1 /* $Id: process.c,v 1.28 2004/05/05 16:54:23 lethal Exp $
3 * linux/arch/sh/kernel/process.c
5 * Copyright (C) 1995 Linus Torvalds
7 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
11 * This file handles the architecture-dependent parts of process handling..
14 #include <linux/module.h>
15 #include <linux/unistd.h>
17 #include <linux/elfcore.h>
18 #include <linux/a.out.h>
19 #include <linux/slab.h>
21 #include <linux/ptrace.h>
22 #include <linux/kallsyms.h>
23 #include <linux/kexec.h>
26 #include <asm/uaccess.h>
27 #include <asm/mmu_context.h>
31 static int hlt_counter=0;
35 #define HARD_IDLE_TIMEOUT (HZ / 3)
37 void (*pm_idle)(void);
39 void (*pm_power_off)(void);
40 EXPORT_SYMBOL(pm_power_off);
42 void disable_hlt(void)
47 EXPORT_SYMBOL(disable_hlt);
54 EXPORT_SYMBOL(enable_hlt);
56 void default_idle(void)
66 /* endless idle loop with no priority at all */
68 void (*idle)(void) = pm_idle;
73 while (!need_resched())
76 preempt_enable_no_resched();
82 void machine_restart(char * __unused)
87 image = xchg(&kexec_image, 0);
94 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
95 asm volatile("ldc %0, sr\n\t"
96 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
99 void machine_halt(void)
107 void machine_power_off(void)
113 void show_regs(struct pt_regs * regs)
116 printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);
117 print_symbol("PC is at %s\n", regs->pc);
118 printk("PC : %08lx SP : %08lx SR : %08lx ",
119 regs->pc, regs->regs[15], regs->sr);
121 printk("TEA : %08x ", ctrl_inl(MMU_TEA));
125 printk("%s\n", print_tainted());
127 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
128 regs->regs[0],regs->regs[1],
129 regs->regs[2],regs->regs[3]);
130 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
131 regs->regs[4],regs->regs[5],
132 regs->regs[6],regs->regs[7]);
133 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
134 regs->regs[8],regs->regs[9],
135 regs->regs[10],regs->regs[11]);
136 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
137 regs->regs[12],regs->regs[13],
139 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
140 regs->mach, regs->macl, regs->gbr, regs->pr);
143 * If we're in kernel mode, dump the stack too..
145 if (!user_mode(regs)) {
146 extern void show_task(unsigned long *sp);
147 unsigned long sp = regs->regs[15];
149 show_task((unsigned long *)sp);
154 * Create a kernel thread
158 * This is the mechanism for creating a new kernel thread.
161 extern void kernel_thread_helper(void);
163 "kernel_thread_helper:\n\t"
172 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
173 { /* Don't use this in BL=1(cli). Or else, CPU resets! */
176 memset(®s, 0, sizeof(regs));
177 regs.regs[4] = (unsigned long) arg;
178 regs.regs[5] = (unsigned long) fn;
180 regs.pc = (unsigned long) kernel_thread_helper;
183 /* Ok, create the new process.. */
184 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
188 * Free current thread data structures etc..
190 void exit_thread(void)
192 if (current->thread.ubc_pc) {
193 current->thread.ubc_pc = 0;
198 void flush_thread(void)
200 #if defined(CONFIG_SH_FPU)
201 struct task_struct *tsk = current;
202 /* Forget lazy FPU state */
203 clear_fpu(tsk, task_pt_regs(tsk));
208 void release_thread(struct task_struct *dead_task)
213 /* Fill in the fpu structure for a core dump.. */
214 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
218 #if defined(CONFIG_SH_FPU)
219 struct task_struct *tsk = current;
221 fpvalid = !!tsk_used_math(tsk);
223 unlazy_fpu(tsk, regs);
224 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
232 * Capture the user space registers if the task is not running (in user space)
234 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
236 struct pt_regs ptregs;
238 ptregs = *task_pt_regs(tsk);
239 elf_core_copy_regs(regs, &ptregs);
245 dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *fpu)
249 #if defined(CONFIG_SH_FPU)
250 fpvalid = !!tsk_used_math(tsk);
252 unlazy_fpu(tsk, task_pt_regs(tsk));
253 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
260 asmlinkage void ret_from_fork(void);
262 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
263 unsigned long unused,
264 struct task_struct *p, struct pt_regs *regs)
266 struct thread_info *ti = task_thread_info(p);
267 struct pt_regs *childregs;
268 #if defined(CONFIG_SH_FPU)
269 struct task_struct *tsk = current;
271 unlazy_fpu(tsk, regs);
272 p->thread.fpu = tsk->thread.fpu;
273 copy_to_stopped_child_used_math(p);
276 childregs = task_pt_regs(p);
279 if (user_mode(regs)) {
280 childregs->regs[15] = usp;
281 ti->addr_limit = USER_DS;
283 childregs->regs[15] = (unsigned long)task_stack_page(p) + THREAD_SIZE;
284 ti->addr_limit = KERNEL_DS;
286 if (clone_flags & CLONE_SETTLS) {
287 childregs->gbr = childregs->regs[0];
289 childregs->regs[0] = 0; /* Set return value for child */
291 p->thread.sp = (unsigned long) childregs;
292 p->thread.pc = (unsigned long) ret_from_fork;
294 p->thread.ubc_pc = 0;
299 /* Tracing by user break controller. */
301 ubc_set_tracing(int asid, unsigned long pc)
303 ctrl_outl(pc, UBC_BARA);
305 /* We don't have any ASID settings for the SH-2! */
306 if (cpu_data->type != CPU_SH7604)
307 ctrl_outb(asid, UBC_BASRA);
309 ctrl_outl(0, UBC_BAMRA);
311 if (cpu_data->type == CPU_SH7729) {
312 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
313 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
315 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
316 ctrl_outw(BRCR_PCBA, UBC_BRCR);
321 * switch_to(x,y) should switch tasks from x to y.
324 struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next)
326 #if defined(CONFIG_SH_FPU)
327 unlazy_fpu(prev, task_pt_regs(prev));
330 #ifdef CONFIG_PREEMPT
333 struct pt_regs *regs;
335 local_irq_save(flags);
336 regs = task_pt_regs(prev);
337 if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
338 int offset = (int)regs->regs[15];
340 /* Reset stack pointer: clear critical region mark */
341 regs->regs[15] = regs->regs[1];
342 if (regs->pc < regs->regs[0])
343 /* Go to rewind point */
344 regs->pc = regs->regs[0] + offset;
346 local_irq_restore(flags);
351 * Restore the kernel mode register
354 asm volatile("ldc %0, r7_bank"
356 : "r" (task_thread_info(next)));
359 /* If no tasks are using the UBC, we're done */
360 if (ubc_usercnt == 0)
361 /* If no tasks are using the UBC, we're done */;
362 else if (next->thread.ubc_pc && next->mm) {
363 ubc_set_tracing(next->mm->context & MMU_CONTEXT_ASID_MASK,
364 next->thread.ubc_pc);
366 ctrl_outw(0, UBC_BBRA);
367 ctrl_outw(0, UBC_BBRB);
374 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
375 unsigned long r6, unsigned long r7,
379 return do_fork(SIGCHLD, regs.regs[15], ®s, 0, NULL, NULL);
381 /* fork almost works, enough to trick you into looking elsewhere :-( */
386 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
387 unsigned long parent_tidptr,
388 unsigned long child_tidptr,
392 newsp = regs.regs[15];
393 return do_fork(clone_flags, newsp, ®s, 0,
394 (int __user *)parent_tidptr, (int __user *)child_tidptr);
398 * This is trivial, and on the face of it looks like it
399 * could equally well be done in user mode.
401 * Not so, for quite unobvious reasons - register pressure.
402 * In user mode vfork() cannot have a stack frame, and if
403 * done by calling the "clone()" system call directly, you
404 * do not have enough call-clobbered registers to hold all
405 * the information you need.
407 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
408 unsigned long r6, unsigned long r7,
411 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.regs[15], ®s,
416 * sys_execve() executes a new program.
418 asmlinkage int sys_execve(char *ufilename, char **uargv,
419 char **uenvp, unsigned long r7,
425 filename = getname((char __user *)ufilename);
426 error = PTR_ERR(filename);
427 if (IS_ERR(filename))
430 error = do_execve(filename,
431 (char __user * __user *)uargv,
432 (char __user * __user *)uenvp,
436 current->ptrace &= ~PT_DTRACE;
437 task_unlock(current);
444 unsigned long get_wchan(struct task_struct *p)
446 unsigned long schedule_frame;
449 if (!p || p == current || p->state == TASK_RUNNING)
453 * The same comment as on the Alpha applies here, too ...
455 pc = thread_saved_pc(p);
456 if (in_sched_functions(pc)) {
457 schedule_frame = ((unsigned long *)(long)p->thread.sp)[1];
458 return (unsigned long)((unsigned long *)schedule_frame)[1];
463 asmlinkage void break_point_trap(unsigned long r4, unsigned long r5,
464 unsigned long r6, unsigned long r7,
468 ctrl_outw(0, UBC_BBRA);
469 ctrl_outw(0, UBC_BBRB);
470 current->thread.ubc_pc = 0;
473 force_sig(SIGTRAP, current);
476 asmlinkage void break_point_trap_software(unsigned long r4, unsigned long r5,
477 unsigned long r6, unsigned long r7,
481 force_sig(SIGTRAP, current);