/*
* arch/sh/kernel/process.c
*
* This file handles the architecture-dependent parts of process handling..
*
* Copyright (C) 1995 Linus Torvalds
*
* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
* Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
* Copyright (C) 2002 - 2008 Paul Mundt
*
* 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.
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/elfcore.h>
#include <linux/kallsyms.h>
#include <linux/fs.h>
#include <linux/ftrace.h>
#include <linux/hw_breakpoint.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/system.h>
#include <asm/fpu.h>
#include <asm/syscalls.h>
void show_regs(struct pt_regs * regs)
{
printk("\n");
printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm);
printk("CPU : %d \t\t%s (%s %.*s)\n\n",
smp_processor_id(), print_tainted(), init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
init_utsname()->version);
print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("PR is at %s\n", regs->pr);
printk("PC : %08lx SP : %08lx SR : %08lx ",
regs->pc, regs->regs[15], regs->sr);
#ifdef CONFIG_MMU
printk("TEA : %08x\n", __raw_readl(MMU_TEA));
#else
printk("\n");
#endif
printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
regs->regs[0],regs->regs[1],
regs->regs[2],regs->regs[3]);
printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
regs->regs[4],regs->regs[5],
regs->regs[6],regs->regs[7]);
printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
regs->regs[8],regs->regs[9],
regs->regs[10],regs->regs[11]);
printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
regs->regs[12],regs->regs[13],
regs->regs[14]);
printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
regs->mach, regs->macl, regs->gbr, regs->pr);
show_trace(NULL, (unsigned long *)regs->regs[15], regs);
show_code(regs);
}
/*
* Create a kernel thread
*/
ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *))
{
do_exit(fn(arg));
}
/* Don't use this in BL=1(cli). Or else, CPU resets! */
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
struct pt_regs regs;
int pid;
memset(®s, 0, sizeof(regs));
regs.regs[4] = (unsigned long)arg;
regs.regs[5] = (unsigned long)fn;
regs.pc = (unsigned long)kernel_thread_helper;
regs.sr = SR_MD;
#if defined(CONFIG_SH_FPU)
regs.sr |= SR_FD;
#endif
/* Ok, create the new process.. */
pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
®s, 0, NULL, NULL);
return pid;
}
EXPORT_SYMBOL(kernel_thread);
void start_thread(struct pt_regs *regs, unsigned long new_pc,
unsigned long new_sp)
{
set_fs(USER_DS);
regs->pr = 0;
regs->sr = SR_FD;
regs->pc = new_pc;
regs->regs[15] = new_sp;
free_thread_xstate(current);
}
EXPORT_SYMBOL(start_thread);
/*
* Free current thread data structures etc..
*/
void exit_thread(void)
{
}
void flush_thread(void)
{
struct task_struct *tsk = current;
flush_ptrace_hw_breakpoint(tsk);
#if defined(CONFIG_SH_FPU)
/* Forget lazy FPU state */
clear_fpu(tsk, task_pt_regs(tsk));
clear_used_math();
#endif
}
void release_thread(struct task_struct *dead_task)
{
/* do nothing */
}
/* Fill in the fpu structure for a core dump.. */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
int fpvalid = 0;
#if defined(CONFIG_SH_FPU)
struct task_struct *tsk = current;
fpvalid = !!tsk_used_math(tsk);
if (fpvalid)
fpvalid = !fpregs_get(tsk, NULL, 0,
sizeof(struct user_fpu_struct),
fpu, NULL);
#endif
return fpvalid;
}
EXPORT_SYMBOL(dump_fpu);
/*
* This gets called before we allocate a new thread and copy
* the current task into it.
*/
void prepare_to_copy(struct task_struct *tsk)
{
unlazy_fpu(tsk, task_pt_regs(tsk));
}
asmlinkage void ret_from_fork(void);
int copy_thread(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;
#if defined(CONFIG_SH_DSP)
struct task_struct *tsk = current;
if (is_dsp_enabled(tsk)) {
/* We can use the __save_dsp or just copy the struct:
* __save_dsp(p);
* p->thread.dsp_status.status |= SR_DSP
*/
p->thread.dsp_status = tsk->thread.dsp_status;
}
#endif
childregs = task_pt_regs(p);
*childregs = *regs;
if (user_mode(regs)) {
childregs->regs[15] = usp;
ti->addr_limit = USER_DS;
} else {
childregs->regs[15] = (unsigned long)childregs;
ti->addr_limit = KERNEL_DS;
ti->status &= ~TS_USEDFPU;
p->fpu_counter = 0;
}
if (clone_flags & CLONE_SETTLS)
childregs->gbr = childregs->regs[0];
childregs->regs[0] = 0; /* Set return value for child */
p->thread.sp = (unsigned long) childregs;
p->thread.pc = (unsigned long) ret_from_fork;
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
return 0;
}
/*
* switch_to(x,y) should switch tasks from x to y.
*
*/
__notrace_funcgraph struct task_struct *
__switch_to(struct task_struct *prev, struct task_struct *next)
{
struct thread_struct *next_t = &next->thread;
unlazy_fpu(prev, task_pt_regs(prev));
/* we're going to use this soon, after a few expensive things */
if (next->fpu_counter > 5)
prefetch(next_t->xstate);
#ifdef CONFIG_MMU
/*
* Restore the kernel mode register
* k7 (r7_bank1)
*/
asm volatile("ldc %0, r7_bank"
: /* no output */
: "r" (task_thread_info(next)));
#endif
/*
* If the task has used fpu the last 5 timeslices, just do a full
* restore of the math state immediately to avoid the trap; the
* chances of needing FPU soon are obviously high now
*/
if (next->fpu_counter > 5)
__fpu_state_restore();
return prev;
}
asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs __regs)
{
#ifdef CONFIG_MMU
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
#else
/* fork almost works, enough to trick you into looking elsewhere :-( */
return -EINVAL;
#endif
}
asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
unsigned long parent_tidptr,
unsigned long child_tidptr,
struct pt_regs __regs)
{
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
if (!newsp)
newsp = regs->regs[15];
return do_fork(clone_flags, newsp, regs, 0,
(int __user *)parent_tidptr,
(int __user *)child_tidptr);
}
/*
* This is trivial, and on the face of it looks like it
* could equally well be done in user mode.
*
* Not so, for quite unobvious reasons - register pressure.
* In user mode vfork() cannot have a stack frame, and if
* done by calling the "clone()" system call directly, you
* do not have enough call-clobbered registers to hold all
* the information you need.
*/
asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs __regs)
{
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
0, NULL, NULL);
}
/*
* sys_execve() executes a new program.
*/
asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv,
char __user * __user *uenvp, unsigned long r7,
struct pt_regs __regs)
{
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
int error;
char *filename;
filename = getname(ufilename);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, uargv, uenvp, regs);
putname(filename);
out:
return error;
}
unsigned long get_wchan(struct task_struct *p)
{
unsigned long pc;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
/*
* The same comment as on the Alpha applies here, too ...
*/
pc = thread_saved_pc(p);
#ifdef CONFIG_FRAME_POINTER
if (in_sched_functions(pc)) {
unsigned long schedule_frame = (unsigned long)p->thread.sp;
return ((unsigned long *)schedule_frame)[21];
}
#endif
return pc;
}
