source: trunk/libs/newlib/src/libgloss/sparc_leon/kernel.c @ 680

Last change on this file since 680 was 444, checked in by satin@…, 6 years ago

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

File size: 6.4 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
33struct leonbare_kernel leonbare_kernel;
34
35/*
36 * queue 0: [ <acc=2>],
37 * queue 1: [ <acc=10>, <acc=8>,<acc=8>,<acc=1> ],
38 * queue 2: [ ... ],
39 * ...
40 * queue n: [ ... ]
41 *
42 *  Seach through ready queue [0 - LEONBARE_RUNQ_READY_NR-1] for the
43 *  first thread in a queue'ss head to discover
44 *  leonbare_thread_tick_callback() will put threads that have their th_caccount
45 *  consumed into the prepare-run queues. th_caccount is already initialized
46 *  to the value for the next schedule round. So all there is to do is to
47 *  move the to prepare-run queues to run queues [0 - LEONBARE_RUNQ_READY_NR-1].
48 *  return the first thread in any queue, similary to leonbare_sched_next().
49 *  Using LEONBARE_KR_RUNQ_WHICH and leonbare_thread.th_runq_which one can
50 *  determine weather the thread is in a runqueue or a prepare-runqueue:
51 *  LEONBARE_KR_RUNQ_WHICH == leonbare_thread.th_runq_which : thread in runqueue
52 *  LEONBARE_KR_RUNQ_WHICH != leonbare_thread.th_runq_which : thread in prepare-runqueue
53 *  after a leonbare_thread_tick_callback() or a run queue change, call
54 *  leonbare_sched_update() to update LEONBARE_KR_NEXT and
55 *  LEONBARE_KR_NEED_SCHEDULE
56 */
57int
58leonbare_sched_update ()
59{
60  int idx;
61  leonbare_thread_t n = 0;
62  int i = 0;
63  LEONBARE_VERIFYIRQDISABLED ();
64  LEONBARE_VERIFYSCHED ();
65  for (i = 0; i < LEONBARE_RUNQ_READY_NR; i++)
66    {
67      leonbare_thread_t c;
68      if (!LBTAILQ_EMPTY (LEONBARE_KR_RUNQ (i)))
69        {
70          n = LBTAILQ_FIRST (LEONBARE_KR_RUNQ (i));
71          break;
72        }
73    }
74  if (!n)
75    {
76      for (idx = 0; idx < LEONBARE_RUNQ_READY_NR; idx++)
77        {
78          struct leonbare_thread_queue *h0 =
79            (struct leonbare_thread_queue *) LEONBARE_KR_RUNQ (idx);
80          struct leonbare_thread_queue *h1 = (struct leonbare_thread_queue *)
81            LEONBARE_KR_RUNQ (idx + LEONBARE_RUNQ_PREPARE_IDX);
82          if (LBTAILQ_EMPTY (h1))
83            {
84              LBTAILQ_INIT (h0);
85            }
86          else
87            {
88              *h0 = *h1;
89              if (LBTAILQ_FIRST (h0))
90                {
91                  LBTAILQ_FIRST (h0)->th_runq.tqe_prev = &(h0)->tqh_first;
92                }
93              if (!n)
94                {
95                  n = LBTAILQ_FIRST (h0);
96                }
97            }
98        }
99      for (idx = 0; idx < LEONBARE_RUNQ_READY_NR; idx++)
100        {
101          LBTAILQ_INIT (LEONBARE_KR_RUNQ (idx + LEONBARE_RUNQ_PREPARE_IDX));
102        }
103      LEONBARE_KR_RUNQ_WHICH++;
104      LEONBARE_VERIFYSCHED ();
105      LEONBARE_PRINTQUEUES ();
106    }
107  LEONBARE_KR_NEXT = n;
108  return (LEONBARE_KR_NEED_SCHEDULE);
109}
110
111/*  called in the timer irq handling. Decrements the
112 *  th_caccount field. On consumption of th_caccount the
113 *  thread will be removed from the ready queue nad placed into the
114 *  prepare-runqueue for later readdition by leonbare_sched_readyprepare()
115 *  called from gettimeofday.c's installed ticker_callback callback
116 *  leonbare_thread_tick_callback() might change the kernel state in which case
117 *  state on return from leonbare_thread_tick_callback() leonbare_thread_schedule_callback()
118 *  will be called from rtrap_fast.S .
119 */
120int
121leonbare_thread_tick_callback ()
122{
123  LEONBARE_PROTECT_DECL (flags);
124  unsigned int r;
125  volatile leonbare_thread_t c = LEONBARE_KR_CURRENT;
126  leonbare_thread_t i;
127  LBDEBUG_FNCALL;
128  if (c && LEONBARE_KR_IS_PREEMPTION)
129    {
130
131      LEONBARE_PROTECT_KERNEL_START ();
132      {
133
134        LEONBARE_VERIFYIRQDISABLED ();
135        LEONBARE_VERIFYSCHED ();
136
137        if ((--c->th_caccount) < 0)
138          {
139            LBDEBUG_HEADER_PRINTF (LBDEBUG_QUEUE_NR, "remove %s(%x)\n",
140                                   LEONBARE_TH_NAME_DBG (c), c);
141            LBTAILQ_REMOVE (LEONBARE_KR_RUNQ (c->th_runq_idx), c, th_runq);
142            LBTAILQ_INSERT_TAIL (LEONBARE_KR_RUNQ
143                                 (c->th_runq_idx + LEONBARE_RUNQ_PREPARE_IDX),
144                                 c, th_runq);
145            c->th_caccount = c->th_account;
146            c->th_runq_which++;
147          }
148        else
149          {
150            /* todo: round robbin scheme */
151          }
152      }
153      LEONBARE_PROTECT_KERNEL_END ();
154    }
155  r = leonbare_sched_update ();
156  return r;
157}
158
159/* called from rtrap_fast.S's installed schedule_callback callback */
160int
161leonbare_thread_schedule_callback (struct leonbare_pt_regs *ptregs)
162{
163  unsigned int retval;
164  LBDEBUG_FNCALL;
165  if (LEONBARE_KR_IS_IN_KERNEL == 0 && LEONBARE_KR_NEED_SCHEDULE)
166    {
167
168      leonbare_sched ();
169
170      //KERNEL_ENTER;
171      //KERNEL_EXIT(LEONBARE_KR_NEED_SCHEDULE, retval);
172    }
173  LBDEBUG_FNEXIT;
174}
175
176
177struct leonbare_thread _thread_main;
178int
179leonbare_thread_init ()
180{
181  int i;
182  LBDEBUG_FNCALL;
183
184  memset ((void *) &_thread_main, 0, sizeof (_thread_main));
185  _thread_main.th_reentp = _impure_ptr;
186  _thread_main.th_name = "<main>";
187  _thread_main.th_runq_idx = 0;
188  _thread_main.th_pri_idx = 0;
189  _thread_main.th_account = 0;
190
191  LBTAILQ_INIT (LEONBARE_KR_ALLQ);
192  for (i = 0; i < LEONBARE_RUNQ_NR; i++)
193    {
194      LBTAILQ_INIT (LEONBARE_KR_RUNQ (i));
195    }
196  LBTAILQ_INIT (LEONBARE_KR_ALLM);
197
198  /* queues */
199  LBTAILQ_INSERT_TAIL (LEONBARE_KR_ALLQ, &_thread_main, th_allq);
200
201  /* inseart into ready queue 0 at head */
202  LBTAILQ_INSERT_HEAD (LEONBARE_KR_RUNQ (_thread_main.th_runq_idx),
203                       &_thread_main, th_runq);
204
205  LEONBARE_KR_CURRENT = &_thread_main;
206  LEONBARE_KR_IS_IN_KERNEL = 0;
207
208  leonbare_init_ticks ();
209  schedule_callback = (schedulehandler) leonbare_thread_schedule_callback;
210  ticker_callback = (tickerhandler) leonbare_thread_tick_callback;
211
212  /* disable later */
213  LEONBARE_KR_IS_PREEMPTION = 1;
214
215
216  LBDEBUG_FNEXIT;
217}
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