154 lines
3.3 KiB
C
154 lines
3.3 KiB
C
/*
|
|
* Port on Texas Instruments TMS320C6x architecture
|
|
*
|
|
* Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
|
|
* Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/unistd.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/init_task.h>
|
|
#include <linux/tick.h>
|
|
#include <linux/mqueue.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/reboot.h>
|
|
|
|
#include <asm/syscalls.h>
|
|
|
|
/* hooks for board specific support */
|
|
void (*c6x_restart)(void);
|
|
void (*c6x_halt)(void);
|
|
|
|
extern asmlinkage void ret_from_fork(void);
|
|
extern asmlinkage void ret_from_kernel_thread(void);
|
|
|
|
/*
|
|
* power off function, if any
|
|
*/
|
|
void (*pm_power_off)(void);
|
|
EXPORT_SYMBOL(pm_power_off);
|
|
|
|
void arch_cpu_idle(void)
|
|
{
|
|
unsigned long tmp;
|
|
|
|
/*
|
|
* Put local_irq_enable and idle in same execute packet
|
|
* to make them atomic and avoid race to idle with
|
|
* interrupts enabled.
|
|
*/
|
|
asm volatile (" mvc .s2 CSR,%0\n"
|
|
" or .d2 1,%0,%0\n"
|
|
" mvc .s2 %0,CSR\n"
|
|
"|| idle\n"
|
|
: "=b"(tmp));
|
|
}
|
|
|
|
static void halt_loop(void)
|
|
{
|
|
printk(KERN_EMERG "System Halted, OK to turn off power\n");
|
|
local_irq_disable();
|
|
while (1)
|
|
asm volatile("idle\n");
|
|
}
|
|
|
|
void machine_restart(char *__unused)
|
|
{
|
|
if (c6x_restart)
|
|
c6x_restart();
|
|
halt_loop();
|
|
}
|
|
|
|
void machine_halt(void)
|
|
{
|
|
if (c6x_halt)
|
|
c6x_halt();
|
|
halt_loop();
|
|
}
|
|
|
|
void machine_power_off(void)
|
|
{
|
|
if (pm_power_off)
|
|
pm_power_off();
|
|
halt_loop();
|
|
}
|
|
|
|
void flush_thread(void)
|
|
{
|
|
}
|
|
|
|
/*
|
|
* Do necessary setup to start up a newly executed thread.
|
|
*/
|
|
void start_thread(struct pt_regs *regs, unsigned int pc, unsigned long usp)
|
|
{
|
|
/*
|
|
* The binfmt loader will setup a "full" stack, but the C6X
|
|
* operates an "empty" stack. So we adjust the usp so that
|
|
* argc doesn't get destroyed if an interrupt is taken before
|
|
* it is read from the stack.
|
|
*
|
|
* NB: Library startup code needs to match this.
|
|
*/
|
|
usp -= 8;
|
|
|
|
regs->pc = pc;
|
|
regs->sp = usp;
|
|
regs->tsr |= 0x40; /* set user mode */
|
|
current->thread.usp = usp;
|
|
}
|
|
|
|
/*
|
|
* Copy a new thread context in its stack.
|
|
*/
|
|
int copy_thread(unsigned long clone_flags, unsigned long usp,
|
|
unsigned long ustk_size,
|
|
struct task_struct *p)
|
|
{
|
|
struct pt_regs *childregs;
|
|
|
|
childregs = task_pt_regs(p);
|
|
|
|
if (unlikely(p->flags & PF_KTHREAD)) {
|
|
/* case of __kernel_thread: we return to supervisor space */
|
|
memset(childregs, 0, sizeof(struct pt_regs));
|
|
childregs->sp = (unsigned long)(childregs + 1);
|
|
p->thread.pc = (unsigned long) ret_from_kernel_thread;
|
|
childregs->a0 = usp; /* function */
|
|
childregs->a1 = ustk_size; /* argument */
|
|
} else {
|
|
/* Otherwise use the given stack */
|
|
*childregs = *current_pt_regs();
|
|
if (usp)
|
|
childregs->sp = usp;
|
|
p->thread.pc = (unsigned long) ret_from_fork;
|
|
}
|
|
|
|
/* Set usp/ksp */
|
|
p->thread.usp = childregs->sp;
|
|
thread_saved_ksp(p) = (unsigned long)childregs - 8;
|
|
p->thread.wchan = p->thread.pc;
|
|
#ifdef __DSBT__
|
|
{
|
|
unsigned long dp;
|
|
|
|
asm volatile ("mv .S2 b14,%0\n" : "=b"(dp));
|
|
|
|
thread_saved_dp(p) = dp;
|
|
if (usp == -1)
|
|
childregs->dp = dp;
|
|
}
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
unsigned long get_wchan(struct task_struct *p)
|
|
{
|
|
return p->thread.wchan;
|
|
}
|