2 * arch/sh/kernel/process.c
4 * This file handles the architecture-dependent parts of process handling..
6 * Copyright (C) 1995 Linus Torvalds
8 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
9 * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
10 * Copyright (C) 2002 - 2007 Paul Mundt
12 #include <linux/module.h>
14 #include <linux/elfcore.h>
16 #include <linux/kallsyms.h>
17 #include <linux/kexec.h>
18 #include <linux/kdebug.h>
19 #include <linux/tick.h>
20 #include <linux/reboot.h>
21 #include <asm/uaccess.h>
22 #include <asm/mmu_context.h>
23 #include <asm/pgalloc.h>
24 #include <asm/system.h>
27 static int hlt_counter;
30 void (*pm_idle)(void);
31 void (*pm_power_off)(void);
32 EXPORT_SYMBOL(pm_power_off);
34 void disable_hlt(void)
38 EXPORT_SYMBOL(disable_hlt);
44 EXPORT_SYMBOL(enable_hlt);
46 static int __init nohlt_setup(char *__unused)
51 __setup("nohlt", nohlt_setup);
53 static int __init hlt_setup(char *__unused)
58 __setup("hlt", hlt_setup);
60 void default_idle(void)
63 clear_thread_flag(TIF_POLLING_NRFLAG);
64 smp_mb__after_clear_bit();
66 while (!need_resched())
69 set_thread_flag(TIF_POLLING_NRFLAG);
71 while (!need_resched())
77 set_thread_flag(TIF_POLLING_NRFLAG);
79 /* endless idle loop with no priority at all */
81 void (*idle)(void) = pm_idle;
86 tick_nohz_stop_sched_tick();
87 while (!need_resched())
89 tick_nohz_restart_sched_tick();
91 preempt_enable_no_resched();
98 void machine_restart(char * __unused)
100 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
101 asm volatile("ldc %0, sr\n\t"
102 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
105 void machine_halt(void)
113 void machine_power_off(void)
119 void show_regs(struct pt_regs * regs)
122 printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);
123 print_symbol("PC is at %s\n", instruction_pointer(regs));
124 printk("PC : %08lx SP : %08lx SR : %08lx ",
125 regs->pc, regs->regs[15], regs->sr);
127 printk("TEA : %08x ", ctrl_inl(MMU_TEA));
131 printk("%s\n", print_tainted());
133 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
134 regs->regs[0],regs->regs[1],
135 regs->regs[2],regs->regs[3]);
136 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
137 regs->regs[4],regs->regs[5],
138 regs->regs[6],regs->regs[7]);
139 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
140 regs->regs[8],regs->regs[9],
141 regs->regs[10],regs->regs[11]);
142 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
143 regs->regs[12],regs->regs[13],
145 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
146 regs->mach, regs->macl, regs->gbr, regs->pr);
148 show_trace(NULL, (unsigned long *)regs->regs[15], regs);
152 * Create a kernel thread
156 * This is the mechanism for creating a new kernel thread.
159 extern void kernel_thread_helper(void);
161 "kernel_thread_helper:\n\t"
170 /* Don't use this in BL=1(cli). Or else, CPU resets! */
171 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
175 memset(®s, 0, sizeof(regs));
176 regs.regs[4] = (unsigned long)arg;
177 regs.regs[5] = (unsigned long)fn;
179 regs.pc = (unsigned long)kernel_thread_helper;
182 /* Ok, create the new process.. */
183 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
184 ®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);
244 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpu)
248 #if defined(CONFIG_SH_FPU)
249 fpvalid = !!tsk_used_math(tsk);
251 unlazy_fpu(tsk, task_pt_regs(tsk));
252 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
259 asmlinkage void ret_from_fork(void);
261 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
262 unsigned long unused,
263 struct task_struct *p, struct pt_regs *regs)
265 struct thread_info *ti = task_thread_info(p);
266 struct pt_regs *childregs;
267 #if defined(CONFIG_SH_FPU)
268 struct task_struct *tsk = current;
270 unlazy_fpu(tsk, regs);
271 p->thread.fpu = tsk->thread.fpu;
272 copy_to_stopped_child_used_math(p);
275 childregs = task_pt_regs(p);
278 if (user_mode(regs)) {
279 childregs->regs[15] = usp;
280 ti->addr_limit = USER_DS;
282 childregs->regs[15] = (unsigned long)childregs;
283 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. */
300 static void ubc_set_tracing(int asid, unsigned long pc)
302 #if defined(CONFIG_CPU_SH4A)
305 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
306 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
308 ctrl_outl(val, UBC_CBR0);
309 ctrl_outl(pc, UBC_CAR0);
310 ctrl_outl(0x0, UBC_CAMR0);
311 ctrl_outl(0x0, UBC_CBCR);
313 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
314 ctrl_outl(val, UBC_CRR0);
316 /* Read UBC register that we wrote last, for checking update */
317 val = ctrl_inl(UBC_CRR0);
319 #else /* CONFIG_CPU_SH4A */
320 ctrl_outl(pc, UBC_BARA);
323 /* We don't have any ASID settings for the SH-2! */
324 if (current_cpu_data.type != CPU_SH7604)
325 ctrl_outb(asid, UBC_BASRA);
328 ctrl_outl(0, UBC_BAMRA);
330 if (current_cpu_data.type == CPU_SH7729 ||
331 current_cpu_data.type == CPU_SH7710 ||
332 current_cpu_data.type == CPU_SH7712) {
333 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
334 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
336 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
337 ctrl_outw(BRCR_PCBA, UBC_BRCR);
339 #endif /* CONFIG_CPU_SH4A */
343 * switch_to(x,y) should switch tasks from x to y.
346 struct task_struct *__switch_to(struct task_struct *prev,
347 struct task_struct *next)
349 #if defined(CONFIG_SH_FPU)
350 unlazy_fpu(prev, task_pt_regs(prev));
353 #ifdef CONFIG_PREEMPT
356 struct pt_regs *regs;
358 local_irq_save(flags);
359 regs = task_pt_regs(prev);
360 if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
361 int offset = (int)regs->regs[15];
363 /* Reset stack pointer: clear critical region mark */
364 regs->regs[15] = regs->regs[1];
365 if (regs->pc < regs->regs[0])
366 /* Go to rewind point */
367 regs->pc = regs->regs[0] + offset;
369 local_irq_restore(flags);
375 * Restore the kernel mode register
378 asm volatile("ldc %0, r7_bank"
380 : "r" (task_thread_info(next)));
383 /* If no tasks are using the UBC, we're done */
384 if (ubc_usercnt == 0)
385 /* If no tasks are using the UBC, we're done */;
386 else if (next->thread.ubc_pc && next->mm) {
389 asid |= cpu_asid(smp_processor_id(), next->mm);
391 ubc_set_tracing(asid, next->thread.ubc_pc);
393 #if defined(CONFIG_CPU_SH4A)
394 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
395 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
397 ctrl_outw(0, UBC_BBRA);
398 ctrl_outw(0, UBC_BBRB);
405 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
406 unsigned long r6, unsigned long r7,
407 struct pt_regs __regs)
409 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
411 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
413 /* fork almost works, enough to trick you into looking elsewhere :-( */
418 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
419 unsigned long parent_tidptr,
420 unsigned long child_tidptr,
421 struct pt_regs __regs)
423 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
425 newsp = regs->regs[15];
426 return do_fork(clone_flags, newsp, regs, 0,
427 (int __user *)parent_tidptr,
428 (int __user *)child_tidptr);
432 * This is trivial, and on the face of it looks like it
433 * could equally well be done in user mode.
435 * Not so, for quite unobvious reasons - register pressure.
436 * In user mode vfork() cannot have a stack frame, and if
437 * done by calling the "clone()" system call directly, you
438 * do not have enough call-clobbered registers to hold all
439 * the information you need.
441 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
442 unsigned long r6, unsigned long r7,
443 struct pt_regs __regs)
445 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
446 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
451 * sys_execve() executes a new program.
453 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv,
454 char __user * __user *uenvp, unsigned long r7,
455 struct pt_regs __regs)
457 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
461 filename = getname(ufilename);
462 error = PTR_ERR(filename);
463 if (IS_ERR(filename))
466 error = do_execve(filename, uargv, uenvp, regs);
469 current->ptrace &= ~PT_DTRACE;
470 task_unlock(current);
477 unsigned long get_wchan(struct task_struct *p)
479 unsigned long schedule_frame;
482 if (!p || p == current || p->state == TASK_RUNNING)
486 * The same comment as on the Alpha applies here, too ...
488 pc = thread_saved_pc(p);
489 if (in_sched_functions(pc)) {
490 schedule_frame = (unsigned long)p->thread.sp;
491 return ((unsigned long *)schedule_frame)[21];
497 asmlinkage void break_point_trap(void)
500 #if defined(CONFIG_CPU_SH4A)
501 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
502 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
504 ctrl_outw(0, UBC_BBRA);
505 ctrl_outw(0, UBC_BBRB);
507 current->thread.ubc_pc = 0;
510 force_sig(SIGTRAP, current);
514 * Generic trap handler.
516 asmlinkage void debug_trap_handler(unsigned long r4, unsigned long r5,
517 unsigned long r6, unsigned long r7,
518 struct pt_regs __regs)
520 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
523 regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
525 if (notify_die(DIE_TRAP, "debug trap", regs, 0, regs->tra & 0xff,
526 SIGTRAP) == NOTIFY_STOP)
529 force_sig(SIGTRAP, current);
533 * Special handler for BUG() traps.
535 asmlinkage void bug_trap_handler(unsigned long r4, unsigned long r5,
536 unsigned long r6, unsigned long r7,
537 struct pt_regs __regs)
539 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
542 regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
544 if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
545 SIGTRAP) == NOTIFY_STOP)
549 if (__kernel_text_address(instruction_pointer(regs))) {
550 u16 insn = *(u16 *)instruction_pointer(regs);
551 if (insn == TRAPA_BUG_OPCODE)
556 force_sig(SIGTRAP, current);