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(®s, 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 ®s, 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