[MEMORY] Process memory management

kernel/proc/procmm.c

@@ -0,0 +1,114 @@
+#include <scheduler.h>
+#include <list.h>
+#include <debug.h>
+
+procmm_mmap_t *procmm_new_map(process_t *proc, procmm_mmap_t *src)
+{
+  procmm_mmap_t *map = kcalloc(1, sizeof(procmm_mmap_t));
+  map->proc = proc;
+  map->P4 = vmm_new_P4();
+  LIST_INIT(map, areas);
+
+  if(src)
+  {
+    LIST_FOREACH(src->areas, procmm_area_t, o, areas)
+    {
+      procmm_map(map, o->start, o->end, o->flags);
+      vmm_p4_memcpy(map->P4, (void *)o->start, src->P4, (void *)o->start, o->end-o->start);
+    }
+  }
+
+  return map;
+}
+
+void procmm_free_map(process_t *proc)
+{
+  procmm_mmap_t *map = proc->mmap;
+  procmm_area_t *o = map->areas.next;
+  while(o)
+  {
+    procmm_area_t *next = o->areas.next;
+    procmm_unmap(o);
+    o = next;
+  }
+  map->brk = 0;
+  map->stack = 0;
+  vmm_free_P4(map->P4);
+  kfree(map);
+}
+
+void procmm_print_map(procmm_mmap_t *map)
+{
+  debug_info("Procmm map (process:%d)\n", map->proc->pid);
+  LIST_FOREACH(map->areas, procmm_area_t, o, areas)
+  {
+    debug("  %x->%x (%x)", o->start, o->end, o->flags);
+    if(o == map->brk)
+      debug(" BRK");
+    if(o == map->stack)
+      debug(" STACK");
+    debug("\n");
+  }
+}
+
+procmm_area_t *procmm_map(procmm_mmap_t *map, uintptr_t start, uintptr_t end, uint64_t flags)
+{
+  procmm_area_t *a = kcalloc(1, sizeof(procmm_area_t));
+  a->start = start;
+  a->end = end;
+  a->flags = flags;
+  a->map = map;
+  LIST_INIT(a, areas);
+
+  LIST_FOREACH(map->areas, procmm_area_t, o, areas)
+  {
+    if(!((o->end < start) || (o->start > a->end)))
+    {
+      // Overlapping areas
+      debug_error("PROCMM - Overlapping areas (unsupported for now)\n");
+      kfree(a);
+      return 0;
+    }
+    if(o->start > a->end)
+    {
+      LIST_INSERT_BEFORE(map->areas, a, areas, o);
+    }
+  }
+  if(LIST_EMPTY(a->areas))
+    LIST_APPEND(map->areas, a, areas);
+
+  uintptr_t p = a->start;
+  while(p < a->end)
+  {
+    vmm_set_page(map->P4, p, pmm_alloc(), PAGE_PRESENT | PAGE_WRITE | PAGE_USER);
+    p += PAGE_SIZE;
+  }
+
+  return a;
+}
+void procmm_unmap(procmm_area_t *a)
+{
+  uintptr_t p = a->start;
+  while(p < a->end)
+  {
+    uintptr_t ph = vmm_get_page(a->map->P4, p);
+    pmm_free(ph);
+    vmm_set_page(a->map->P4, p, 0, 0);
+    p += PAGE_SIZE;
+  }
+  LIST_REMOVE(a->map->areas, a, areas);
+  kfree(a);
+}
+
+uintptr_t procmm_setup(process_t *proc)
+{
+  procmm_mmap_t *map = proc->mmap;
+  procmm_area_t *last_a = map->areas.prev;
+
+  uintptr_t brk_start = (last_a->end + PAGE_SIZE) & ~(PAGE_SIZE-1);
+  map->brk = procmm_map(map, brk_start, brk_start, 0);
+
+  map->stack = procmm_map(map, USERSPACE_TOP, USERSPACE_TOP, 0);
+
+  return brk_start;
+}