Changeset 01029fc in mainline

Timestamp:

2012-11-07T21:30:44Z (12 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

3b8a990

Parents:

c387838

Message:

Define two new as area backend callbacks.

• Add is_resizable(as_area_t *)
• Add is_shareable(as_area_t *)
• Remove special knowledge of the phys backend from as_area_resize()

Location:

kernel/generic

Files:

• include/mm/as.h (modified) (1 diff)
• src/mm/as.c (modified) (2 diffs)
• src/mm/backend_anon.c (modified) (3 diffs)
• src/mm/backend_elf.c (modified) (3 diffs)
• src/mm/backend_phys.c (modified) (3 diffs)

kernel/generic/include/mm/as.h

@@ -224 +224 @@
         void (* destroy)(as_area_t *);
 
+        bool (* is_resizable)(as_area_t *);
+        bool (* is_shareable)(as_area_t *);
+
         int (* page_fault)(as_area_t *, uintptr_t, pf_access_t);
         void (* frame_free)(as_area_t *, uintptr_t, uintptr_t);

kernel/generic/src/mm/as.c

@@ -696 +696 @@
                 return ENOENT;
         }
-        
-        if (area->backend == &phys_backend) {
-                /*
-                 * Remapping of address space areas associated
-                 * with memory mapped devices is not supported.
+
+        if (!area->backend->is_resizable(area)) {
+                /*
+                 * The backend does not support resizing for this area.
                  */
                 mutex_unlock(&area->lock);
@@ -1057 +1056 @@
         }
         
-        if ((!src_area->backend) || (!src_area->backend->share)) {
-                /*
-                 * There is no backend or the backend does not
-                 * know how to share the area.
+        if (!src_area->backend->is_shareable(src_area)) {
+                /*
+                 * The backend does not permit sharing of this area.
                  */
                 mutex_unlock(&src_area->lock);

kernel/generic/src/mm/backend_anon.c

@@ -59 +59 @@
 static void anon_destroy(as_area_t *);
 
+static bool anon_is_resizable(as_area_t *);
+static bool anon_is_shareable(as_area_t *);
+
 static int anon_page_fault(as_area_t *, uintptr_t, pf_access_t);
 static void anon_frame_free(as_area_t *, uintptr_t, uintptr_t);
@@ -67 +70 @@
         .share = anon_share,
         .destroy = anon_destroy,
+
+        .is_resizable = anon_is_resizable,
+        .is_shareable = anon_is_shareable,
 
         .page_fault = anon_page_fault,
@@ -152 +158 @@
 }
 
+bool anon_is_resizable(as_area_t *area)
+{
+        return true;
+}
+
+bool anon_is_shareable(as_area_t *area)
+{
+        return !(area->flags & AS_AREA_LATE_RESERVE);
+}
 
 /** Service a page fault in the anonymous memory address space area.

kernel/generic/src/mm/backend_elf.c

@@ -58 +58 @@
 static void elf_destroy(as_area_t *);
 
+static bool elf_is_resizable(as_area_t *);
+static bool elf_is_shareable(as_area_t *);
+
 static int elf_page_fault(as_area_t *, uintptr_t, pf_access_t);
 static void elf_frame_free(as_area_t *, uintptr_t, uintptr_t);
@@ -66 +69 @@
         .share = elf_share,
         .destroy = elf_destroy,
+
+        .is_resizable = elf_is_resizable,
+        .is_shareable = elf_is_shareable,
 
         .page_fault = elf_page_fault,
@@ -213 +219 @@
 }
 
+bool elf_is_resizable(as_area_t *area)
+{
+        return true;
+}
+
+bool elf_is_shareable(as_area_t *area)
+{
+        return true;
+}
+
+
 /** Service a page fault in the ELF backend address space area.
  *

kernel/generic/src/mm/backend_phys.c

@@ -52 +52 @@
 static void phys_destroy(as_area_t *);
 
+static bool phys_is_resizable(as_area_t *);
+static bool phys_is_shareable(as_area_t *);
+
+
 static int phys_page_fault(as_area_t *, uintptr_t, pf_access_t);
 
@@ -59 +63 @@
         .share = phys_share,
         .destroy = phys_destroy,
+
+        .is_resizable = phys_is_resizable,
+        .is_shareable = phys_is_shareable,
 
         .page_fault = phys_page_fault,
@@ -87 +94 @@
         /* Nothing to do. */
 }
+
+bool phys_is_resizable(as_area_t *area)
+{
+        return false;
+}
+
+bool phys_is_shareable(as_area_t *area)
+{
+        return true;
+}
+
 
 /** Service a page fault in the address space area backed by physical memory.