2 * Blackfin architecture-dependent process handling
4 * Copyright 2004-2009 Analog Devices Inc.
6 * Licensed under the GPL-2 or later
9 #include <linux/module.h>
10 #include <linux/smp_lock.h>
11 #include <linux/unistd.h>
12 #include <linux/user.h>
13 #include <linux/uaccess.h>
14 #include <linux/slab.h>
15 #include <linux/sched.h>
16 #include <linux/tick.h>
18 #include <linux/err.h>
20 #include <asm/blackfin.h>
21 #include <asm/fixed_code.h>
22 #include <asm/mem_map.h>
24 asmlinkage
void ret_from_fork(void);
26 /* Points to the SDRAM backup memory for the stack that is currently in
27 * L1 scratchpad memory.
29 void *current_l1_stack_save
;
31 /* The number of tasks currently using a L1 stack area. The SRAM is
32 * allocated/deallocated whenever this changes from/to zero.
36 /* Start and length of the area in L1 scratchpad memory which we've allocated
40 unsigned long l1_stack_len
;
43 * Powermanagement idle function, if any..
45 void (*pm_idle
)(void) = NULL
;
46 EXPORT_SYMBOL(pm_idle
);
48 void (*pm_power_off
)(void) = NULL
;
49 EXPORT_SYMBOL(pm_power_off
);
52 * The idle loop on BFIN
55 static void default_idle(void)__attribute__((l1_text
));
56 void cpu_idle(void)__attribute__((l1_text
));
60 * This is our default idle handler. We need to disable
61 * interrupts here to ensure we don't miss a wakeup call.
63 static void default_idle(void)
66 ipipe_suspend_domain();
68 hard_local_irq_disable();
70 idle_with_irq_disabled();
72 hard_local_irq_enable();
76 * The idle thread. We try to conserve power, while trying to keep
77 * overall latency low. The architecture specific idle is passed
78 * a value to indicate the level of "idleness" of the system.
82 /* endless idle loop with no priority at all */
84 void (*idle
)(void) = pm_idle
;
86 #ifdef CONFIG_HOTPLUG_CPU
87 if (cpu_is_offline(smp_processor_id()))
92 tick_nohz_stop_sched_tick(1);
93 while (!need_resched())
95 tick_nohz_restart_sched_tick();
96 preempt_enable_no_resched();
103 * This gets run with P1 containing the
104 * function to call, and R1 containing
105 * the "args". Note P0 is clobbered on the way here.
107 void kernel_thread_helper(void);
108 __asm__(".section .text\n"
110 "_kernel_thread_helper:\n\t"
112 "\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");
115 * Create a kernel thread.
117 pid_t
kernel_thread(int (*fn
) (void *), void *arg
, unsigned long flags
)
121 memset(®s
, 0, sizeof(regs
));
123 regs
.r1
= (unsigned long)arg
;
124 regs
.p1
= (unsigned long)fn
;
125 regs
.pc
= (unsigned long)kernel_thread_helper
;
127 /* Set bit 2 to tell ret_from_fork we should be returning to kernel
130 __asm__
__volatile__("%0 = syscfg;":"=da"(regs
.syscfg
):);
131 return do_fork(flags
| CLONE_VM
| CLONE_UNTRACED
, 0, ®s
, 0, NULL
,
134 EXPORT_SYMBOL(kernel_thread
);
137 * Do necessary setup to start up a newly executed thread.
139 * pass the data segment into user programs if it exists,
140 * it can't hurt anything as far as I can tell
142 void start_thread(struct pt_regs
*regs
, unsigned long new_ip
, unsigned long new_sp
)
147 regs
->p5
= current
->mm
->start_data
;
149 task_thread_info(current
)->l1_task_info
.stack_start
=
150 (void *)current
->mm
->context
.stack_start
;
151 task_thread_info(current
)->l1_task_info
.lowest_sp
= (void *)new_sp
;
152 memcpy(L1_SCRATCH_TASK_INFO
, &task_thread_info(current
)->l1_task_info
,
153 sizeof(*L1_SCRATCH_TASK_INFO
));
157 EXPORT_SYMBOL_GPL(start_thread
);
159 void flush_thread(void)
163 asmlinkage
int bfin_vfork(struct pt_regs
*regs
)
165 return do_fork(CLONE_VFORK
| CLONE_VM
| SIGCHLD
, rdusp(), regs
, 0, NULL
,
169 asmlinkage
int bfin_clone(struct pt_regs
*regs
)
171 unsigned long clone_flags
;
174 #ifdef __ARCH_SYNC_CORE_DCACHE
175 if (current
->rt
.nr_cpus_allowed
== num_possible_cpus()) {
176 current
->cpus_allowed
= cpumask_of_cpu(smp_processor_id());
177 current
->rt
.nr_cpus_allowed
= 1;
181 /* syscall2 puts clone_flags in r0 and usp in r1 */
182 clone_flags
= regs
->r0
;
188 return do_fork(clone_flags
, newsp
, regs
, 0, NULL
, NULL
);
192 copy_thread(unsigned long clone_flags
,
193 unsigned long usp
, unsigned long topstk
,
194 struct task_struct
*p
, struct pt_regs
*regs
)
196 struct pt_regs
*childregs
;
198 childregs
= (struct pt_regs
*) (task_stack_page(p
) + THREAD_SIZE
) - 1;
203 p
->thread
.ksp
= (unsigned long)childregs
;
204 p
->thread
.pc
= (unsigned long)ret_from_fork
;
210 * sys_execve() executes a new program.
212 asmlinkage
int sys_execve(const char __user
*name
,
213 const char __user
*const __user
*argv
,
214 const char __user
*const __user
*envp
)
218 struct pt_regs
*regs
= (struct pt_regs
*)((&name
) + 6);
220 filename
= getname(name
);
221 error
= PTR_ERR(filename
);
222 if (IS_ERR(filename
))
224 error
= do_execve(filename
, argv
, envp
, regs
);
229 unsigned long get_wchan(struct task_struct
*p
)
231 unsigned long fp
, pc
;
232 unsigned long stack_page
;
234 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
237 stack_page
= (unsigned long)p
;
240 if (fp
< stack_page
+ sizeof(struct thread_info
) ||
241 fp
>= 8184 + stack_page
)
243 pc
= ((unsigned long *)fp
)[1];
244 if (!in_sched_functions(pc
))
246 fp
= *(unsigned long *)fp
;
248 while (count
++ < 16);
252 void finish_atomic_sections (struct pt_regs
*regs
)
254 int __user
*up0
= (int __user
*)regs
->p0
;
258 /* not in middle of an atomic step, so resume like normal */
261 case ATOMIC_XCHG32
+ 2:
262 put_user(regs
->r1
, up0
);
265 case ATOMIC_CAS32
+ 2:
266 case ATOMIC_CAS32
+ 4:
267 if (regs
->r0
== regs
->r1
)
268 case ATOMIC_CAS32
+ 6:
269 put_user(regs
->r2
, up0
);
272 case ATOMIC_ADD32
+ 2:
273 regs
->r0
= regs
->r1
+ regs
->r0
;
275 case ATOMIC_ADD32
+ 4:
276 put_user(regs
->r0
, up0
);
279 case ATOMIC_SUB32
+ 2:
280 regs
->r0
= regs
->r1
- regs
->r0
;
282 case ATOMIC_SUB32
+ 4:
283 put_user(regs
->r0
, up0
);
286 case ATOMIC_IOR32
+ 2:
287 regs
->r0
= regs
->r1
| regs
->r0
;
289 case ATOMIC_IOR32
+ 4:
290 put_user(regs
->r0
, up0
);
293 case ATOMIC_AND32
+ 2:
294 regs
->r0
= regs
->r1
& regs
->r0
;
296 case ATOMIC_AND32
+ 4:
297 put_user(regs
->r0
, up0
);
300 case ATOMIC_XOR32
+ 2:
301 regs
->r0
= regs
->r1
^ regs
->r0
;
303 case ATOMIC_XOR32
+ 4:
304 put_user(regs
->r0
, up0
);
309 * We've finished the atomic section, and the only thing left for
310 * userspace is to do a RTS, so we might as well handle that too
311 * since we need to update the PC anyways.
313 regs
->pc
= regs
->rets
;
317 int in_mem(unsigned long addr
, unsigned long size
,
318 unsigned long start
, unsigned long end
)
320 return addr
>= start
&& addr
+ size
<= end
;
323 int in_mem_const_off(unsigned long addr
, unsigned long size
, unsigned long off
,
324 unsigned long const_addr
, unsigned long const_size
)
327 in_mem(addr
, size
, const_addr
+ off
, const_addr
+ const_size
);
330 int in_mem_const(unsigned long addr
, unsigned long size
,
331 unsigned long const_addr
, unsigned long const_size
)
333 return in_mem_const_off(addr
, size
, 0, const_addr
, const_size
);
335 #define ASYNC_ENABLED(bnum, bctlnum) \
337 (bfin_read_EBIU_AMGCTL() & 0xe) < ((bnum + 1) << 1) ? 0 : \
338 bfin_read_EBIU_AMBCTL##bctlnum() & B##bnum##RDYEN ? 0 : \
342 * We can't read EBIU banks that aren't enabled or we end up hanging
343 * on the access to the async space. Make sure we validate accesses
344 * that cross async banks too.
345 * 0 - found, but unusable
350 int in_async(unsigned long addr
, unsigned long size
)
352 if (addr
>= ASYNC_BANK0_BASE
&& addr
< ASYNC_BANK0_BASE
+ ASYNC_BANK0_SIZE
) {
353 if (!ASYNC_ENABLED(0, 0))
355 if (addr
+ size
<= ASYNC_BANK0_BASE
+ ASYNC_BANK0_SIZE
)
357 size
-= ASYNC_BANK0_BASE
+ ASYNC_BANK0_SIZE
- addr
;
358 addr
= ASYNC_BANK0_BASE
+ ASYNC_BANK0_SIZE
;
360 if (addr
>= ASYNC_BANK1_BASE
&& addr
< ASYNC_BANK1_BASE
+ ASYNC_BANK1_SIZE
) {
361 if (!ASYNC_ENABLED(1, 0))
363 if (addr
+ size
<= ASYNC_BANK1_BASE
+ ASYNC_BANK1_SIZE
)
365 size
-= ASYNC_BANK1_BASE
+ ASYNC_BANK1_SIZE
- addr
;
366 addr
= ASYNC_BANK1_BASE
+ ASYNC_BANK1_SIZE
;
368 if (addr
>= ASYNC_BANK2_BASE
&& addr
< ASYNC_BANK2_BASE
+ ASYNC_BANK2_SIZE
) {
369 if (!ASYNC_ENABLED(2, 1))
371 if (addr
+ size
<= ASYNC_BANK2_BASE
+ ASYNC_BANK2_SIZE
)
373 size
-= ASYNC_BANK2_BASE
+ ASYNC_BANK2_SIZE
- addr
;
374 addr
= ASYNC_BANK2_BASE
+ ASYNC_BANK2_SIZE
;
376 if (addr
>= ASYNC_BANK3_BASE
&& addr
< ASYNC_BANK3_BASE
+ ASYNC_BANK3_SIZE
) {
377 if (ASYNC_ENABLED(3, 1))
379 if (addr
+ size
<= ASYNC_BANK3_BASE
+ ASYNC_BANK3_SIZE
)
384 /* not within async bounds */
388 int bfin_mem_access_type(unsigned long addr
, unsigned long size
)
390 int cpu
= raw_smp_processor_id();
392 /* Check that things do not wrap around */
393 if (addr
> ULONG_MAX
- size
)
396 if (in_mem(addr
, size
, FIXED_CODE_START
, physical_mem_end
))
397 return BFIN_MEM_ACCESS_CORE
;
399 if (in_mem_const(addr
, size
, L1_CODE_START
, L1_CODE_LENGTH
))
400 return cpu
== 0 ? BFIN_MEM_ACCESS_ITEST
: BFIN_MEM_ACCESS_IDMA
;
401 if (in_mem_const(addr
, size
, L1_SCRATCH_START
, L1_SCRATCH_LENGTH
))
402 return cpu
== 0 ? BFIN_MEM_ACCESS_CORE_ONLY
: -EFAULT
;
403 if (in_mem_const(addr
, size
, L1_DATA_A_START
, L1_DATA_A_LENGTH
))
404 return cpu
== 0 ? BFIN_MEM_ACCESS_CORE
: BFIN_MEM_ACCESS_IDMA
;
405 if (in_mem_const(addr
, size
, L1_DATA_B_START
, L1_DATA_B_LENGTH
))
406 return cpu
== 0 ? BFIN_MEM_ACCESS_CORE
: BFIN_MEM_ACCESS_IDMA
;
407 #ifdef COREB_L1_CODE_START
408 if (in_mem_const(addr
, size
, COREB_L1_CODE_START
, COREB_L1_CODE_LENGTH
))
409 return cpu
== 1 ? BFIN_MEM_ACCESS_ITEST
: BFIN_MEM_ACCESS_IDMA
;
410 if (in_mem_const(addr
, size
, COREB_L1_SCRATCH_START
, L1_SCRATCH_LENGTH
))
411 return cpu
== 1 ? BFIN_MEM_ACCESS_CORE_ONLY
: -EFAULT
;
412 if (in_mem_const(addr
, size
, COREB_L1_DATA_A_START
, COREB_L1_DATA_A_LENGTH
))
413 return cpu
== 1 ? BFIN_MEM_ACCESS_CORE
: BFIN_MEM_ACCESS_IDMA
;
414 if (in_mem_const(addr
, size
, COREB_L1_DATA_B_START
, COREB_L1_DATA_B_LENGTH
))
415 return cpu
== 1 ? BFIN_MEM_ACCESS_CORE
: BFIN_MEM_ACCESS_IDMA
;
417 if (in_mem_const(addr
, size
, L2_START
, L2_LENGTH
))
418 return BFIN_MEM_ACCESS_CORE
;
420 if (addr
>= SYSMMR_BASE
)
421 return BFIN_MEM_ACCESS_CORE_ONLY
;
423 switch (in_async(addr
, size
)) {
424 case 0: return -EFAULT
;
425 case 1: return BFIN_MEM_ACCESS_CORE
;
426 case 2: /* fall through */;
429 if (in_mem_const(addr
, size
, BOOT_ROM_START
, BOOT_ROM_LENGTH
))
430 return BFIN_MEM_ACCESS_CORE
;
431 if (in_mem_const(addr
, size
, L1_ROM_START
, L1_ROM_LENGTH
))
432 return BFIN_MEM_ACCESS_DMA
;
437 #if defined(CONFIG_ACCESS_CHECK)
438 #ifdef CONFIG_ACCESS_OK_L1
439 __attribute__((l1_text
))
441 /* Return 1 if access to memory range is OK, 0 otherwise */
442 int _access_ok(unsigned long addr
, unsigned long size
)
448 /* Check that things do not wrap around */
449 if (addr
> ULONG_MAX
- size
)
451 if (segment_eq(get_fs(), KERNEL_DS
))
453 #ifdef CONFIG_MTD_UCLINUX
459 if (in_mem(addr
, size
, memory_start
, memory_end
))
461 if (in_mem(addr
, size
, memory_mtd_end
, physical_mem_end
))
463 # ifndef CONFIG_ROMFS_ON_MTD
466 /* For XIP, allow user space to use pointers within the ROMFS. */
467 if (in_mem(addr
, size
, memory_mtd_start
, memory_mtd_end
))
470 if (in_mem(addr
, size
, memory_start
, physical_mem_end
))
474 if (in_mem(addr
, size
, (unsigned long)__init_begin
, (unsigned long)__init_end
))
477 if (in_mem_const(addr
, size
, L1_CODE_START
, L1_CODE_LENGTH
))
479 if (in_mem_const_off(addr
, size
, _etext_l1
- _stext_l1
, L1_CODE_START
, L1_CODE_LENGTH
))
481 if (in_mem_const_off(addr
, size
, _ebss_l1
- _sdata_l1
, L1_DATA_A_START
, L1_DATA_A_LENGTH
))
483 if (in_mem_const_off(addr
, size
, _ebss_b_l1
- _sdata_b_l1
, L1_DATA_B_START
, L1_DATA_B_LENGTH
))
485 #ifdef COREB_L1_CODE_START
486 if (in_mem_const(addr
, size
, COREB_L1_CODE_START
, COREB_L1_CODE_LENGTH
))
488 if (in_mem_const(addr
, size
, COREB_L1_SCRATCH_START
, L1_SCRATCH_LENGTH
))
490 if (in_mem_const(addr
, size
, COREB_L1_DATA_A_START
, COREB_L1_DATA_A_LENGTH
))
492 if (in_mem_const(addr
, size
, COREB_L1_DATA_B_START
, COREB_L1_DATA_B_LENGTH
))
496 #ifndef CONFIG_EXCEPTION_L1_SCRATCH
497 if (in_mem_const(addr
, size
, (unsigned long)l1_stack_base
, l1_stack_len
))
501 aret
= in_async(addr
, size
);
505 if (in_mem_const_off(addr
, size
, _ebss_l2
- _stext_l2
, L2_START
, L2_LENGTH
))
508 if (in_mem_const(addr
, size
, BOOT_ROM_START
, BOOT_ROM_LENGTH
))
510 if (in_mem_const(addr
, size
, L1_ROM_START
, L1_ROM_LENGTH
))
515 EXPORT_SYMBOL(_access_ok
);
516 #endif /* CONFIG_ACCESS_CHECK */