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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 by Ulf Ralberg
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "thread.h"
typedef union
{
struct regs_t
{
unsigned int r[7]; /* Registers r8 thru r14 */
void *sp; /* Stack pointer (r15) */
unsigned int sr; /* Status register */
void* gbr; /* Global base register */
void* pr; /* Procedure register */
} regs;
unsigned int mem[32];
} ctx_t;
typedef struct
{
int created;
int current;
ctx_t ctx[MAXTHREADS] __attribute__ ((aligned (32)));
} thread_t;
static thread_t threads = {1, 0};
/*---------------------------------------------------------------------------
* Store non-volatile context.
*---------------------------------------------------------------------------
*/
static __inline__ void stctx(void* addr)
{
__asm__ __volatile__ ("mov.l r8, @(0, %0)" :: "r" (addr));
__asm__ __volatile__ ("mov.l r9, @(4, %0)" :: "r" (addr));
__asm__ __volatile__ ("mov.l r10, @(8, %0)" :: "r" (addr));
__asm__ __volatile__ ("mov.l r11, @(12, %0)" :: "r" (addr));
__asm__ __volatile__ ("mov.l r12, @(16, %0)" :: "r" (addr));
__asm__ __volatile__ ("mov.l r13, @(20, %0)" :: "r" (addr));
__asm__ __volatile__ ("mov.l r14, @(24, %0)" :: "r" (addr));
__asm__ __volatile__ ("mov.l r15, @(28, %0)" :: "r" (addr));
__asm__ __volatile__ ("stc sr, r0");
__asm__ __volatile__ ("mov.l r0, @(32, %0)" :: "r" (addr));
__asm__ __volatile__ ("stc gbr, r0");
__asm__ __volatile__ ("mov.l r0, @(36, %0)" :: "r" (addr));
__asm__ __volatile__ ("sts pr, r0");
__asm__ __volatile__ ("mov.l r0, @(40, %0)" :: "r" (addr));
}
/*---------------------------------------------------------------------------
* Load non-volatile context.
*---------------------------------------------------------------------------
*/
static __inline__ void ldctx(void* addr)
{
__asm__ __volatile__ ("mov.l @(0, %0), r8" :: "r" (addr));
__asm__ __volatile__ ("mov.l @(4, %0), r9" :: "r" (addr));
__asm__ __volatile__ ("mov.l @(8, %0), r10" :: "r" (addr));
__asm__ __volatile__ ("mov.l @(12, %0), r11" :: "r" (addr));
__asm__ __volatile__ ("mov.l @(16, %0), r12" :: "r" (addr));
__asm__ __volatile__ ("mov.l @(20, %0), r13" :: "r" (addr));
__asm__ __volatile__ ("mov.l @(24, %0), r14" :: "r" (addr));
__asm__ __volatile__ ("mov.l @(28, %0), r15" :: "r" (addr));
__asm__ __volatile__ ("mov.l @(32, %0), r0" :: "r" (addr));
__asm__ __volatile__ ("ldc r0, sr");
__asm__ __volatile__ ("mov.l @(36, %0), r0" :: "r" (addr));
__asm__ __volatile__ ("ldc r0, gbr");
__asm__ __volatile__ ("mov.l @(40, %0), r0" :: "r" (addr));
__asm__ __volatile__ ("lds r0, pr");
__asm__ __volatile__ ("mov.l r0, @(0, r15)");
}
/*---------------------------------------------------------------------------
* Switch thread in round robin fashion.
*---------------------------------------------------------------------------
*/
void
switch_thread(void)
{
int ct;
int nt;
thread_t* t = &threads;
nt = ct = t->current;
if (++nt >= t->created)
nt = 0;
t->current = nt;
stctx(&t->ctx[ct]);
ldctx(&t->ctx[nt]);
}
/*---------------------------------------------------------------------------
* Create thread. Stack is aligned at 32 byte boundary to fit cache line.
* > 220 bytes allocated on top for exception handlers as per EABI spec.
* Return 0 if context area could be allocated, else -1.
*---------------------------------------------------------------------------
*/
int create_thread(void* fp, void* sp, int stk_size)
{
thread_t* t = &threads;
if (t->created >= MAXTHREADS)
return -1;
else
{
ctx_t* ctxp = &t->ctx[t->created++];
stctx(ctxp);
ctxp->regs.sp = (void*)(((unsigned int)sp + stk_size) & ~31);
ctxp->regs.pr = fp;
}
return 0;
}
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