* This work is licensed under the terms of the GNU GPL, version 2 or later.
*/
-#include <glib.h>
+#include "qemu/osdep.h"
#include "qemu/iova-tree.h"
struct IOVATree {
GTree *tree;
};
+/* Args to pass to iova_tree_alloc foreach function. */
+struct IOVATreeAllocArgs {
+ /* Size of the desired allocation */
+ size_t new_size;
+
+ /* The minimum address allowed in the allocation */
+ hwaddr iova_begin;
+
+ /* Map at the left of the hole, can be NULL if "this" is first one */
+ const DMAMap *prev;
+
+ /* Map at the right of the hole, can be NULL if "prev" is the last one */
+ const DMAMap *this;
+
+ /* If found, we fill in the IOVA here */
+ hwaddr iova_result;
+
+ /* Whether have we found a valid IOVA */
+ bool iova_found;
+};
+
+typedef struct IOVATreeFindIOVAArgs {
+ const DMAMap *needle;
+ const DMAMap *result;
+} IOVATreeFindIOVAArgs;
+
+/**
+ * Iterate args to the next hole
+ *
+ * @args: The alloc arguments
+ * @next: The next mapping in the tree. Can be NULL to signal the last one
+ */
+static void iova_tree_alloc_args_iterate(struct IOVATreeAllocArgs *args,
+ const DMAMap *next)
+{
+ args->prev = args->this;
+ args->this = next;
+}
+
static int iova_tree_compare(gconstpointer a, gconstpointer b, gpointer data)
{
const DMAMap *m1 = a, *m2 = b;
return iova_tree;
}
-DMAMap *iova_tree_find(IOVATree *tree, DMAMap *map)
+const DMAMap *iova_tree_find(const IOVATree *tree, const DMAMap *map)
{
return g_tree_lookup(tree->tree, map);
}
-DMAMap *iova_tree_find_address(IOVATree *tree, hwaddr iova)
+static gboolean iova_tree_find_address_iterator(gpointer key, gpointer value,
+ gpointer data)
+{
+ const DMAMap *map = key;
+ IOVATreeFindIOVAArgs *args = data;
+ const DMAMap *needle;
+
+ g_assert(key == value);
+
+ needle = args->needle;
+ if (map->translated_addr + map->size < needle->translated_addr ||
+ needle->translated_addr + needle->size < map->translated_addr) {
+ return false;
+ }
+
+ args->result = map;
+ return true;
+}
+
+const DMAMap *iova_tree_find_iova(const IOVATree *tree, const DMAMap *map)
{
- DMAMap map = { .iova = iova, .size = 0 };
+ IOVATreeFindIOVAArgs args = {
+ .needle = map,
+ };
+
+ g_tree_foreach(tree->tree, iova_tree_find_address_iterator, &args);
+ return args.result;
+}
+
+const DMAMap *iova_tree_find_address(const IOVATree *tree, hwaddr iova)
+{
+ const DMAMap map = { .iova = iova, .size = 0 };
return iova_tree_find(tree, &map);
}
g_tree_insert(gtree, range, range);
}
-int iova_tree_insert(IOVATree *tree, DMAMap *map)
+int iova_tree_insert(IOVATree *tree, const DMAMap *map)
{
DMAMap *new;
g_tree_foreach(tree->tree, iova_tree_traverse, iterator);
}
-int iova_tree_remove(IOVATree *tree, DMAMap *map)
+void iova_tree_remove(IOVATree *tree, DMAMap map)
{
- DMAMap *overlap;
+ const DMAMap *overlap;
- while ((overlap = iova_tree_find(tree, map))) {
+ while ((overlap = iova_tree_find(tree, &map))) {
g_tree_remove(tree->tree, overlap);
}
+}
- return IOVA_OK;
+/**
+ * Try to find an unallocated IOVA range between prev and this elements.
+ *
+ * @args: Arguments to allocation
+ *
+ * Cases:
+ *
+ * (1) !prev, !this: No entries allocated, always succeed
+ *
+ * (2) !prev, this: We're iterating at the 1st element.
+ *
+ * (3) prev, !this: We're iterating at the last element.
+ *
+ * (4) prev, this: this is the most common case, we'll try to find a hole
+ * between "prev" and "this" mapping.
+ *
+ * Note that this function assumes the last valid iova is HWADDR_MAX, but it
+ * searches linearly so it's easy to discard the result if it's not the case.
+ */
+static void iova_tree_alloc_map_in_hole(struct IOVATreeAllocArgs *args)
+{
+ const DMAMap *prev = args->prev, *this = args->this;
+ uint64_t hole_start, hole_last;
+
+ if (this && this->iova + this->size < args->iova_begin) {
+ return;
+ }
+
+ hole_start = MAX(prev ? prev->iova + prev->size + 1 : 0, args->iova_begin);
+ hole_last = this ? this->iova : HWADDR_MAX;
+
+ if (hole_last - hole_start > args->new_size) {
+ args->iova_result = hole_start;
+ args->iova_found = true;
+ }
+}
+
+/**
+ * Foreach dma node in the tree, compare if there is a hole with its previous
+ * node (or minimum iova address allowed) and the node.
+ *
+ * @key: Node iterating
+ * @value: Node iterating
+ * @pargs: Struct to communicate with the outside world
+ *
+ * Return: false to keep iterating, true if needs break.
+ */
+static gboolean iova_tree_alloc_traverse(gpointer key, gpointer value,
+ gpointer pargs)
+{
+ struct IOVATreeAllocArgs *args = pargs;
+ DMAMap *node = value;
+
+ assert(key == value);
+
+ iova_tree_alloc_args_iterate(args, node);
+ iova_tree_alloc_map_in_hole(args);
+ return args->iova_found;
+}
+
+int iova_tree_alloc_map(IOVATree *tree, DMAMap *map, hwaddr iova_begin,
+ hwaddr iova_last)
+{
+ struct IOVATreeAllocArgs args = {
+ .new_size = map->size,
+ .iova_begin = iova_begin,
+ };
+
+ if (unlikely(iova_last < iova_begin)) {
+ return IOVA_ERR_INVALID;
+ }
+
+ /*
+ * Find a valid hole for the mapping
+ *
+ * Assuming low iova_begin, so no need to do a binary search to
+ * locate the first node.
+ *
+ * TODO: Replace all this with g_tree_node_first/next/last when available
+ * (from glib since 2.68). To do it with g_tree_foreach complicates the
+ * code a lot.
+ *
+ */
+ g_tree_foreach(tree->tree, iova_tree_alloc_traverse, &args);
+ if (!args.iova_found) {
+ /*
+ * Either tree is empty or the last hole is still not checked.
+ * g_tree_foreach does not compare (last, iova_last] range, so we check
+ * it here.
+ */
+ iova_tree_alloc_args_iterate(&args, NULL);
+ iova_tree_alloc_map_in_hole(&args);
+ }
+
+ if (!args.iova_found || args.iova_result + map->size > iova_last) {
+ return IOVA_ERR_NOMEM;
+ }
+
+ map->iova = args.iova_result;
+ return iova_tree_insert(tree, map);
}
void iova_tree_destroy(IOVATree *tree)
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