved_binding { >> + struct kref kref; >> + struct rb_node node; >> + struct iommu_domain *domain; > > Hang on, the tree these are in is already embedded in a domain. Ergo we > can't look them up without first knowing the domain they belong to, so > what purpose does this guy serve? this is used on the kref_put. The release function takes a kref; then we get the container to retrieve the binding and storing the domain here enables to unlink the node. Best Regards Eric > > Robin. > >> + phys_addr_t addr; >> + dma_addr_t iova; >> + size_t size; >> +}; >> + >> +/* Reserved binding RB-tree manipulation */ >> + >> +/* @d->reserved_lock must be held */ >> +static struct iommu_reserved_binding *find_reserved_binding( >> + struct iommu_domain *d, >> + phys_addr_t start, size_t size) >> +{ >> + struct rb_node *node = d->reserved_binding_list.rb_node; >> + >> + while (node) { >> + struct iommu_reserved_binding *binding = >> + rb_entry(node, struct iommu_reserved_binding, node); >> + >> + if (start + size <= binding->addr) >> + node = node->rb_left; >> + else if (start >= binding->addr + binding->size) >> + node = node->rb_right; >> + else >> + return binding; >> + } >> + >> + return NULL; >> +} >> + >> +/* @d->reserved_lock must be held */ >> +static void link_reserved_binding(struct iommu_domain *d, >> + struct iommu_reserved_binding *new) >> +{ >> + struct rb_node **link = &d->reserved_binding_list.rb_node; >> + struct rb_node *parent = NULL; >> + struct iommu_reserved_binding *binding; >> + >> + while (*link) { >> + parent = *link; >> + binding = rb_entry(parent, struct iommu_reserved_binding, >> + node); >> + >> + if (new->addr + new->size <= binding->addr) >> + link = &(*link)->rb_left; >> + else >> + link = &(*link)->rb_right; >> + } >> + >> + rb_link_node(&new->node, parent, link); >> + rb_insert_color(&new->node, &d->reserved_binding_list); >> +} >> + >> +/* @d->reserved_lock must be held */ >> +static void unlink_reserved_binding(struct iommu_domain *d, >> + struct iommu_reserved_binding *old) >> +{ >> + rb_erase(&old->node, &d->reserved_binding_list); >> +} >> + >> int iommu_alloc_reserved_iova_domain(struct iommu_domain *domain, >> dma_addr_t iova, size_t size, int prot, >> unsigned long order) >> >
diff --git a/drivers/iommu/dma-reserved-iommu.c b/drivers/iommu/dma-reserved-iommu.c index 2562af0..f6fa18e 100644 --- a/drivers/iommu/dma-reserved-iommu.c +++ b/drivers/iommu/dma-reserved-iommu.c @@ -23,6 +23,69 @@ struct reserved_iova_domain { int prot; /* iommu protection attributes to be obeyed */ }; +struct iommu_reserved_binding { + struct kref kref; + struct rb_node node; + struct iommu_domain *domain; + phys_addr_t addr; + dma_addr_t iova; + size_t size; +}; + +/* Reserved binding RB-tree manipulation */ + +/* @d->reserved_lock must be held */ +static struct iommu_reserved_binding *find_reserved_binding( + struct iommu_domain *d, + phys_addr_t start, size_t size) +{ + struct rb_node *node = d->reserved_binding_list.rb_node; + + while (node) { + struct iommu_reserved_binding *binding = + rb_entry(node, struct iommu_reserved_binding, node); + + if (start + size <= binding->addr) + node = node->rb_left; + else if (start >= binding->addr + binding->size) + node = node->rb_right; + else + return binding; + } + + return NULL; +} + +/* @d->reserved_lock must be held */ +static void link_reserved_binding(struct iommu_domain *d, + struct iommu_reserved_binding *new) +{ + struct rb_node **link = &d->reserved_binding_list.rb_node; + struct rb_node *parent = NULL; + struct iommu_reserved_binding *binding; + + while (*link) { + parent = *link; + binding = rb_entry(parent, struct iommu_reserved_binding, + node); + + if (new->addr + new->size <= binding->addr) + link = &(*link)->rb_left; + else + link = &(*link)->rb_right; + } + + rb_link_node(&new->node, parent, link); + rb_insert_color(&new->node, &d->reserved_binding_list); +} + +/* @d->reserved_lock must be held */ +static void unlink_reserved_binding(struct iommu_domain *d, + struct iommu_reserved_binding *old) +{ + rb_erase(&old->node, &d->reserved_binding_list); +} + int iommu_alloc_reserved_iova_domain(struct iommu_domain *domain, dma_addr_t iova, size_t size, int prot, unsigned long order)
we will need to track which host physical addresses are mapped to reserved IOVA. In that prospect we introduce a new RB tree indexed by physical address. This RB tree only is used for reserved IOVA bindings. It is expected this RB tree will contain very few bindings. Those generally correspond to single page mapping one MSI frame (GICv2m frame or ITS GITS_TRANSLATER frame). Signed-off-by: Eric Auger <eric.auger@linaro.org> --- v5 -> v6: - add comment about @d->reserved_lock to be held v3 -> v4: - that code was formerly in "iommu/arm-smmu: add a reserved binding RB tree" --- drivers/iommu/dma-reserved-iommu.c | 63 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) -- 1.9.1