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
16 #include <linux/module.h>
18 #include <linux/elfcore.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>
26 #include <linux/ftrace.h>
27 #include <linux/preempt.h>
28 #include <asm/uaccess.h>
29 #include <asm/mmu_context.h>
30 #include <asm/pgalloc.h>
31 #include <asm/system.h>
34 #include <asm/syscalls.h>
35 #include <asm/watchdog.h>
40 static void watchdog_trigger_immediate(void)
42 sh_wdt_write_cnt(0xFF);
43 sh_wdt_write_csr(0xC2);
46 void machine_restart(char * __unused)
50 /* Use watchdog timer to trigger reset */
51 watchdog_trigger_immediate();
57 void machine_restart(char * __unused)
59 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
60 asm volatile("ldc %0, sr\n\t"
61 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
65 void machine_halt(void)
73 void machine_power_off(void)
79 void show_regs(struct pt_regs * regs)
82 printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm);
83 printk("CPU : %d \t\t%s (%s %.*s)\n\n",
84 smp_processor_id(), print_tainted(), init_utsname()->release,
85 (int)strcspn(init_utsname()->version, " "),
86 init_utsname()->version);
88 print_symbol("PC is at %s\n", instruction_pointer(regs));
89 print_symbol("PR is at %s\n", regs->pr);
91 printk("PC : %08lx SP : %08lx SR : %08lx ",
92 regs->pc, regs->regs[15], regs->sr);
94 printk("TEA : %08x\n", ctrl_inl(MMU_TEA));
99 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
100 regs->regs[0],regs->regs[1],
101 regs->regs[2],regs->regs[3]);
102 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
103 regs->regs[4],regs->regs[5],
104 regs->regs[6],regs->regs[7]);
105 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
106 regs->regs[8],regs->regs[9],
107 regs->regs[10],regs->regs[11]);
108 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
109 regs->regs[12],regs->regs[13],
111 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
112 regs->mach, regs->macl, regs->gbr, regs->pr);
114 show_trace(NULL, (unsigned long *)regs->regs[15], regs);
119 * Create a kernel thread
121 ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *))
126 /* Don't use this in BL=1(cli). Or else, CPU resets! */
127 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
132 memset(®s, 0, sizeof(regs));
133 regs.regs[4] = (unsigned long)arg;
134 regs.regs[5] = (unsigned long)fn;
136 regs.pc = (unsigned long)kernel_thread_helper;
139 /* Ok, create the new process.. */
140 pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
141 ®s, 0, NULL, NULL);
145 EXPORT_SYMBOL(kernel_thread);
148 * Free current thread data structures etc..
150 void exit_thread(void)
152 if (current->thread.ubc_pc) {
153 current->thread.ubc_pc = 0;
158 void flush_thread(void)
160 #if defined(CONFIG_SH_FPU)
161 struct task_struct *tsk = current;
162 /* Forget lazy FPU state */
163 clear_fpu(tsk, task_pt_regs(tsk));
168 void release_thread(struct task_struct *dead_task)
173 /* Fill in the fpu structure for a core dump.. */
174 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
178 #if defined(CONFIG_SH_FPU)
179 struct task_struct *tsk = current;
181 fpvalid = !!tsk_used_math(tsk);
183 fpvalid = !fpregs_get(tsk, NULL, 0,
184 sizeof(struct user_fpu_struct),
190 EXPORT_SYMBOL(dump_fpu);
192 asmlinkage void ret_from_fork(void);
194 int copy_thread(unsigned long clone_flags, unsigned long usp,
195 unsigned long unused,
196 struct task_struct *p, struct pt_regs *regs)
198 struct thread_info *ti = task_thread_info(p);
199 struct pt_regs *childregs;
200 #if defined(CONFIG_SH_FPU) || defined(CONFIG_SH_DSP)
201 struct task_struct *tsk = current;
204 #if defined(CONFIG_SH_FPU)
205 unlazy_fpu(tsk, regs);
206 p->thread.fpu = tsk->thread.fpu;
207 copy_to_stopped_child_used_math(p);
210 #if defined(CONFIG_SH_DSP)
211 if (is_dsp_enabled(tsk)) {
212 /* We can use the __save_dsp or just copy the struct:
214 * p->thread.dsp_status.status |= SR_DSP
216 p->thread.dsp_status = tsk->thread.dsp_status;
220 childregs = task_pt_regs(p);
223 if (user_mode(regs)) {
224 childregs->regs[15] = usp;
225 ti->addr_limit = USER_DS;
227 childregs->regs[15] = (unsigned long)childregs;
228 ti->addr_limit = KERNEL_DS;
231 if (clone_flags & CLONE_SETTLS)
232 childregs->gbr = childregs->regs[0];
234 childregs->regs[0] = 0; /* Set return value for child */
236 p->thread.sp = (unsigned long) childregs;
237 p->thread.pc = (unsigned long) ret_from_fork;
239 p->thread.ubc_pc = 0;
244 /* Tracing by user break controller. */
245 static void ubc_set_tracing(int asid, unsigned long pc)
247 #if defined(CONFIG_CPU_SH4A)
250 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
251 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
253 ctrl_outl(val, UBC_CBR0);
254 ctrl_outl(pc, UBC_CAR0);
255 ctrl_outl(0x0, UBC_CAMR0);
256 ctrl_outl(0x0, UBC_CBCR);
258 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
259 ctrl_outl(val, UBC_CRR0);
261 /* Read UBC register that we wrote last, for checking update */
262 val = ctrl_inl(UBC_CRR0);
264 #else /* CONFIG_CPU_SH4A */
265 ctrl_outl(pc, UBC_BARA);
268 ctrl_outb(asid, UBC_BASRA);
271 ctrl_outl(0, UBC_BAMRA);
273 if (current_cpu_data.type == CPU_SH7729 ||
274 current_cpu_data.type == CPU_SH7710 ||
275 current_cpu_data.type == CPU_SH7712 ||
276 current_cpu_data.type == CPU_SH7203){
277 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
278 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
280 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
281 ctrl_outw(BRCR_PCBA, UBC_BRCR);
283 #endif /* CONFIG_CPU_SH4A */
287 * switch_to(x,y) should switch tasks from x to y.
290 __notrace_funcgraph struct task_struct *
291 __switch_to(struct task_struct *prev, struct task_struct *next)
293 struct thread_struct *next_t = &next->thread;
295 #if defined(CONFIG_SH_FPU)
296 unlazy_fpu(prev, task_pt_regs(prev));
298 /* we're going to use this soon, after a few expensive things */
299 if (next->fpu_counter > 5)
300 prefetch(&next_t->fpu.hard);
305 * Restore the kernel mode register
308 asm volatile("ldc %0, r7_bank"
310 : "r" (task_thread_info(next)));
313 /* If no tasks are using the UBC, we're done */
314 if (ubc_usercnt == 0)
315 /* If no tasks are using the UBC, we're done */;
316 else if (next->thread.ubc_pc && next->mm) {
319 asid |= cpu_asid(smp_processor_id(), next->mm);
321 ubc_set_tracing(asid, next->thread.ubc_pc);
323 #if defined(CONFIG_CPU_SH4A)
324 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
325 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
327 ctrl_outw(0, UBC_BBRA);
328 ctrl_outw(0, UBC_BBRB);
332 #if defined(CONFIG_SH_FPU)
333 /* If the task has used fpu the last 5 timeslices, just do a full
334 * restore of the math state immediately to avoid the trap; the
335 * chances of needing FPU soon are obviously high now
337 if (next->fpu_counter > 5) {
338 fpu_state_restore(task_pt_regs(next));
345 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
346 unsigned long r6, unsigned long r7,
347 struct pt_regs __regs)
350 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
351 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
353 /* fork almost works, enough to trick you into looking elsewhere :-( */
358 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
359 unsigned long parent_tidptr,
360 unsigned long child_tidptr,
361 struct pt_regs __regs)
363 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
365 newsp = regs->regs[15];
366 return do_fork(clone_flags, newsp, regs, 0,
367 (int __user *)parent_tidptr,
368 (int __user *)child_tidptr);
372 * This is trivial, and on the face of it looks like it
373 * could equally well be done in user mode.
375 * Not so, for quite unobvious reasons - register pressure.
376 * In user mode vfork() cannot have a stack frame, and if
377 * done by calling the "clone()" system call directly, you
378 * do not have enough call-clobbered registers to hold all
379 * the information you need.
381 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
382 unsigned long r6, unsigned long r7,
383 struct pt_regs __regs)
385 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
386 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
391 * sys_execve() executes a new program.
393 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv,
394 char __user * __user *uenvp, unsigned long r7,
395 struct pt_regs __regs)
397 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
401 filename = getname(ufilename);
402 error = PTR_ERR(filename);
403 if (IS_ERR(filename))
406 error = do_execve(filename, uargv, uenvp, regs);
412 unsigned long get_wchan(struct task_struct *p)
416 if (!p || p == current || p->state == TASK_RUNNING)
420 * The same comment as on the Alpha applies here, too ...
422 pc = thread_saved_pc(p);
424 #ifdef CONFIG_FRAME_POINTER
425 if (in_sched_functions(pc)) {
426 unsigned long schedule_frame = (unsigned long)p->thread.sp;
427 return ((unsigned long *)schedule_frame)[21];
434 asmlinkage void break_point_trap(void)
437 #if defined(CONFIG_CPU_SH4A)
438 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
439 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
441 ctrl_outw(0, UBC_BBRA);
442 ctrl_outw(0, UBC_BBRB);
443 ctrl_outl(0, UBC_BRCR);
445 current->thread.ubc_pc = 0;
448 force_sig(SIGTRAP, current);