5 files changed, 77 insertions, 34 deletions

diff --git a/common/dispatch.c b/common/dispatch.c
new file mode 100644
index 0000000..1325d62
--- /dev/null
+++ b/common/dispatch.c
@@ -0,0 +1,12 @@
+#include <apos/uapi.h>
+#include <apos/ipi.h>
+
+struct sys_ret dispatch(sys_arg_t a, sys_arg_t b, sys_arg_t c,
+                        sys_arg_t d, sys_arg_t e, sys_arg_t f)
+{
+	struct tcb *t = cur_tcb();
+	if (clear_ipi(t))
+		return handle_ipi(t);
+
+	return handle_syscall(t, a, b, c, d, e, f);
+}
diff --git a/common/ipi.c b/common/ipi.c
new file mode 100644
index 0000000..32f1432
--- /dev/null
+++ b/common/ipi.c
@@ -0,0 +1,32 @@
+#include <apos/ipi.h>
+#include <arch/cpu.h>
+
+#include <arch/proc.h>
+
+/**
+ * @file ipi.c
+ *
+ * IPI function implementations.
+ */
+
+bool clear_ipi(struct tcb *t)
+{
+	bool r = t->ipi;
+	t->ipi = false;
+	return r;
+}
+
+void send_ipi(struct tcb *t)
+{
+	t->ipi = true;
+	cpu_send_ipi(t->cpu_id);
+}
+
+struct sys_ret handle_ipi(struct tcb *t)
+{
+	adjust_ipi(t);
+
+	/** @todo use rpc stack */
+	set_return(t, t->callback);
+	return get_args(t);
+}
diff --git a/common/tcb.c b/common/tcb.c
index 9000941..417ca45 100644
--- a/common/tcb.c
+++ b/common/tcb.c
@@ -36,7 +36,7 @@ static struct tcb **tcbs;
  * \todo If we ever support systems with massive amounts of cpus, this should probably
  * be allocated at runtime.
  */
-static struct tcb *cpu_tcb[MAX_CPUS] = { 0 };
+static struct tcb *__cpu_tcb[MAX_CPUS] = { 0 };
 
 void init_tcbs()
 {
@@ -294,7 +294,12 @@ DEFINE_DETACH(detach_proc, proc);
 /* weak to allow optimisation on risc-v, but provide fallback for future */
 __weak struct tcb *cur_tcb()
 {
-	return cpu_tcb[cpu_id()];
+	return cpu_tcb(cpu_id());
+}
+
+struct tcb *cpu_tcb(id_t cpu_id)
+{
+	return __cpu_tcb[cpu_id];
 }
 
 struct tcb *cur_proc()
@@ -313,7 +318,7 @@ void use_tcb(struct tcb *t)
 {
 	cpu_assign(t);
 
-	cpu_tcb[t->cpu_id] = t;
+	__cpu_tcb[t->cpu_id] = t;
 
 	use_vmem(t->proc.vmem);
 }
@@ -355,3 +360,8 @@ void set_return(struct tcb *t, vm_t v)
 {
 	t->exec = v;
 }
+
+bool running(struct tcb *t)
+{
+	return cpu_tcb(t->cpu_id) == t;
+}
diff --git a/common/uapi/dispatch.c b/common/uapi/dispatch.c
index 27cc001..2cf19fb 100644
--- a/common/uapi/dispatch.c
+++ b/common/uapi/dispatch.c
@@ -10,6 +10,8 @@
 #include <apos/debug.h>
 #include <apos/uapi.h>
 
+#include <arch/proc.h>
+
 /** Syscall number to syscall handler conversion. */
 static const sys_t syscall_table[] = {
 	/* noop */
@@ -79,10 +81,11 @@ SYSCALL_DEFINE1(putch)(sys_arg_t a){
 	return SYS_RET1(OK);
 }
 
-struct sys_ret syscall_dispatch(sys_arg_t syscall, sys_arg_t a, sys_arg_t b,
-                                sys_arg_t c, sys_arg_t d, sys_arg_t e)
+struct sys_ret handle_syscall(struct tcb *t,
+                              sys_arg_t syscall, sys_arg_t a, sys_arg_t b,
+                              sys_arg_t c, sys_arg_t d, sys_arg_t e)
 {
-	struct tcb *t = cur_tcb();
+	adjust_syscall(t);
 
 	size_t sc = syscall;
 	if (sc >= ARRAY_SIZE(syscall_table)) {
diff --git a/common/uapi/ipc.c b/common/uapi/ipc.c
index 34f707a..cb53ee3 100644
--- a/common/uapi/ipc.c
+++ b/common/uapi/ipc.c
@@ -8,6 +8,7 @@
 
 #include <apos/uapi.h>
 #include <apos/tcb.h>
+#include <apos/ipi.h>
 
 /**
  * IPC server notification syscall handler.
@@ -114,36 +115,21 @@ SYSCALL_DEFINE4(ipc_resp)(sys_arg_t d0, sys_arg_t d1, sys_arg_t d2,
  * \todo Implement.
  *
  * @param tid Thread ID to notify.
- * @param swap Whether to swap immediately if possible.
  * @return \ref OK and 0.
  */
-SYSCALL_DEFINE2(ipc_notify)(sys_arg_t tid, sys_arg_t swap){
-	/** \todo masquerade as kernel call, set from to 0 and set us as
-	 * notify type, no arguments as that would require too much state
-	 * handling for my liking. Instead, a server and a client have to agree
-	 * on some rpc API, and ipc_notify is just used to asynchronously inform
-	 * the client that it should check the status of its async operations.
-	 * Arguably slower than directly telling the client which operation was
-	 * finished, but this would require the kernel to keep track of a notify
-	 * stack. While not impossible, probably too complex. */
+SYSCALL_DEFINE1(ipc_notify)(sys_arg_t tid){
+	struct tcb *t = get_tcb(tid);
+	if (t->notify_state == NOTIFY_QUEUED)
+		return SYS_RET1(OK);
+
+	if (t->notify_state == NOTIFY_RUNNING) {
+		t->notify_state = NOTIFY_QUEUED;
+		return SYS_RET1(OK);
+	}
+
+	t->notify_state = NOTIFY_QUEUED;
+	if (running(t))
+		send_ipi(t);
 
-	/* Something like
-	 *
-	 * struct tcb *t = get_tcb(tid);
-	 * if (t->notify_state == NOTIFY_QUEUED)
-	 *	return;
-	 *
-	 * if (t->notify_state == NOTIFY_RUNNING) {
-	 *	t->notify = NOTIFY_QUEUED;
-	 *	return;
-	 * }
-	 *
-	 * t->notify_state = NOTIFY_QUEUED;
-	 * if (swap)
-	 *	do_swap(); // clears t->notify when swapped to
-	 *		   // if already running in base state, interrupt,
-	 *		   otherwise wait for return from rpc. If not running,
-	 *		   just queue the interrupt.
-	 */
 	return SYS_RET1(OK);
 }