Changeset 83b6ba9f in mainline for kernel/generic/src/mm/backend_phys.c

Timestamp:

2014-02-18T00:18:48Z (11 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

8aaf9dc

Parents:

89dcf93

Message:

Support for AS area backend shared data.

• share_info_t is now created for every new address space area.
• share_info_t was extended to point to AS area backend shared data.
• AS area backend may decide to define create/destroy_shared_data() methods.
• Anonymous backend_phys frames are now freed from phys_destroy_shared_data().
• Fixed one case of forgotten locked mutex.

File:

• kernel/generic/src/mm/backend_phys.c (modified) (4 diffs)

kernel/generic/src/mm/backend_phys.c

@@ -55 +55 @@
 static bool phys_is_shareable(as_area_t *);
 
+static int phys_page_fault(as_area_t *, uintptr_t, pf_access_t);
 
-static int phys_page_fault(as_area_t *, uintptr_t, pf_access_t);
+static bool phys_create_shared_data(as_area_t *);
+static void phys_destroy_shared_data(void *);
+
+typedef struct {
+        uintptr_t base;
+        size_t frames;  
+} phys_shared_data_t;
 
 mem_backend_t phys_backend = {
@@ -69 +76 @@
         .page_fault = phys_page_fault,
         .frame_free = NULL,
+        
+        .create_shared_data = phys_create_shared_data,
+        .destroy_shared_data = phys_destroy_shared_data
 };
+
 
 bool phys_create(as_area_t *area)
@@ -92 +103 @@
 void phys_destroy(as_area_t *area)
 {
-        mem_backend_data_t *data = &area->backend_data;
-        bool last = true;
-
-        if (area->sh_info) {
-                mutex_lock(&area->sh_info->lock);
-                if (area->sh_info->refcount != 1)
-                        last = false;
-                mutex_unlock(&area->sh_info->lock);
-        }
-        
-        if (last && data->anonymous)
-                frame_free(data->base, data->frames);
+        /*
+         * Nothing to do.
+         * The anonymous frames, if any, are released in
+         * phys_destroy_shared_data().
+         */
 }
 
@@ -149 +153 @@
 }
 
+bool phys_create_shared_data(as_area_t *area)
+{
+        /*
+         * For anonymous phys areas, create the shared data.
+         */
+        if (area->backend_data.anonymous) {
+                phys_shared_data_t *data;
+
+                data = (phys_shared_data_t *) malloc(sizeof(*data), 0);
+
+                data->base = area->backend_data.base;
+                data->frames = area->backend_data.frames;
+                area->sh_info->backend_shared_data = data;
+        }
+
+        return true;
+}
+
+void phys_destroy_shared_data(void *opaque_data)
+{
+        phys_shared_data_t *data = (phys_shared_data_t *) opaque_data;
+
+        if (data) {
+                frame_free(data->base, data->frames);
+                free(data);
+        }
+}
+
 /** @}
  */