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 <asm/uaccess.h>
21 #include <asm/mmu_context.h>
22 #include <asm/pgalloc.h>
23 #include <asm/system.h>
26 static int hlt_counter;
29 #define HARD_IDLE_TIMEOUT (HZ / 3)
31 void (*pm_idle)(void);
32 void (*pm_power_off)(void);
33 EXPORT_SYMBOL(pm_power_off);
35 void disable_hlt(void)
39 EXPORT_SYMBOL(disable_hlt);
45 EXPORT_SYMBOL(enable_hlt);
47 void default_idle(void)
57 /* endless idle loop with no priority at all */
59 void (*idle)(void) = pm_idle;
64 tick_nohz_stop_sched_tick();
65 while (!need_resched())
67 tick_nohz_restart_sched_tick();
69 preempt_enable_no_resched();
76 void machine_restart(char * __unused)
78 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
79 asm volatile("ldc %0, sr\n\t"
80 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
83 void machine_halt(void)
91 void machine_power_off(void)
97 void show_regs(struct pt_regs * regs)
100 printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);
101 print_symbol("PC is at %s\n", instruction_pointer(regs));
102 printk("PC : %08lx SP : %08lx SR : %08lx ",
103 regs->pc, regs->regs[15], regs->sr);
105 printk("TEA : %08x ", ctrl_inl(MMU_TEA));
109 printk("%s\n", print_tainted());
111 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
112 regs->regs[0],regs->regs[1],
113 regs->regs[2],regs->regs[3]);
114 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
115 regs->regs[4],regs->regs[5],
116 regs->regs[6],regs->regs[7]);
117 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
118 regs->regs[8],regs->regs[9],
119 regs->regs[10],regs->regs[11]);
120 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
121 regs->regs[12],regs->regs[13],
123 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
124 regs->mach, regs->macl, regs->gbr, regs->pr);
126 show_trace(NULL, (unsigned long *)regs->regs[15], regs);
130 * Create a kernel thread
134 * This is the mechanism for creating a new kernel thread.
137 extern void kernel_thread_helper(void);
139 "kernel_thread_helper:\n\t"
148 /* Don't use this in BL=1(cli). Or else, CPU resets! */
149 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
153 memset(®s, 0, sizeof(regs));
154 regs.regs[4] = (unsigned long)arg;
155 regs.regs[5] = (unsigned long)fn;
157 regs.pc = (unsigned long)kernel_thread_helper;
160 /* Ok, create the new process.. */
161 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
162 ®s, 0, NULL, NULL);
166 * Free current thread data structures etc..
168 void exit_thread(void)
170 if (current->thread.ubc_pc) {
171 current->thread.ubc_pc = 0;
176 void flush_thread(void)
178 #if defined(CONFIG_SH_FPU)
179 struct task_struct *tsk = current;
180 /* Forget lazy FPU state */
181 clear_fpu(tsk, task_pt_regs(tsk));
186 void release_thread(struct task_struct *dead_task)
191 /* Fill in the fpu structure for a core dump.. */
192 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
196 #if defined(CONFIG_SH_FPU)
197 struct task_struct *tsk = current;
199 fpvalid = !!tsk_used_math(tsk);
201 unlazy_fpu(tsk, regs);
202 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
210 * Capture the user space registers if the task is not running (in user space)
212 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
214 struct pt_regs ptregs;
216 ptregs = *task_pt_regs(tsk);
217 elf_core_copy_regs(regs, &ptregs);
222 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpu)
226 #if defined(CONFIG_SH_FPU)
227 fpvalid = !!tsk_used_math(tsk);
229 unlazy_fpu(tsk, task_pt_regs(tsk));
230 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
237 asmlinkage void ret_from_fork(void);
239 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
240 unsigned long unused,
241 struct task_struct *p, struct pt_regs *regs)
243 struct thread_info *ti = task_thread_info(p);
244 struct pt_regs *childregs;
245 #if defined(CONFIG_SH_FPU)
246 struct task_struct *tsk = current;
248 unlazy_fpu(tsk, regs);
249 p->thread.fpu = tsk->thread.fpu;
250 copy_to_stopped_child_used_math(p);
253 childregs = task_pt_regs(p);
256 if (user_mode(regs)) {
257 childregs->regs[15] = usp;
258 ti->addr_limit = USER_DS;
260 childregs->regs[15] = (unsigned long)childregs;
261 ti->addr_limit = KERNEL_DS;
264 if (clone_flags & CLONE_SETTLS)
265 childregs->gbr = childregs->regs[0];
267 childregs->regs[0] = 0; /* Set return value for child */
269 p->thread.sp = (unsigned long) childregs;
270 p->thread.pc = (unsigned long) ret_from_fork;
272 p->thread.ubc_pc = 0;
277 /* Tracing by user break controller. */
278 static void ubc_set_tracing(int asid, unsigned long pc)
280 #if defined(CONFIG_CPU_SH4A)
283 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
284 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
286 ctrl_outl(val, UBC_CBR0);
287 ctrl_outl(pc, UBC_CAR0);
288 ctrl_outl(0x0, UBC_CAMR0);
289 ctrl_outl(0x0, UBC_CBCR);
291 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
292 ctrl_outl(val, UBC_CRR0);
294 /* Read UBC register that we wrote last, for checking update */
295 val = ctrl_inl(UBC_CRR0);
297 #else /* CONFIG_CPU_SH4A */
298 ctrl_outl(pc, UBC_BARA);
301 /* We don't have any ASID settings for the SH-2! */
302 if (current_cpu_data.type != CPU_SH7604)
303 ctrl_outb(asid, UBC_BASRA);
306 ctrl_outl(0, UBC_BAMRA);
308 if (current_cpu_data.type == CPU_SH7729 ||
309 current_cpu_data.type == CPU_SH7710 ||
310 current_cpu_data.type == CPU_SH7712) {
311 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
312 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
314 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
315 ctrl_outw(BRCR_PCBA, UBC_BRCR);
317 #endif /* CONFIG_CPU_SH4A */
321 * switch_to(x,y) should switch tasks from x to y.
324 struct task_struct *__switch_to(struct task_struct *prev,
325 struct task_struct *next)
327 #if defined(CONFIG_SH_FPU)
328 unlazy_fpu(prev, task_pt_regs(prev));
331 #ifdef CONFIG_PREEMPT
334 struct pt_regs *regs;
336 local_irq_save(flags);
337 regs = task_pt_regs(prev);
338 if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
339 int offset = (int)regs->regs[15];
341 /* Reset stack pointer: clear critical region mark */
342 regs->regs[15] = regs->regs[1];
343 if (regs->pc < regs->regs[0])
344 /* Go to rewind point */
345 regs->pc = regs->regs[0] + offset;
347 local_irq_restore(flags);
353 * Restore the kernel mode register
356 asm volatile("ldc %0, r7_bank"
358 : "r" (task_thread_info(next)));
361 /* If no tasks are using the UBC, we're done */
362 if (ubc_usercnt == 0)
363 /* If no tasks are using the UBC, we're done */;
364 else if (next->thread.ubc_pc && next->mm) {
367 asid |= cpu_asid(smp_processor_id(), next->mm);
369 ubc_set_tracing(asid, next->thread.ubc_pc);
371 #if defined(CONFIG_CPU_SH4A)
372 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
373 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
375 ctrl_outw(0, UBC_BBRA);
376 ctrl_outw(0, UBC_BBRB);
383 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
384 unsigned long r6, unsigned long r7,
385 struct pt_regs __regs)
387 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
389 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
391 /* fork almost works, enough to trick you into looking elsewhere :-( */
396 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
397 unsigned long parent_tidptr,
398 unsigned long child_tidptr,
399 struct pt_regs __regs)
401 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
403 newsp = regs->regs[15];
404 return do_fork(clone_flags, newsp, regs, 0,
405 (int __user *)parent_tidptr,
406 (int __user *)child_tidptr);
410 * This is trivial, and on the face of it looks like it
411 * could equally well be done in user mode.
413 * Not so, for quite unobvious reasons - register pressure.
414 * In user mode vfork() cannot have a stack frame, and if
415 * done by calling the "clone()" system call directly, you
416 * do not have enough call-clobbered registers to hold all
417 * the information you need.
419 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
420 unsigned long r6, unsigned long r7,
421 struct pt_regs __regs)
423 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
424 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
429 * sys_execve() executes a new program.
431 asmlinkage int sys_execve(char *ufilename, char **uargv,
432 char **uenvp, unsigned long r7,
433 struct pt_regs __regs)
435 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
439 filename = getname((char __user *)ufilename);
440 error = PTR_ERR(filename);
441 if (IS_ERR(filename))
444 error = do_execve(filename,
445 (char __user * __user *)uargv,
446 (char __user * __user *)uenvp,
450 current->ptrace &= ~PT_DTRACE;
451 task_unlock(current);
458 unsigned long get_wchan(struct task_struct *p)
460 unsigned long schedule_frame;
463 if (!p || p == current || p->state == TASK_RUNNING)
467 * The same comment as on the Alpha applies here, too ...
469 pc = thread_saved_pc(p);
470 if (in_sched_functions(pc)) {
471 schedule_frame = (unsigned long)p->thread.sp;
472 return ((unsigned long *)schedule_frame)[21];
478 asmlinkage void break_point_trap(void)
481 #if defined(CONFIG_CPU_SH4A)
482 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
483 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
485 ctrl_outw(0, UBC_BBRA);
486 ctrl_outw(0, UBC_BBRB);
488 current->thread.ubc_pc = 0;
491 force_sig(SIGTRAP, current);
495 * Generic trap handler.
497 asmlinkage void debug_trap_handler(unsigned long r4, unsigned long r5,
498 unsigned long r6, unsigned long r7,
499 struct pt_regs __regs)
501 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
504 regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
506 if (notify_die(DIE_TRAP, "debug trap", regs, 0, regs->tra & 0xff,
507 SIGTRAP) == NOTIFY_STOP)
510 force_sig(SIGTRAP, current);
514 * Special handler for BUG() traps.
516 asmlinkage void bug_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, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
526 SIGTRAP) == NOTIFY_STOP)
530 if (__kernel_text_address(instruction_pointer(regs))) {
531 u16 insn = *(u16 *)instruction_pointer(regs);
532 if (insn == TRAPA_BUG_OPCODE)
537 force_sig(SIGTRAP, current);