9124467651c4a794659b147f37e874b603524521
[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 void show_regs(struct pt_regs *regs)
138 {
139         printk(KERN_NOTICE "\n");
140         printk(KERN_NOTICE
141                "PC: %08lu  Status: %04lu  SysStatus: %04lu  RETS: %08lu\n",
142                regs->pc, regs->astat, regs->seqstat, regs->rets);
143         printk(KERN_NOTICE
144                "A0.x: %08lx  A0.w: %08lx  A1.x: %08lx  A1.w: %08lx\n",
145                regs->a0x, regs->a0w, regs->a1x, regs->a1w);
146         printk(KERN_NOTICE "P0: %08lx  P1: %08lx  P2: %08lx  P3: %08lx\n",
147                regs->p0, regs->p1, regs->p2, regs->p3);
148         printk(KERN_NOTICE "P4: %08lx  P5: %08lx\n", regs->p4, regs->p5);
149         printk(KERN_NOTICE "R0: %08lx  R1: %08lx  R2: %08lx  R3: %08lx\n",
150                regs->r0, regs->r1, regs->r2, regs->r3);
151         printk(KERN_NOTICE "R4: %08lx  R5: %08lx  R6: %08lx  R7: %08lx\n",
152                regs->r4, regs->r5, regs->r6, regs->r7);
153
154         if (!regs->ipend)
155                 printk(KERN_NOTICE "USP: %08lx\n", rdusp());
156 }
157
158 /* Fill in the fpu structure for a core dump.  */
159
160 int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpregs)
161 {
162         return 1;
163 }
164
165 /*
166  * This gets run with P1 containing the
167  * function to call, and R1 containing
168  * the "args".  Note P0 is clobbered on the way here.
169  */
170 void kernel_thread_helper(void);
171 __asm__(".section .text\n"
172         ".align 4\n"
173         "_kernel_thread_helper:\n\t"
174         "\tsp += -12;\n\t"
175         "\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");
176
177 /*
178  * Create a kernel thread.
179  */
180 pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
181 {
182         struct pt_regs regs;
183
184         memset(&regs, 0, sizeof(regs));
185
186         regs.r1 = (unsigned long)arg;
187         regs.p1 = (unsigned long)fn;
188         regs.pc = (unsigned long)kernel_thread_helper;
189         regs.orig_p0 = -1;
190         /* Set bit 2 to tell ret_from_fork we should be returning to kernel
191            mode.  */
192         regs.ipend = 0x8002;
193         __asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):);
194         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
195                        NULL);
196 }
197
198 void flush_thread(void)
199 {
200 }
201
202 asmlinkage int bfin_vfork(struct pt_regs *regs)
203 {
204         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
205                        NULL);
206 }
207
208 asmlinkage int bfin_clone(struct pt_regs *regs)
209 {
210         unsigned long clone_flags;
211         unsigned long newsp;
212
213         /* syscall2 puts clone_flags in r0 and usp in r1 */
214         clone_flags = regs->r0;
215         newsp = regs->r1;
216         if (!newsp)
217                 newsp = rdusp();
218         else
219                 newsp -= 12;
220         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
221 }
222
223 int
224 copy_thread(int nr, unsigned long clone_flags,
225             unsigned long usp, unsigned long topstk,
226             struct task_struct *p, struct pt_regs *regs)
227 {
228         struct pt_regs *childregs;
229
230         childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
231         *childregs = *regs;
232         childregs->r0 = 0;
233
234         p->thread.usp = usp;
235         p->thread.ksp = (unsigned long)childregs;
236         p->thread.pc = (unsigned long)ret_from_fork;
237
238         return 0;
239 }
240
241 /*
242  * fill in the user structure for a core dump..
243  */
244 void dump_thread(struct pt_regs *regs, struct user *dump)
245 {
246         dump->magic = CMAGIC;
247         dump->start_code = 0;
248         dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
249         dump->u_tsize = ((unsigned long)current->mm->end_code) >> PAGE_SHIFT;
250         dump->u_dsize = ((unsigned long)(current->mm->brk +
251                                          (PAGE_SIZE - 1))) >> PAGE_SHIFT;
252         dump->u_dsize -= dump->u_tsize;
253         dump->u_ssize = 0;
254
255         if (dump->start_stack < TASK_SIZE)
256                 dump->u_ssize =
257                     ((unsigned long)(TASK_SIZE -
258                                      dump->start_stack)) >> PAGE_SHIFT;
259
260         dump->u_ar0 = (struct user_regs_struct *)((int)&dump->regs - (int)dump);
261
262         dump->regs.r0 = regs->r0;
263         dump->regs.r1 = regs->r1;
264         dump->regs.r2 = regs->r2;
265         dump->regs.r3 = regs->r3;
266         dump->regs.r4 = regs->r4;
267         dump->regs.r5 = regs->r5;
268         dump->regs.r6 = regs->r6;
269         dump->regs.r7 = regs->r7;
270         dump->regs.p0 = regs->p0;
271         dump->regs.p1 = regs->p1;
272         dump->regs.p2 = regs->p2;
273         dump->regs.p3 = regs->p3;
274         dump->regs.p4 = regs->p4;
275         dump->regs.p5 = regs->p5;
276         dump->regs.orig_p0 = regs->orig_p0;
277         dump->regs.a0w = regs->a0w;
278         dump->regs.a1w = regs->a1w;
279         dump->regs.a0x = regs->a0x;
280         dump->regs.a1x = regs->a1x;
281         dump->regs.rets = regs->rets;
282         dump->regs.astat = regs->astat;
283         dump->regs.pc = regs->pc;
284 }
285
286 /*
287  * sys_execve() executes a new program.
288  */
289
290 asmlinkage int sys_execve(char *name, char **argv, char **envp)
291 {
292         int error;
293         char *filename;
294         struct pt_regs *regs = (struct pt_regs *)((&name) + 6);
295
296         lock_kernel();
297         filename = getname(name);
298         error = PTR_ERR(filename);
299         if (IS_ERR(filename))
300                 goto out;
301         error = do_execve(filename, argv, envp, regs);
302         putname(filename);
303  out:
304         unlock_kernel();
305         return error;
306 }
307
308 unsigned long get_wchan(struct task_struct *p)
309 {
310         unsigned long fp, pc;
311         unsigned long stack_page;
312         int count = 0;
313         if (!p || p == current || p->state == TASK_RUNNING)
314                 return 0;
315
316         stack_page = (unsigned long)p;
317         fp = p->thread.usp;
318         do {
319                 if (fp < stack_page + sizeof(struct thread_info) ||
320                     fp >= 8184 + stack_page)
321                         return 0;
322                 pc = ((unsigned long *)fp)[1];
323                 if (!in_sched_functions(pc))
324                         return pc;
325                 fp = *(unsigned long *)fp;
326         }
327         while (count++ < 16);
328         return 0;
329 }
330
331 void finish_atomic_sections (struct pt_regs *regs)
332 {
333         if (regs->pc < ATOMIC_SEQS_START || regs->pc >= ATOMIC_SEQS_END)
334                 return;
335
336         switch (regs->pc) {
337         case ATOMIC_XCHG32 + 2:
338                 put_user(regs->r1, (int *)regs->p0);
339                 regs->pc += 2;
340                 break;
341
342         case ATOMIC_CAS32 + 2:
343         case ATOMIC_CAS32 + 4:
344                 if (regs->r0 == regs->r1)
345                         put_user(regs->r2, (int *)regs->p0);
346                 regs->pc = ATOMIC_CAS32 + 8;
347                 break;
348         case ATOMIC_CAS32 + 6:
349                 put_user(regs->r2, (int *)regs->p0);
350                 regs->pc += 2;
351                 break;
352
353         case ATOMIC_ADD32 + 2:
354                 regs->r0 = regs->r1 + regs->r0;
355                 /* fall through */
356         case ATOMIC_ADD32 + 4:
357                 put_user(regs->r0, (int *)regs->p0);
358                 regs->pc = ATOMIC_ADD32 + 6;
359                 break;
360
361         case ATOMIC_SUB32 + 2:
362                 regs->r0 = regs->r1 - regs->r0;
363                 /* fall through */
364         case ATOMIC_SUB32 + 4:
365                 put_user(regs->r0, (int *)regs->p0);
366                 regs->pc = ATOMIC_SUB32 + 6;
367                 break;
368
369         case ATOMIC_IOR32 + 2:
370                 regs->r0 = regs->r1 | regs->r0;
371                 /* fall through */
372         case ATOMIC_IOR32 + 4:
373                 put_user(regs->r0, (int *)regs->p0);
374                 regs->pc = ATOMIC_IOR32 + 6;
375                 break;
376
377         case ATOMIC_AND32 + 2:
378                 regs->r0 = regs->r1 & regs->r0;
379                 /* fall through */
380         case ATOMIC_AND32 + 4:
381                 put_user(regs->r0, (int *)regs->p0);
382                 regs->pc = ATOMIC_AND32 + 6;
383                 break;
384
385         case ATOMIC_XOR32 + 2:
386                 regs->r0 = regs->r1 ^ regs->r0;
387                 /* fall through */
388         case ATOMIC_XOR32 + 4:
389                 put_user(regs->r0, (int *)regs->p0);
390                 regs->pc = ATOMIC_XOR32 + 6;
391                 break;
392         }
393 }
394
395 #if defined(CONFIG_ACCESS_CHECK)
396 int _access_ok(unsigned long addr, unsigned long size)
397 {
398         if (size == 0)
399                 return 1;
400         if (addr > (addr + size))
401                 return 0;
402         if (segment_eq(get_fs(), KERNEL_DS))
403                 return 1;
404 #ifdef CONFIG_MTD_UCLINUX
405         if (addr >= memory_start && (addr + size) <= memory_end)
406                 return 1;
407         if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end)
408                 return 1;
409 #else
410         if (addr >= memory_start && (addr + size) <= physical_mem_end)
411                 return 1;
412 #endif
413         if (addr >= (unsigned long)__init_begin &&
414             addr + size <= (unsigned long)__init_end)
415                 return 1;
416         if (addr >= L1_SCRATCH_START
417             && addr + size <= L1_SCRATCH_START + L1_SCRATCH_LENGTH)
418                 return 1;
419 #if L1_CODE_LENGTH != 0
420         if (addr >= L1_CODE_START + (_etext_l1 - _stext_l1)
421             && addr + size <= L1_CODE_START + L1_CODE_LENGTH)
422                 return 1;
423 #endif
424 #if L1_DATA_A_LENGTH != 0
425         if (addr >= L1_DATA_A_START + (_ebss_l1 - _sdata_l1)
426             && addr + size <= L1_DATA_A_START + L1_DATA_A_LENGTH)
427                 return 1;
428 #endif
429 #if L1_DATA_B_LENGTH != 0
430         if (addr >= L1_DATA_B_START
431             && addr + size <= L1_DATA_B_START + L1_DATA_B_LENGTH)
432                 return 1;
433 #endif
434         return 0;
435 }
436 EXPORT_SYMBOL(_access_ok);
437 #endif /* CONFIG_ACCESS_CHECK */