Merge git://git.kernel.org/pub/scm/linux/kernel/git/bart/linux-hdreg-h-cleanup
[linux-2.6-block.git] / arch / blackfin / kernel / process.c
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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>
1f83b8f1 34#include <linux/uaccess.h>
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35#include <linux/sched.h>
36#include <linux/tick.h>
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37#include <linux/fs.h>
38#include <linux/err.h>
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39
40#include <asm/blackfin.h>
7adfb58f 41#include <asm/fixed_code.h>
dbc895f9 42#include <asm/mem_map.h>
1394f032 43
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44asmlinkage void ret_from_fork(void);
45
46/* Points to the SDRAM backup memory for the stack that is currently in
47 * L1 scratchpad memory.
48 */
49void *current_l1_stack_save;
50
51/* The number of tasks currently using a L1 stack area. The SRAM is
52 * allocated/deallocated whenever this changes from/to zero.
53 */
54int nr_l1stack_tasks;
55
56/* Start and length of the area in L1 scratchpad memory which we've allocated
57 * for process stacks.
58 */
59void *l1_stack_base;
60unsigned long l1_stack_len;
61
62/*
63 * Powermanagement idle function, if any..
64 */
65void (*pm_idle)(void) = NULL;
66EXPORT_SYMBOL(pm_idle);
67
68void (*pm_power_off)(void) = NULL;
69EXPORT_SYMBOL(pm_power_off);
70
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71/*
72 * The idle loop on BFIN
73 */
74#ifdef CONFIG_IDLE_L1
8b5f79f9 75static void default_idle(void)__attribute__((l1_text));
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76void cpu_idle(void)__attribute__((l1_text));
77#endif
78
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79/*
80 * This is our default idle handler. We need to disable
81 * interrupts here to ensure we don't miss a wakeup call.
82 */
83static void default_idle(void)
1394f032 84{
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85#ifdef CONFIG_IPIPE
86 ipipe_suspend_domain();
87#endif
88 local_irq_disable_hw();
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89 if (!need_resched())
90 idle_with_irq_disabled();
1394f032 91
6a01f230 92 local_irq_enable_hw();
8b5f79f9 93}
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94
95/*
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96 * The idle thread. We try to conserve power, while trying to keep
97 * overall latency low. The architecture specific idle is passed
98 * a value to indicate the level of "idleness" of the system.
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99 */
100void cpu_idle(void)
101{
102 /* endless idle loop with no priority at all */
103 while (1) {
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104 void (*idle)(void) = pm_idle;
105
106#ifdef CONFIG_HOTPLUG_CPU
107 if (cpu_is_offline(smp_processor_id()))
108 cpu_die();
109#endif
110 if (!idle)
111 idle = default_idle;
b8f8c3cf 112 tick_nohz_stop_sched_tick(1);
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113 while (!need_resched())
114 idle();
115 tick_nohz_restart_sched_tick();
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116 preempt_enable_no_resched();
117 schedule();
118 preempt_disable();
119 }
120}
121
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122/* Fill in the fpu structure for a core dump. */
123
124int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpregs)
125{
126 return 1;
127}
128
129/*
130 * This gets run with P1 containing the
131 * function to call, and R1 containing
132 * the "args". Note P0 is clobbered on the way here.
133 */
134void kernel_thread_helper(void);
135__asm__(".section .text\n"
136 ".align 4\n"
137 "_kernel_thread_helper:\n\t"
138 "\tsp += -12;\n\t"
139 "\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");
140
141/*
142 * Create a kernel thread.
143 */
144pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
145{
146 struct pt_regs regs;
147
148 memset(&regs, 0, sizeof(regs));
149
150 regs.r1 = (unsigned long)arg;
151 regs.p1 = (unsigned long)fn;
152 regs.pc = (unsigned long)kernel_thread_helper;
153 regs.orig_p0 = -1;
154 /* Set bit 2 to tell ret_from_fork we should be returning to kernel
155 mode. */
156 regs.ipend = 0x8002;
157 __asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):);
158 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
159 NULL);
160}
fe8015ce 161EXPORT_SYMBOL(kernel_thread);
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162
163void flush_thread(void)
164{
165}
166
167asmlinkage int bfin_vfork(struct pt_regs *regs)
168{
169 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
170 NULL);
171}
172
173asmlinkage int bfin_clone(struct pt_regs *regs)
174{
175 unsigned long clone_flags;
176 unsigned long newsp;
177
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178#ifdef __ARCH_SYNC_CORE_DCACHE
179 if (current->rt.nr_cpus_allowed == num_possible_cpus()) {
180 current->cpus_allowed = cpumask_of_cpu(smp_processor_id());
181 current->rt.nr_cpus_allowed = 1;
182 }
183#endif
184
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185 /* syscall2 puts clone_flags in r0 and usp in r1 */
186 clone_flags = regs->r0;
187 newsp = regs->r1;
188 if (!newsp)
189 newsp = rdusp();
190 else
191 newsp -= 12;
192 return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
193}
194
195int
6f2c55b8 196copy_thread(unsigned long clone_flags,
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197 unsigned long usp, unsigned long topstk,
198 struct task_struct *p, struct pt_regs *regs)
199{
200 struct pt_regs *childregs;
201
202 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
203 *childregs = *regs;
204 childregs->r0 = 0;
205
206 p->thread.usp = usp;
207 p->thread.ksp = (unsigned long)childregs;
208 p->thread.pc = (unsigned long)ret_from_fork;
209
210 return 0;
211}
212
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213/*
214 * sys_execve() executes a new program.
215 */
216
0ddeeca2 217asmlinkage int sys_execve(char __user *name, char __user * __user *argv, char __user * __user *envp)
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218{
219 int error;
220 char *filename;
221 struct pt_regs *regs = (struct pt_regs *)((&name) + 6);
222
223 lock_kernel();
224 filename = getname(name);
225 error = PTR_ERR(filename);
226 if (IS_ERR(filename))
227 goto out;
228 error = do_execve(filename, argv, envp, regs);
229 putname(filename);
1f83b8f1 230 out:
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231 unlock_kernel();
232 return error;
233}
234
235unsigned long get_wchan(struct task_struct *p)
236{
237 unsigned long fp, pc;
238 unsigned long stack_page;
239 int count = 0;
240 if (!p || p == current || p->state == TASK_RUNNING)
241 return 0;
242
243 stack_page = (unsigned long)p;
244 fp = p->thread.usp;
245 do {
246 if (fp < stack_page + sizeof(struct thread_info) ||
247 fp >= 8184 + stack_page)
248 return 0;
249 pc = ((unsigned long *)fp)[1];
250 if (!in_sched_functions(pc))
251 return pc;
252 fp = *(unsigned long *)fp;
253 }
254 while (count++ < 16);
255 return 0;
256}
257
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258void finish_atomic_sections (struct pt_regs *regs)
259{
19d6d7d5 260 int __user *up0 = (int __user *)regs->p0;
0ddeeca2 261
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262 if (regs->pc < ATOMIC_SEQS_START || regs->pc >= ATOMIC_SEQS_END)
263 return;
264
265 switch (regs->pc) {
266 case ATOMIC_XCHG32 + 2:
0ddeeca2 267 put_user(regs->r1, up0);
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268 regs->pc += 2;
269 break;
270
271 case ATOMIC_CAS32 + 2:
272 case ATOMIC_CAS32 + 4:
273 if (regs->r0 == regs->r1)
0ddeeca2 274 put_user(regs->r2, up0);
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275 regs->pc = ATOMIC_CAS32 + 8;
276 break;
277 case ATOMIC_CAS32 + 6:
0ddeeca2 278 put_user(regs->r2, up0);
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279 regs->pc += 2;
280 break;
281
282 case ATOMIC_ADD32 + 2:
283 regs->r0 = regs->r1 + regs->r0;
284 /* fall through */
285 case ATOMIC_ADD32 + 4:
0ddeeca2 286 put_user(regs->r0, up0);
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287 regs->pc = ATOMIC_ADD32 + 6;
288 break;
289
290 case ATOMIC_SUB32 + 2:
291 regs->r0 = regs->r1 - regs->r0;
292 /* fall through */
293 case ATOMIC_SUB32 + 4:
0ddeeca2 294 put_user(regs->r0, up0);
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295 regs->pc = ATOMIC_SUB32 + 6;
296 break;
297
298 case ATOMIC_IOR32 + 2:
299 regs->r0 = regs->r1 | regs->r0;
300 /* fall through */
301 case ATOMIC_IOR32 + 4:
0ddeeca2 302 put_user(regs->r0, up0);
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303 regs->pc = ATOMIC_IOR32 + 6;
304 break;
305
306 case ATOMIC_AND32 + 2:
307 regs->r0 = regs->r1 & regs->r0;
308 /* fall through */
309 case ATOMIC_AND32 + 4:
0ddeeca2 310 put_user(regs->r0, up0);
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311 regs->pc = ATOMIC_AND32 + 6;
312 break;
313
314 case ATOMIC_XOR32 + 2:
315 regs->r0 = regs->r1 ^ regs->r0;
316 /* fall through */
317 case ATOMIC_XOR32 + 4:
0ddeeca2 318 put_user(regs->r0, up0);
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319 regs->pc = ATOMIC_XOR32 + 6;
320 break;
321 }
322}
323
1394f032 324#if defined(CONFIG_ACCESS_CHECK)
b03b08ba 325/* Return 1 if access to memory range is OK, 0 otherwise */
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326int _access_ok(unsigned long addr, unsigned long size)
327{
bc41bb11
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328 if (size == 0)
329 return 1;
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330 if (addr > (addr + size))
331 return 0;
1f83b8f1 332 if (segment_eq(get_fs(), KERNEL_DS))
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333 return 1;
334#ifdef CONFIG_MTD_UCLINUX
335 if (addr >= memory_start && (addr + size) <= memory_end)
336 return 1;
337 if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end)
338 return 1;
d5adb029
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339
340#ifdef CONFIG_ROMFS_MTD_FS
341 /* For XIP, allow user space to use pointers within the ROMFS. */
342 if (addr >= memory_mtd_start && (addr + size) <= memory_mtd_end)
343 return 1;
344#endif
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345#else
346 if (addr >= memory_start && (addr + size) <= physical_mem_end)
347 return 1;
348#endif
349 if (addr >= (unsigned long)__init_begin &&
350 addr + size <= (unsigned long)__init_end)
351 return 1;
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352 if (addr >= get_l1_scratch_start()
353 && addr + size <= get_l1_scratch_start() + L1_SCRATCH_LENGTH)
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354 return 1;
355#if L1_CODE_LENGTH != 0
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356 if (addr >= get_l1_code_start() + (_etext_l1 - _stext_l1)
357 && addr + size <= get_l1_code_start() + L1_CODE_LENGTH)
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358 return 1;
359#endif
360#if L1_DATA_A_LENGTH != 0
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361 if (addr >= get_l1_data_a_start() + (_ebss_l1 - _sdata_l1)
362 && addr + size <= get_l1_data_a_start() + L1_DATA_A_LENGTH)
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363 return 1;
364#endif
365#if L1_DATA_B_LENGTH != 0
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366 if (addr >= get_l1_data_b_start() + (_ebss_b_l1 - _sdata_b_l1)
367 && addr + size <= get_l1_data_b_start() + L1_DATA_B_LENGTH)
1394f032 368 return 1;
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369#endif
370#if L2_LENGTH != 0
371 if (addr >= L2_START + (_ebss_l2 - _stext_l2)
372 && addr + size <= L2_START + L2_LENGTH)
373 return 1;
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374#endif
375 return 0;
376}
377EXPORT_SYMBOL(_access_ok);
378#endif /* CONFIG_ACCESS_CHECK */