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:#%u, Comm: %20s\n",
108 current->pid, current->xid, current->comm);
109 print_symbol("PC is at %s\n", instruction_pointer(regs));
110 printk("PC : %08lx SP : %08lx SR : %08lx ",
111 regs->pc, regs->regs[15], regs->sr);
113 printk("TEA : %08x ", ctrl_inl(MMU_TEA));
117 printk("%s\n", print_tainted());
119 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
120 regs->regs[0],regs->regs[1],
121 regs->regs[2],regs->regs[3]);
122 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
123 regs->regs[4],regs->regs[5],
124 regs->regs[6],regs->regs[7]);
125 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
126 regs->regs[8],regs->regs[9],
127 regs->regs[10],regs->regs[11]);
128 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
129 regs->regs[12],regs->regs[13],
131 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
132 regs->mach, regs->macl, regs->gbr, regs->pr);
134 show_trace(NULL, (unsigned long *)regs->regs[15], regs);
138 * Create a kernel thread
142 * This is the mechanism for creating a new kernel thread.
145 extern void kernel_thread_helper(void);
147 "kernel_thread_helper:\n\t"
156 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
157 { /* Don't use this in BL=1(cli). Or else, CPU resets! */
160 memset(®s, 0, sizeof(regs));
161 regs.regs[4] = (unsigned long) arg;
162 regs.regs[5] = (unsigned long) fn;
164 regs.pc = (unsigned long) kernel_thread_helper;
167 /* Ok, create the new process.. */
168 return do_fork(flags | CLONE_VM | CLONE_UNTRACED | CLONE_KTHREAD,
169 0, ®s, 0, NULL, NULL);
173 * Free current thread data structures etc..
175 void exit_thread(void)
177 if (current->thread.ubc_pc) {
178 current->thread.ubc_pc = 0;
183 void flush_thread(void)
185 #if defined(CONFIG_SH_FPU)
186 struct task_struct *tsk = current;
187 /* Forget lazy FPU state */
188 clear_fpu(tsk, task_pt_regs(tsk));
193 void release_thread(struct task_struct *dead_task)
198 /* Fill in the fpu structure for a core dump.. */
199 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
203 #if defined(CONFIG_SH_FPU)
204 struct task_struct *tsk = current;
206 fpvalid = !!tsk_used_math(tsk);
208 unlazy_fpu(tsk, regs);
209 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
217 * Capture the user space registers if the task is not running (in user space)
219 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
221 struct pt_regs ptregs;
223 ptregs = *task_pt_regs(tsk);
224 elf_core_copy_regs(regs, &ptregs);
230 dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *fpu)
234 #if defined(CONFIG_SH_FPU)
235 fpvalid = !!tsk_used_math(tsk);
237 unlazy_fpu(tsk, task_pt_regs(tsk));
238 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
245 asmlinkage void ret_from_fork(void);
247 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
248 unsigned long unused,
249 struct task_struct *p, struct pt_regs *regs)
251 struct thread_info *ti = task_thread_info(p);
252 struct pt_regs *childregs;
253 #if defined(CONFIG_SH_FPU)
254 struct task_struct *tsk = current;
256 unlazy_fpu(tsk, regs);
257 p->thread.fpu = tsk->thread.fpu;
258 copy_to_stopped_child_used_math(p);
261 childregs = task_pt_regs(p);
264 if (user_mode(regs)) {
265 childregs->regs[15] = usp;
266 ti->addr_limit = USER_DS;
268 childregs->regs[15] = (unsigned long)task_stack_page(p) + THREAD_SIZE;
269 ti->addr_limit = KERNEL_DS;
271 if (clone_flags & CLONE_SETTLS) {
272 childregs->gbr = childregs->regs[0];
274 childregs->regs[0] = 0; /* Set return value for child */
276 p->thread.sp = (unsigned long) childregs;
277 p->thread.pc = (unsigned long) ret_from_fork;
279 p->thread.ubc_pc = 0;
284 /* Tracing by user break controller. */
286 ubc_set_tracing(int asid, unsigned long pc)
288 #if defined(CONFIG_CPU_SH4A)
291 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
292 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
294 ctrl_outl(val, UBC_CBR0);
295 ctrl_outl(pc, UBC_CAR0);
296 ctrl_outl(0x0, UBC_CAMR0);
297 ctrl_outl(0x0, UBC_CBCR);
299 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
300 ctrl_outl(val, UBC_CRR0);
302 /* Read UBC register that we writed last. For chekking UBC Register changed */
303 val = ctrl_inl(UBC_CRR0);
305 #else /* CONFIG_CPU_SH4A */
306 ctrl_outl(pc, UBC_BARA);
309 /* We don't have any ASID settings for the SH-2! */
310 if (cpu_data->type != CPU_SH7604)
311 ctrl_outb(asid, UBC_BASRA);
314 ctrl_outl(0, UBC_BAMRA);
316 if (cpu_data->type == CPU_SH7729 || cpu_data->type == CPU_SH7710) {
317 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
318 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
320 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
321 ctrl_outw(BRCR_PCBA, UBC_BRCR);
323 #endif /* CONFIG_CPU_SH4A */
327 * switch_to(x,y) should switch tasks from x to y.
330 struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next)
332 #if defined(CONFIG_SH_FPU)
333 unlazy_fpu(prev, task_pt_regs(prev));
336 #ifdef CONFIG_PREEMPT
339 struct pt_regs *regs;
341 local_irq_save(flags);
342 regs = task_pt_regs(prev);
343 if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
344 int offset = (int)regs->regs[15];
346 /* Reset stack pointer: clear critical region mark */
347 regs->regs[15] = regs->regs[1];
348 if (regs->pc < regs->regs[0])
349 /* Go to rewind point */
350 regs->pc = regs->regs[0] + offset;
352 local_irq_restore(flags);
358 * Restore the kernel mode register
361 asm volatile("ldc %0, r7_bank"
363 : "r" (task_thread_info(next)));
366 /* If no tasks are using the UBC, we're done */
367 if (ubc_usercnt == 0)
368 /* If no tasks are using the UBC, we're done */;
369 else if (next->thread.ubc_pc && next->mm) {
372 asid |= next->mm->context.id & MMU_CONTEXT_ASID_MASK;
374 ubc_set_tracing(asid, next->thread.ubc_pc);
376 #if defined(CONFIG_CPU_SH4A)
377 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
378 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
380 ctrl_outw(0, UBC_BBRA);
381 ctrl_outw(0, UBC_BBRB);
388 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
389 unsigned long r6, unsigned long r7,
390 struct pt_regs __regs)
392 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
394 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
396 /* fork almost works, enough to trick you into looking elsewhere :-( */
401 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
402 unsigned long parent_tidptr,
403 unsigned long child_tidptr,
404 struct pt_regs __regs)
406 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
408 newsp = regs->regs[15];
409 return do_fork(clone_flags, newsp, regs, 0,
410 (int __user *)parent_tidptr, (int __user *)child_tidptr);
414 * This is trivial, and on the face of it looks like it
415 * could equally well be done in user mode.
417 * Not so, for quite unobvious reasons - register pressure.
418 * In user mode vfork() cannot have a stack frame, and if
419 * done by calling the "clone()" system call directly, you
420 * do not have enough call-clobbered registers to hold all
421 * the information you need.
423 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
424 unsigned long r6, unsigned long r7,
425 struct pt_regs __regs)
427 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
428 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
433 * sys_execve() executes a new program.
435 asmlinkage int sys_execve(char *ufilename, char **uargv,
436 char **uenvp, unsigned long r7,
437 struct pt_regs __regs)
439 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
443 filename = getname((char __user *)ufilename);
444 error = PTR_ERR(filename);
445 if (IS_ERR(filename))
448 error = do_execve(filename,
449 (char __user * __user *)uargv,
450 (char __user * __user *)uenvp,
454 current->ptrace &= ~PT_DTRACE;
455 task_unlock(current);
462 unsigned long get_wchan(struct task_struct *p)
464 unsigned long schedule_frame;
467 if (!p || p == current || p->state == TASK_RUNNING)
471 * The same comment as on the Alpha applies here, too ...
473 pc = thread_saved_pc(p);
474 if (in_sched_functions(pc)) {
475 schedule_frame = (unsigned long)p->thread.sp;
476 return ((unsigned long *)schedule_frame)[21];
482 asmlinkage void break_point_trap(void)
485 #if defined(CONFIG_CPU_SH4A)
486 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
487 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
489 ctrl_outw(0, UBC_BBRA);
490 ctrl_outw(0, UBC_BBRB);
492 current->thread.ubc_pc = 0;
495 force_sig(SIGTRAP, current);
498 asmlinkage void break_point_trap_software(unsigned long r4, unsigned long r5,
499 unsigned long r6, unsigned long r7,
500 struct pt_regs __regs)
502 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
508 if (__kernel_text_address(instruction_pointer(regs))) {
509 u16 insn = *(u16 *)instruction_pointer(regs);
510 if (insn == TRAPA_BUG_OPCODE)
515 force_sig(SIGTRAP, current);