source: trunk/libs/newlib/src/libgloss/sparc_leon/kernel_sched.c @ 467

Last change on this file since 467 was 444, checked in by satin@…, 6 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc

File size: 2.6 KB
Line 
1/*
2 * Copyright (c) 2011 Aeroflex Gaisler
3 *
4 * BSD license:
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25
26#include <asm-leon/contextswitch.h>
27#include <asm-leon/leonbare_kernel.h>
28#include <asm-leon/leonbare_debug.h>
29#include <asm-leon/stack.h>
30#include <asm-leon/leonstack.h>
31#include <asm-leon/irq.h>
32
33unsigned int
34reschedule ()
35{
36  leonbare_sched_update ();
37  return leonbare_sched ();
38}
39
40unsigned int
41leonbare_sched ()
42{
43  unsigned int ret = 0;
44  volatile leonbare_thread_t old = LEONBARE_KR_CURRENT, new =
45    LEONBARE_KR_NEXT;
46  LBDEBUG_FNCALL;
47  LBDEBUG_HEADER_PRINTF (LBDEBUG_SCHED_NR, "switch %s[%x]->%s[%x]\n",
48                         LEONBARE_TH_NAME_DBG (old), old,
49                         LEONBARE_TH_NAME_DBG (new), new);
50
51  LBPASSERT ((old != new),
52             "leonbare_sched should only be called with reschedule work to do",
53             0);
54
55  LEONBARE_KR_CURRENT = new;
56
57  /* to be able to programm symetrically on kernel level each thread
58     saves it's spinlock on mutexes and kernel and irq flags in its
59     own save region. On a kernel switch they are released until the
60     thread is reawakened. Then the locks will be reaquired (and finally
61     released when the codeblock exits). The locking can be recursive. */
62  if (old->th_prot.krp_k_depth)
63    {
64      LEONBARE_SMP_SPINLOCK_RELEASE (LEONBARE_KR_LOCK);
65    }
66  if (old->th_prot.krp_m_depth)
67    {
68      LEONBARE_SMP_SPINLOCK_RELEASE (old->th_prot.krp_m);
69    }
70
71  ret = _leonbare_kernel_switchto (old, new);
72  optbarrier ();
73
74  if (new->th_prot.krp_m_depth)
75    {
76      LEONBARE_SMP_SPINLOCK_AQUIRE (new->th_prot.krp_m);
77    }
78  if (old->th_prot.krp_k_depth)
79    {
80      LEONBARE_SMP_SPINLOCK_AQUIRE (LEONBARE_KR_LOCK);
81    }
82
83  return ret;
84}
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