thread.h

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/*
 * (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
 *               Alexander Warg <warg@os.inf.tu-dresden.de>,
 *               Björn Döbel <doebel@os.inf.tu-dresden.de>,
 *               Torsten Frenzel <frenzel@os.inf.tu-dresden.de>
 *     economic rights: Technische Universität Dresden (Germany)
 *
 * License: see LICENSE.spdx (in this directory or the directories above)
 */
#pragma once
 
#include <l4/sys/types.h>
#include <l4/sys/utcb.h>
#include <l4/sys/ipc.h>
 
L4_INLINE l4_msgtag_t
l4_thread_ex_regs(l4_cap_idx_t thread, l4_addr_t ip, l4_addr_t sp,
                  l4_umword_t flags) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_ex_regs_u(l4_cap_idx_t thread, l4_addr_t ip, l4_addr_t sp,
                    l4_umword_t flags, l4_utcb_t *utcb) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_ex_regs_ret(l4_cap_idx_t thread, l4_addr_t *ip, l4_addr_t *sp,
                      l4_umword_t *flags) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_ex_regs_ret_u(l4_cap_idx_t thread, l4_addr_t *ip, l4_addr_t *sp,
                        l4_umword_t *flags, l4_utcb_t *utcb) L4_NOTHROW;
 
 
 
L4_INLINE void
l4_thread_control_start(void) L4_NOTHROW;
 
L4_INLINE void
l4_thread_control_start_u(l4_utcb_t *utcb) L4_NOTHROW;
 
L4_INLINE void
l4_thread_control_pager(l4_cap_idx_t pager) L4_NOTHROW;
 
L4_INLINE void
l4_thread_control_pager_u(l4_cap_idx_t pager, l4_utcb_t *utcb) L4_NOTHROW;
 
L4_INLINE void
l4_thread_control_exc_handler(l4_cap_idx_t exc_handler) L4_NOTHROW;
 
L4_INLINE void
l4_thread_control_exc_handler_u(l4_cap_idx_t exc_handler,
                                l4_utcb_t *utcb) L4_NOTHROW;
 
L4_INLINE void
l4_thread_control_bind(l4_utcb_t *thread_utcb,
                       l4_cap_idx_t task) L4_NOTHROW;
 
L4_INLINE void
l4_thread_control_bind_u(l4_utcb_t *thread_utcb,
                         l4_cap_idx_t task, l4_utcb_t *utcb) L4_NOTHROW;
 
L4_INLINE void
l4_thread_control_alien(int on) L4_NOTHROW;
 
L4_INLINE void
l4_thread_control_alien_u(l4_utcb_t *utcb, int on) L4_NOTHROW;
 
 
 
 
L4_INLINE l4_msgtag_t
l4_thread_control_commit(l4_cap_idx_t thread) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_control_commit_u(l4_cap_idx_t thread, l4_utcb_t *utcb) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_yield(void) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_switch(l4_cap_idx_t to_thread) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_switch_u(l4_cap_idx_t to_thread, l4_utcb_t *utcb) L4_NOTHROW;
 
 
 
L4_INLINE l4_msgtag_t
l4_thread_stats_time(l4_cap_idx_t thread, l4_kernel_clock_t *us) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_stats_time_u(l4_cap_idx_t thread, l4_kernel_clock_t *us,
                       l4_utcb_t *utcb) L4_NOTHROW;
 
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_resume_start(void) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_resume_start_u(l4_utcb_t *utcb) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_resume_commit(l4_cap_idx_t thread,
                             l4_msgtag_t tag) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_resume_commit_u(l4_cap_idx_t thread,
                               l4_msgtag_t tag, l4_utcb_t *utcb) L4_NOTHROW;
 
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_control(l4_cap_idx_t thread, l4_addr_t vcpu_state) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_control_u(l4_cap_idx_t thread, l4_addr_t vcpu_state,
                         l4_utcb_t *utcb) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_control_ext(l4_cap_idx_t thread, l4_addr_t ext_vcpu_state) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_control_ext_u(l4_cap_idx_t thread, l4_addr_t ext_vcpu_state,
                             l4_utcb_t *utcb) L4_NOTHROW;
 
 
L4_INLINE l4_msgtag_t
l4_thread_register_del_irq(l4_cap_idx_t thread, l4_cap_idx_t irq) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_register_del_irq_u(l4_cap_idx_t thread, l4_cap_idx_t irq,
                             l4_utcb_t *utcb) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_modify_sender_start(void) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_modify_sender_start_u(l4_utcb_t *u) L4_NOTHROW;
 
L4_INLINE int
l4_thread_modify_sender_add(l4_umword_t match_mask,
                            l4_umword_t match,
                            l4_umword_t del_bits,
                            l4_umword_t add_bits,
                            l4_msgtag_t *tag) L4_NOTHROW;
 
L4_INLINE int
l4_thread_modify_sender_add_u(l4_umword_t match_mask,
                              l4_umword_t match,
                              l4_umword_t del_bits,
                              l4_umword_t add_bits,
                              l4_msgtag_t *tag, l4_utcb_t *u) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_modify_sender_commit(l4_cap_idx_t thread, l4_msgtag_t tag) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_modify_sender_commit_u(l4_cap_idx_t thread, l4_msgtag_t tag,
                                 l4_utcb_t *u) L4_NOTHROW;
 
 
L4_INLINE l4_msgtag_t
l4_thread_register_doorbell_irq(l4_cap_idx_t thread,
                                l4_cap_idx_t irq) L4_NOTHROW;
 
L4_INLINE l4_msgtag_t
l4_thread_register_doorbell_irq_u(l4_cap_idx_t thread, l4_cap_idx_t irq,
                                  l4_utcb_t *u) L4_NOTHROW;
 
 
enum L4_thread_ops
{
  L4_THREAD_CONTROL_OP                = 0UL,    
  L4_THREAD_EX_REGS_OP                = 1UL,    
  L4_THREAD_SWITCH_OP                 = 2UL,    
  L4_THREAD_STATS_OP                  = 3UL,    
  L4_THREAD_VCPU_RESUME_OP            = 4UL,    
  L4_THREAD_REGISTER_DELETE_IRQ_OP    = 5UL,    
  L4_THREAD_MODIFY_SENDER_OP          = 6UL,    
  L4_THREAD_VCPU_CONTROL_OP           = 7UL,    
  L4_THREAD_VCPU_CONTROL_EXT_OP       = L4_THREAD_VCPU_CONTROL_OP | 0x10000,
  L4_THREAD_REGISTER_DOORBELL_IRQ_OP  = 8UL,    
  L4_THREAD_X86_GDT_OP                = 0x10UL, 
  L4_THREAD_ARM_TPIDRURO_OP           = 0x10UL, 
  L4_THREAD_AMD64_SET_SEGMENT_BASE_OP = 0x12UL, 
  L4_THREAD_AMD64_GET_SEGMENT_INFO_OP = 0x13UL, 
  L4_THREAD_OPCODE_MASK               = 0xffff, 
};
 
enum L4_thread_control_flags
{
  L4_THREAD_CONTROL_SET_PAGER       = 0x0010000,
  L4_THREAD_CONTROL_BIND_TASK       = 0x0200000,
  L4_THREAD_CONTROL_ALIEN           = 0x0400000,
  L4_THREAD_CONTROL_SET_EXC_HANDLER = 0x1000000,
};
 
enum L4_thread_control_mr_indices
{
  L4_THREAD_CONTROL_MR_IDX_FLAGS       = 0, 
  L4_THREAD_CONTROL_MR_IDX_PAGER       = 1, 
  L4_THREAD_CONTROL_MR_IDX_EXC_HANDLER = 2, 
  L4_THREAD_CONTROL_MR_IDX_FLAG_VALS   = 4, 
  L4_THREAD_CONTROL_MR_IDX_BIND_UTCB   = 5, 
  L4_THREAD_CONTROL_MR_IDX_BIND_TASK   = 6, 
};
 
enum L4_thread_ex_regs_flags
{
  L4_THREAD_EX_REGS_CANCEL            = 0x10000UL, 
  L4_THREAD_EX_REGS_TRIGGER_EXCEPTION = 0x20000UL, 
  L4_THREAD_EX_REGS_ARCH_MASK         = 0xff000000UL, 
};
 
 
/* IMPLEMENTATION -----------------------------------------------------------*/
 
#include <l4/sys/ipc.h>
#include <l4/sys/types.h>
 
L4_INLINE l4_msgtag_t
l4_thread_ex_regs_u(l4_cap_idx_t thread, l4_addr_t ip, l4_addr_t sp,
                    l4_umword_t flags, l4_utcb_t *utcb) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  v->mr[0] = L4_THREAD_EX_REGS_OP | flags;
  v->mr[1] = ip;
  v->mr[2] = sp;
  return l4_ipc_call(thread, utcb, l4_msgtag(L4_PROTO_THREAD, 3, 0, 0), L4_IPC_NEVER);
}
 
L4_INLINE l4_msgtag_t
l4_thread_ex_regs_ret_u(l4_cap_idx_t thread, l4_addr_t *ip, l4_addr_t *sp,
                        l4_umword_t *flags, l4_utcb_t *utcb) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  l4_msgtag_t ret = l4_thread_ex_regs_u(thread, *ip, *sp, *flags, utcb);
  if (l4_error_u(ret, utcb))
    return ret;
 
  *flags = v->mr[0];
  *ip    = v->mr[1];
  *sp    = v->mr[2];
  return ret;
}
 
L4_INLINE void
l4_thread_control_start_u(l4_utcb_t *utcb) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  v->mr[L4_THREAD_CONTROL_MR_IDX_FLAGS] = L4_THREAD_CONTROL_OP;
}
 
L4_INLINE void
l4_thread_control_pager_u(l4_cap_idx_t pager, l4_utcb_t *utcb) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  v->mr[L4_THREAD_CONTROL_MR_IDX_FLAGS] |= L4_THREAD_CONTROL_SET_PAGER;
  v->mr[L4_THREAD_CONTROL_MR_IDX_PAGER]  = pager;
}
 
L4_INLINE void
l4_thread_control_exc_handler_u(l4_cap_idx_t exc_handler,
                                l4_utcb_t *utcb) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  v->mr[L4_THREAD_CONTROL_MR_IDX_FLAGS]       |= L4_THREAD_CONTROL_SET_EXC_HANDLER;
  v->mr[L4_THREAD_CONTROL_MR_IDX_EXC_HANDLER]  = exc_handler;
}
 
L4_INLINE void
l4_thread_control_bind_u(l4_utcb_t *thread_utcb, l4_cap_idx_t task,
                         l4_utcb_t *utcb) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  v->mr[L4_THREAD_CONTROL_MR_IDX_FLAGS]         |= L4_THREAD_CONTROL_BIND_TASK;
  v->mr[L4_THREAD_CONTROL_MR_IDX_BIND_UTCB]      = (l4_addr_t)thread_utcb;
  v->mr[L4_THREAD_CONTROL_MR_IDX_BIND_TASK]      = L4_ITEM_MAP;
  v->mr[L4_THREAD_CONTROL_MR_IDX_BIND_TASK + 1]  = l4_obj_fpage(task, 0, L4_CAP_FPAGE_RWS).raw;
}
 
L4_INLINE void
l4_thread_control_alien_u(l4_utcb_t *utcb, int on) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  v->mr[L4_THREAD_CONTROL_MR_IDX_FLAGS]     |= L4_THREAD_CONTROL_ALIEN;
  v->mr[L4_THREAD_CONTROL_MR_IDX_FLAG_VALS] |= on ? L4_THREAD_CONTROL_ALIEN : 0;
}
 
L4_INLINE l4_msgtag_t
l4_thread_control_commit_u(l4_cap_idx_t thread, l4_utcb_t *utcb) L4_NOTHROW
{
  int items = 0;
  if (l4_utcb_mr_u(utcb)->mr[L4_THREAD_CONTROL_MR_IDX_FLAGS] & L4_THREAD_CONTROL_BIND_TASK)
    items = 1;
  return l4_ipc_call(thread, utcb, l4_msgtag(L4_PROTO_THREAD, 6, items, 0), L4_IPC_NEVER);
}
 
 
L4_INLINE l4_msgtag_t
l4_thread_yield(void) L4_NOTHROW
{
  l4_ipc_receive(L4_INVALID_CAP, NULL, L4_IPC_BOTH_TIMEOUT_0);
  return l4_msgtag(0, 0, 0, 0);
}
 
/* Preliminary, to be changed */
L4_INLINE l4_msgtag_t
l4_thread_switch_u(l4_cap_idx_t to_thread, l4_utcb_t *utcb) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  v->mr[0] = L4_THREAD_SWITCH_OP;
  return l4_ipc_call(to_thread, utcb, l4_msgtag(L4_PROTO_THREAD, 1, 0, 0), L4_IPC_NEVER);
}
 
 
L4_INLINE l4_msgtag_t
l4_thread_stats_time_u(l4_cap_idx_t thread, l4_kernel_clock_t *us,
                       l4_utcb_t *utcb) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  l4_msgtag_t res;
 
  v->mr[0] = L4_THREAD_STATS_OP;
 
  res = l4_ipc_call(thread, utcb, l4_msgtag(L4_PROTO_THREAD, 1, 0, 0), L4_IPC_NEVER);
 
  if (l4_msgtag_has_error(res))
    return res;
 
  *us = v->mr64[l4_utcb_mr64_idx(0)];
 
  return res;
}
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_resume_start_u(l4_utcb_t *utcb) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  v->mr[0] = L4_THREAD_VCPU_RESUME_OP;
  return l4_msgtag(L4_PROTO_THREAD, 1, 0, 0);
}
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_resume_commit_u(l4_cap_idx_t thread,
                               l4_msgtag_t tag, l4_utcb_t *utcb) L4_NOTHROW
{
  return l4_ipc_call(thread, utcb, tag, L4_IPC_NEVER);
}
 
L4_INLINE l4_msgtag_t
l4_thread_ex_regs(l4_cap_idx_t thread, l4_addr_t ip, l4_addr_t sp,
                    l4_umword_t flags) L4_NOTHROW
{
  return l4_thread_ex_regs_u(thread, ip, sp, flags, l4_utcb());
}
 
L4_INLINE l4_msgtag_t
l4_thread_ex_regs_ret(l4_cap_idx_t thread, l4_addr_t *ip, l4_addr_t *sp,
                      l4_umword_t *flags) L4_NOTHROW
{
  return l4_thread_ex_regs_ret_u(thread, ip, sp, flags, l4_utcb());
}
 
L4_INLINE void
l4_thread_control_start(void) L4_NOTHROW
{
  l4_thread_control_start_u(l4_utcb());
}
 
L4_INLINE void
l4_thread_control_pager(l4_cap_idx_t pager) L4_NOTHROW
{
  l4_thread_control_pager_u(pager, l4_utcb());
}
 
L4_INLINE void
l4_thread_control_exc_handler(l4_cap_idx_t exc_handler) L4_NOTHROW
{
  l4_thread_control_exc_handler_u(exc_handler, l4_utcb());
}
 
 
L4_INLINE void
l4_thread_control_bind(l4_utcb_t *thread_utcb, l4_cap_idx_t task) L4_NOTHROW
{
  l4_thread_control_bind_u(thread_utcb, task, l4_utcb());
}
 
L4_INLINE void
l4_thread_control_alien(int on) L4_NOTHROW
{
  l4_thread_control_alien_u(l4_utcb(), on);
}
 
L4_INLINE l4_msgtag_t
l4_thread_control_commit(l4_cap_idx_t thread) L4_NOTHROW
{
  return l4_thread_control_commit_u(thread, l4_utcb());
}
 
 
 
 
L4_INLINE l4_msgtag_t
l4_thread_switch(l4_cap_idx_t to_thread) L4_NOTHROW
{
  return l4_thread_switch_u(to_thread, l4_utcb());
}
 
 
 
 
L4_INLINE l4_msgtag_t
l4_thread_stats_time(l4_cap_idx_t thread, l4_kernel_clock_t *us) L4_NOTHROW
{
  return l4_thread_stats_time_u(thread, us, l4_utcb());
}
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_resume_start(void) L4_NOTHROW
{
  return l4_thread_vcpu_resume_start_u(l4_utcb());
}
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_resume_commit(l4_cap_idx_t thread,
                             l4_msgtag_t tag) L4_NOTHROW
{
  return l4_thread_vcpu_resume_commit_u(thread, tag, l4_utcb());
}
 
 
L4_INLINE l4_msgtag_t
l4_thread_register_del_irq_u(l4_cap_idx_t thread, l4_cap_idx_t irq,
                             l4_utcb_t *u) L4_NOTHROW
{
  l4_msg_regs_t *m = l4_utcb_mr_u(u);
  m->mr[0] = L4_THREAD_REGISTER_DELETE_IRQ_OP;
  m->mr[1] = l4_map_obj_control(0,0);
  m->mr[2] = l4_obj_fpage(irq, 0, L4_CAP_FPAGE_RWS).raw;
  return l4_ipc_call(thread, u, l4_msgtag(L4_PROTO_THREAD, 1, 1, 0), L4_IPC_NEVER);
 
}
 
L4_INLINE l4_msgtag_t
l4_thread_register_del_irq(l4_cap_idx_t thread, l4_cap_idx_t irq) L4_NOTHROW
{
  return l4_thread_register_del_irq_u(thread, irq, l4_utcb());
}
 
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_control_u(l4_cap_idx_t thread, l4_addr_t vcpu_state,
                         l4_utcb_t *utcb) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  v->mr[0] = L4_THREAD_VCPU_CONTROL_OP;
  v->mr[1] = vcpu_state;
  return l4_ipc_call(thread, utcb, l4_msgtag(L4_PROTO_THREAD, 2, 0, 0), L4_IPC_NEVER);
}
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_control(l4_cap_idx_t thread, l4_addr_t vcpu_state) L4_NOTHROW
{ return l4_thread_vcpu_control_u(thread, vcpu_state, l4_utcb()); }
 
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_control_ext_u(l4_cap_idx_t thread, l4_addr_t ext_vcpu_state,
                             l4_utcb_t *utcb) L4_NOTHROW
{
  l4_msg_regs_t *v = l4_utcb_mr_u(utcb);
  v->mr[0] = L4_THREAD_VCPU_CONTROL_EXT_OP;
  v->mr[1] = ext_vcpu_state;
  return l4_ipc_call(thread, utcb, l4_msgtag(L4_PROTO_THREAD, 2, 0, 0), L4_IPC_NEVER);
}
 
L4_INLINE l4_msgtag_t
l4_thread_vcpu_control_ext(l4_cap_idx_t thread, l4_addr_t ext_vcpu_state) L4_NOTHROW
{ return l4_thread_vcpu_control_ext_u(thread, ext_vcpu_state, l4_utcb()); }
 
L4_INLINE l4_msgtag_t
l4_thread_modify_sender_start_u(l4_utcb_t *u) L4_NOTHROW
{
  l4_msg_regs_t *m = l4_utcb_mr_u(u);
  m->mr[0] = L4_THREAD_MODIFY_SENDER_OP;
  return l4_msgtag(L4_PROTO_THREAD, 1, 0, 0);
}
 
L4_INLINE int
l4_thread_modify_sender_add_u(l4_umword_t match_mask,
                              l4_umword_t match,
                              l4_umword_t del_bits,
                              l4_umword_t add_bits,
                              l4_msgtag_t *tag, l4_utcb_t *u) L4_NOTHROW
{
  l4_msg_regs_t *m = l4_utcb_mr_u(u);
  unsigned w = l4_msgtag_words(*tag);
  if (w >= L4_UTCB_GENERIC_DATA_SIZE - 4)
    return -L4_ENOMEM;
 
  m->mr[w]   = match_mask;
  m->mr[w+1] = match;
  m->mr[w+2] = del_bits;
  m->mr[w+3] = add_bits;
 
  *tag = l4_msgtag(l4_msgtag_label(*tag), w + 4, 0, 0);
 
  return 0;
}
 
L4_INLINE l4_msgtag_t
l4_thread_modify_sender_commit_u(l4_cap_idx_t thread, l4_msgtag_t tag,
                                 l4_utcb_t *u) L4_NOTHROW
{
  return l4_ipc_call(thread, u, tag, L4_IPC_NEVER);
}
 
L4_INLINE l4_msgtag_t
l4_thread_modify_sender_start(void) L4_NOTHROW
{
  return l4_thread_modify_sender_start_u(l4_utcb());
}
 
L4_INLINE int
l4_thread_modify_sender_add(l4_umword_t match_mask,
                            l4_umword_t match,
                            l4_umword_t del_bits,
                            l4_umword_t add_bits,
                            l4_msgtag_t *tag) L4_NOTHROW
{
  return l4_thread_modify_sender_add_u(match_mask, match,
                                       del_bits, add_bits, tag, l4_utcb());
}
 
L4_INLINE l4_msgtag_t
l4_thread_modify_sender_commit(l4_cap_idx_t thread, l4_msgtag_t tag) L4_NOTHROW
{
  return l4_thread_modify_sender_commit_u(thread, tag, l4_utcb());
}
 
 
L4_INLINE l4_msgtag_t
l4_thread_register_doorbell_irq_u(l4_cap_idx_t thread, l4_cap_idx_t irq,
                                  l4_utcb_t *u) L4_NOTHROW
{
  l4_msg_regs_t *m = l4_utcb_mr_u(u);
  m->mr[0] = L4_THREAD_REGISTER_DOORBELL_IRQ_OP;
  m->mr[1] = l4_map_obj_control(0,0);
  m->mr[2] = l4_obj_fpage(irq, 0, L4_CAP_FPAGE_RWS).raw;
  return l4_ipc_call(thread, u, l4_msgtag(L4_PROTO_THREAD, 1, 1, 0),
                     L4_IPC_NEVER);
}
 
L4_INLINE l4_msgtag_t
l4_thread_register_doorbell_irq(l4_cap_idx_t thread,
                                l4_cap_idx_t irq) L4_NOTHROW
{
  return l4_thread_register_doorbell_irq_u(thread, irq, l4_utcb());
}