Changeset 68f11ddc in mainline for kernel/generic/src/mm/as.c

Timestamp:

2018-12-03T16:54:22Z (5 years ago)

Author:

Jiri Svoboda <jiri@…>

Parents:

a0765f6

git-author:

Jiri Svoboda <jiri@…> (2018-12-03 16:53:27)

git-committer:

Jiri Svoboda <jiri@…> (2018-12-03 16:54:22)

Message:

Use ordered dictionary for pagemap instead of B+tree

At the same time we add a little bit more abstraction around the pagemap.

File:

• kernel/generic/src/mm/as.c (modified) (6 diffs)

kernel/generic/src/mm/as.c

@@ -89 +89 @@
 as_operations_t *as_operations = NULL;
 
-/** Slab for as_t objects.
- *
- */
+/** Cache for as_t objects */
 static slab_cache_t *as_cache;
+
+/** Cache for as_page_mapping_t objects */
+static slab_cache_t *as_page_mapping_cache;
 
 /** ASID subsystem lock.
@@ -138 +139 @@
         as_cache = slab_cache_create("as_t", sizeof(as_t), 0,
             as_constructor, as_destructor, SLAB_CACHE_MAGDEFERRED);
+
+        as_page_mapping_cache = slab_cache_create("as_page_mapping_t",
+            sizeof(as_page_mapping_t), 0, NULL, NULL, SLAB_CACHE_MAGDEFERRED);
 
         AS_KERNEL = as_create(FLAG_AS_KERNEL);
@@ -524 +528 @@
 }
 
+/** Get key function for pagemap ordered dictionary.
+ *
+ * The key is the virtual address of the page (as_page_mapping_t.vaddr)
+ *
+ * @param odlink Link to as_pagemap_t.map ordered dictionary
+ * @return Pointer to virtual address cast as @c void *
+ */
+static void *as_pagemap_getkey(odlink_t *odlink)
+{
+        as_page_mapping_t *mapping;
+
+        mapping = odict_get_instance(odlink, as_page_mapping_t, lpagemap);
+        return (void *) &mapping->vaddr;
+}
+
+/** Comparison function for pagemap ordered dictionary.
+ *
+ * @param a Pointer to virtual address cast as @c void *
+ * @param b Pointer to virtual address cast as @c void *
+ * @return <0, =0, >0 if virtual address a is less than, equal to, or
+ *         greater-than b, respectively.
+ */
+static int as_pagemap_cmp(void *a, void *b)
+{
+        uintptr_t va = *(uintptr_t *)a;
+        uintptr_t vb = *(uintptr_t *)b;
+
+        return va - vb;
+}
+
+/** Initialize pagemap.
+ *
+ * @param pagemap Pagemap
+ */
+NO_TRACE void as_pagemap_initialize(as_pagemap_t *pagemap)
+{
+        odict_initialize(&pagemap->map, as_pagemap_getkey, as_pagemap_cmp);
+}
+
+/** Finalize pagemap.
+ *
+ * Destroy any entries in the pagemap.
+ *
+ * @param pagemap Pagemap
+ */
+NO_TRACE void as_pagemap_finalize(as_pagemap_t *pagemap)
+{
+        as_page_mapping_t *mapping = as_pagemap_first(pagemap);
+        while (mapping != NULL) {
+                as_pagemap_remove(mapping);
+                mapping = as_pagemap_first(pagemap);
+        }
+        odict_finalize(&pagemap->map);
+}
+
+/** Get first page mapping.
+ *
+ * @param pagemap Pagemap
+ * @return First mapping or @c NULL if there is none
+ */
+NO_TRACE as_page_mapping_t *as_pagemap_first(as_pagemap_t *pagemap)
+{
+        odlink_t *odlink;
+
+        odlink = odict_first(&pagemap->map);
+        if (odlink == NULL)
+                return NULL;
+
+        return odict_get_instance(odlink, as_page_mapping_t, lpagemap);
+}
+
+/** Get next page mapping.
+ *
+ * @param cur Current mapping
+ * @return Next mapping or @c NULL if @a cur is the last one
+ */
+NO_TRACE as_page_mapping_t *as_pagemap_next(as_page_mapping_t *cur)
+{
+        odlink_t *odlink;
+
+        odlink = odict_next(&cur->lpagemap, &cur->pagemap->map);
+        if (odlink == NULL)
+                return NULL;
+
+        return odict_get_instance(odlink, as_page_mapping_t, lpagemap);
+}
+
+/** Find frame by virtual address.
+ *
+ * @param pagemap Pagemap
+ * @param vaddr Virtual address of page
+ * @param rframe Place to store physical frame address
+ * @return EOK on succcess or ENOENT if no mapping found
+ */
+NO_TRACE errno_t as_pagemap_find(as_pagemap_t *pagemap, uintptr_t vaddr,
+    uintptr_t *rframe)
+{
+        odlink_t *odlink;
+        as_page_mapping_t *mapping;
+
+        odlink = odict_find_eq(&pagemap->map, &vaddr, NULL);
+        if (odlink == NULL)
+                return ENOENT;
+
+        mapping = odict_get_instance(odlink, as_page_mapping_t, lpagemap);
+        *rframe = mapping->frame;
+        return EOK;
+}
+
+/** Insert new page mapping.
+ *
+ * This function can block to allocate kernel memory.
+ *
+ * @param pagemap Pagemap
+ * @param vaddr Virtual page address
+ * @param frame Physical frame address
+ */
+NO_TRACE void as_pagemap_insert(as_pagemap_t *pagemap, uintptr_t vaddr,
+    uintptr_t frame)
+{
+        as_page_mapping_t *mapping;
+
+        mapping = slab_alloc(as_page_mapping_cache, 0);
+        mapping->pagemap = pagemap;
+        odlink_initialize(&mapping->lpagemap);
+        mapping->vaddr = vaddr;
+        mapping->frame = frame;
+        odict_insert(&mapping->lpagemap, &pagemap->map, NULL);
+}
+
+/** Remove page mapping.
+ *
+ * @param mapping Mapping
+ */
+NO_TRACE void as_pagemap_remove(as_page_mapping_t *mapping)
+{
+        odict_remove(&mapping->lpagemap);
+        slab_free(as_page_mapping_cache, mapping);
+}
+
 /** Remove reference to address space area share info.
  *
@@ -545 +689 @@
                  * reference from all frames found there.
                  */
-                list_foreach(sh_info->pagemap.leaf_list, leaf_link,
-                    btree_node_t, node) {
-                        btree_key_t i;
-
-                        for (i = 0; i < node->keys; i++)
-                                frame_free((uintptr_t) node->value[i], 1);
+                as_page_mapping_t *mapping = as_pagemap_first(&sh_info->pagemap);
+                while (mapping != NULL) {
+                        frame_free(mapping->frame, 1);
+                        mapping = as_pagemap_next(mapping);
                 }
 
@@ -561 +703 @@
                             sh_info->backend_shared_data);
                 }
-                btree_destroy(&sh_info->pagemap);
+                as_pagemap_finalize(&sh_info->pagemap);
                 free(sh_info);
         }
@@ -665 +807 @@
                 si->backend_shared_data = NULL;
                 si->backend = backend;
-                btree_create(&si->pagemap);
+                as_pagemap_initialize(&si->pagemap);
 
                 area->sh_info = si;