[ported from 2008.3] Add File Descriptor Attached Shared Objects (FDSO) infrastructure

1 files changed, 69 insertions, 0 deletions

diff --git a/include/litmus/fdso.h b/include/litmus/fdso.h
new file mode 100644
index 000000000000..286e10f86de0
--- /dev/null
+++ b/include/litmus/fdso.h
@@ -0,0 +1,69 @@
+/* fdso.h - file descriptor attached shared objects
+ *
+ * (c) 2007 B. Brandenburg, LITMUS^RT project
+ */
+
+#ifndef _LINUX_FDSO_H_
+#define _LINUX_FDSO_H_
+
+#include <linux/list.h>
+#include <asm/atomic.h>
+
+#include <linux/fs.h>
+
+#define MAX_OBJECT_DESCRIPTORS 32
+
+typedef enum  {
+        MIN_OBJ_TYPE    = 0,
+
+        FMLP_SEM        = 0,
+        SRP_SEM         = 1,
+
+        MAX_OBJ_TYPE    = 1
+} obj_type_t;
+
+struct inode_obj_id {
+        struct list_head        list;
+        atomic_t                count;
+        struct inode*           inode;
+
+        obj_type_t              type;
+        void*                   obj;
+        unsigned int            id;
+};
+
+
+struct od_table_entry {
+        unsigned int            used;
+
+        struct inode_obj_id*    obj;
+        void*                   extra;
+};
+
+struct fdso_ops {
+        void* (*create) (void);
+        void  (*destroy)(void*);
+        int   (*open)   (struct od_table_entry*, void* __user);
+        int   (*close)  (struct od_table_entry*);
+};
+
+/* translate a userspace supplied od into the raw table entry
+ * returns NULL if od is invalid
+ */
+struct od_table_entry* __od_lookup(int od);
+
+/* translate a userspace supplied od into the associated object
+ * returns NULL if od is invalid
+ */
+static inline void* od_lookup(int od, obj_type_t type)
+{
+        struct od_table_entry* e = __od_lookup(od);
+        return e && e->obj->type == type ? e->obj->obj : NULL;
+}
+
+#define lookup_fmlp_sem(od)((struct pi_semaphore*)  od_lookup(od, FMLP_SEM))
+#define lookup_srp_sem(od) ((struct srp_semaphore*) od_lookup(od, SRP_SEM))
+#define lookup_ics(od)     ((struct ics*)           od_lookup(od, ICS_ID))
+
+
+#endif