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kernel_samsung_sm7125/arch/mips/kernel/process.c

440 lines
10 KiB

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others.
* Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2004 Thiemo Seufer
*/
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/mman.h>
#include <linux/personality.h>
#include <linux/sys.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/kallsyms.h>
#include <asm/abi.h>
#include <asm/bootinfo.h>
#include <asm/cpu.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/mipsregs.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/elf.h>
#include <asm/isadep.h>
#include <asm/inst.h>
#ifdef CONFIG_MIPS_MT_SMTC
#include <asm/mipsmtregs.h>
extern void smtc_idle_loop_hook(void);
#endif /* CONFIG_MIPS_MT_SMTC */
/*
* 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)
*/
ATTRIB_NORET void cpu_idle(void)
{
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched()) {
#ifdef CONFIG_MIPS_MT_SMTC
smtc_idle_loop_hook();
#endif /* CONFIG_MIPS_MT_SMTC */
if (cpu_wait)
(*cpu_wait)();
}
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
/*
* Native o32 and N64 ABI without DSP ASE
*/
struct mips_abi mips_abi = {
.do_signal = do_signal,
#ifdef CONFIG_TRAD_SIGNALS
.setup_frame = setup_frame,
#endif
.setup_rt_frame = setup_rt_frame
};
#ifdef CONFIG_MIPS32_O32
/*
* o32 compatibility on 64-bit kernels, without DSP ASE
*/
struct mips_abi mips_abi_32 = {
.do_signal = do_signal32,
.setup_frame = setup_frame_32,
.setup_rt_frame = setup_rt_frame_32
};
#endif /* CONFIG_MIPS32_O32 */
#ifdef CONFIG_MIPS32_N32
/*
* N32 on 64-bit kernels, without DSP ASE
*/
struct mips_abi mips_abi_n32 = {
.do_signal = do_signal,
.setup_rt_frame = setup_rt_frame_n32
};
#endif /* CONFIG_MIPS32_N32 */
asmlinkage void ret_from_fork(void);
void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
{
unsigned long status;
/* New thread loses kernel privileges. */
status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|KU_MASK);
#ifdef CONFIG_64BIT
status &= ~ST0_FR;
status |= (current->thread.mflags & MF_32BIT_REGS) ? 0 : ST0_FR;
#endif
status |= KU_USER;
regs->cp0_status = status;
clear_used_math();
lose_fpu();
if (cpu_has_dsp)
__init_dsp();
regs->cp0_epc = pc;
regs->regs[29] = sp;
current_thread_info()->addr_limit = USER_DS;
}
void exit_thread(void)
{
}
void flush_thread(void)
{
}
int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
unsigned long unused, struct task_struct *p, struct pt_regs *regs)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs;
long childksp;
p->set_child_tid = p->clear_child_tid = NULL;
childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32;
preempt_disable();
if (is_fpu_owner())
save_fp(p);
if (cpu_has_dsp)
save_dsp(p);
preempt_enable();
/* set up new TSS. */
childregs = (struct pt_regs *) childksp - 1;
*childregs = *regs;
childregs->regs[7] = 0; /* Clear error flag */
#if defined(CONFIG_BINFMT_IRIX)
if (current->personality != PER_LINUX) {
/* Under IRIX things are a little different. */
childregs->regs[3] = 1;
regs->regs[3] = 0;
}
#endif
childregs->regs[2] = 0; /* Child gets zero as return value */
regs->regs[2] = p->pid;
if (childregs->cp0_status & ST0_CU0) {
childregs->regs[28] = (unsigned long) ti;
childregs->regs[29] = childksp;
ti->addr_limit = KERNEL_DS;
} else {
childregs->regs[29] = usp;
ti->addr_limit = USER_DS;
}
p->thread.reg29 = (unsigned long) childregs;
p->thread.reg31 = (unsigned long) ret_from_fork;
/*
* New tasks lose permission to use the fpu. This accelerates context
* switching for most programs since they don't use the fpu.
*/
p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1);
childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);
clear_tsk_thread_flag(p, TIF_USEDFPU);
#ifdef CONFIG_MIPS_MT_FPAFF
/*
* FPU affinity support is cleaner if we track the
* user-visible CPU affinity from the very beginning.
* The generic cpus_allowed mask will already have
* been copied from the parent before copy_thread
* is invoked.
*/
p->thread.user_cpus_allowed = p->cpus_allowed;
#endif /* CONFIG_MIPS_MT_FPAFF */
if (clone_flags & CLONE_SETTLS)
ti->tp_value = regs->regs[7];
return 0;
}
/* Fill in the fpu structure for a core dump.. */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r)
{
memcpy(r, &current->thread.fpu, sizeof(current->thread.fpu));
return 1;
}
void elf_dump_regs(elf_greg_t *gp, struct pt_regs *regs)
{
int i;
for (i = 0; i < EF_R0; i++)
gp[i] = 0;
gp[EF_R0] = 0;
for (i = 1; i <= 31; i++)
gp[EF_R0 + i] = regs->regs[i];
gp[EF_R26] = 0;
gp[EF_R27] = 0;
gp[EF_LO] = regs->lo;
gp[EF_HI] = regs->hi;
gp[EF_CP0_EPC] = regs->cp0_epc;
gp[EF_CP0_BADVADDR] = regs->cp0_badvaddr;
gp[EF_CP0_STATUS] = regs->cp0_status;
gp[EF_CP0_CAUSE] = regs->cp0_cause;
#ifdef EF_UNUSED0
gp[EF_UNUSED0] = 0;
#endif
}
int dump_task_regs (struct task_struct *tsk, elf_gregset_t *regs)
{
elf_dump_regs(*regs, task_pt_regs(tsk));
return 1;
}
int dump_task_fpu (struct task_struct *t, elf_fpregset_t *fpr)
{
memcpy(fpr, &t->thread.fpu, sizeof(current->thread.fpu));
return 1;
}
/*
* Create a kernel thread
*/
ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *))
{
do_exit(fn(arg));
}
long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
regs.regs[4] = (unsigned long) arg;
regs.regs[5] = (unsigned long) fn;
regs.cp0_epc = (unsigned long) kernel_thread_helper;
regs.cp0_status = read_c0_status();
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
regs.cp0_status &= ~(ST0_KUP | ST0_IEC);
regs.cp0_status |= ST0_IEP;
#else
regs.cp0_status |= ST0_EXL;
#endif
/* Ok, create the new process.. */
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
}
static struct mips_frame_info {
void *func;
unsigned long func_size;
int frame_size;
int pc_offset;
} *schedule_frame, mfinfo[64];
static int mfinfo_num;
static int __init get_frame_info(struct mips_frame_info *info)
{
int i;
void *func = info->func;
union mips_instruction *ip = (union mips_instruction *)func;
info->pc_offset = -1;
info->frame_size = 0;
for (i = 0; i < 128; i++, ip++) {
/* if jal, jalr, jr, stop. */
if (ip->j_format.opcode == jal_op ||
(ip->r_format.opcode == spec_op &&
(ip->r_format.func == jalr_op ||
ip->r_format.func == jr_op)))
break;
if (info->func_size && i >= info->func_size / 4)
break;
if (
#ifdef CONFIG_32BIT
ip->i_format.opcode == addiu_op &&
#endif
#ifdef CONFIG_64BIT
ip->i_format.opcode == daddiu_op &&
#endif
ip->i_format.rs == 29 &&
ip->i_format.rt == 29) {
/* addiu/daddiu sp,sp,-imm */
if (info->frame_size)
continue;
info->frame_size = - ip->i_format.simmediate;
}
if (
#ifdef CONFIG_32BIT
ip->i_format.opcode == sw_op &&
#endif
#ifdef CONFIG_64BIT
ip->i_format.opcode == sd_op &&
#endif
ip->i_format.rs == 29 &&
ip->i_format.rt == 31) {
/* sw / sd $ra, offset($sp) */
if (info->pc_offset != -1)
continue;
info->pc_offset =
ip->i_format.simmediate / sizeof(long);
}
}
if (info->pc_offset == -1 || info->frame_size == 0) {
if (func == schedule)
printk("Can't analyze prologue code at %p\n", func);
info->pc_offset = -1;
info->frame_size = 0;
}
return 0;
}
static int __init frame_info_init(void)
{
int i;
#ifdef CONFIG_KALLSYMS
char *modname;
char namebuf[KSYM_NAME_LEN + 1];
unsigned long start, size, ofs;
extern char __sched_text_start[], __sched_text_end[];
extern char __lock_text_start[], __lock_text_end[];
start = (unsigned long)__sched_text_start;
for (i = 0; i < ARRAY_SIZE(mfinfo); i++) {
if (start == (unsigned long)schedule)
schedule_frame = &mfinfo[i];
if (!kallsyms_lookup(start, &size, &ofs, &modname, namebuf))
break;
mfinfo[i].func = (void *)(start + ofs);
mfinfo[i].func_size = size;
start += size - ofs;
if (start >= (unsigned long)__lock_text_end)
break;
if (start == (unsigned long)__sched_text_end)
start = (unsigned long)__lock_text_start;
}
#else
mfinfo[0].func = schedule;
schedule_frame = &mfinfo[0];
#endif
for (i = 0; i < ARRAY_SIZE(mfinfo) && mfinfo[i].func; i++)
get_frame_info(&mfinfo[i]);
mfinfo_num = i;
return 0;
}
arch_initcall(frame_info_init);
/*
* Return saved PC of a blocked thread.
*/
unsigned long thread_saved_pc(struct task_struct *tsk)
{
struct thread_struct *t = &tsk->thread;
/* New born processes are a special case */
if (t->reg31 == (unsigned long) ret_from_fork)
return t->reg31;
if (!schedule_frame || schedule_frame->pc_offset < 0)
return 0;
return ((unsigned long *)t->reg29)[schedule_frame->pc_offset];
}
/* get_wchan - a maintenance nightmare^W^Wpain in the ass ... */
unsigned long get_wchan(struct task_struct *p)
{
unsigned long stack_page;
unsigned long pc;
#ifdef CONFIG_KALLSYMS
unsigned long frame;
#endif
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_page = (unsigned long)task_stack_page(p);
if (!stack_page || !mfinfo_num)
return 0;
pc = thread_saved_pc(p);
#ifdef CONFIG_KALLSYMS
if (!in_sched_functions(pc))
return pc;
frame = p->thread.reg29 + schedule_frame->frame_size;
do {
int i;
if (frame < stack_page || frame > stack_page + THREAD_SIZE - 32)
return 0;
for (i = mfinfo_num - 1; i >= 0; i--) {
if (pc >= (unsigned long) mfinfo[i].func)
break;
}
if (i < 0)
break;
pc = ((unsigned long *)frame)[mfinfo[i].pc_offset];
if (!mfinfo[i].frame_size)
break;
frame += mfinfo[i].frame_size;
} while (in_sched_functions(pc));
#endif
return pc;
}