Blackfin arch: split apart dump_bfin_regs and merge/remove show_regs from process...
[linux-2.6.git] / arch / blackfin / kernel / process.c
1 /*
2  * File:         arch/blackfin/kernel/process.c
3  * Based on:
4  * Author:
5  *
6  * Created:
7  * Description:  Blackfin architecture-dependent process handling.
8  *
9  * Modified:
10  *               Copyright 2004-2006 Analog Devices Inc.
11  *
12  * Bugs:         Enter bugs at http://blackfin.uclinux.org/
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2 of the License, or
17  * (at your option) any later version.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  *
24  * You should have received a copy of the GNU General Public License
25  * along with this program; if not, see the file COPYING, or write
26  * to the Free Software Foundation, Inc.,
27  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
28  */
29
30 #include <linux/module.h>
31 #include <linux/smp_lock.h>
32 #include <linux/unistd.h>
33 #include <linux/user.h>
34 #include <linux/a.out.h>
35 #include <linux/uaccess.h>
36 #include <linux/fs.h>
37 #include <linux/err.h>
38
39 #include <asm/blackfin.h>
40 #include <asm/fixed_code.h>
41
42 #define LED_ON  0
43 #define LED_OFF 1
44
45 asmlinkage void ret_from_fork(void);
46
47 /* Points to the SDRAM backup memory for the stack that is currently in
48  * L1 scratchpad memory.
49  */
50 void *current_l1_stack_save;
51
52 /* The number of tasks currently using a L1 stack area.  The SRAM is
53  * allocated/deallocated whenever this changes from/to zero.
54  */
55 int nr_l1stack_tasks;
56
57 /* Start and length of the area in L1 scratchpad memory which we've allocated
58  * for process stacks.
59  */
60 void *l1_stack_base;
61 unsigned long l1_stack_len;
62
63 /*
64  * Powermanagement idle function, if any..
65  */
66 void (*pm_idle)(void) = NULL;
67 EXPORT_SYMBOL(pm_idle);
68
69 void (*pm_power_off)(void) = NULL;
70 EXPORT_SYMBOL(pm_power_off);
71
72 /*
73  * We are using a different LED from the one used to indicate timer interrupt.
74  */
75 #if defined(CONFIG_BFIN_IDLE_LED)
76 static inline void leds_switch(int flag)
77 {
78         unsigned short tmp = 0;
79
80         tmp = bfin_read_CONFIG_BFIN_IDLE_LED_PORT();
81         SSYNC();
82
83         if (flag == LED_ON)
84                 tmp &= ~CONFIG_BFIN_IDLE_LED_PIN;       /* light on */
85         else
86                 tmp |= CONFIG_BFIN_IDLE_LED_PIN;        /* light off */
87
88         bfin_write_CONFIG_BFIN_IDLE_LED_PORT(tmp);
89         SSYNC();
90
91 }
92 #else
93 static inline void leds_switch(int flag)
94 {
95 }
96 #endif
97
98 /*
99  * The idle loop on BFIN
100  */
101 #ifdef CONFIG_IDLE_L1
102 void default_idle(void)__attribute__((l1_text));
103 void cpu_idle(void)__attribute__((l1_text));
104 #endif
105
106 void default_idle(void)
107 {
108         while (!need_resched()) {
109                 leds_switch(LED_OFF);
110                 local_irq_disable();
111                 if (likely(!need_resched()))
112                         idle_with_irq_disabled();
113                 local_irq_enable();
114                 leds_switch(LED_ON);
115         }
116 }
117
118 void (*idle)(void) = default_idle;
119
120 /*
121  * The idle thread. There's no useful work to be
122  * done, so just try to conserve power and have a
123  * low exit latency (ie sit in a loop waiting for
124  * somebody to say that they'd like to reschedule)
125  */
126 void cpu_idle(void)
127 {
128         /* endless idle loop with no priority at all */
129         while (1) {
130                 idle();
131                 preempt_enable_no_resched();
132                 schedule();
133                 preempt_disable();
134         }
135 }
136
137 /* Fill in the fpu structure for a core dump.  */
138
139 int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpregs)
140 {
141         return 1;
142 }
143
144 /*
145  * This gets run with P1 containing the
146  * function to call, and R1 containing
147  * the "args".  Note P0 is clobbered on the way here.
148  */
149 void kernel_thread_helper(void);
150 __asm__(".section .text\n"
151         ".align 4\n"
152         "_kernel_thread_helper:\n\t"
153         "\tsp += -12;\n\t"
154         "\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");
155
156 /*
157  * Create a kernel thread.
158  */
159 pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
160 {
161         struct pt_regs regs;
162
163         memset(&regs, 0, sizeof(regs));
164
165         regs.r1 = (unsigned long)arg;
166         regs.p1 = (unsigned long)fn;
167         regs.pc = (unsigned long)kernel_thread_helper;
168         regs.orig_p0 = -1;
169         /* Set bit 2 to tell ret_from_fork we should be returning to kernel
170            mode.  */
171         regs.ipend = 0x8002;
172         __asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):);
173         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
174                        NULL);
175 }
176
177 void flush_thread(void)
178 {
179 }
180
181 asmlinkage int bfin_vfork(struct pt_regs *regs)
182 {
183         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
184                        NULL);
185 }
186
187 asmlinkage int bfin_clone(struct pt_regs *regs)
188 {
189         unsigned long clone_flags;
190         unsigned long newsp;
191
192         /* syscall2 puts clone_flags in r0 and usp in r1 */
193         clone_flags = regs->r0;
194         newsp = regs->r1;
195         if (!newsp)
196                 newsp = rdusp();
197         else
198                 newsp -= 12;
199         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
200 }
201
202 int
203 copy_thread(int nr, unsigned long clone_flags,
204             unsigned long usp, unsigned long topstk,
205             struct task_struct *p, struct pt_regs *regs)
206 {
207         struct pt_regs *childregs;
208
209         childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
210         *childregs = *regs;
211         childregs->r0 = 0;
212
213         p->thread.usp = usp;
214         p->thread.ksp = (unsigned long)childregs;
215         p->thread.pc = (unsigned long)ret_from_fork;
216
217         return 0;
218 }
219
220 /*
221  * sys_execve() executes a new program.
222  */
223
224 asmlinkage int sys_execve(char *name, char **argv, char **envp)
225 {
226         int error;
227         char *filename;
228         struct pt_regs *regs = (struct pt_regs *)((&name) + 6);
229
230         lock_kernel();
231         filename = getname(name);
232         error = PTR_ERR(filename);
233         if (IS_ERR(filename))
234                 goto out;
235         error = do_execve(filename, argv, envp, regs);
236         putname(filename);
237  out:
238         unlock_kernel();
239         return error;
240 }
241
242 unsigned long get_wchan(struct task_struct *p)
243 {
244         unsigned long fp, pc;
245         unsigned long stack_page;
246         int count = 0;
247         if (!p || p == current || p->state == TASK_RUNNING)
248                 return 0;
249
250         stack_page = (unsigned long)p;
251         fp = p->thread.usp;
252         do {
253                 if (fp < stack_page + sizeof(struct thread_info) ||
254                     fp >= 8184 + stack_page)
255                         return 0;
256                 pc = ((unsigned long *)fp)[1];
257                 if (!in_sched_functions(pc))
258                         return pc;
259                 fp = *(unsigned long *)fp;
260         }
261         while (count++ < 16);
262         return 0;
263 }
264
265 void finish_atomic_sections (struct pt_regs *regs)
266 {
267         if (regs->pc < ATOMIC_SEQS_START || regs->pc >= ATOMIC_SEQS_END)
268                 return;
269
270         switch (regs->pc) {
271         case ATOMIC_XCHG32 + 2:
272                 put_user(regs->r1, (int *)regs->p0);
273                 regs->pc += 2;
274                 break;
275
276         case ATOMIC_CAS32 + 2:
277         case ATOMIC_CAS32 + 4:
278                 if (regs->r0 == regs->r1)
279                         put_user(regs->r2, (int *)regs->p0);
280                 regs->pc = ATOMIC_CAS32 + 8;
281                 break;
282         case ATOMIC_CAS32 + 6:
283                 put_user(regs->r2, (int *)regs->p0);
284                 regs->pc += 2;
285                 break;
286
287         case ATOMIC_ADD32 + 2:
288                 regs->r0 = regs->r1 + regs->r0;
289                 /* fall through */
290         case ATOMIC_ADD32 + 4:
291                 put_user(regs->r0, (int *)regs->p0);
292                 regs->pc = ATOMIC_ADD32 + 6;
293                 break;
294
295         case ATOMIC_SUB32 + 2:
296                 regs->r0 = regs->r1 - regs->r0;
297                 /* fall through */
298         case ATOMIC_SUB32 + 4:
299                 put_user(regs->r0, (int *)regs->p0);
300                 regs->pc = ATOMIC_SUB32 + 6;
301                 break;
302
303         case ATOMIC_IOR32 + 2:
304                 regs->r0 = regs->r1 | regs->r0;
305                 /* fall through */
306         case ATOMIC_IOR32 + 4:
307                 put_user(regs->r0, (int *)regs->p0);
308                 regs->pc = ATOMIC_IOR32 + 6;
309                 break;
310
311         case ATOMIC_AND32 + 2:
312                 regs->r0 = regs->r1 & regs->r0;
313                 /* fall through */
314         case ATOMIC_AND32 + 4:
315                 put_user(regs->r0, (int *)regs->p0);
316                 regs->pc = ATOMIC_AND32 + 6;
317                 break;
318
319         case ATOMIC_XOR32 + 2:
320                 regs->r0 = regs->r1 ^ regs->r0;
321                 /* fall through */
322         case ATOMIC_XOR32 + 4:
323                 put_user(regs->r0, (int *)regs->p0);
324                 regs->pc = ATOMIC_XOR32 + 6;
325                 break;
326         }
327 }
328
329 #if defined(CONFIG_ACCESS_CHECK)
330 int _access_ok(unsigned long addr, unsigned long size)
331 {
332         if (size == 0)
333                 return 1;
334         if (addr > (addr + size))
335                 return 0;
336         if (segment_eq(get_fs(), KERNEL_DS))
337                 return 1;
338 #ifdef CONFIG_MTD_UCLINUX
339         if (addr >= memory_start && (addr + size) <= memory_end)
340                 return 1;
341         if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end)
342                 return 1;
343 #else
344         if (addr >= memory_start && (addr + size) <= physical_mem_end)
345                 return 1;
346 #endif
347         if (addr >= (unsigned long)__init_begin &&
348             addr + size <= (unsigned long)__init_end)
349                 return 1;
350         if (addr >= L1_SCRATCH_START
351             && addr + size <= L1_SCRATCH_START + L1_SCRATCH_LENGTH)
352                 return 1;
353 #if L1_CODE_LENGTH != 0
354         if (addr >= L1_CODE_START + (_etext_l1 - _stext_l1)
355             && addr + size <= L1_CODE_START + L1_CODE_LENGTH)
356                 return 1;
357 #endif
358 #if L1_DATA_A_LENGTH != 0
359         if (addr >= L1_DATA_A_START + (_ebss_l1 - _sdata_l1)
360             && addr + size <= L1_DATA_A_START + L1_DATA_A_LENGTH)
361                 return 1;
362 #endif
363 #if L1_DATA_B_LENGTH != 0
364         if (addr >= L1_DATA_B_START
365             && addr + size <= L1_DATA_B_START + L1_DATA_B_LENGTH)
366                 return 1;
367 #endif
368         return 0;
369 }
370 EXPORT_SYMBOL(_access_ok);
371 #endif /* CONFIG_ACCESS_CHECK */