rockbox/firmware/target/sh/thread-sh.c

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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 by Ulf Ralberg
*
* SH processor threading support
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
/*---------------------------------------------------------------------------
* Start the thread running and terminate it if it returns
*---------------------------------------------------------------------------
*/
void start_thread(void); /* Provide C access to ASM label */
static void __attribute__((used)) __start_thread(void)
{
/* r8 = context */
asm volatile (
"_start_thread: \n" /* Start here - no naked attribute */
"mov.l @(4, r8), r0 \n" /* Fetch thread function pointer */
"mov.l @(28, r8), r15 \n" /* Set initial sp */
"mov #0, r1 \n" /* Start the thread */
"jsr @r0 \n"
"mov.l r1, @(36, r8) \n" /* Clear start address */
);
thread_exit();
}
/* Place context pointer in r8 slot, function pointer in r9 slot, and
* start_thread pointer in context_start */
#define THREAD_STARTUP_INIT(core, thread, function) \
({ (thread)->context.r[0] = (uint32_t)&(thread)->context, \
(thread)->context.r[1] = (uint32_t)(function), \
(thread)->context.start = (uint32_t)start_thread; })
/*---------------------------------------------------------------------------
* Store non-volatile context.
*---------------------------------------------------------------------------
*/
static inline void store_context(void* addr)
{
asm volatile (
"add #36, %0 \n" /* Start at last reg. By the time routine */
"sts.l pr, @-%0 \n" /* is done, %0 will have the original value */
"mov.l r15,@-%0 \n"
"mov.l r14,@-%0 \n"
"mov.l r13,@-%0 \n"
"mov.l r12,@-%0 \n"
"mov.l r11,@-%0 \n"
"mov.l r10,@-%0 \n"
"mov.l r9, @-%0 \n"
"mov.l r8, @-%0 \n"
: : "r" (addr)
);
}
/*---------------------------------------------------------------------------
* Load non-volatile context.
*---------------------------------------------------------------------------
*/
static inline void load_context(const void* addr)
{
asm volatile (
"mov.l @(36, %0), r0 \n" /* Get start address */
"tst r0, r0 \n"
"bt .running \n" /* NULL -> already running */
"jmp @r0 \n" /* r8 = context */
".running: \n"
"mov.l @%0+, r8 \n" /* Executes in delay slot and outside it */
"mov.l @%0+, r9 \n"
"mov.l @%0+, r10 \n"
"mov.l @%0+, r11 \n"
"mov.l @%0+, r12 \n"
"mov.l @%0+, r13 \n"
"mov.l @%0+, r14 \n"
"mov.l @%0+, r15 \n"
"lds.l @%0+, pr \n"
: : "r" (addr) : "r0" /* only! */
);
}
/*---------------------------------------------------------------------------
* Put core in a power-saving state.
*---------------------------------------------------------------------------
*/
static inline void core_sleep(void)
{
asm volatile (
"and.b #0x7f, @(r0, gbr) \n" /* Clear SBY (bit 7) in SBYCR */
"mov #0, r1 \n" /* Enable interrupts */
"ldc r1, sr \n" /* Following instruction cannot be interrupted */
"sleep \n" /* Execute standby */
: : "z"(&SBYCR-GBR) : "r1");
}