change syscalls to take 5 params and return 6

+ In total, a syscall is built up of 6 values, with the first being the
  syscall number. Symmetrically, the first value is now a status and the
  following five values return "values". This allows us to cram in more
  info into the ipc_* functions. The performance difference is
  absolutely minimal, at least from my testing in qemu.

1 files changed, 24 insertions, 18 deletions

diff --git a/common/uapi/ipc.c b/common/uapi/ipc.c
index 4cdec0c..ecfced5 100644
--- a/common/uapi/ipc.c
+++ b/common/uapi/ipc.c
@@ -13,17 +13,12 @@
  * IPC server notification syscall handler.
  *
  * @param callback Address of server callback.
- * @return \ref ERR_EXT and \c 0 if process already is a server,
- * \ref OK and \c 0 otherwise.
+ * @return \ref OK and \c 0.
  */
 SYSCALL_DEFINE1(ipc_server)(sys_arg_t callback)
 {
-	struct tcb *r = cur_tcb();
-	if (r->callback) /* server can't be reinitialized */
-		return (struct sys_ret){ ERR_EXT, 0 };
-
-	r->callback = callback;
-	return (struct sys_ret){ OK, 0 };
+	cur_tcb()->callback = callback;
+	return (struct sys_ret){ OK, 0, 0, 0, 0, 0 };
 }
 
 /**
@@ -32,29 +27,37 @@ SYSCALL_DEFINE1(ipc_server)(sys_arg_t callback)
  * @param pid Process to request RPC to.
  * @param d0 IPC argument 0.
  * @param d1 IPC argument 1.
+ * @param d2 IPC argument 2.
+ * @param d3 IPC argument 3.
  * @return \c d0 and \c d1.
  */
-SYSCALL_DEFINE3(ipc_req)(sys_arg_t pid, sys_arg_t d0, sys_arg_t d1)
+SYSCALL_DEFINE5(ipc_req)(sys_arg_t pid,
+                         sys_arg_t d0, sys_arg_t d1, sys_arg_t d2, sys_arg_t d3)
 {
+	struct tcb *t = cur_tcb();
 	struct tcb *r = get_tcb(pid);
 	/** \todo something like jump_to_callback(t) */
 	/* remember difference between ipc_req and ipc_fwd! */
-	return (struct sys_ret){ d0, d1 };
+	return (struct sys_ret){ OK, t->tid, d0, d1, d2, d3 };
 }
 
 /**
  * IPC forwarding syscall handler.
  *
- * @param pid Process to rquest RPC to.
+ * @param pid Process to request RPC to.
  * @param d0 IPC argument 0.
  * @param d1 IPC argument 1.
- * @return \c d0 and \c d1.
+ * @param d2 IPC argument 2.
+ * @param d3 IPC argument 3.
+ * @return \p d0 and \p d1.
  */
-SYSCALL_DEFINE3(ipc_fwd)(sys_arg_t pid, sys_arg_t d0, sys_arg_t d1)
+SYSCALL_DEFINE5(ipc_fwd)(sys_arg_t pid,
+                         sys_arg_t d0, sys_arg_t d1, sys_arg_t d2, sys_arg_t d3)
 {
-	struct tcb *t = get_tcb(pid);
+	struct tcb *t = cur_tcb();
+	struct tcb *r = get_tcb(pid);
 	/* ditto */
-	return (struct sys_ret){ d0, d1 };
+	return (struct sys_ret){ OK, t->tid, d0, d1, d2, d3 };
 }
 
 /**
@@ -62,11 +65,14 @@ SYSCALL_DEFINE3(ipc_fwd)(sys_arg_t pid, sys_arg_t d0, sys_arg_t d1)
  *
  * @param d0 IPC return value 0.
  * @param d1 IPC return value 1.
+ * @param d2 IPC return value 2.
+ * @param d3 IPC return value 3.
  * @return \c d0 and \c d1.
  */
-SYSCALL_DEFINE2(ipc_resp)(sys_arg_t d0, sys_arg_t d1)
+SYSCALL_DEFINE4(ipc_resp)(sys_arg_t d0, sys_arg_t d1, sys_arg_t d2,
+                          sys_arg_t d3)
 {
-	struct tcb *r = cur_tcb();
+	struct tcb *t = cur_tcb();
 	/* something like return_from_callback(t, r) */
-	return (struct sys_ret){ d0, d1 };
+	return (struct sys_ret){ OK, t->tid, d0, d1, d2, d3 };
 }