summaryrefslogtreecommitdiffstats
path: root/arch/blackfin/kernel/process.c
blob: 53c2cd255441ff5a23a55ce9cc8e5702ef1ec966 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
/*
 * File:         arch/blackfin/kernel/process.c
 * Based on:
 * Author:
 *
 * Created:
 * Description:  Blackfin architecture-dependent process handling.
 *
 * Modified:
 *               Copyright 2004-2006 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <linux/module.h>
#include <linux/smp_lock.h>
#include <linux/unistd.h>
#include <linux/user.h>
#include <linux/uaccess.h>
#include <linux/sched.h>
#include <linux/tick.h>
#include <linux/fs.h>
#include <linux/err.h>

#include <asm/blackfin.h>
#include <asm/fixed_code.h>

asmlinkage void ret_from_fork(void);

/* Points to the SDRAM backup memory for the stack that is currently in
 * L1 scratchpad memory.
 */
void *current_l1_stack_save;

/* The number of tasks currently using a L1 stack area.  The SRAM is
 * allocated/deallocated whenever this changes from/to zero.
 */
int nr_l1stack_tasks;

/* Start and length of the area in L1 scratchpad memory which we've allocated
 * for process stacks.
 */
void *l1_stack_base;
unsigned long l1_stack_len;

/*
 * Powermanagement idle function, if any..
 */
void (*pm_idle)(void) = NULL;
EXPORT_SYMBOL(pm_idle);

void (*pm_power_off)(void) = NULL;
EXPORT_SYMBOL(pm_power_off);

/*
 * The idle loop on BFIN
 */
#ifdef CONFIG_IDLE_L1
static void default_idle(void)__attribute__((l1_text));
void cpu_idle(void)__attribute__((l1_text));
#endif

/*
 * This is our default idle handler.  We need to disable
 * interrupts here to ensure we don't miss a wakeup call.
 */
static void default_idle(void)
{
	local_irq_disable();
	if (!need_resched())
		idle_with_irq_disabled();

	local_irq_enable();
}

/*
 * The idle thread.  We try to conserve power, while trying to keep
 * overall latency low.  The architecture specific idle is passed
 * a value to indicate the level of "idleness" of the system.
 */
void cpu_idle(void)
{
	/* endless idle loop with no priority at all */
	while (1) {
		void (*idle)(void) = pm_idle;

#ifdef CONFIG_HOTPLUG_CPU
		if (cpu_is_offline(smp_processor_id()))
			cpu_die();
#endif
		if (!idle)
			idle = default_idle;
		tick_nohz_stop_sched_tick();
		while (!need_resched())
			idle();
		tick_nohz_restart_sched_tick();
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}

/* Fill in the fpu structure for a core dump.  */

int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpregs)
{
	return 1;
}

/*
 * This gets run with P1 containing the
 * function to call, and R1 containing
 * the "args".  Note P0 is clobbered on the way here.
 */
void kernel_thread_helper(void);
__asm__(".section .text\n"
	".align 4\n"
	"_kernel_thread_helper:\n\t"
	"\tsp += -12;\n\t"
	"\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");

/*
 * Create a kernel thread.
 */
pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
{
	struct pt_regs regs;

	memset(&regs, 0, sizeof(regs));

	regs.r1 = (unsigned long)arg;
	regs.p1 = (unsigned long)fn;
	regs.pc = (unsigned long)kernel_thread_helper;
	regs.orig_p0 = -1;
	/* Set bit 2 to tell ret_from_fork we should be returning to kernel
	   mode.  */
	regs.ipend = 0x8002;
	__asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):);
	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
		       NULL);
}

void flush_thread(void)
{
}

asmlinkage int bfin_vfork(struct pt_regs *regs)
{
	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
		       NULL);
}

asmlinkage int bfin_clone(struct pt_regs *regs)
{
	unsigned long clone_flags;
	unsigned long newsp;

	/* syscall2 puts clone_flags in r0 and usp in r1 */
	clone_flags = regs->r0;
	newsp = regs->r1;
	if (!newsp)
		newsp = rdusp();
	else
		newsp -= 12;
	return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
}

int
copy_thread(int nr, unsigned long clone_flags,
	    unsigned long usp, unsigned long topstk,
	    struct task_struct *p, struct pt_regs *regs)
{
	struct pt_regs *childregs;

	childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
	*childregs = *regs;
	childregs->r0 = 0;

	p->thread.usp = usp;
	p->thread.ksp = (unsigned long)childregs;
	p->thread.pc = (unsigned long)ret_from_fork;

	return 0;
}

/*
 * sys_execve() executes a new program.
 */

asmlinkage int sys_execve(char __user *name, char __user * __user *argv, char __user * __user *envp)
{
	int error;
	char *filename;
	struct pt_regs *regs = (struct pt_regs *)((&name) + 6);

	lock_kernel();
	filename = getname(name);
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
		goto out;
	error = do_execve(filename, argv, envp, regs);
	putname(filename);
 out:
	unlock_kernel();
	return error;
}

unsigned long get_wchan(struct task_struct *p)
{
	unsigned long fp, pc;
	unsigned long stack_page;
	int count = 0;
	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;

	stack_page = (unsigned long)p;
	fp = p->thread.usp;
	do {
		if (fp < stack_page + sizeof(struct thread_info) ||
		    fp >= 8184 + stack_page)
			return 0;
		pc = ((unsigned long *)fp)[1];
		if (!in_sched_functions(pc))
			return pc;
		fp = *(unsigned long *)fp;
	}
	while (count++ < 16);
	return 0;
}

void finish_atomic_sections (struct pt_regs *regs)
{
	int __user *up0 = (int __user *)regs->p0;

	if (regs->pc < ATOMIC_SEQS_START || regs->pc >= ATOMIC_SEQS_END)
		return;

	switch (regs->pc) {
	case ATOMIC_XCHG32 + 2:
		put_user(regs->r1, up0);
		regs->pc += 2;
		break;

	case ATOMIC_CAS32 + 2:
	case ATOMIC_CAS32 + 4:
		if (regs->r0 == regs->r1)
			put_user(regs->r2, up0);
		regs->pc = ATOMIC_CAS32 + 8;
		break;
	case ATOMIC_CAS32 + 6:
		put_user(regs->r2, up0);
		regs->pc += 2;
		break;

	case ATOMIC_ADD32 + 2:
		regs->r0 = regs->r1 + regs->r0;
		/* fall through */
	case ATOMIC_ADD32 + 4:
		put_user(regs->r0, up0);
		regs->pc = ATOMIC_ADD32 + 6;
		break;

	case ATOMIC_SUB32 + 2:
		regs->r0 = regs->r1 - regs->r0;
		/* fall through */
	case ATOMIC_SUB32 + 4:
		put_user(regs->r0, up0);
		regs->pc = ATOMIC_SUB32 + 6;
		break;

	case ATOMIC_IOR32 + 2:
		regs->r0 = regs->r1 | regs->r0;
		/* fall through */
	case ATOMIC_IOR32 + 4:
		put_user(regs->r0, up0);
		regs->pc = ATOMIC_IOR32 + 6;
		break;

	case ATOMIC_AND32 + 2:
		regs->r0 = regs->r1 & regs->r0;
		/* fall through */
	case ATOMIC_AND32 + 4:
		put_user(regs->r0, up0);
		regs->pc = ATOMIC_AND32 + 6;
		break;

	case ATOMIC_XOR32 + 2:
		regs->r0 = regs->r1 ^ regs->r0;
		/* fall through */
	case ATOMIC_XOR32 + 4:
		put_user(regs->r0, up0);
		regs->pc = ATOMIC_XOR32 + 6;
		break;
	}
}

#if defined(CONFIG_ACCESS_CHECK)
/* Return 1 if access to memory range is OK, 0 otherwise */
int _access_ok(unsigned long addr, unsigned long size)
{
	if (size == 0)
		return 1;
	if (addr > (addr + size))
		return 0;
	if (segment_eq(get_fs(), KERNEL_DS))
		return 1;
#ifdef CONFIG_MTD_UCLINUX
	if (addr >= memory_start && (addr + size) <= memory_end)
		return 1;
	if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end)
		return 1;

#ifdef CONFIG_ROMFS_MTD_FS
	/* For XIP, allow user space to use pointers within the ROMFS.  */
	if (addr >= memory_mtd_start && (addr + size) <= memory_mtd_end)
		return 1;
#endif
#else
	if (addr >= memory_start && (addr + size) <= physical_mem_end)
		return 1;
#endif
	if (addr >= (unsigned long)__init_begin &&
	    addr + size <= (unsigned long)__init_end)
		return 1;
	if (addr >= L1_SCRATCH_START
	    && addr + size <= L1_SCRATCH_START + L1_SCRATCH_LENGTH)
		return 1;
#if L1_CODE_LENGTH != 0
	if (addr >= L1_CODE_START + (_etext_l1 - _stext_l1)
	    && addr + size <= L1_CODE_START + L1_CODE_LENGTH)
		return 1;
#endif
#if L1_DATA_A_LENGTH != 0
	if (addr >= L1_DATA_A_START + (_ebss_l1 - _sdata_l1)
	    && addr + size <= L1_DATA_A_START + L1_DATA_A_LENGTH)
		return 1;
#endif
#if L1_DATA_B_LENGTH != 0
	if (addr >= L1_DATA_B_START
	    && addr + size <= L1_DATA_B_START + L1_DATA_B_LENGTH)
		return 1;
#endif
	return 0;
}
EXPORT_SYMBOL(_access_ok);
#endif /* CONFIG_ACCESS_CHECK */
OpenPOWER on IntegriCloud