| /* |
| * Copyright (c) 2011 Aeroflex Gaisler |
| * |
| * BSD license: |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| |
| |
| #include <asm-leon/contextswitch.h> |
| #include <asm-leon/leonbare_kernel.h> |
| #include <asm-leon/leonbare_debug.h> |
| #include <asm-leon/stack.h> |
| #include <asm-leon/leonstack.h> |
| #include <asm-leon/irq.h> |
| |
| struct leonbare_kernel leonbare_kernel; |
| |
| /* |
| * queue 0: [ <acc=2>], |
| * queue 1: [ <acc=10>, <acc=8>,<acc=8>,<acc=1> ], |
| * queue 2: [ ... ], |
| * ... |
| * queue n: [ ... ] |
| * |
| * Seach through ready queue [0 - LEONBARE_RUNQ_READY_NR-1] for the |
| * first thread in a queue'ss head to discover |
| * leonbare_thread_tick_callback() will put threads that have their th_caccount |
| * consumed into the prepare-run queues. th_caccount is already initialized |
| * to the value for the next schedule round. So all there is to do is to |
| * move the to prepare-run queues to run queues [0 - LEONBARE_RUNQ_READY_NR-1]. |
| * return the first thread in any queue, similary to leonbare_sched_next(). |
| * Using LEONBARE_KR_RUNQ_WHICH and leonbare_thread.th_runq_which one can |
| * determine weather the thread is in a runqueue or a prepare-runqueue: |
| * LEONBARE_KR_RUNQ_WHICH == leonbare_thread.th_runq_which : thread in runqueue |
| * LEONBARE_KR_RUNQ_WHICH != leonbare_thread.th_runq_which : thread in prepare-runqueue |
| * after a leonbare_thread_tick_callback() or a run queue change, call |
| * leonbare_sched_update() to update LEONBARE_KR_NEXT and |
| * LEONBARE_KR_NEED_SCHEDULE |
| */ |
| int |
| leonbare_sched_update () |
| { |
| int idx; |
| leonbare_thread_t n = 0; |
| int i = 0; |
| LEONBARE_VERIFYIRQDISABLED (); |
| LEONBARE_VERIFYSCHED (); |
| for (i = 0; i < LEONBARE_RUNQ_READY_NR; i++) |
| { |
| leonbare_thread_t c; |
| if (!LBTAILQ_EMPTY (LEONBARE_KR_RUNQ (i))) |
| { |
| n = LBTAILQ_FIRST (LEONBARE_KR_RUNQ (i)); |
| break; |
| } |
| } |
| if (!n) |
| { |
| for (idx = 0; idx < LEONBARE_RUNQ_READY_NR; idx++) |
| { |
| struct leonbare_thread_queue *h0 = |
| (struct leonbare_thread_queue *) LEONBARE_KR_RUNQ (idx); |
| struct leonbare_thread_queue *h1 = (struct leonbare_thread_queue *) |
| LEONBARE_KR_RUNQ (idx + LEONBARE_RUNQ_PREPARE_IDX); |
| if (LBTAILQ_EMPTY (h1)) |
| { |
| LBTAILQ_INIT (h0); |
| } |
| else |
| { |
| *h0 = *h1; |
| if (LBTAILQ_FIRST (h0)) |
| { |
| LBTAILQ_FIRST (h0)->th_runq.tqe_prev = &(h0)->tqh_first; |
| } |
| if (!n) |
| { |
| n = LBTAILQ_FIRST (h0); |
| } |
| } |
| } |
| for (idx = 0; idx < LEONBARE_RUNQ_READY_NR; idx++) |
| { |
| LBTAILQ_INIT (LEONBARE_KR_RUNQ (idx + LEONBARE_RUNQ_PREPARE_IDX)); |
| } |
| LEONBARE_KR_RUNQ_WHICH++; |
| LEONBARE_VERIFYSCHED (); |
| LEONBARE_PRINTQUEUES (); |
| } |
| LEONBARE_KR_NEXT = n; |
| return (LEONBARE_KR_NEED_SCHEDULE); |
| } |
| |
| /* called in the timer irq handling. Decrements the |
| * th_caccount field. On consumption of th_caccount the |
| * thread will be removed from the ready queue nad placed into the |
| * prepare-runqueue for later readdition by leonbare_sched_readyprepare() |
| * called from gettimeofday.c's installed ticker_callback callback |
| * leonbare_thread_tick_callback() might change the kernel state in which case |
| * state on return from leonbare_thread_tick_callback() leonbare_thread_schedule_callback() |
| * will be called from rtrap_fast.S . |
| */ |
| int |
| leonbare_thread_tick_callback () |
| { |
| LEONBARE_PROTECT_DECL (flags); |
| unsigned int r; |
| volatile leonbare_thread_t c = LEONBARE_KR_CURRENT; |
| leonbare_thread_t i; |
| LBDEBUG_FNCALL; |
| if (c && LEONBARE_KR_IS_PREEMPTION) |
| { |
| |
| LEONBARE_PROTECT_KERNEL_START (); |
| { |
| |
| LEONBARE_VERIFYIRQDISABLED (); |
| LEONBARE_VERIFYSCHED (); |
| |
| if ((--c->th_caccount) < 0) |
| { |
| LBDEBUG_HEADER_PRINTF (LBDEBUG_QUEUE_NR, "remove %s(%x)\n", |
| LEONBARE_TH_NAME_DBG (c), c); |
| LBTAILQ_REMOVE (LEONBARE_KR_RUNQ (c->th_runq_idx), c, th_runq); |
| LBTAILQ_INSERT_TAIL (LEONBARE_KR_RUNQ |
| (c->th_runq_idx + LEONBARE_RUNQ_PREPARE_IDX), |
| c, th_runq); |
| c->th_caccount = c->th_account; |
| c->th_runq_which++; |
| } |
| else |
| { |
| /* todo: round robbin scheme */ |
| } |
| } |
| LEONBARE_PROTECT_KERNEL_END (); |
| } |
| r = leonbare_sched_update (); |
| return r; |
| } |
| |
| /* called from rtrap_fast.S's installed schedule_callback callback */ |
| int |
| leonbare_thread_schedule_callback (struct leonbare_pt_regs *ptregs) |
| { |
| unsigned int retval; |
| LBDEBUG_FNCALL; |
| if (LEONBARE_KR_IS_IN_KERNEL == 0 && LEONBARE_KR_NEED_SCHEDULE) |
| { |
| |
| leonbare_sched (); |
| |
| //KERNEL_ENTER; |
| //KERNEL_EXIT(LEONBARE_KR_NEED_SCHEDULE, retval); |
| } |
| LBDEBUG_FNEXIT; |
| } |
| |
| |
| struct leonbare_thread _thread_main; |
| int |
| leonbare_thread_init () |
| { |
| int i; |
| LBDEBUG_FNCALL; |
| |
| memset ((void *) &_thread_main, 0, sizeof (_thread_main)); |
| _thread_main.th_reentp = _impure_ptr; |
| _thread_main.th_name = "<main>"; |
| _thread_main.th_runq_idx = 0; |
| _thread_main.th_pri_idx = 0; |
| _thread_main.th_account = 0; |
| |
| LBTAILQ_INIT (LEONBARE_KR_ALLQ); |
| for (i = 0; i < LEONBARE_RUNQ_NR; i++) |
| { |
| LBTAILQ_INIT (LEONBARE_KR_RUNQ (i)); |
| } |
| LBTAILQ_INIT (LEONBARE_KR_ALLM); |
| |
| /* queues */ |
| LBTAILQ_INSERT_TAIL (LEONBARE_KR_ALLQ, &_thread_main, th_allq); |
| |
| /* inseart into ready queue 0 at head */ |
| LBTAILQ_INSERT_HEAD (LEONBARE_KR_RUNQ (_thread_main.th_runq_idx), |
| &_thread_main, th_runq); |
| |
| LEONBARE_KR_CURRENT = &_thread_main; |
| LEONBARE_KR_IS_IN_KERNEL = 0; |
| |
| leonbare_init_ticks (); |
| schedule_callback = (schedulehandler) leonbare_thread_schedule_callback; |
| ticker_callback = (tickerhandler) leonbare_thread_tick_callback; |
| |
| /* disable later */ |
| LEONBARE_KR_IS_PREEMPTION = 1; |
| |
| |
| LBDEBUG_FNEXIT; |
| } |