Blackfin: bf54x: drop unused legacy MMR names
[linux-2.6.git] / arch / blackfin / kernel / process.c
1 /*
2  * Blackfin architecture-dependent process handling
3  *
4  * Copyright 2004-2009 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later
7  */
8
9 #include <linux/module.h>
10 #include <linux/unistd.h>
11 #include <linux/user.h>
12 #include <linux/uaccess.h>
13 #include <linux/slab.h>
14 #include <linux/sched.h>
15 #include <linux/tick.h>
16 #include <linux/fs.h>
17 #include <linux/err.h>
18
19 #include <asm/blackfin.h>
20 #include <asm/fixed_code.h>
21 #include <asm/mem_map.h>
22
23 asmlinkage void ret_from_fork(void);
24
25 /* Points to the SDRAM backup memory for the stack that is currently in
26  * L1 scratchpad memory.
27  */
28 void *current_l1_stack_save;
29
30 /* The number of tasks currently using a L1 stack area.  The SRAM is
31  * allocated/deallocated whenever this changes from/to zero.
32  */
33 int nr_l1stack_tasks;
34
35 /* Start and length of the area in L1 scratchpad memory which we've allocated
36  * for process stacks.
37  */
38 void *l1_stack_base;
39 unsigned long l1_stack_len;
40
41 /*
42  * Powermanagement idle function, if any..
43  */
44 void (*pm_idle)(void) = NULL;
45 EXPORT_SYMBOL(pm_idle);
46
47 void (*pm_power_off)(void) = NULL;
48 EXPORT_SYMBOL(pm_power_off);
49
50 /*
51  * The idle loop on BFIN
52  */
53 #ifdef CONFIG_IDLE_L1
54 static void default_idle(void)__attribute__((l1_text));
55 void cpu_idle(void)__attribute__((l1_text));
56 #endif
57
58 /*
59  * This is our default idle handler.  We need to disable
60  * interrupts here to ensure we don't miss a wakeup call.
61  */
62 static void default_idle(void)
63 {
64 #ifdef CONFIG_IPIPE
65         ipipe_suspend_domain();
66 #endif
67         hard_local_irq_disable();
68         if (!need_resched())
69                 idle_with_irq_disabled();
70
71         hard_local_irq_enable();
72 }
73
74 /*
75  * The idle thread.  We try to conserve power, while trying to keep
76  * overall latency low.  The architecture specific idle is passed
77  * a value to indicate the level of "idleness" of the system.
78  */
79 void cpu_idle(void)
80 {
81         /* endless idle loop with no priority at all */
82         while (1) {
83                 void (*idle)(void) = pm_idle;
84
85 #ifdef CONFIG_HOTPLUG_CPU
86                 if (cpu_is_offline(smp_processor_id()))
87                         cpu_die();
88 #endif
89                 if (!idle)
90                         idle = default_idle;
91                 tick_nohz_stop_sched_tick(1);
92                 while (!need_resched())
93                         idle();
94                 tick_nohz_restart_sched_tick();
95                 preempt_enable_no_resched();
96                 schedule();
97                 preempt_disable();
98         }
99 }
100
101 /*
102  * This gets run with P1 containing the
103  * function to call, and R1 containing
104  * the "args".  Note P0 is clobbered on the way here.
105  */
106 void kernel_thread_helper(void);
107 __asm__(".section .text\n"
108         ".align 4\n"
109         "_kernel_thread_helper:\n\t"
110         "\tsp += -12;\n\t"
111         "\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");
112
113 /*
114  * Create a kernel thread.
115  */
116 pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
117 {
118         struct pt_regs regs;
119
120         memset(&regs, 0, sizeof(regs));
121
122         regs.r1 = (unsigned long)arg;
123         regs.p1 = (unsigned long)fn;
124         regs.pc = (unsigned long)kernel_thread_helper;
125         regs.orig_p0 = -1;
126         /* Set bit 2 to tell ret_from_fork we should be returning to kernel
127            mode.  */
128         regs.ipend = 0x8002;
129         __asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):);
130         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
131                        NULL);
132 }
133 EXPORT_SYMBOL(kernel_thread);
134
135 /*
136  * Do necessary setup to start up a newly executed thread.
137  *
138  * pass the data segment into user programs if it exists,
139  * it can't hurt anything as far as I can tell
140  */
141 void start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
142 {
143         set_fs(USER_DS);
144         regs->pc = new_ip;
145         if (current->mm)
146                 regs->p5 = current->mm->start_data;
147 #ifndef CONFIG_SMP
148         task_thread_info(current)->l1_task_info.stack_start =
149                 (void *)current->mm->context.stack_start;
150         task_thread_info(current)->l1_task_info.lowest_sp = (void *)new_sp;
151         memcpy(L1_SCRATCH_TASK_INFO, &task_thread_info(current)->l1_task_info,
152                sizeof(*L1_SCRATCH_TASK_INFO));
153 #endif
154         wrusp(new_sp);
155 }
156 EXPORT_SYMBOL_GPL(start_thread);
157
158 void flush_thread(void)
159 {
160 }
161
162 asmlinkage int bfin_vfork(struct pt_regs *regs)
163 {
164         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
165                        NULL);
166 }
167
168 asmlinkage int bfin_clone(struct pt_regs *regs)
169 {
170         unsigned long clone_flags;
171         unsigned long newsp;
172
173 #ifdef __ARCH_SYNC_CORE_DCACHE
174         if (current->rt.nr_cpus_allowed == num_possible_cpus()) {
175                 current->cpus_allowed = cpumask_of_cpu(smp_processor_id());
176                 current->rt.nr_cpus_allowed = 1;
177         }
178 #endif
179
180         /* syscall2 puts clone_flags in r0 and usp in r1 */
181         clone_flags = regs->r0;
182         newsp = regs->r1;
183         if (!newsp)
184                 newsp = rdusp();
185         else
186                 newsp -= 12;
187         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
188 }
189
190 int
191 copy_thread(unsigned long clone_flags,
192             unsigned long usp, unsigned long topstk,
193             struct task_struct *p, struct pt_regs *regs)
194 {
195         struct pt_regs *childregs;
196
197         childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
198         *childregs = *regs;
199         childregs->r0 = 0;
200
201         p->thread.usp = usp;
202         p->thread.ksp = (unsigned long)childregs;
203         p->thread.pc = (unsigned long)ret_from_fork;
204
205         return 0;
206 }
207
208 /*
209  * sys_execve() executes a new program.
210  */
211 asmlinkage int sys_execve(const char __user *name,
212                           const char __user *const __user *argv,
213                           const char __user *const __user *envp)
214 {
215         int error;
216         char *filename;
217         struct pt_regs *regs = (struct pt_regs *)((&name) + 6);
218
219         filename = getname(name);
220         error = PTR_ERR(filename);
221         if (IS_ERR(filename))
222                 return error;
223         error = do_execve(filename, argv, envp, regs);
224         putname(filename);
225         return error;
226 }
227
228 unsigned long get_wchan(struct task_struct *p)
229 {
230         unsigned long fp, pc;
231         unsigned long stack_page;
232         int count = 0;
233         if (!p || p == current || p->state == TASK_RUNNING)
234                 return 0;
235
236         stack_page = (unsigned long)p;
237         fp = p->thread.usp;
238         do {
239                 if (fp < stack_page + sizeof(struct thread_info) ||
240                     fp >= 8184 + stack_page)
241                         return 0;
242                 pc = ((unsigned long *)fp)[1];
243                 if (!in_sched_functions(pc))
244                         return pc;
245                 fp = *(unsigned long *)fp;
246         }
247         while (count++ < 16);
248         return 0;
249 }
250
251 void finish_atomic_sections (struct pt_regs *regs)
252 {
253         int __user *up0 = (int __user *)regs->p0;
254
255         switch (regs->pc) {
256         default:
257                 /* not in middle of an atomic step, so resume like normal */
258                 return;
259
260         case ATOMIC_XCHG32 + 2:
261                 put_user(regs->r1, up0);
262                 break;
263
264         case ATOMIC_CAS32 + 2:
265         case ATOMIC_CAS32 + 4:
266                 if (regs->r0 == regs->r1)
267         case ATOMIC_CAS32 + 6:
268                         put_user(regs->r2, up0);
269                 break;
270
271         case ATOMIC_ADD32 + 2:
272                 regs->r0 = regs->r1 + regs->r0;
273                 /* fall through */
274         case ATOMIC_ADD32 + 4:
275                 put_user(regs->r0, up0);
276                 break;
277
278         case ATOMIC_SUB32 + 2:
279                 regs->r0 = regs->r1 - regs->r0;
280                 /* fall through */
281         case ATOMIC_SUB32 + 4:
282                 put_user(regs->r0, up0);
283                 break;
284
285         case ATOMIC_IOR32 + 2:
286                 regs->r0 = regs->r1 | regs->r0;
287                 /* fall through */
288         case ATOMIC_IOR32 + 4:
289                 put_user(regs->r0, up0);
290                 break;
291
292         case ATOMIC_AND32 + 2:
293                 regs->r0 = regs->r1 & regs->r0;
294                 /* fall through */
295         case ATOMIC_AND32 + 4:
296                 put_user(regs->r0, up0);
297                 break;
298
299         case ATOMIC_XOR32 + 2:
300                 regs->r0 = regs->r1 ^ regs->r0;
301                 /* fall through */
302         case ATOMIC_XOR32 + 4:
303                 put_user(regs->r0, up0);
304                 break;
305         }
306
307         /*
308          * We've finished the atomic section, and the only thing left for
309          * userspace is to do a RTS, so we might as well handle that too
310          * since we need to update the PC anyways.
311          */
312         regs->pc = regs->rets;
313 }
314
315 static inline
316 int in_mem(unsigned long addr, unsigned long size,
317            unsigned long start, unsigned long end)
318 {
319         return addr >= start && addr + size <= end;
320 }
321 static inline
322 int in_mem_const_off(unsigned long addr, unsigned long size, unsigned long off,
323                      unsigned long const_addr, unsigned long const_size)
324 {
325         return const_size &&
326                in_mem(addr, size, const_addr + off, const_addr + const_size);
327 }
328 static inline
329 int in_mem_const(unsigned long addr, unsigned long size,
330                  unsigned long const_addr, unsigned long const_size)
331 {
332         return in_mem_const_off(addr, size, 0, const_addr, const_size);
333 }
334 #define ASYNC_ENABLED(bnum, bctlnum) \
335 ({ \
336         (bfin_read_EBIU_AMGCTL() & 0xe) < ((bnum + 1) << 1) ? 0 : \
337         bfin_read_EBIU_AMBCTL##bctlnum() & B##bnum##RDYEN ? 0 : \
338         1; \
339 })
340 /*
341  * We can't read EBIU banks that aren't enabled or we end up hanging
342  * on the access to the async space.  Make sure we validate accesses
343  * that cross async banks too.
344  *      0 - found, but unusable
345  *      1 - found & usable
346  *      2 - not found
347  */
348 static
349 int in_async(unsigned long addr, unsigned long size)
350 {
351         if (addr >= ASYNC_BANK0_BASE && addr < ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE) {
352                 if (!ASYNC_ENABLED(0, 0))
353                         return 0;
354                 if (addr + size <= ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE)
355                         return 1;
356                 size -= ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE - addr;
357                 addr = ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE;
358         }
359         if (addr >= ASYNC_BANK1_BASE && addr < ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE) {
360                 if (!ASYNC_ENABLED(1, 0))
361                         return 0;
362                 if (addr + size <= ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE)
363                         return 1;
364                 size -= ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE - addr;
365                 addr = ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE;
366         }
367         if (addr >= ASYNC_BANK2_BASE && addr < ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE) {
368                 if (!ASYNC_ENABLED(2, 1))
369                         return 0;
370                 if (addr + size <= ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE)
371                         return 1;
372                 size -= ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE - addr;
373                 addr = ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE;
374         }
375         if (addr >= ASYNC_BANK3_BASE && addr < ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE) {
376                 if (ASYNC_ENABLED(3, 1))
377                         return 0;
378                 if (addr + size <= ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE)
379                         return 1;
380                 return 0;
381         }
382
383         /* not within async bounds */
384         return 2;
385 }
386
387 int bfin_mem_access_type(unsigned long addr, unsigned long size)
388 {
389         int cpu = raw_smp_processor_id();
390
391         /* Check that things do not wrap around */
392         if (addr > ULONG_MAX - size)
393                 return -EFAULT;
394
395         if (in_mem(addr, size, FIXED_CODE_START, physical_mem_end))
396                 return BFIN_MEM_ACCESS_CORE;
397
398         if (in_mem_const(addr, size, L1_CODE_START, L1_CODE_LENGTH))
399                 return cpu == 0 ? BFIN_MEM_ACCESS_ITEST : BFIN_MEM_ACCESS_IDMA;
400         if (in_mem_const(addr, size, L1_SCRATCH_START, L1_SCRATCH_LENGTH))
401                 return cpu == 0 ? BFIN_MEM_ACCESS_CORE_ONLY : -EFAULT;
402         if (in_mem_const(addr, size, L1_DATA_A_START, L1_DATA_A_LENGTH))
403                 return cpu == 0 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
404         if (in_mem_const(addr, size, L1_DATA_B_START, L1_DATA_B_LENGTH))
405                 return cpu == 0 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
406 #ifdef COREB_L1_CODE_START
407         if (in_mem_const(addr, size, COREB_L1_CODE_START, COREB_L1_CODE_LENGTH))
408                 return cpu == 1 ? BFIN_MEM_ACCESS_ITEST : BFIN_MEM_ACCESS_IDMA;
409         if (in_mem_const(addr, size, COREB_L1_SCRATCH_START, L1_SCRATCH_LENGTH))
410                 return cpu == 1 ? BFIN_MEM_ACCESS_CORE_ONLY : -EFAULT;
411         if (in_mem_const(addr, size, COREB_L1_DATA_A_START, COREB_L1_DATA_A_LENGTH))
412                 return cpu == 1 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
413         if (in_mem_const(addr, size, COREB_L1_DATA_B_START, COREB_L1_DATA_B_LENGTH))
414                 return cpu == 1 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
415 #endif
416         if (in_mem_const(addr, size, L2_START, L2_LENGTH))
417                 return BFIN_MEM_ACCESS_CORE;
418
419         if (addr >= SYSMMR_BASE)
420                 return BFIN_MEM_ACCESS_CORE_ONLY;
421
422         switch (in_async(addr, size)) {
423         case 0: return -EFAULT;
424         case 1: return BFIN_MEM_ACCESS_CORE;
425         case 2: /* fall through */;
426         }
427
428         if (in_mem_const(addr, size, BOOT_ROM_START, BOOT_ROM_LENGTH))
429                 return BFIN_MEM_ACCESS_CORE;
430         if (in_mem_const(addr, size, L1_ROM_START, L1_ROM_LENGTH))
431                 return BFIN_MEM_ACCESS_DMA;
432
433         return -EFAULT;
434 }
435
436 #if defined(CONFIG_ACCESS_CHECK)
437 #ifdef CONFIG_ACCESS_OK_L1
438 __attribute__((l1_text))
439 #endif
440 /* Return 1 if access to memory range is OK, 0 otherwise */
441 int _access_ok(unsigned long addr, unsigned long size)
442 {
443         int aret;
444
445         if (size == 0)
446                 return 1;
447         /* Check that things do not wrap around */
448         if (addr > ULONG_MAX - size)
449                 return 0;
450         if (segment_eq(get_fs(), KERNEL_DS))
451                 return 1;
452 #ifdef CONFIG_MTD_UCLINUX
453         if (1)
454 #else
455         if (0)
456 #endif
457         {
458                 if (in_mem(addr, size, memory_start, memory_end))
459                         return 1;
460                 if (in_mem(addr, size, memory_mtd_end, physical_mem_end))
461                         return 1;
462 # ifndef CONFIG_ROMFS_ON_MTD
463                 if (0)
464 # endif
465                         /* For XIP, allow user space to use pointers within the ROMFS.  */
466                         if (in_mem(addr, size, memory_mtd_start, memory_mtd_end))
467                                 return 1;
468         } else {
469                 if (in_mem(addr, size, memory_start, physical_mem_end))
470                         return 1;
471         }
472
473         if (in_mem(addr, size, (unsigned long)__init_begin, (unsigned long)__init_end))
474                 return 1;
475
476         if (in_mem_const(addr, size, L1_CODE_START, L1_CODE_LENGTH))
477                 return 1;
478         if (in_mem_const_off(addr, size, _etext_l1 - _stext_l1, L1_CODE_START, L1_CODE_LENGTH))
479                 return 1;
480         if (in_mem_const_off(addr, size, _ebss_l1 - _sdata_l1, L1_DATA_A_START, L1_DATA_A_LENGTH))
481                 return 1;
482         if (in_mem_const_off(addr, size, _ebss_b_l1 - _sdata_b_l1, L1_DATA_B_START, L1_DATA_B_LENGTH))
483                 return 1;
484 #ifdef COREB_L1_CODE_START
485         if (in_mem_const(addr, size, COREB_L1_CODE_START, COREB_L1_CODE_LENGTH))
486                 return 1;
487         if (in_mem_const(addr, size, COREB_L1_SCRATCH_START, L1_SCRATCH_LENGTH))
488                 return 1;
489         if (in_mem_const(addr, size, COREB_L1_DATA_A_START, COREB_L1_DATA_A_LENGTH))
490                 return 1;
491         if (in_mem_const(addr, size, COREB_L1_DATA_B_START, COREB_L1_DATA_B_LENGTH))
492                 return 1;
493 #endif
494
495 #ifndef CONFIG_EXCEPTION_L1_SCRATCH
496         if (in_mem_const(addr, size, (unsigned long)l1_stack_base, l1_stack_len))
497                 return 1;
498 #endif
499
500         aret = in_async(addr, size);
501         if (aret < 2)
502                 return aret;
503
504         if (in_mem_const_off(addr, size, _ebss_l2 - _stext_l2, L2_START, L2_LENGTH))
505                 return 1;
506
507         if (in_mem_const(addr, size, BOOT_ROM_START, BOOT_ROM_LENGTH))
508                 return 1;
509         if (in_mem_const(addr, size, L1_ROM_START, L1_ROM_LENGTH))
510                 return 1;
511
512         return 0;
513 }
514 EXPORT_SYMBOL(_access_ok);
515 #endif /* CONFIG_ACCESS_CHECK */