Introduce concept of Process Resources (PR_MEM), implement necessary syscalls

kernel/proc/resource.c

@@ -0,0 +1,100 @@
+#include <libk/assert.h>
+#include <libk/rbtree.h>
+#include <libk/std.h>
+#include <libk/string.h>
+#include <mm/liballoc.h>
+#include <mm/pmm.h>
+#include <proc/proc.h>
+#include <sync/spin_lock.h>
+#include <sys/debug.h>
+
+void proc_cleanup_resources (struct proc* proc) {
+  struct proc_resource* resource = NULL;
+
+  struct rb_node_link* rnode;
+  rbtree_first (&proc->resource_tree, rnode);
+
+  while (rnode) {
+    struct rb_node_link* next;
+    rbtree_next (rnode, next);
+    resource = rbtree_entry (rnode, struct proc_resource, proc_resource_tree_link);
+    rbtree_delete (&proc->resource_tree, rnode);
+    resource->ops.cleanup (resource);
+    free (resource);
+    rnode = next;
+  }
+
+  assert (proc->resource_tree == NULL);
+}
+
+void proc_drop_resource (struct proc* proc, struct proc_resource* resource) {
+  if (atomic_fetch_sub (&resource->refs, 1) == 1) {
+    spin_lock (&proc->lock);
+    rbtree_delete (&proc->resource_tree, &resource->proc_resource_tree_link);
+    spin_unlock (&proc->lock);
+
+    resource->ops.cleanup (resource);
+    free (resource);
+  }
+}
+
+static bool proc_create_resource_mem (struct proc_resource_mem* mem,
+                                      struct proc_resource_mem_init* init) {
+  if (init->pages == 0)
+    return false;
+
+  uintptr_t paddr = pmm_alloc (init->pages);
+  if (paddr == PMM_ALLOC_ERR)
+    return false;
+
+  mem->paddr = paddr;
+  mem->pages = init->pages;
+  DEBUG ("paddr=%p, pages=%zu\n", mem->paddr, mem->pages);
+
+  return true;
+}
+
+static void proc_cleanup_resource_mem (struct proc_resource* resource) {
+  pmm_free (resource->u.mem.paddr, resource->u.mem.pages);
+}
+
+struct proc_resource* proc_create_resource (struct proc* proc, int rid, int type, int vis,
+                                            void* data) {
+  /* Check if resource RID already exists */
+  struct proc_resource* resource_check;
+  rbtree_find (struct proc_resource, &proc->resource_tree, rid, resource_check,
+               proc_resource_tree_link, rid);
+  if (resource_check != NULL)
+    return NULL;
+
+  struct proc_resource* resource = malloc (sizeof (*resource));
+  if (resource == NULL)
+    return NULL;
+
+  memset (resource, 0, sizeof (*resource));
+
+  resource->lock = SPIN_LOCK_INIT;
+  resource->type = type;
+  resource->refs = 1;
+  resource->rid = rid;
+  resource->visibility = vis;
+
+  switch (resource->type) {
+  case PR_MEM: {
+    struct proc_resource_mem_init* mem_init = data;
+    proc_create_resource_mem (&resource->u.mem, mem_init);
+    resource->ops.cleanup = &proc_cleanup_resource_mem;
+  } break;
+  default: {
+    free (resource);
+    return NULL;
+  } break;
+  }
+
+  spin_lock (&proc->lock);
+  rbtree_insert (struct proc_resource, &proc->resource_tree, &resource->proc_resource_tree_link,
+                 proc_resource_tree_link, rid);
+  spin_unlock (&proc->lock);
+
+  return resource;
+}