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 <asm/kdebug.h>
19 #include <asm/uaccess.h>
20 #include <asm/mmu_context.h>
21 #include <asm/pgalloc.h>
24 static int hlt_counter;
27 #define HARD_IDLE_TIMEOUT (HZ / 3)
29 void (*pm_idle)(void);
30 void (*pm_power_off)(void);
31 EXPORT_SYMBOL(pm_power_off);
33 void disable_hlt(void)
37 EXPORT_SYMBOL(disable_hlt);
43 EXPORT_SYMBOL(enable_hlt);
45 void default_idle(void)
55 /* endless idle loop with no priority at all */
57 void (*idle)(void) = pm_idle;
62 while (!need_resched())
65 preempt_enable_no_resched();
72 void machine_restart(char * __unused)
74 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
75 asm volatile("ldc %0, sr\n\t"
76 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
79 void machine_halt(void)
87 void machine_power_off(void)
93 void show_regs(struct pt_regs * regs)
96 printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);
97 print_symbol("PC is at %s\n", instruction_pointer(regs));
98 printk("PC : %08lx SP : %08lx SR : %08lx ",
99 regs->pc, regs->regs[15], regs->sr);
101 printk("TEA : %08x ", ctrl_inl(MMU_TEA));
105 printk("%s\n", print_tainted());
107 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
108 regs->regs[0],regs->regs[1],
109 regs->regs[2],regs->regs[3]);
110 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
111 regs->regs[4],regs->regs[5],
112 regs->regs[6],regs->regs[7]);
113 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
114 regs->regs[8],regs->regs[9],
115 regs->regs[10],regs->regs[11]);
116 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
117 regs->regs[12],regs->regs[13],
119 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
120 regs->mach, regs->macl, regs->gbr, regs->pr);
122 show_trace(NULL, (unsigned long *)regs->regs[15], regs);
126 * Create a kernel thread
130 * This is the mechanism for creating a new kernel thread.
133 extern void kernel_thread_helper(void);
135 "kernel_thread_helper:\n\t"
144 /* Don't use this in BL=1(cli). Or else, CPU resets! */
145 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
149 memset(®s, 0, sizeof(regs));
150 regs.regs[4] = (unsigned long)arg;
151 regs.regs[5] = (unsigned long)fn;
153 regs.pc = (unsigned long)kernel_thread_helper;
156 /* Ok, create the new process.. */
157 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
158 ®s, 0, NULL, NULL);
162 * Free current thread data structures etc..
164 void exit_thread(void)
166 if (current->thread.ubc_pc) {
167 current->thread.ubc_pc = 0;
172 void flush_thread(void)
174 #if defined(CONFIG_SH_FPU)
175 struct task_struct *tsk = current;
176 /* Forget lazy FPU state */
177 clear_fpu(tsk, task_pt_regs(tsk));
182 void release_thread(struct task_struct *dead_task)
187 /* Fill in the fpu structure for a core dump.. */
188 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
192 #if defined(CONFIG_SH_FPU)
193 struct task_struct *tsk = current;
195 fpvalid = !!tsk_used_math(tsk);
197 unlazy_fpu(tsk, regs);
198 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
206 * Capture the user space registers if the task is not running (in user space)
208 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
210 struct pt_regs ptregs;
212 ptregs = *task_pt_regs(tsk);
213 elf_core_copy_regs(regs, &ptregs);
218 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpu)
222 #if defined(CONFIG_SH_FPU)
223 fpvalid = !!tsk_used_math(tsk);
225 unlazy_fpu(tsk, task_pt_regs(tsk));
226 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
233 asmlinkage void ret_from_fork(void);
235 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
236 unsigned long unused,
237 struct task_struct *p, struct pt_regs *regs)
239 struct thread_info *ti = task_thread_info(p);
240 struct pt_regs *childregs;
241 #if defined(CONFIG_SH_FPU)
242 struct task_struct *tsk = current;
244 unlazy_fpu(tsk, regs);
245 p->thread.fpu = tsk->thread.fpu;
246 copy_to_stopped_child_used_math(p);
249 childregs = task_pt_regs(p);
252 if (user_mode(regs)) {
253 childregs->regs[15] = usp;
254 ti->addr_limit = USER_DS;
256 childregs->regs[15] = (unsigned long)childregs;
257 ti->addr_limit = KERNEL_DS;
260 if (clone_flags & CLONE_SETTLS)
261 childregs->gbr = childregs->regs[0];
263 childregs->regs[0] = 0; /* Set return value for child */
265 p->thread.sp = (unsigned long) childregs;
266 p->thread.pc = (unsigned long) ret_from_fork;
268 p->thread.ubc_pc = 0;
273 /* Tracing by user break controller. */
274 static void ubc_set_tracing(int asid, unsigned long pc)
276 #if defined(CONFIG_CPU_SH4A)
279 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
280 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
282 ctrl_outl(val, UBC_CBR0);
283 ctrl_outl(pc, UBC_CAR0);
284 ctrl_outl(0x0, UBC_CAMR0);
285 ctrl_outl(0x0, UBC_CBCR);
287 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
288 ctrl_outl(val, UBC_CRR0);
290 /* Read UBC register that we wrote last, for checking update */
291 val = ctrl_inl(UBC_CRR0);
293 #else /* CONFIG_CPU_SH4A */
294 ctrl_outl(pc, UBC_BARA);
297 /* We don't have any ASID settings for the SH-2! */
298 if (current_cpu_data.type != CPU_SH7604)
299 ctrl_outb(asid, UBC_BASRA);
302 ctrl_outl(0, UBC_BAMRA);
304 if (current_cpu_data.type == CPU_SH7729 ||
305 current_cpu_data.type == CPU_SH7710 ||
306 current_cpu_data.type == CPU_SH7712) {
307 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
308 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
310 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
311 ctrl_outw(BRCR_PCBA, UBC_BRCR);
313 #endif /* CONFIG_CPU_SH4A */
317 * switch_to(x,y) should switch tasks from x to y.
320 struct task_struct *__switch_to(struct task_struct *prev,
321 struct task_struct *next)
323 #if defined(CONFIG_SH_FPU)
324 unlazy_fpu(prev, task_pt_regs(prev));
327 #ifdef CONFIG_PREEMPT
330 struct pt_regs *regs;
332 local_irq_save(flags);
333 regs = task_pt_regs(prev);
334 if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
335 int offset = (int)regs->regs[15];
337 /* Reset stack pointer: clear critical region mark */
338 regs->regs[15] = regs->regs[1];
339 if (regs->pc < regs->regs[0])
340 /* Go to rewind point */
341 regs->pc = regs->regs[0] + offset;
343 local_irq_restore(flags);
349 * Restore the kernel mode register
352 asm volatile("ldc %0, r7_bank"
354 : "r" (task_thread_info(next)));
357 /* If no tasks are using the UBC, we're done */
358 if (ubc_usercnt == 0)
359 /* If no tasks are using the UBC, we're done */;
360 else if (next->thread.ubc_pc && next->mm) {
363 asid |= cpu_asid(smp_processor_id(), next->mm);
365 ubc_set_tracing(asid, next->thread.ubc_pc);
367 #if defined(CONFIG_CPU_SH4A)
368 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
369 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
371 ctrl_outw(0, UBC_BBRA);
372 ctrl_outw(0, UBC_BBRB);
379 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
380 unsigned long r6, unsigned long r7,
381 struct pt_regs __regs)
383 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
385 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
387 /* fork almost works, enough to trick you into looking elsewhere :-( */
392 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
393 unsigned long parent_tidptr,
394 unsigned long child_tidptr,
395 struct pt_regs __regs)
397 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
399 newsp = regs->regs[15];
400 return do_fork(clone_flags, newsp, regs, 0,
401 (int __user *)parent_tidptr,
402 (int __user *)child_tidptr);
406 * This is trivial, and on the face of it looks like it
407 * could equally well be done in user mode.
409 * Not so, for quite unobvious reasons - register pressure.
410 * In user mode vfork() cannot have a stack frame, and if
411 * done by calling the "clone()" system call directly, you
412 * do not have enough call-clobbered registers to hold all
413 * the information you need.
415 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
416 unsigned long r6, unsigned long r7,
417 struct pt_regs __regs)
419 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
420 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
425 * sys_execve() executes a new program.
427 asmlinkage int sys_execve(char *ufilename, char **uargv,
428 char **uenvp, unsigned long r7,
429 struct pt_regs __regs)
431 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
435 filename = getname((char __user *)ufilename);
436 error = PTR_ERR(filename);
437 if (IS_ERR(filename))
440 error = do_execve(filename,
441 (char __user * __user *)uargv,
442 (char __user * __user *)uenvp,
446 current->ptrace &= ~PT_DTRACE;
447 task_unlock(current);
454 unsigned long get_wchan(struct task_struct *p)
456 unsigned long schedule_frame;
459 if (!p || p == current || p->state == TASK_RUNNING)
463 * The same comment as on the Alpha applies here, too ...
465 pc = thread_saved_pc(p);
466 if (in_sched_functions(pc)) {
467 schedule_frame = (unsigned long)p->thread.sp;
468 return ((unsigned long *)schedule_frame)[21];
474 asmlinkage void break_point_trap(void)
477 #if defined(CONFIG_CPU_SH4A)
478 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
479 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
481 ctrl_outw(0, UBC_BBRA);
482 ctrl_outw(0, UBC_BBRB);
484 current->thread.ubc_pc = 0;
487 force_sig(SIGTRAP, current);
491 * Generic trap handler.
493 asmlinkage void debug_trap_handler(unsigned long r4, unsigned long r5,
494 unsigned long r6, unsigned long r7,
495 struct pt_regs __regs)
497 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
502 if (notify_die(DIE_TRAP, regs, regs->tra & 0xff,
503 SIGTRAP) == NOTIFY_STOP)
506 force_sig(SIGTRAP, current);
510 * Special handler for BUG() traps.
512 asmlinkage void bug_trap_handler(unsigned long r4, unsigned long r5,
513 unsigned long r6, unsigned long r7,
514 struct pt_regs __regs)
516 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
521 if (notify_die(DIE_TRAP, regs, TRAPA_BUG_OPCODE & 0xff,
522 SIGTRAP) == NOTIFY_STOP)
526 if (__kernel_text_address(instruction_pointer(regs))) {
527 u16 insn = *(u16 *)instruction_pointer(regs);
528 if (insn == TRAPA_BUG_OPCODE)
533 force_sig(SIGTRAP, current);