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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* process.c: FRV specific parts of process handling
2 *
3 * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * - Derived from arch/m68k/kernel/process.c
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
David Howells9dec17e2006-07-10 04:44:51 -070013#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/errno.h>
15#include <linux/sched.h>
16#include <linux/kernel.h>
17#include <linux/mm.h>
18#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/stddef.h>
20#include <linux/unistd.h>
21#include <linux/ptrace.h>
22#include <linux/slab.h>
23#include <linux/user.h>
24#include <linux/elf.h>
25#include <linux/reboot.h>
26#include <linux/interrupt.h>
Christoph Lameter8defab32007-05-09 02:32:48 -070027#include <linux/pagemap.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
David Howells84e8cd62006-07-10 04:44:55 -070029#include <asm/asm-offsets.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <asm/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <asm/setup.h>
32#include <asm/pgtable.h>
Christoph Lameter8defab32007-05-09 02:32:48 -070033#include <asm/tlb.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <asm/gdb-stub.h>
35#include <asm/mb-regs.h>
36
37#include "local.h"
38
39asmlinkage void ret_from_fork(void);
40
41#include <asm/pgalloc.h>
42
David Howells9dec17e2006-07-10 04:44:51 -070043void (*pm_power_off)(void);
44EXPORT_SYMBOL(pm_power_off);
45
Linus Torvalds1da177e2005-04-16 15:20:36 -070046static void core_sleep_idle(void)
47{
48#ifdef LED_DEBUG_SLEEP
49 /* Show that we're sleeping... */
50 __set_LEDS(0x55aa);
51#endif
52 frv_cpu_core_sleep();
53#ifdef LED_DEBUG_SLEEP
54 /* ... and that we woke up */
55 __set_LEDS(0);
56#endif
57 mb();
58}
59
60void (*idle)(void) = core_sleep_idle;
61
62/*
63 * The idle thread. There's no useful work to be
64 * done, so just try to conserve power and have a
65 * low exit latency (ie sit in a loop waiting for
66 * somebody to say that they'd like to reschedule)
67 */
68void cpu_idle(void)
69{
70 /* endless idle loop with no priority at all */
71 while (1) {
72 while (!need_resched()) {
Christoph Lameter8defab32007-05-09 02:32:48 -070073 check_pgt_cache();
74
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 if (!frv_dma_inprogress && idle)
76 idle();
77 }
78
Thomas Gleixnerbd2f5532011-03-21 12:33:18 +010079 schedule_preempt_disabled();
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 }
81}
82
83void machine_restart(char * __unused)
84{
85 unsigned long reset_addr;
86#ifdef CONFIG_GDBSTUB
87 gdbstub_exit(0);
88#endif
89
90 if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551)
91 reset_addr = 0xfefff500;
92 else
93 reset_addr = 0xfeff0500;
94
95 /* Software reset. */
96 asm volatile(" dcef @(gr0,gr0),1 ! membar !"
97 " sti %1,@(%0,0) !"
98 " nop ! nop ! nop ! nop ! nop ! "
99 " nop ! nop ! nop ! nop ! nop ! "
100 " nop ! nop ! nop ! nop ! nop ! "
101 " nop ! nop ! nop ! nop ! nop ! "
102 : : "r" (reset_addr), "r" (1) );
103
104 for (;;)
105 ;
106}
107
108void machine_halt(void)
109{
110#ifdef CONFIG_GDBSTUB
111 gdbstub_exit(0);
112#endif
113
114 for (;;);
115}
116
117void machine_power_off(void)
118{
119#ifdef CONFIG_GDBSTUB
120 gdbstub_exit(0);
121#endif
122
123 for (;;);
124}
125
126void flush_thread(void)
127{
Mathias Krauseadc400f2011-07-26 16:08:15 -0700128 /* nothing */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129}
130
131inline unsigned long user_stack(const struct pt_regs *regs)
132{
133 while (regs->next_frame)
134 regs = regs->next_frame;
135 return user_mode(regs) ? regs->sp : 0;
136}
137
138asmlinkage int sys_fork(void)
139{
140#ifndef CONFIG_MMU
141 /* fork almost works, enough to trick you into looking elsewhere:-( */
142 return -EINVAL;
143#else
144 return do_fork(SIGCHLD, user_stack(__frame), __frame, 0, NULL, NULL);
145#endif
146}
147
148asmlinkage int sys_vfork(void)
149{
150 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, user_stack(__frame), __frame, 0,
151 NULL, NULL);
152}
153
154/*****************************************************************************/
155/*
156 * clone a process
157 * - tlsptr is retrieved by copy_thread()
158 */
159asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
160 int __user *parent_tidptr, int __user *child_tidptr,
161 int __user *tlsptr)
162{
163 if (!newsp)
164 newsp = user_stack(__frame);
165 return do_fork(clone_flags, newsp, __frame, 0, parent_tidptr, child_tidptr);
166} /* end sys_clone() */
167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168/*
169 * set up the kernel stack and exception frames for a new process
170 */
Alexey Dobriyan6f2c55b2009-04-02 16:56:59 -0700171int copy_thread(unsigned long clone_flags,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 unsigned long usp, unsigned long topstk,
173 struct task_struct *p, struct pt_regs *regs)
174{
175 struct pt_regs *childregs0, *childregs, *regs0;
176
177 regs0 = __kernel_frame0_ptr;
178 childregs0 = (struct pt_regs *)
David Howells84e8cd62006-07-10 04:44:55 -0700179 (task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 childregs = childregs0;
181
182 /* set up the userspace frame (the only place that the USP is stored) */
183 *childregs0 = *regs0;
184
185 childregs0->gr8 = 0;
186 childregs0->sp = usp;
187 childregs0->next_frame = NULL;
188
189 /* set up the return kernel frame if called from kernel_thread() */
190 if (regs != regs0) {
191 childregs--;
192 *childregs = *regs;
193 childregs->sp = (unsigned long) childregs0;
194 childregs->next_frame = childregs0;
Al Viro097cb332006-01-12 01:05:53 -0800195 childregs->gr15 = (unsigned long) task_thread_info(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 childregs->gr29 = (unsigned long) p;
197 }
198
199 p->set_child_tid = p->clear_child_tid = NULL;
200
201 p->thread.frame = childregs;
202 p->thread.curr = p;
203 p->thread.sp = (unsigned long) childregs;
204 p->thread.fp = 0;
205 p->thread.lr = 0;
206 p->thread.pc = (unsigned long) ret_from_fork;
207 p->thread.frame0 = childregs0;
208
209 /* the new TLS pointer is passed in as arg #5 to sys_clone() */
210 if (clone_flags & CLONE_SETTLS)
211 childregs->gr29 = childregs->gr12;
212
213 save_user_regs(p->thread.user);
214
215 return 0;
216} /* end copy_thread() */
217
218/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 * sys_execve() executes a new program.
220 */
David Howellsd7627462010-08-17 23:52:56 +0100221asmlinkage int sys_execve(const char __user *name,
222 const char __user *const __user *argv,
223 const char __user *const __user *envp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224{
225 int error;
226 char * filename;
227
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 filename = getname(name);
229 error = PTR_ERR(filename);
230 if (IS_ERR(filename))
John Kacurb69975a2009-10-12 22:53:25 +0200231 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 error = do_execve(filename, argv, envp, __frame);
233 putname(filename);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 return error;
235}
236
237unsigned long get_wchan(struct task_struct *p)
238{
239 struct pt_regs *regs0;
240 unsigned long fp, pc;
241 unsigned long stack_limit;
242 int count = 0;
243 if (!p || p == current || p->state == TASK_RUNNING)
244 return 0;
245
246 stack_limit = (unsigned long) (p + 1);
247 fp = p->thread.fp;
248 regs0 = p->thread.frame0;
249
250 do {
251 if (fp < stack_limit || fp >= (unsigned long) regs0 || fp & 3)
252 return 0;
253
254 pc = ((unsigned long *) fp)[2];
255
256 /* FIXME: This depends on the order of these functions. */
257 if (!in_sched_functions(pc))
258 return pc;
259
260 fp = *(unsigned long *) fp;
261 } while (count++ < 16);
262
263 return 0;
264}
265
266unsigned long thread_saved_pc(struct task_struct *tsk)
267{
268 /* Check whether the thread is blocked in resume() */
269 if (in_sched_functions(tsk->thread.pc))
270 return ((unsigned long *)tsk->thread.fp)[2];
271 else
272 return tsk->thread.pc;
273}
274
275int elf_check_arch(const struct elf32_hdr *hdr)
276{
277 unsigned long hsr0 = __get_HSR(0);
278 unsigned long psr = __get_PSR();
279
280 if (hdr->e_machine != EM_FRV)
281 return 0;
282
283 switch (hdr->e_flags & EF_FRV_GPR_MASK) {
284 case EF_FRV_GPR64:
285 if ((hsr0 & HSR0_GRN) == HSR0_GRN_32)
286 return 0;
287 case EF_FRV_GPR32:
288 case 0:
289 break;
290 default:
291 return 0;
292 }
293
294 switch (hdr->e_flags & EF_FRV_FPR_MASK) {
295 case EF_FRV_FPR64:
296 if ((hsr0 & HSR0_FRN) == HSR0_FRN_32)
297 return 0;
298 case EF_FRV_FPR32:
299 case EF_FRV_FPR_NONE:
300 case 0:
301 break;
302 default:
303 return 0;
304 }
305
306 if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD)
307 if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
308 PSR_IMPLE(psr) != PSR_IMPLE_FR451)
309 return 0;
310
311 switch (hdr->e_flags & EF_FRV_CPU_MASK) {
312 case EF_FRV_CPU_GENERIC:
313 break;
314 case EF_FRV_CPU_FR300:
315 case EF_FRV_CPU_SIMPLE:
316 case EF_FRV_CPU_TOMCAT:
317 default:
318 return 0;
319 case EF_FRV_CPU_FR400:
320 if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 &&
321 PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
322 PSR_IMPLE(psr) != PSR_IMPLE_FR451 &&
323 PSR_IMPLE(psr) != PSR_IMPLE_FR551)
324 return 0;
325 break;
326 case EF_FRV_CPU_FR450:
327 if (PSR_IMPLE(psr) != PSR_IMPLE_FR451)
328 return 0;
329 break;
330 case EF_FRV_CPU_FR500:
331 if (PSR_IMPLE(psr) != PSR_IMPLE_FR501)
332 return 0;
333 break;
334 case EF_FRV_CPU_FR550:
335 if (PSR_IMPLE(psr) != PSR_IMPLE_FR551)
336 return 0;
337 break;
338 }
339
340 return 1;
341}
David Howells6d8c4e32006-07-10 04:44:55 -0700342
343int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
344{
345 memcpy(fpregs,
346 &current->thread.user->f,
347 sizeof(current->thread.user->f));
348 return 1;
349}