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 ;)
Those
generally correspond to single page mapping one MSI frame (GICv2m
frame or ITS GITS_TRANSLATER frame).
Signed-off-by: Eric Auger <eric.au...@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?
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)
