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;
138 #if defined(CONFIG_SH_FPU)
142 /* Ok, create the new process.. */
143 pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
144 ®s, 0, NULL, NULL);
148 EXPORT_SYMBOL(kernel_thread);
151 * Free current thread data structures etc..
153 void exit_thread(void)
155 if (current->thread.ubc_pc) {
156 current->thread.ubc_pc = 0;
161 void flush_thread(void)
163 #if defined(CONFIG_SH_FPU)
164 struct task_struct *tsk = current;
165 /* Forget lazy FPU state */
166 clear_fpu(tsk, task_pt_regs(tsk));
171 void release_thread(struct task_struct *dead_task)
176 /* Fill in the fpu structure for a core dump.. */
177 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
181 #if defined(CONFIG_SH_FPU)
182 struct task_struct *tsk = current;
184 fpvalid = !!tsk_used_math(tsk);
186 fpvalid = !fpregs_get(tsk, NULL, 0,
187 sizeof(struct user_fpu_struct),
193 EXPORT_SYMBOL(dump_fpu);
196 * This gets called before we allocate a new thread and copy
197 * the current task into it.
199 void prepare_to_copy(struct task_struct *tsk)
201 unlazy_fpu(tsk, task_pt_regs(tsk));
204 asmlinkage void ret_from_fork(void);
206 int copy_thread(unsigned long clone_flags, unsigned long usp,
207 unsigned long unused,
208 struct task_struct *p, struct pt_regs *regs)
210 struct thread_info *ti = task_thread_info(p);
211 struct pt_regs *childregs;
212 #if defined(CONFIG_SH_DSP)
213 struct task_struct *tsk = current;
216 #if defined(CONFIG_SH_DSP)
217 if (is_dsp_enabled(tsk)) {
218 /* We can use the __save_dsp or just copy the struct:
220 * p->thread.dsp_status.status |= SR_DSP
222 p->thread.dsp_status = tsk->thread.dsp_status;
226 childregs = task_pt_regs(p);
229 if (user_mode(regs)) {
230 childregs->regs[15] = usp;
231 ti->addr_limit = USER_DS;
233 childregs->regs[15] = (unsigned long)childregs;
234 ti->addr_limit = KERNEL_DS;
235 ti->status &= ~TS_USEDFPU;
239 if (clone_flags & CLONE_SETTLS)
240 childregs->gbr = childregs->regs[0];
242 childregs->regs[0] = 0; /* Set return value for child */
244 p->thread.sp = (unsigned long) childregs;
245 p->thread.pc = (unsigned long) ret_from_fork;
247 p->thread.ubc_pc = 0;
252 /* Tracing by user break controller. */
253 static void ubc_set_tracing(int asid, unsigned long pc)
255 #if defined(CONFIG_CPU_SH4A)
258 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
259 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
261 ctrl_outl(val, UBC_CBR0);
262 ctrl_outl(pc, UBC_CAR0);
263 ctrl_outl(0x0, UBC_CAMR0);
264 ctrl_outl(0x0, UBC_CBCR);
266 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
267 ctrl_outl(val, UBC_CRR0);
269 /* Read UBC register that we wrote last, for checking update */
270 val = ctrl_inl(UBC_CRR0);
272 #else /* CONFIG_CPU_SH4A */
273 ctrl_outl(pc, UBC_BARA);
276 ctrl_outb(asid, UBC_BASRA);
279 ctrl_outl(0, UBC_BAMRA);
281 if (current_cpu_data.type == CPU_SH7729 ||
282 current_cpu_data.type == CPU_SH7710 ||
283 current_cpu_data.type == CPU_SH7712 ||
284 current_cpu_data.type == CPU_SH7203){
285 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
286 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
288 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
289 ctrl_outw(BRCR_PCBA, UBC_BRCR);
291 #endif /* CONFIG_CPU_SH4A */
295 * switch_to(x,y) should switch tasks from x to y.
298 __notrace_funcgraph struct task_struct *
299 __switch_to(struct task_struct *prev, struct task_struct *next)
301 struct thread_struct *next_t = &next->thread;
303 unlazy_fpu(prev, task_pt_regs(prev));
305 /* we're going to use this soon, after a few expensive things */
306 if (next->fpu_counter > 5)
307 prefetch(&next_t->fpu.hard);
311 * Restore the kernel mode register
314 asm volatile("ldc %0, r7_bank"
316 : "r" (task_thread_info(next)));
319 /* If no tasks are using the UBC, we're done */
320 if (ubc_usercnt == 0)
321 /* If no tasks are using the UBC, we're done */;
322 else if (next->thread.ubc_pc && next->mm) {
325 asid |= cpu_asid(smp_processor_id(), next->mm);
327 ubc_set_tracing(asid, next->thread.ubc_pc);
329 #if defined(CONFIG_CPU_SH4A)
330 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
331 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
333 ctrl_outw(0, UBC_BBRA);
334 ctrl_outw(0, UBC_BBRB);
339 * If the task has used fpu the last 5 timeslices, just do a full
340 * restore of the math state immediately to avoid the trap; the
341 * chances of needing FPU soon are obviously high now
343 if (next->fpu_counter > 5)
344 fpu_state_restore(task_pt_regs(next));
349 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
350 unsigned long r6, unsigned long r7,
351 struct pt_regs __regs)
354 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
355 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
357 /* fork almost works, enough to trick you into looking elsewhere :-( */
362 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
363 unsigned long parent_tidptr,
364 unsigned long child_tidptr,
365 struct pt_regs __regs)
367 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
369 newsp = regs->regs[15];
370 return do_fork(clone_flags, newsp, regs, 0,
371 (int __user *)parent_tidptr,
372 (int __user *)child_tidptr);
376 * This is trivial, and on the face of it looks like it
377 * could equally well be done in user mode.
379 * Not so, for quite unobvious reasons - register pressure.
380 * In user mode vfork() cannot have a stack frame, and if
381 * done by calling the "clone()" system call directly, you
382 * do not have enough call-clobbered registers to hold all
383 * the information you need.
385 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
386 unsigned long r6, unsigned long r7,
387 struct pt_regs __regs)
389 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
390 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
395 * sys_execve() executes a new program.
397 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv,
398 char __user * __user *uenvp, unsigned long r7,
399 struct pt_regs __regs)
401 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
405 filename = getname(ufilename);
406 error = PTR_ERR(filename);
407 if (IS_ERR(filename))
410 error = do_execve(filename, uargv, uenvp, regs);
416 unsigned long get_wchan(struct task_struct *p)
420 if (!p || p == current || p->state == TASK_RUNNING)
424 * The same comment as on the Alpha applies here, too ...
426 pc = thread_saved_pc(p);
428 #ifdef CONFIG_FRAME_POINTER
429 if (in_sched_functions(pc)) {
430 unsigned long schedule_frame = (unsigned long)p->thread.sp;
431 return ((unsigned long *)schedule_frame)[21];
438 asmlinkage void break_point_trap(void)
441 #if defined(CONFIG_CPU_SH4A)
442 ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
443 ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
445 ctrl_outw(0, UBC_BBRA);
446 ctrl_outw(0, UBC_BBRB);
447 ctrl_outl(0, UBC_BRCR);
449 current->thread.ubc_pc = 0;
452 force_sig(SIGTRAP, current);