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-rw-r--r--arch/blackfin/kernel/process.c394
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diff --git a/arch/blackfin/kernel/process.c b/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>
34#include <linux/a.out.h>
35
36#include <asm/blackfin.h>
37#include <asm/uaccess.h>
38
39#define LED_ON 0
40#define LED_OFF 1
41
42asmlinkage void ret_from_fork(void);
43
44/* Points to the SDRAM backup memory for the stack that is currently in
45 * L1 scratchpad memory.
46 */
47void *current_l1_stack_save;
48
49/* The number of tasks currently using a L1 stack area. The SRAM is
50 * allocated/deallocated whenever this changes from/to zero.
51 */
52int nr_l1stack_tasks;
53
54/* Start and length of the area in L1 scratchpad memory which we've allocated
55 * for process stacks.
56 */
57void *l1_stack_base;
58unsigned long l1_stack_len;
59
60/*
61 * Powermanagement idle function, if any..
62 */
63void (*pm_idle)(void) = NULL;
64EXPORT_SYMBOL(pm_idle);
65
66void (*pm_power_off)(void) = NULL;
67EXPORT_SYMBOL(pm_power_off);
68
69/*
70 * We are using a different LED from the one used to indicate timer interrupt.
71 */
72#if defined(CONFIG_BFIN_IDLE_LED)
73static inline void leds_switch(int flag)
74{
75 unsigned short tmp = 0;
76
77 tmp = bfin_read_CONFIG_BFIN_IDLE_LED_PORT();
78 SSYNC();
79
80 if (flag == LED_ON)
81 tmp &= ~CONFIG_BFIN_IDLE_LED_PIN; /* light on */
82 else
83 tmp |= CONFIG_BFIN_IDLE_LED_PIN; /* light off */
84
85 bfin_write_CONFIG_BFIN_IDLE_LED_PORT(tmp);
86 SSYNC();
87
88}
89#else
90static inline void leds_switch(int flag)
91{
92}
93#endif
94
95/*
96 * The idle loop on BFIN
97 */
98#ifdef CONFIG_IDLE_L1
99void default_idle(void)__attribute__((l1_text));
100void cpu_idle(void)__attribute__((l1_text));
101#endif
102
103void default_idle(void)
104{
105 while (!need_resched()) {
106 leds_switch(LED_OFF);
107 local_irq_disable();
108 if (likely(!need_resched()))
109 idle_with_irq_disabled();
110 local_irq_enable();
111 leds_switch(LED_ON);
112 }
113}
114
115void (*idle)(void) = default_idle;
116
117/*
118 * The idle thread. There's no useful work to be
119 * done, so just try to conserve power and have a
120 * low exit latency (ie sit in a loop waiting for
121 * somebody to say that they'd like to reschedule)
122 */
123void cpu_idle(void)
124{
125 /* endless idle loop with no priority at all */
126 while (1) {
127 idle();
128 preempt_enable_no_resched();
129 schedule();
130 preempt_disable();
131 }
132}
133
134void machine_restart(char *__unused)
135{
136#if defined(CONFIG_BLKFIN_CACHE)
137 bfin_write_IMEM_CONTROL(0x01);
138 SSYNC();
139#endif
140 bfin_reset();
141 /* Dont do anything till the reset occurs */
142 while (1) {
143 SSYNC();
144 }
145}
146
147void machine_halt(void)
148{
149 for (;;)
150 asm volatile ("idle");
151}
152
153void machine_power_off(void)
154{
155 for (;;)
156 asm volatile ("idle");
157}
158
159void show_regs(struct pt_regs *regs)
160{
161 printk(KERN_NOTICE "\n");
162 printk(KERN_NOTICE
163 "PC: %08lu Status: %04lu SysStatus: %04lu RETS: %08lu\n",
164 regs->pc, regs->astat, regs->seqstat, regs->rets);
165 printk(KERN_NOTICE
166 "A0.x: %08lx A0.w: %08lx A1.x: %08lx A1.w: %08lx\n",
167 regs->a0x, regs->a0w, regs->a1x, regs->a1w);
168 printk(KERN_NOTICE "P0: %08lx P1: %08lx P2: %08lx P3: %08lx\n",
169 regs->p0, regs->p1, regs->p2, regs->p3);
170 printk(KERN_NOTICE "P4: %08lx P5: %08lx\n", regs->p4, regs->p5);
171 printk(KERN_NOTICE "R0: %08lx R1: %08lx R2: %08lx R3: %08lx\n",
172 regs->r0, regs->r1, regs->r2, regs->r3);
173 printk(KERN_NOTICE "R4: %08lx R5: %08lx R6: %08lx R7: %08lx\n",
174 regs->r4, regs->r5, regs->r6, regs->r7);
175
176 if (!(regs->ipend))
177 printk("USP: %08lx\n", rdusp());
178}
179
180/* Fill in the fpu structure for a core dump. */
181
182int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpregs)
183{
184 return 1;
185}
186
187/*
188 * This gets run with P1 containing the
189 * function to call, and R1 containing
190 * the "args". Note P0 is clobbered on the way here.
191 */
192void kernel_thread_helper(void);
193__asm__(".section .text\n"
194 ".align 4\n"
195 "_kernel_thread_helper:\n\t"
196 "\tsp += -12;\n\t"
197 "\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");
198
199/*
200 * Create a kernel thread.
201 */
202pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
203{
204 struct pt_regs regs;
205
206 memset(&regs, 0, sizeof(regs));
207
208 regs.r1 = (unsigned long)arg;
209 regs.p1 = (unsigned long)fn;
210 regs.pc = (unsigned long)kernel_thread_helper;
211 regs.orig_p0 = -1;
212 /* Set bit 2 to tell ret_from_fork we should be returning to kernel
213 mode. */
214 regs.ipend = 0x8002;
215 __asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):);
216 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
217 NULL);
218}
219
220void flush_thread(void)
221{
222}
223
224asmlinkage int bfin_vfork(struct pt_regs *regs)
225{
226 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
227 NULL);
228}
229
230asmlinkage int bfin_clone(struct pt_regs *regs)
231{
232 unsigned long clone_flags;
233 unsigned long newsp;
234
235 /* syscall2 puts clone_flags in r0 and usp in r1 */
236 clone_flags = regs->r0;
237 newsp = regs->r1;
238 if (!newsp)
239 newsp = rdusp();
240 else
241 newsp -= 12;
242 return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
243}
244
245int
246copy_thread(int nr, unsigned long clone_flags,
247 unsigned long usp, unsigned long topstk,
248 struct task_struct *p, struct pt_regs *regs)
249{
250 struct pt_regs *childregs;
251
252 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
253 *childregs = *regs;
254 childregs->r0 = 0;
255
256 p->thread.usp = usp;
257 p->thread.ksp = (unsigned long)childregs;
258 p->thread.pc = (unsigned long)ret_from_fork;
259
260 return 0;
261}
262
263/*
264 * fill in the user structure for a core dump..
265 */
266void dump_thread(struct pt_regs *regs, struct user *dump)
267{
268 dump->magic = CMAGIC;
269 dump->start_code = 0;
270 dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
271 dump->u_tsize = ((unsigned long)current->mm->end_code) >> PAGE_SHIFT;
272 dump->u_dsize = ((unsigned long)(current->mm->brk +
273 (PAGE_SIZE - 1))) >> PAGE_SHIFT;
274 dump->u_dsize -= dump->u_tsize;
275 dump->u_ssize = 0;
276
277 if (dump->start_stack < TASK_SIZE)
278 dump->u_ssize =
279 ((unsigned long)(TASK_SIZE -
280 dump->start_stack)) >> PAGE_SHIFT;
281
282 dump->u_ar0 = (struct user_regs_struct *)((int)&dump->regs - (int)dump);
283
284 dump->regs.r0 = regs->r0;
285 dump->regs.r1 = regs->r1;
286 dump->regs.r2 = regs->r2;
287 dump->regs.r3 = regs->r3;
288 dump->regs.r4 = regs->r4;
289 dump->regs.r5 = regs->r5;
290 dump->regs.r6 = regs->r6;
291 dump->regs.r7 = regs->r7;
292 dump->regs.p0 = regs->p0;
293 dump->regs.p1 = regs->p1;
294 dump->regs.p2 = regs->p2;
295 dump->regs.p3 = regs->p3;
296 dump->regs.p4 = regs->p4;
297 dump->regs.p5 = regs->p5;
298 dump->regs.orig_p0 = regs->orig_p0;
299 dump->regs.a0w = regs->a0w;
300 dump->regs.a1w = regs->a1w;
301 dump->regs.a0x = regs->a0x;
302 dump->regs.a1x = regs->a1x;
303 dump->regs.rets = regs->rets;
304 dump->regs.astat = regs->astat;
305 dump->regs.pc = regs->pc;
306}
307
308/*
309 * sys_execve() executes a new program.
310 */
311
312asmlinkage int sys_execve(char *name, char **argv, char **envp)
313{
314 int error;
315 char *filename;
316 struct pt_regs *regs = (struct pt_regs *)((&name) + 6);
317
318 lock_kernel();
319 filename = getname(name);
320 error = PTR_ERR(filename);
321 if (IS_ERR(filename))
322 goto out;
323 error = do_execve(filename, argv, envp, regs);
324 putname(filename);
325 out:
326 unlock_kernel();
327 return error;
328}
329
330unsigned long get_wchan(struct task_struct *p)
331{
332 unsigned long fp, pc;
333 unsigned long stack_page;
334 int count = 0;
335 if (!p || p == current || p->state == TASK_RUNNING)
336 return 0;
337
338 stack_page = (unsigned long)p;
339 fp = p->thread.usp;
340 do {
341 if (fp < stack_page + sizeof(struct thread_info) ||
342 fp >= 8184 + stack_page)
343 return 0;
344 pc = ((unsigned long *)fp)[1];
345 if (!in_sched_functions(pc))
346 return pc;
347 fp = *(unsigned long *)fp;
348 }
349 while (count++ < 16);
350 return 0;
351}
352
353#if defined(CONFIG_ACCESS_CHECK)
354int _access_ok(unsigned long addr, unsigned long size)
355{
356
357 if (addr > (addr + size))
358 return 0;
359 if (segment_eq(get_fs(),KERNEL_DS))
360 return 1;
361#ifdef CONFIG_MTD_UCLINUX
362 if (addr >= memory_start && (addr + size) <= memory_end)
363 return 1;
364 if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end)
365 return 1;
366#else
367 if (addr >= memory_start && (addr + size) <= physical_mem_end)
368 return 1;
369#endif
370 if (addr >= (unsigned long)__init_begin &&
371 addr + size <= (unsigned long)__init_end)
372 return 1;
373 if (addr >= L1_SCRATCH_START
374 && addr + size <= L1_SCRATCH_START + L1_SCRATCH_LENGTH)
375 return 1;
376#if L1_CODE_LENGTH != 0
377 if (addr >= L1_CODE_START + (_etext_l1 - _stext_l1)
378 && addr + size <= L1_CODE_START + L1_CODE_LENGTH)
379 return 1;
380#endif
381#if L1_DATA_A_LENGTH != 0
382 if (addr >= L1_DATA_A_START + (_ebss_l1 - _sdata_l1)
383 && addr + size <= L1_DATA_A_START + L1_DATA_A_LENGTH)
384 return 1;
385#endif
386#if L1_DATA_B_LENGTH != 0
387 if (addr >= L1_DATA_B_START
388 && addr + size <= L1_DATA_B_START + L1_DATA_B_LENGTH)
389 return 1;
390#endif
391 return 0;
392}
393EXPORT_SYMBOL(_access_ok);
394#endif /* CONFIG_ACCESS_CHECK */
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