Linux 2.6.28-rc5
[cris-mirror.git] / arch / sh / kernel / process_32.c
blobb965f0282c7dab650ec30fa1b02d532ed6674be5
1 /*
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 - 2008 Paul Mundt
12 * This file is subject to the terms and conditions of the GNU General Public
13 * License. See the file "COPYING" in the main directory of this archive
14 * for more details.
16 #include <linux/module.h>
17 #include <linux/mm.h>
18 #include <linux/elfcore.h>
19 #include <linux/pm.h>
20 #include <linux/kallsyms.h>
21 #include <linux/kexec.h>
22 #include <linux/kdebug.h>
23 #include <linux/tick.h>
24 #include <linux/reboot.h>
25 #include <linux/fs.h>
26 #include <linux/preempt.h>
27 #include <asm/uaccess.h>
28 #include <asm/mmu_context.h>
29 #include <asm/pgalloc.h>
30 #include <asm/system.h>
31 #include <asm/ubc.h>
32 #include <asm/fpu.h>
33 #include <asm/syscalls.h>
35 static int hlt_counter;
36 int ubc_usercnt = 0;
38 void (*pm_idle)(void);
39 void (*pm_power_off)(void);
40 EXPORT_SYMBOL(pm_power_off);
42 static int __init nohlt_setup(char *__unused)
44 hlt_counter = 1;
45 return 1;
47 __setup("nohlt", nohlt_setup);
49 static int __init hlt_setup(char *__unused)
51 hlt_counter = 0;
52 return 1;
54 __setup("hlt", hlt_setup);
56 static void default_idle(void)
58 if (!hlt_counter) {
59 clear_thread_flag(TIF_POLLING_NRFLAG);
60 smp_mb__after_clear_bit();
61 set_bl_bit();
62 while (!need_resched())
63 cpu_sleep();
64 clear_bl_bit();
65 set_thread_flag(TIF_POLLING_NRFLAG);
66 } else
67 while (!need_resched())
68 cpu_relax();
71 void cpu_idle(void)
73 set_thread_flag(TIF_POLLING_NRFLAG);
75 /* endless idle loop with no priority at all */
76 while (1) {
77 void (*idle)(void) = pm_idle;
79 if (!idle)
80 idle = default_idle;
82 tick_nohz_stop_sched_tick(1);
83 while (!need_resched())
84 idle();
85 tick_nohz_restart_sched_tick();
87 preempt_enable_no_resched();
88 schedule();
89 preempt_disable();
90 check_pgt_cache();
94 void machine_restart(char * __unused)
96 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
97 asm volatile("ldc %0, sr\n\t"
98 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
101 void machine_halt(void)
103 local_irq_disable();
105 while (1)
106 cpu_sleep();
109 void machine_power_off(void)
111 if (pm_power_off)
112 pm_power_off();
115 void show_regs(struct pt_regs * regs)
117 printk("\n");
118 printk("Pid : %d, Comm: %20s\n", task_pid_nr(current), current->comm);
119 printk("CPU : %d %s (%s %.*s)\n",
120 smp_processor_id(), print_tainted(), init_utsname()->release,
121 (int)strcspn(init_utsname()->version, " "),
122 init_utsname()->version);
124 print_symbol("PC is at %s\n", instruction_pointer(regs));
125 print_symbol("PR is at %s\n", regs->pr);
127 printk("PC : %08lx SP : %08lx SR : %08lx ",
128 regs->pc, regs->regs[15], regs->sr);
129 #ifdef CONFIG_MMU
130 printk("TEA : %08x\n", ctrl_inl(MMU_TEA));
131 #else
132 printk("\n");
133 #endif
135 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
136 regs->regs[0],regs->regs[1],
137 regs->regs[2],regs->regs[3]);
138 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
139 regs->regs[4],regs->regs[5],
140 regs->regs[6],regs->regs[7]);
141 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
142 regs->regs[8],regs->regs[9],
143 regs->regs[10],regs->regs[11]);
144 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
145 regs->regs[12],regs->regs[13],
146 regs->regs[14]);
147 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
148 regs->mach, regs->macl, regs->gbr, regs->pr);
150 show_trace(NULL, (unsigned long *)regs->regs[15], regs);
154 * Create a kernel thread
158 * This is the mechanism for creating a new kernel thread.
161 extern void kernel_thread_helper(void);
162 __asm__(".align 5\n"
163 "kernel_thread_helper:\n\t"
164 "jsr @r5\n\t"
165 " nop\n\t"
166 "mov.l 1f, r1\n\t"
167 "jsr @r1\n\t"
168 " mov r0, r4\n\t"
169 ".align 2\n\t"
170 "1:.long do_exit");
172 /* Don't use this in BL=1(cli). Or else, CPU resets! */
173 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
175 struct pt_regs regs;
176 int pid;
178 memset(&regs, 0, sizeof(regs));
179 regs.regs[4] = (unsigned long)arg;
180 regs.regs[5] = (unsigned long)fn;
182 regs.pc = (unsigned long)kernel_thread_helper;
183 regs.sr = (1 << 30);
185 /* Ok, create the new process.. */
186 pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
187 &regs, 0, NULL, NULL);
189 trace_mark(kernel_arch_kthread_create, "pid %d fn %p", pid, fn);
191 return pid;
195 * Free current thread data structures etc..
197 void exit_thread(void)
199 if (current->thread.ubc_pc) {
200 current->thread.ubc_pc = 0;
201 ubc_usercnt -= 1;
205 void flush_thread(void)
207 #if defined(CONFIG_SH_FPU)
208 struct task_struct *tsk = current;
209 /* Forget lazy FPU state */
210 clear_fpu(tsk, task_pt_regs(tsk));
211 clear_used_math();
212 #endif
215 void release_thread(struct task_struct *dead_task)
217 /* do nothing */
220 /* Fill in the fpu structure for a core dump.. */
221 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
223 int fpvalid = 0;
225 #if defined(CONFIG_SH_FPU)
226 struct task_struct *tsk = current;
228 fpvalid = !!tsk_used_math(tsk);
229 if (fpvalid)
230 fpvalid = !fpregs_get(tsk, NULL, 0,
231 sizeof(struct user_fpu_struct),
232 fpu, NULL);
233 #endif
235 return fpvalid;
238 asmlinkage void ret_from_fork(void);
240 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
241 unsigned long unused,
242 struct task_struct *p, struct pt_regs *regs)
244 struct thread_info *ti = task_thread_info(p);
245 struct pt_regs *childregs;
246 #if defined(CONFIG_SH_FPU)
247 struct task_struct *tsk = current;
249 unlazy_fpu(tsk, regs);
250 p->thread.fpu = tsk->thread.fpu;
251 copy_to_stopped_child_used_math(p);
252 #endif
254 childregs = task_pt_regs(p);
255 *childregs = *regs;
257 if (user_mode(regs)) {
258 childregs->regs[15] = usp;
259 ti->addr_limit = USER_DS;
260 } else {
261 childregs->regs[15] = (unsigned long)childregs;
262 ti->addr_limit = KERNEL_DS;
265 if (clone_flags & CLONE_SETTLS)
266 childregs->gbr = childregs->regs[0];
268 childregs->regs[0] = 0; /* Set return value for child */
270 p->thread.sp = (unsigned long) childregs;
271 p->thread.pc = (unsigned long) ret_from_fork;
273 p->thread.ubc_pc = 0;
275 return 0;
278 /* Tracing by user break controller. */
279 static void ubc_set_tracing(int asid, unsigned long pc)
281 #if defined(CONFIG_CPU_SH4A)
282 unsigned long val;
284 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
285 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
287 ctrl_outl(val, UBC_CBR0);
288 ctrl_outl(pc, UBC_CAR0);
289 ctrl_outl(0x0, UBC_CAMR0);
290 ctrl_outl(0x0, UBC_CBCR);
292 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
293 ctrl_outl(val, UBC_CRR0);
295 /* Read UBC register that we wrote last, for checking update */
296 val = ctrl_inl(UBC_CRR0);
298 #else /* CONFIG_CPU_SH4A */
299 ctrl_outl(pc, UBC_BARA);
301 #ifdef CONFIG_MMU
302 ctrl_outb(asid, UBC_BASRA);
303 #endif
305 ctrl_outl(0, UBC_BAMRA);
307 if (current_cpu_data.type == CPU_SH7729 ||
308 current_cpu_data.type == CPU_SH7710 ||
309 current_cpu_data.type == CPU_SH7712) {
310 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
311 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
312 } else {
313 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
314 ctrl_outw(BRCR_PCBA, UBC_BRCR);
316 #endif /* CONFIG_CPU_SH4A */
320 * switch_to(x,y) should switch tasks from x to y.
323 struct task_struct *__switch_to(struct task_struct *prev,
324 struct task_struct *next)
326 #if defined(CONFIG_SH_FPU)
327 unlazy_fpu(prev, task_pt_regs(prev));
328 #endif
330 #ifdef CONFIG_MMU
332 * Restore the kernel mode register
333 * k7 (r7_bank1)
335 asm volatile("ldc %0, r7_bank"
336 : /* no output */
337 : "r" (task_thread_info(next)));
338 #endif
340 /* If no tasks are using the UBC, we're done */
341 if (ubc_usercnt == 0)
342 /* If no tasks are using the UBC, we're done */;
343 else if (next->thread.ubc_pc && next->mm) {
344 int asid = 0;
345 #ifdef CONFIG_MMU
346 asid |= cpu_asid(smp_processor_id(), next->mm);
347 #endif
348 ubc_set_tracing(asid, next->thread.ubc_pc);
349 } else {
350 #if defined(CONFIG_CPU_SH4A)
351 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
352 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
353 #else
354 ctrl_outw(0, UBC_BBRA);
355 ctrl_outw(0, UBC_BBRB);
356 #endif
359 return prev;
362 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
363 unsigned long r6, unsigned long r7,
364 struct pt_regs __regs)
366 #ifdef CONFIG_MMU
367 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
368 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
369 #else
370 /* fork almost works, enough to trick you into looking elsewhere :-( */
371 return -EINVAL;
372 #endif
375 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
376 unsigned long parent_tidptr,
377 unsigned long child_tidptr,
378 struct pt_regs __regs)
380 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
381 if (!newsp)
382 newsp = regs->regs[15];
383 return do_fork(clone_flags, newsp, regs, 0,
384 (int __user *)parent_tidptr,
385 (int __user *)child_tidptr);
389 * This is trivial, and on the face of it looks like it
390 * could equally well be done in user mode.
392 * Not so, for quite unobvious reasons - register pressure.
393 * In user mode vfork() cannot have a stack frame, and if
394 * done by calling the "clone()" system call directly, you
395 * do not have enough call-clobbered registers to hold all
396 * the information you need.
398 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
399 unsigned long r6, unsigned long r7,
400 struct pt_regs __regs)
402 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
403 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
404 0, NULL, NULL);
408 * sys_execve() executes a new program.
410 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv,
411 char __user * __user *uenvp, unsigned long r7,
412 struct pt_regs __regs)
414 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
415 int error;
416 char *filename;
418 filename = getname(ufilename);
419 error = PTR_ERR(filename);
420 if (IS_ERR(filename))
421 goto out;
423 error = do_execve(filename, uargv, uenvp, regs);
424 if (error == 0) {
425 task_lock(current);
426 current->ptrace &= ~PT_DTRACE;
427 task_unlock(current);
429 putname(filename);
430 out:
431 return error;
434 unsigned long get_wchan(struct task_struct *p)
436 unsigned long pc;
438 if (!p || p == current || p->state == TASK_RUNNING)
439 return 0;
442 * The same comment as on the Alpha applies here, too ...
444 pc = thread_saved_pc(p);
446 #ifdef CONFIG_FRAME_POINTER
447 if (in_sched_functions(pc)) {
448 unsigned long schedule_frame = (unsigned long)p->thread.sp;
449 return ((unsigned long *)schedule_frame)[21];
451 #endif
453 return pc;
456 asmlinkage void break_point_trap(void)
458 /* Clear tracing. */
459 #if defined(CONFIG_CPU_SH4A)
460 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
461 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
462 #else
463 ctrl_outw(0, UBC_BBRA);
464 ctrl_outw(0, UBC_BBRB);
465 #endif
466 current->thread.ubc_pc = 0;
467 ubc_usercnt -= 1;
469 force_sig(SIGTRAP, current);