• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * arch/sh/kernel/process.c
3  *
4  * This file handles the architecture-dependent parts of process handling..
5  *
6  *  Copyright (C) 1995  Linus Torvalds
7  *
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
11  *
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.
15  */
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>
34 
35 int ubc_usercnt = 0;
36 
machine_restart(char * __unused)37 void machine_restart(char * __unused)
38 {
39 	/* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
40 	asm volatile("ldc %0, sr\n\t"
41 		     "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
42 }
43 
machine_halt(void)44 void machine_halt(void)
45 {
46 	local_irq_disable();
47 
48 	while (1)
49 		cpu_sleep();
50 }
51 
machine_power_off(void)52 void machine_power_off(void)
53 {
54 	if (pm_power_off)
55 		pm_power_off();
56 }
57 
show_regs(struct pt_regs * regs)58 void show_regs(struct pt_regs * regs)
59 {
60 	printk("\n");
61 	printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm);
62 	printk("CPU : %d        \t\t%s  (%s %.*s)\n\n",
63 	       smp_processor_id(), print_tainted(), init_utsname()->release,
64 	       (int)strcspn(init_utsname()->version, " "),
65 	       init_utsname()->version);
66 
67 	print_symbol("PC is at %s\n", instruction_pointer(regs));
68 	print_symbol("PR is at %s\n", regs->pr);
69 
70 	printk("PC  : %08lx SP  : %08lx SR  : %08lx ",
71 	       regs->pc, regs->regs[15], regs->sr);
72 #ifdef CONFIG_MMU
73 	printk("TEA : %08x\n", ctrl_inl(MMU_TEA));
74 #else
75 	printk("\n");
76 #endif
77 
78 	printk("R0  : %08lx R1  : %08lx R2  : %08lx R3  : %08lx\n",
79 	       regs->regs[0],regs->regs[1],
80 	       regs->regs[2],regs->regs[3]);
81 	printk("R4  : %08lx R5  : %08lx R6  : %08lx R7  : %08lx\n",
82 	       regs->regs[4],regs->regs[5],
83 	       regs->regs[6],regs->regs[7]);
84 	printk("R8  : %08lx R9  : %08lx R10 : %08lx R11 : %08lx\n",
85 	       regs->regs[8],regs->regs[9],
86 	       regs->regs[10],regs->regs[11]);
87 	printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
88 	       regs->regs[12],regs->regs[13],
89 	       regs->regs[14]);
90 	printk("MACH: %08lx MACL: %08lx GBR : %08lx PR  : %08lx\n",
91 	       regs->mach, regs->macl, regs->gbr, regs->pr);
92 
93 	show_trace(NULL, (unsigned long *)regs->regs[15], regs);
94 	show_code(regs);
95 }
96 
97 /*
98  * Create a kernel thread
99  */
kernel_thread_helper(void * arg,int (* fn)(void *))100 ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *))
101 {
102 	do_exit(fn(arg));
103 }
104 
105 /* Don't use this in BL=1(cli).  Or else, CPU resets! */
kernel_thread(int (* fn)(void *),void * arg,unsigned long flags)106 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
107 {
108 	struct pt_regs regs;
109 	int pid;
110 
111 	memset(&regs, 0, sizeof(regs));
112 	regs.regs[4] = (unsigned long)arg;
113 	regs.regs[5] = (unsigned long)fn;
114 
115 	regs.pc = (unsigned long)kernel_thread_helper;
116 	regs.sr = (1 << 30);
117 
118 	/* Ok, create the new process.. */
119 	pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
120 		      &regs, 0, NULL, NULL);
121 
122 	trace_mark(kernel_arch_kthread_create, "pid %d fn %p", pid, fn);
123 
124 	return pid;
125 }
126 
127 /*
128  * Free current thread data structures etc..
129  */
exit_thread(void)130 void exit_thread(void)
131 {
132 	if (current->thread.ubc_pc) {
133 		current->thread.ubc_pc = 0;
134 		ubc_usercnt -= 1;
135 	}
136 }
137 
flush_thread(void)138 void flush_thread(void)
139 {
140 #if defined(CONFIG_SH_FPU)
141 	struct task_struct *tsk = current;
142 	/* Forget lazy FPU state */
143 	clear_fpu(tsk, task_pt_regs(tsk));
144 	clear_used_math();
145 #endif
146 }
147 
release_thread(struct task_struct * dead_task)148 void release_thread(struct task_struct *dead_task)
149 {
150 	/* do nothing */
151 }
152 
153 /* Fill in the fpu structure for a core dump.. */
dump_fpu(struct pt_regs * regs,elf_fpregset_t * fpu)154 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
155 {
156 	int fpvalid = 0;
157 
158 #if defined(CONFIG_SH_FPU)
159 	struct task_struct *tsk = current;
160 
161 	fpvalid = !!tsk_used_math(tsk);
162 	if (fpvalid)
163 		fpvalid = !fpregs_get(tsk, NULL, 0,
164 				      sizeof(struct user_fpu_struct),
165 				      fpu, NULL);
166 #endif
167 
168 	return fpvalid;
169 }
170 
171 asmlinkage void ret_from_fork(void);
172 
copy_thread(int nr,unsigned long clone_flags,unsigned long usp,unsigned long unused,struct task_struct * p,struct pt_regs * regs)173 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
174 		unsigned long unused,
175 		struct task_struct *p, struct pt_regs *regs)
176 {
177 	struct thread_info *ti = task_thread_info(p);
178 	struct pt_regs *childregs;
179 #if defined(CONFIG_SH_FPU)
180 	struct task_struct *tsk = current;
181 
182 	unlazy_fpu(tsk, regs);
183 	p->thread.fpu = tsk->thread.fpu;
184 	copy_to_stopped_child_used_math(p);
185 #endif
186 
187 	childregs = task_pt_regs(p);
188 	*childregs = *regs;
189 
190 	if (user_mode(regs)) {
191 		childregs->regs[15] = usp;
192 		ti->addr_limit = USER_DS;
193 	} else {
194 		childregs->regs[15] = (unsigned long)childregs;
195 		ti->addr_limit = KERNEL_DS;
196 	}
197 
198 	if (clone_flags & CLONE_SETTLS)
199 		childregs->gbr = childregs->regs[0];
200 
201 	childregs->regs[0] = 0; /* Set return value for child */
202 
203 	p->thread.sp = (unsigned long) childregs;
204 	p->thread.pc = (unsigned long) ret_from_fork;
205 
206 	p->thread.ubc_pc = 0;
207 
208 	return 0;
209 }
210 
211 /* Tracing by user break controller.  */
ubc_set_tracing(int asid,unsigned long pc)212 static void ubc_set_tracing(int asid, unsigned long pc)
213 {
214 #if defined(CONFIG_CPU_SH4A)
215 	unsigned long val;
216 
217 	val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
218 	val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
219 
220 	ctrl_outl(val, UBC_CBR0);
221 	ctrl_outl(pc,  UBC_CAR0);
222 	ctrl_outl(0x0, UBC_CAMR0);
223 	ctrl_outl(0x0, UBC_CBCR);
224 
225 	val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
226 	ctrl_outl(val, UBC_CRR0);
227 
228 	/* Read UBC register that we wrote last, for checking update */
229 	val = ctrl_inl(UBC_CRR0);
230 
231 #else	/* CONFIG_CPU_SH4A */
232 	ctrl_outl(pc, UBC_BARA);
233 
234 #ifdef CONFIG_MMU
235 	ctrl_outb(asid, UBC_BASRA);
236 #endif
237 
238 	ctrl_outl(0, UBC_BAMRA);
239 
240 	if (current_cpu_data.type == CPU_SH7729 ||
241 	    current_cpu_data.type == CPU_SH7710 ||
242 	    current_cpu_data.type == CPU_SH7712) {
243 		ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
244 		ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
245 	} else {
246 		ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
247 		ctrl_outw(BRCR_PCBA, UBC_BRCR);
248 	}
249 #endif	/* CONFIG_CPU_SH4A */
250 }
251 
252 /*
253  *	switch_to(x,y) should switch tasks from x to y.
254  *
255  */
__switch_to(struct task_struct * prev,struct task_struct * next)256 struct task_struct *__switch_to(struct task_struct *prev,
257 				struct task_struct *next)
258 {
259 #if defined(CONFIG_SH_FPU)
260 	unlazy_fpu(prev, task_pt_regs(prev));
261 #endif
262 
263 #ifdef CONFIG_MMU
264 	/*
265 	 * Restore the kernel mode register
266 	 *	k7 (r7_bank1)
267 	 */
268 	asm volatile("ldc	%0, r7_bank"
269 		     : /* no output */
270 		     : "r" (task_thread_info(next)));
271 #endif
272 
273 	/* If no tasks are using the UBC, we're done */
274 	if (ubc_usercnt == 0)
275 		/* If no tasks are using the UBC, we're done */;
276 	else if (next->thread.ubc_pc && next->mm) {
277 		int asid = 0;
278 #ifdef CONFIG_MMU
279 		asid |= cpu_asid(smp_processor_id(), next->mm);
280 #endif
281 		ubc_set_tracing(asid, next->thread.ubc_pc);
282 	} else {
283 #if defined(CONFIG_CPU_SH4A)
284 		ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
285 		ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
286 #else
287 		ctrl_outw(0, UBC_BBRA);
288 		ctrl_outw(0, UBC_BBRB);
289 #endif
290 	}
291 
292 	return prev;
293 }
294 
sys_fork(unsigned long r4,unsigned long r5,unsigned long r6,unsigned long r7,struct pt_regs __regs)295 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
296 			unsigned long r6, unsigned long r7,
297 			struct pt_regs __regs)
298 {
299 #ifdef CONFIG_MMU
300 	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
301 	return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
302 #else
303 	/* fork almost works, enough to trick you into looking elsewhere :-( */
304 	return -EINVAL;
305 #endif
306 }
307 
sys_clone(unsigned long clone_flags,unsigned long newsp,unsigned long parent_tidptr,unsigned long child_tidptr,struct pt_regs __regs)308 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
309 			 unsigned long parent_tidptr,
310 			 unsigned long child_tidptr,
311 			 struct pt_regs __regs)
312 {
313 	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
314 	if (!newsp)
315 		newsp = regs->regs[15];
316 	return do_fork(clone_flags, newsp, regs, 0,
317 			(int __user *)parent_tidptr,
318 			(int __user *)child_tidptr);
319 }
320 
321 /*
322  * This is trivial, and on the face of it looks like it
323  * could equally well be done in user mode.
324  *
325  * Not so, for quite unobvious reasons - register pressure.
326  * In user mode vfork() cannot have a stack frame, and if
327  * done by calling the "clone()" system call directly, you
328  * do not have enough call-clobbered registers to hold all
329  * the information you need.
330  */
sys_vfork(unsigned long r4,unsigned long r5,unsigned long r6,unsigned long r7,struct pt_regs __regs)331 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
332 			 unsigned long r6, unsigned long r7,
333 			 struct pt_regs __regs)
334 {
335 	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
336 	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
337 		       0, NULL, NULL);
338 }
339 
340 /*
341  * sys_execve() executes a new program.
342  */
sys_execve(char __user * ufilename,char __user * __user * uargv,char __user * __user * uenvp,unsigned long r7,struct pt_regs __regs)343 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv,
344 			  char __user * __user *uenvp, unsigned long r7,
345 			  struct pt_regs __regs)
346 {
347 	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
348 	int error;
349 	char *filename;
350 
351 	filename = getname(ufilename);
352 	error = PTR_ERR(filename);
353 	if (IS_ERR(filename))
354 		goto out;
355 
356 	error = do_execve(filename, uargv, uenvp, regs);
357 	if (error == 0) {
358 		task_lock(current);
359 		current->ptrace &= ~PT_DTRACE;
360 		task_unlock(current);
361 	}
362 	putname(filename);
363 out:
364 	return error;
365 }
366 
get_wchan(struct task_struct * p)367 unsigned long get_wchan(struct task_struct *p)
368 {
369 	unsigned long pc;
370 
371 	if (!p || p == current || p->state == TASK_RUNNING)
372 		return 0;
373 
374 	/*
375 	 * The same comment as on the Alpha applies here, too ...
376 	 */
377 	pc = thread_saved_pc(p);
378 
379 #ifdef CONFIG_FRAME_POINTER
380 	if (in_sched_functions(pc)) {
381 		unsigned long schedule_frame = (unsigned long)p->thread.sp;
382 		return ((unsigned long *)schedule_frame)[21];
383 	}
384 #endif
385 
386 	return pc;
387 }
388 
break_point_trap(void)389 asmlinkage void break_point_trap(void)
390 {
391 	/* Clear tracing.  */
392 #if defined(CONFIG_CPU_SH4A)
393 	ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
394 	ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
395 #else
396 	ctrl_outw(0, UBC_BBRA);
397 	ctrl_outw(0, UBC_BBRB);
398 #endif
399 	current->thread.ubc_pc = 0;
400 	ubc_usercnt -= 1;
401 
402 	force_sig(SIGTRAP, current);
403 }
404