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Diffstat (limited to 'libgloss/sparc_leon/kernel.c')
| -rw-r--r-- | libgloss/sparc_leon/kernel.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/libgloss/sparc_leon/kernel.c b/libgloss/sparc_leon/kernel.c new file mode 100644 index 000000000..ecdeb219c --- /dev/null +++ b/libgloss/sparc_leon/kernel.c @@ -0,0 +1,217 @@ +/* + * 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; +} |