rockbox/firmware/asm/m68k/thread.c
Thomas Martitz 991ae1e395 Create fimrware/asm directory for assembly optimized stuff.
This dir is suitable for stuff that doesn't fit the target tree, e.g. because
it also builds on hosted or otherwise. It also has a generic subfolder for
fallback C implementations so that not all archs need to provide asm files.

SOURCES should only contain "foo.c" where foo.c includes the specific
<arch>/foo.c files from the subdirs using the preprocessor. This way automatic
selection of asm versions or generic C verion is possible.

For the start, the thread support files are moved, since ASM threads can
be used on hosted platforms as well. Since core_sleep() remains platform
specific it's moved to the corresponding system.h headers.

Change-Id: Iebff272f3407a6eaafeb7656ceb0ae9eca3f7cb9
2012-01-22 18:46:44 +01:00

101 lines
4.3 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2004 by Linus Nielsen Feltzing
*
* Coldfire 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 USED_ATTR __start_thread(void)
{
/* a0=macsr, a1=context */
asm volatile (
"start_thread: \n" /* Start here - no naked attribute */
"move.l %a0, %macsr \n" /* Set initial mac status reg */
"lea.l 48(%a1), %a1 \n"
"move.l (%a1)+, %sp \n" /* Set initial stack */
"move.l (%a1), %a2 \n" /* Fetch thread function pointer */
"clr.l (%a1) \n" /* Mark thread running */
"jsr (%a2) \n" /* Call thread function */
);
thread_exit();
}
/* Set EMAC unit to fractional mode with saturation for each new thread,
* since that's what'll be the most useful for most things which the dsp
* will do. Codecs should still initialize their preferred modes
* explicitly. Context pointer is placed in d2 slot and start_thread
* pointer in d3 slot. thread function pointer is placed in context.start.
* See load_context for what happens when thread is initially going to
* run.
*/
#define THREAD_STARTUP_INIT(core, thread, function) \
({ (thread)->context.macsr = EMAC_FRACTIONAL | EMAC_SATURATE, \
(thread)->context.d[0] = (uint32_t)&(thread)->context, \
(thread)->context.d[1] = (uint32_t)start_thread, \
(thread)->context.start = (uint32_t)(function); })
/*---------------------------------------------------------------------------
* Store non-volatile context.
*---------------------------------------------------------------------------
*/
static inline void store_context(void* addr)
{
asm volatile (
"move.l %%macsr,%%d0 \n"
"movem.l %%d0/%%d2-%%d7/%%a2-%%a7,(%0) \n"
: : "a" (addr) : "d0" /* only! */
);
}
/*---------------------------------------------------------------------------
* Load non-volatile context.
*---------------------------------------------------------------------------
*/
static inline void load_context(const void* addr)
{
asm volatile (
"move.l 52(%0), %%d0 \n" /* Get start address */
"beq.b 1f \n" /* NULL -> already running */
"movem.l (%0), %%a0-%%a2 \n" /* a0=macsr, a1=context, a2=start_thread */
"jmp (%%a2) \n" /* Start the thread */
"1: \n"
"movem.l (%0), %%d0/%%d2-%%d7/%%a2-%%a7 \n" /* Load context */
"move.l %%d0, %%macsr \n"
: : "a" (addr) : "d0" /* only! */
);
}
/*---------------------------------------------------------------------------
* Call this from asm to make sure the sp is pointing to the
* correct place before the context is saved.
*---------------------------------------------------------------------------
*/
static inline void _profile_thread_stopped(int current_thread)
{
asm volatile ("move.l %[id], -(%%sp)\n\t"
"jsr profile_thread_stopped\n\t"
"addq.l #4, %%sp\n\t"
:: [id] "r" (current_thread)
: "cc", "memory");
}