void do_ipc(tcb_t* from, tcb_t* to) {
ipc_msg_tag_t tag;
ipc_typed_item typed_item;
int untyped_idx, typed_idx, typed_item_idx;
int typed_last, untyped_last;
uint32_t typed_data; /* typed item extra word*/
/*Copy tag of message*/
tag.raw = ipc_read_mr(from, 0);
untyped_last = tag.s.n_untyped + 1;
typed_last = untyped_last + tag.s.n_typed;
if(typed_last > IPC_MR_COUNT) {
set_user_error(from, UE_IPC_MSG_OVERFLOW | UE_IPC_PHASE_SEND);
set_user_error(to, UE_IPC_MSG_OVERFLOW | UE_IPC_PHASE_RECV);
return;
}
ipc_write_mr(to, 0, tag.s.label << 16);
/*Copy untyped words*/
for(untyped_idx = 1; untyped_idx < untyped_last; ++untyped_idx) {
ipc_write_mr(to, untyped_idx, ipc_read_mr(from, untyped_idx));
}
typed_item_idx = -1;
/* Copy typed words
* FSM: j - number of byte*/
for(typed_idx = untyped_idx; typed_idx < typed_last; ++typed_idx) {
if(typed_item_idx == -1) {
/*If typed_item_idx == -1 - read ti's tag*/
typed_item.raw = ipc_read_mr(from, typed_idx);
++typed_item_idx;
}
else if(typed_item.s.header & IPC_TI_MAP_GRANT) {
/* MapItem / GrantItem have 1xxx in header */
typed_data = ipc_read_mr(from, typed_idx);
map_area(from->as, to->as, typed_item.raw & 0xFFFFFFC0, typed_data & 0xFFFFFFC0,
(typed_item.s.header & IPC_TI_GRANT)? GRANT : MAP, thread_ispriviliged(from));
typed_item_idx = -1;
}
/*TODO: StringItem support*/
}
to->utcb->sender = from->t_globalid;
to->state = T_RUNNABLE;
to->ipc_from = L4_NILTHREAD;
from->state = T_RUNNABLE;
/*Dispatch communicating threads*/
sched_slot_dispatch(SSI_NORMAL_THREAD, from);
sched_slot_dispatch(SSI_IPC_THREAD, to);
dbg_printf(DL_IPC, "IPC: %t to %t\n", caller->t_globalid, to->t_globalid);
}
void set_caller_error(enum user_error_t error)
{
if (caller)
set_user_error((tcb_t *) caller, error);
else
panic("User-level error %d during in-kernel call!", error);
}
static void user_ipc_error(tcb_t *thr, enum user_error_t error)
{
ipc_msg_tag_t tag;
/* Set ipc unsuccessful */
tag.raw = ipc_read_mr(thr, 0);
tag.s.flags |= 0x8;
ipc_write_mr(thr, 0, tag.raw);
set_user_error(thr, error);
}
