ACPI tables translator

Exposes x86 ACPI tables as a netfs on a mount point

* acpi: New directory.
* Makefile (prog-subdirs): Add acpi.
* hurd/hurd_types.h (FSTYPE_ACPI): New macro.

1 files changed, 90 insertions, 0 deletions

diff --git a/acpi/ncache.c b/acpi/ncache.c
new file mode 100644
index 00000000..61bc6592
--- /dev/null
+++ b/acpi/ncache.c
@@ -0,0 +1,90 @@
+/* Node caching
+
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   Written by Miles Bader <address@hidden>
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+#include <ncache.h>
+
+#include <unistd.h>
+#include <string.h>
+#include <hurd/netfs.h>
+
+#include <acpifs.h>
+#include <netfs_impl.h>
+
+/* Implementation of node caching functions */
+
+/* Remove NN's node from its position in FS's node cache.  */
+void
+node_unlink (struct node *node, struct acpifs *fs)
+{
+  struct netnode *nn = node->nn;
+  if (nn->ncache_next)
+    nn->ncache_next->nn->ncache_prev = nn->ncache_prev;
+  if (nn->ncache_prev)
+    nn->ncache_prev->nn->ncache_next = nn->ncache_next;
+  if (fs->node_cache_mru == node)
+    fs->node_cache_mru = nn->ncache_next;
+  if (fs->node_cache_lru == node)
+    fs->node_cache_lru = nn->ncache_prev;
+  nn->ncache_next = 0;
+  nn->ncache_prev = 0;
+  fs->node_cache_len--;
+}
+
+/* Add NODE to the recently-used-node cache, which adds a reference to
+   prevent it from going away.  NODE should be locked.  */
+void
+node_cache (struct node *node)
+{
+  struct netnode *nn = node->nn;
+
+  pthread_mutex_lock (&fs->node_cache_lock);
+
+  if (fs->node_cache_max > 0 || fs->node_cache_len > 0)
+    {
+      if (fs->node_cache_mru != node)
+       {
+         if (nn->ncache_next || nn->ncache_prev)
+           /* Node is already in the cache.  */
+           node_unlink (node, fs);
+         else
+           /* Add a reference from the cache.  */
+           netfs_nref (node);
+
+         nn->ncache_next = fs->node_cache_mru;
+         nn->ncache_prev = 0;
+         if (fs->node_cache_mru)
+           fs->node_cache_mru->nn->ncache_prev = node;
+         if (!fs->node_cache_lru)
+           fs->node_cache_lru = node;
+         fs->node_cache_mru = node;
+         fs->node_cache_len++;
+       }
+
+      /* Forget the least used nodes.  */
+      while (fs->node_cache_len > fs->node_cache_max)
+       {
+         struct node *lru = fs->node_cache_lru;
+         node_unlink (lru, fs);
+         netfs_nrele (lru);
+       }
+    }
+
+  pthread_mutex_unlock (&fs->node_cache_lock);
+}