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
8 * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
12 * This file handles the architecture-dependent parts of process handling..
15 #include <linux/module.h>
16 #include <linux/unistd.h>
18 #include <linux/elfcore.h>
19 #include <linux/a.out.h>
20 #include <linux/slab.h>
22 #include <linux/ptrace.h>
23 #include <linux/kallsyms.h>
24 #include <linux/kexec.h>
27 #include <asm/uaccess.h>
28 #include <asm/mmu_context.h>
32 static int hlt_counter=0;
36 #define HARD_IDLE_TIMEOUT (HZ / 3)
38 void (*pm_idle)(void);
40 void (*pm_power_off)(void);
41 EXPORT_SYMBOL(pm_power_off);
43 void disable_hlt(void)
48 EXPORT_SYMBOL(disable_hlt);
55 EXPORT_SYMBOL(enable_hlt);
57 void default_idle(void)
67 /* endless idle loop with no priority at all */
69 void (*idle)(void) = pm_idle;
74 while (!need_resched())
77 preempt_enable_no_resched();
83 void machine_restart(char * __unused)
85 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
86 asm volatile("ldc %0, sr\n\t"
87 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
90 void machine_halt(void)
98 void machine_power_off(void)
104 void show_regs(struct pt_regs * regs)
107 printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);
108 print_symbol("PC is at %s\n", regs->pc);
109 printk("PC : %08lx SP : %08lx SR : %08lx ",
110 regs->pc, regs->regs[15], regs->sr);
112 printk("TEA : %08x ", ctrl_inl(MMU_TEA));
116 printk("%s\n", print_tainted());
118 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
119 regs->regs[0],regs->regs[1],
120 regs->regs[2],regs->regs[3]);
121 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
122 regs->regs[4],regs->regs[5],
123 regs->regs[6],regs->regs[7]);
124 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
125 regs->regs[8],regs->regs[9],
126 regs->regs[10],regs->regs[11]);
127 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
128 regs->regs[12],regs->regs[13],
130 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
131 regs->mach, regs->macl, regs->gbr, regs->pr);
134 * If we're in kernel mode, dump the stack too..
136 if (!user_mode(regs)) {
137 extern void show_task(unsigned long *sp);
138 unsigned long sp = regs->regs[15];
140 show_task((unsigned long *)sp);
145 * Create a kernel thread
149 * This is the mechanism for creating a new kernel thread.
152 extern void kernel_thread_helper(void);
154 "kernel_thread_helper:\n\t"
163 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
164 { /* Don't use this in BL=1(cli). Or else, CPU resets! */
167 memset(®s, 0, sizeof(regs));
168 regs.regs[4] = (unsigned long) arg;
169 regs.regs[5] = (unsigned long) fn;
171 regs.pc = (unsigned long) kernel_thread_helper;
174 /* Ok, create the new process.. */
175 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
179 * Free current thread data structures etc..
181 void exit_thread(void)
183 if (current->thread.ubc_pc) {
184 current->thread.ubc_pc = 0;
189 void flush_thread(void)
191 #if defined(CONFIG_SH_FPU)
192 struct task_struct *tsk = current;
193 /* Forget lazy FPU state */
194 clear_fpu(tsk, task_pt_regs(tsk));
199 void release_thread(struct task_struct *dead_task)
204 /* Fill in the fpu structure for a core dump.. */
205 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
209 #if defined(CONFIG_SH_FPU)
210 struct task_struct *tsk = current;
212 fpvalid = !!tsk_used_math(tsk);
214 unlazy_fpu(tsk, regs);
215 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
223 * Capture the user space registers if the task is not running (in user space)
225 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
227 struct pt_regs ptregs;
229 ptregs = *task_pt_regs(tsk);
230 elf_core_copy_regs(regs, &ptregs);
236 dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *fpu)
240 #if defined(CONFIG_SH_FPU)
241 fpvalid = !!tsk_used_math(tsk);
243 unlazy_fpu(tsk, task_pt_regs(tsk));
244 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
251 asmlinkage void ret_from_fork(void);
253 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
254 unsigned long unused,
255 struct task_struct *p, struct pt_regs *regs)
257 struct thread_info *ti = task_thread_info(p);
258 struct pt_regs *childregs;
259 #if defined(CONFIG_SH_FPU)
260 struct task_struct *tsk = current;
262 unlazy_fpu(tsk, regs);
263 p->thread.fpu = tsk->thread.fpu;
264 copy_to_stopped_child_used_math(p);
267 childregs = task_pt_regs(p);
270 if (user_mode(regs)) {
271 childregs->regs[15] = usp;
272 ti->addr_limit = USER_DS;
274 childregs->regs[15] = (unsigned long)task_stack_page(p) + THREAD_SIZE;
275 ti->addr_limit = KERNEL_DS;
277 if (clone_flags & CLONE_SETTLS) {
278 childregs->gbr = childregs->regs[0];
280 childregs->regs[0] = 0; /* Set return value for child */
282 p->thread.sp = (unsigned long) childregs;
283 p->thread.pc = (unsigned long) ret_from_fork;
285 p->thread.ubc_pc = 0;
290 /* Tracing by user break controller. */
292 ubc_set_tracing(int asid, unsigned long pc)
294 #if defined(CONFIG_CPU_SH4A)
297 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
298 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
300 ctrl_outl(val, UBC_CBR0);
301 ctrl_outl(pc, UBC_CAR0);
302 ctrl_outl(0x0, UBC_CAMR0);
303 ctrl_outl(0x0, UBC_CBCR);
305 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
306 ctrl_outl(val, UBC_CRR0);
308 /* Read UBC register that we writed last. For chekking UBC Register changed */
309 val = ctrl_inl(UBC_CRR0);
311 #else /* CONFIG_CPU_SH4A */
312 ctrl_outl(pc, UBC_BARA);
315 /* We don't have any ASID settings for the SH-2! */
316 if (cpu_data->type != CPU_SH7604)
317 ctrl_outb(asid, UBC_BASRA);
320 ctrl_outl(0, UBC_BAMRA);
322 if (cpu_data->type == CPU_SH7729 || cpu_data->type == CPU_SH7710) {
323 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
324 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
326 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
327 ctrl_outw(BRCR_PCBA, UBC_BRCR);
329 #endif /* CONFIG_CPU_SH4A */
333 * switch_to(x,y) should switch tasks from x to y.
336 struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next)
338 #if defined(CONFIG_SH_FPU)
339 unlazy_fpu(prev, task_pt_regs(prev));
342 #ifdef CONFIG_PREEMPT
345 struct pt_regs *regs;
347 local_irq_save(flags);
348 regs = task_pt_regs(prev);
349 if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
350 int offset = (int)regs->regs[15];
352 /* Reset stack pointer: clear critical region mark */
353 regs->regs[15] = regs->regs[1];
354 if (regs->pc < regs->regs[0])
355 /* Go to rewind point */
356 regs->pc = regs->regs[0] + offset;
358 local_irq_restore(flags);
364 * Restore the kernel mode register
367 asm volatile("ldc %0, r7_bank"
369 : "r" (task_thread_info(next)));
372 /* If no tasks are using the UBC, we're done */
373 if (ubc_usercnt == 0)
374 /* If no tasks are using the UBC, we're done */;
375 else if (next->thread.ubc_pc && next->mm) {
378 asid |= next->mm->context.id & MMU_CONTEXT_ASID_MASK;
380 ubc_set_tracing(asid, next->thread.ubc_pc);
382 #if defined(CONFIG_CPU_SH4A)
383 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
384 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
386 ctrl_outw(0, UBC_BBRA);
387 ctrl_outw(0, UBC_BBRB);
394 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
395 unsigned long r6, unsigned long r7,
399 return do_fork(SIGCHLD, regs.regs[15], ®s, 0, NULL, NULL);
401 /* fork almost works, enough to trick you into looking elsewhere :-( */
406 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
407 unsigned long parent_tidptr,
408 unsigned long child_tidptr,
412 newsp = regs.regs[15];
413 return do_fork(clone_flags, newsp, ®s, 0,
414 (int __user *)parent_tidptr, (int __user *)child_tidptr);
418 * This is trivial, and on the face of it looks like it
419 * could equally well be done in user mode.
421 * Not so, for quite unobvious reasons - register pressure.
422 * In user mode vfork() cannot have a stack frame, and if
423 * done by calling the "clone()" system call directly, you
424 * do not have enough call-clobbered registers to hold all
425 * the information you need.
427 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
428 unsigned long r6, unsigned long r7,
431 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.regs[15], ®s,
436 * sys_execve() executes a new program.
438 asmlinkage int sys_execve(char *ufilename, char **uargv,
439 char **uenvp, unsigned long r7,
445 filename = getname((char __user *)ufilename);
446 error = PTR_ERR(filename);
447 if (IS_ERR(filename))
450 error = do_execve(filename,
451 (char __user * __user *)uargv,
452 (char __user * __user *)uenvp,
456 current->ptrace &= ~PT_DTRACE;
457 task_unlock(current);
464 unsigned long get_wchan(struct task_struct *p)
466 unsigned long schedule_frame;
469 if (!p || p == current || p->state == TASK_RUNNING)
473 * The same comment as on the Alpha applies here, too ...
475 pc = thread_saved_pc(p);
476 if (in_sched_functions(pc)) {
477 schedule_frame = ((unsigned long *)(long)p->thread.sp)[1];
478 return (unsigned long)((unsigned long *)schedule_frame)[1];
483 asmlinkage void break_point_trap(unsigned long r4, unsigned long r5,
484 unsigned long r6, unsigned long r7,
488 #if defined(CONFIG_CPU_SH4A)
489 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
490 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
492 ctrl_outw(0, UBC_BBRA);
493 ctrl_outw(0, UBC_BBRB);
495 current->thread.ubc_pc = 0;
498 force_sig(SIGTRAP, current);
501 asmlinkage void break_point_trap_software(unsigned long r4, unsigned long r5,
502 unsigned long r6, unsigned long r7,
506 force_sig(SIGTRAP, current);