linux/arch/frv/kernel/process.c

299 lines
6.3 KiB
C

/* process.c: FRV specific parts of process handling
*
* Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
* - Derived from arch/m68k/kernel/process.c
*
* 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.
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/elf.h>
#include <linux/reboot.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
#include <linux/rcupdate.h>
#include <asm/asm-offsets.h>
#include <asm/uaccess.h>
#include <asm/setup.h>
#include <asm/pgtable.h>
#include <asm/tlb.h>
#include <asm/gdb-stub.h>
#include <asm/mb-regs.h>
#include "local.h"
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
#include <asm/pgalloc.h>
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
static void core_sleep_idle(void)
{
#ifdef LED_DEBUG_SLEEP
/* Show that we're sleeping... */
__set_LEDS(0x55aa);
#endif
frv_cpu_core_sleep();
#ifdef LED_DEBUG_SLEEP
/* ... and that we woke up */
__set_LEDS(0);
#endif
mb();
}
void (*idle)(void) = core_sleep_idle;
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
* low exit latency (ie sit in a loop waiting for
* somebody to say that they'd like to reschedule)
*/
void cpu_idle(void)
{
/* endless idle loop with no priority at all */
while (1) {
rcu_idle_enter();
while (!need_resched()) {
check_pgt_cache();
if (!frv_dma_inprogress && idle)
idle();
}
rcu_idle_exit();
schedule_preempt_disabled();
}
}
void machine_restart(char * __unused)
{
unsigned long reset_addr;
#ifdef CONFIG_GDBSTUB
gdbstub_exit(0);
#endif
if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551)
reset_addr = 0xfefff500;
else
reset_addr = 0xfeff0500;
/* Software reset. */
asm volatile(" dcef @(gr0,gr0),1 ! membar !"
" sti %1,@(%0,0) !"
" nop ! nop ! nop ! nop ! nop ! "
" nop ! nop ! nop ! nop ! nop ! "
" nop ! nop ! nop ! nop ! nop ! "
" nop ! nop ! nop ! nop ! nop ! "
: : "r" (reset_addr), "r" (1) );
for (;;)
;
}
void machine_halt(void)
{
#ifdef CONFIG_GDBSTUB
gdbstub_exit(0);
#endif
for (;;);
}
void machine_power_off(void)
{
#ifdef CONFIG_GDBSTUB
gdbstub_exit(0);
#endif
for (;;);
}
void flush_thread(void)
{
/* nothing */
}
inline unsigned long user_stack(const struct pt_regs *regs)
{
while (regs->next_frame)
regs = regs->next_frame;
return user_mode(regs) ? regs->sp : 0;
}
/*
* set up the kernel stack and exception frames for a new process
*/
int copy_thread(unsigned long clone_flags,
unsigned long usp, unsigned long arg,
struct task_struct *p)
{
struct pt_regs *childregs;
childregs = (struct pt_regs *)
(task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE);
/* set up the userspace frame (the only place that the USP is stored) */
*childregs = *current_pt_regs();
p->thread.frame = childregs;
p->thread.curr = p;
p->thread.sp = (unsigned long) childregs;
p->thread.fp = 0;
p->thread.lr = 0;
p->thread.frame0 = childregs;
if (unlikely(p->flags & PF_KTHREAD)) {
childregs->gr9 = usp; /* function */
childregs->gr8 = arg;
p->thread.pc = (unsigned long) ret_from_kernel_thread;
save_user_regs(p->thread.user);
return 0;
}
if (usp)
childregs->sp = usp;
childregs->next_frame = NULL;
p->thread.pc = (unsigned long) ret_from_fork;
/* the new TLS pointer is passed in as arg #5 to sys_clone() */
if (clone_flags & CLONE_SETTLS)
childregs->gr29 = childregs->gr12;
save_user_regs(p->thread.user);
return 0;
} /* end copy_thread() */
unsigned long get_wchan(struct task_struct *p)
{
struct pt_regs *regs0;
unsigned long fp, pc;
unsigned long stack_limit;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_limit = (unsigned long) (p + 1);
fp = p->thread.fp;
regs0 = p->thread.frame0;
do {
if (fp < stack_limit || fp >= (unsigned long) regs0 || fp & 3)
return 0;
pc = ((unsigned long *) fp)[2];
/* FIXME: This depends on the order of these functions. */
if (!in_sched_functions(pc))
return pc;
fp = *(unsigned long *) fp;
} while (count++ < 16);
return 0;
}
unsigned long thread_saved_pc(struct task_struct *tsk)
{
/* Check whether the thread is blocked in resume() */
if (in_sched_functions(tsk->thread.pc))
return ((unsigned long *)tsk->thread.fp)[2];
else
return tsk->thread.pc;
}
int elf_check_arch(const struct elf32_hdr *hdr)
{
unsigned long hsr0 = __get_HSR(0);
unsigned long psr = __get_PSR();
if (hdr->e_machine != EM_FRV)
return 0;
switch (hdr->e_flags & EF_FRV_GPR_MASK) {
case EF_FRV_GPR64:
if ((hsr0 & HSR0_GRN) == HSR0_GRN_32)
return 0;
case EF_FRV_GPR32:
case 0:
break;
default:
return 0;
}
switch (hdr->e_flags & EF_FRV_FPR_MASK) {
case EF_FRV_FPR64:
if ((hsr0 & HSR0_FRN) == HSR0_FRN_32)
return 0;
case EF_FRV_FPR32:
case EF_FRV_FPR_NONE:
case 0:
break;
default:
return 0;
}
if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD)
if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
PSR_IMPLE(psr) != PSR_IMPLE_FR451)
return 0;
switch (hdr->e_flags & EF_FRV_CPU_MASK) {
case EF_FRV_CPU_GENERIC:
break;
case EF_FRV_CPU_FR300:
case EF_FRV_CPU_SIMPLE:
case EF_FRV_CPU_TOMCAT:
default:
return 0;
case EF_FRV_CPU_FR400:
if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 &&
PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
PSR_IMPLE(psr) != PSR_IMPLE_FR451 &&
PSR_IMPLE(psr) != PSR_IMPLE_FR551)
return 0;
break;
case EF_FRV_CPU_FR450:
if (PSR_IMPLE(psr) != PSR_IMPLE_FR451)
return 0;
break;
case EF_FRV_CPU_FR500:
if (PSR_IMPLE(psr) != PSR_IMPLE_FR501)
return 0;
break;
case EF_FRV_CPU_FR550:
if (PSR_IMPLE(psr) != PSR_IMPLE_FR551)
return 0;
break;
}
return 1;
}
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
{
memcpy(fpregs,
&current->thread.user->f,
sizeof(current->thread.user->f));
return 1;
}