mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-30 08:02:30 +00:00
166c0eaedf
The following commits replaced the tick_nohz_{stop,restart}_sched_tick API with separate tick and rcu calls:280f06774a
2bbb6817c0
1268fbc746
This patch replaces the C6X use of the old API with the newer interfaces. Signed-off-by: Mark Salter <msalter@redhat.com>
265 lines
5.4 KiB
C
265 lines
5.4 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);
|
|
|
|
static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
|
|
static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
|
|
|
|
/*
|
|
* Initial thread structure.
|
|
*/
|
|
union thread_union init_thread_union __init_task_data = {
|
|
INIT_THREAD_INFO(init_task)
|
|
};
|
|
|
|
/*
|
|
* Initial task structure.
|
|
*/
|
|
struct task_struct init_task = INIT_TASK(init_task);
|
|
EXPORT_SYMBOL(init_task);
|
|
|
|
/*
|
|
* power off function, if any
|
|
*/
|
|
void (*pm_power_off)(void);
|
|
EXPORT_SYMBOL(pm_power_off);
|
|
|
|
static void c6x_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));
|
|
}
|
|
|
|
/*
|
|
* The idle loop for C64x
|
|
*/
|
|
void cpu_idle(void)
|
|
{
|
|
/* endless idle loop with no priority at all */
|
|
while (1) {
|
|
tick_nohz_idle_enter();
|
|
rcu_idle_enter();
|
|
while (1) {
|
|
local_irq_disable();
|
|
if (need_resched()) {
|
|
local_irq_enable();
|
|
break;
|
|
}
|
|
c6x_idle(); /* enables local irqs */
|
|
}
|
|
rcu_idle_exit();
|
|
tick_nohz_idle_exit();
|
|
|
|
preempt_enable_no_resched();
|
|
schedule();
|
|
preempt_disable();
|
|
}
|
|
}
|
|
|
|
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();
|
|
}
|
|
|
|
static void kernel_thread_helper(int dummy, void *arg, int (*fn)(void *))
|
|
{
|
|
do_exit(fn(arg));
|
|
}
|
|
|
|
/*
|
|
* Create a kernel thread
|
|
*/
|
|
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
|
|
{
|
|
struct pt_regs regs;
|
|
|
|
/*
|
|
* copy_thread sets a4 to zero (child return from fork)
|
|
* so we can't just set things up to directly return to
|
|
* fn.
|
|
*/
|
|
memset(®s, 0, sizeof(regs));
|
|
regs.b4 = (unsigned long) arg;
|
|
regs.a6 = (unsigned long) fn;
|
|
regs.pc = (unsigned long) kernel_thread_helper;
|
|
local_save_flags(regs.csr);
|
|
regs.csr |= 1;
|
|
regs.tsr = 5; /* Set GEE and GIE in TSR */
|
|
|
|
/* Ok, create the new process.. */
|
|
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, -1, ®s,
|
|
0, NULL, NULL);
|
|
}
|
|
EXPORT_SYMBOL(kernel_thread);
|
|
|
|
void flush_thread(void)
|
|
{
|
|
}
|
|
|
|
void exit_thread(void)
|
|
{
|
|
}
|
|
|
|
SYSCALL_DEFINE1(c6x_clone, struct pt_regs *, regs)
|
|
{
|
|
unsigned long clone_flags;
|
|
unsigned long newsp;
|
|
|
|
/* syscall puts clone_flags in A4 and usp in B4 */
|
|
clone_flags = regs->orig_a4;
|
|
if (regs->b4)
|
|
newsp = regs->b4;
|
|
else
|
|
newsp = regs->sp;
|
|
|
|
return do_fork(clone_flags, newsp, regs, 0, (int __user *)regs->a6,
|
|
(int __user *)regs->b6);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
set_fs(USER_DS);
|
|
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 *regs)
|
|
{
|
|
struct pt_regs *childregs;
|
|
|
|
childregs = task_pt_regs(p);
|
|
|
|
*childregs = *regs;
|
|
childregs->a4 = 0;
|
|
|
|
if (usp == -1)
|
|
/* case of __kernel_thread: we return to supervisor space */
|
|
childregs->sp = (unsigned long)(childregs + 1);
|
|
else
|
|
/* Otherwise use the given stack */
|
|
childregs->sp = usp;
|
|
|
|
/* Set usp/ksp */
|
|
p->thread.usp = childregs->sp;
|
|
/* switch_to uses stack to save/restore 14 callee-saved regs */
|
|
thread_saved_ksp(p) = (unsigned long)childregs - 8;
|
|
p->thread.pc = (unsigned int) ret_from_fork;
|
|
p->thread.wchan = (unsigned long) ret_from_fork;
|
|
#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;
|
|
}
|
|
|
|
/*
|
|
* c6x_execve() executes a new program.
|
|
*/
|
|
SYSCALL_DEFINE4(c6x_execve, const char __user *, name,
|
|
const char __user *const __user *, argv,
|
|
const char __user *const __user *, envp,
|
|
struct pt_regs *, regs)
|
|
{
|
|
int error;
|
|
char *filename;
|
|
|
|
filename = getname(name);
|
|
error = PTR_ERR(filename);
|
|
if (IS_ERR(filename))
|
|
goto out;
|
|
|
|
error = do_execve(filename, argv, envp, regs);
|
|
putname(filename);
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
unsigned long get_wchan(struct task_struct *p)
|
|
{
|
|
return p->thread.wchan;
|
|
}
|