1 /* 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
13 #include <linux/module.h>
14 #include <linux/errno.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/mm.h>
18 #include <linux/smp.h>
19 #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>
27 #include <linux/pagemap.h>
28 #include <linux/rcupdate.h>
29
30 #include <asm/asm-offsets.h>
31 #include <asm/uaccess.h>
32 #include <asm/setup.h>
33 #include <asm/pgtable.h>
34 #include <asm/tlb.h>
35 #include <asm/gdb-stub.h>
36 #include <asm/mb-regs.h>
37
38 #include "local.h"
39
40 asmlinkage void ret_from_fork(void);
41 asmlinkage void ret_from_kernel_thread(void);
42
43 #include <asm/pgalloc.h>
44
45 void (*pm_power_off)(void);
46 EXPORT_SYMBOL(pm_power_off);
47
core_sleep_idle(void)48 static void core_sleep_idle(void)
49 {
50 #ifdef LED_DEBUG_SLEEP
51 /* Show that we're sleeping... */
52 __set_LEDS(0x55aa);
53 #endif
54 frv_cpu_core_sleep();
55 #ifdef LED_DEBUG_SLEEP
56 /* ... and that we woke up */
57 __set_LEDS(0);
58 #endif
59 mb();
60 }
61
arch_cpu_idle(void)62 void arch_cpu_idle(void)
63 {
64 if (!frv_dma_inprogress)
65 core_sleep_idle();
66 else
67 local_irq_enable();
68 }
69
machine_restart(char * __unused)70 void machine_restart(char * __unused)
71 {
72 unsigned long reset_addr;
73 #ifdef CONFIG_GDBSTUB
74 gdbstub_exit(0);
75 #endif
76
77 if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551)
78 reset_addr = 0xfefff500;
79 else
80 reset_addr = 0xfeff0500;
81
82 /* Software reset. */
83 asm volatile(" dcef @(gr0,gr0),1 ! membar !"
84 " sti %1,@(%0,0) !"
85 " nop ! nop ! nop ! nop ! nop ! "
86 " nop ! nop ! nop ! nop ! nop ! "
87 " nop ! nop ! nop ! nop ! nop ! "
88 " nop ! nop ! nop ! nop ! nop ! "
89 : : "r" (reset_addr), "r" (1) );
90
91 for (;;)
92 ;
93 }
94
machine_halt(void)95 void machine_halt(void)
96 {
97 #ifdef CONFIG_GDBSTUB
98 gdbstub_exit(0);
99 #endif
100
101 for (;;);
102 }
103
machine_power_off(void)104 void machine_power_off(void)
105 {
106 #ifdef CONFIG_GDBSTUB
107 gdbstub_exit(0);
108 #endif
109
110 for (;;);
111 }
112
flush_thread(void)113 void flush_thread(void)
114 {
115 /* nothing */
116 }
117
user_stack(const struct pt_regs * regs)118 inline unsigned long user_stack(const struct pt_regs *regs)
119 {
120 while (regs->next_frame)
121 regs = regs->next_frame;
122 return user_mode(regs) ? regs->sp : 0;
123 }
124
125 /*
126 * set up the kernel stack and exception frames for a new process
127 */
copy_thread(unsigned long clone_flags,unsigned long usp,unsigned long arg,struct task_struct * p)128 int copy_thread(unsigned long clone_flags,
129 unsigned long usp, unsigned long arg,
130 struct task_struct *p)
131 {
132 struct pt_regs *childregs;
133
134 childregs = (struct pt_regs *)
135 (task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE);
136
137 /* set up the userspace frame (the only place that the USP is stored) */
138 *childregs = *current_pt_regs();
139
140 p->thread.frame = childregs;
141 p->thread.curr = p;
142 p->thread.sp = (unsigned long) childregs;
143 p->thread.fp = 0;
144 p->thread.lr = 0;
145 p->thread.frame0 = childregs;
146
147 if (unlikely(p->flags & PF_KTHREAD)) {
148 childregs->gr9 = usp; /* function */
149 childregs->gr8 = arg;
150 p->thread.pc = (unsigned long) ret_from_kernel_thread;
151 save_user_regs(p->thread.user);
152 return 0;
153 }
154 if (usp)
155 childregs->sp = usp;
156 childregs->next_frame = NULL;
157
158 p->thread.pc = (unsigned long) ret_from_fork;
159
160 /* the new TLS pointer is passed in as arg #5 to sys_clone() */
161 if (clone_flags & CLONE_SETTLS)
162 childregs->gr29 = childregs->gr12;
163
164 save_user_regs(p->thread.user);
165
166 return 0;
167 } /* end copy_thread() */
168
get_wchan(struct task_struct * p)169 unsigned long get_wchan(struct task_struct *p)
170 {
171 struct pt_regs *regs0;
172 unsigned long fp, pc;
173 unsigned long stack_limit;
174 int count = 0;
175 if (!p || p == current || p->state == TASK_RUNNING)
176 return 0;
177
178 stack_limit = (unsigned long) (p + 1);
179 fp = p->thread.fp;
180 regs0 = p->thread.frame0;
181
182 do {
183 if (fp < stack_limit || fp >= (unsigned long) regs0 || fp & 3)
184 return 0;
185
186 pc = ((unsigned long *) fp)[2];
187
188 /* FIXME: This depends on the order of these functions. */
189 if (!in_sched_functions(pc))
190 return pc;
191
192 fp = *(unsigned long *) fp;
193 } while (count++ < 16);
194
195 return 0;
196 }
197
thread_saved_pc(struct task_struct * tsk)198 unsigned long thread_saved_pc(struct task_struct *tsk)
199 {
200 /* Check whether the thread is blocked in resume() */
201 if (in_sched_functions(tsk->thread.pc))
202 return ((unsigned long *)tsk->thread.fp)[2];
203 else
204 return tsk->thread.pc;
205 }
206
elf_check_arch(const struct elf32_hdr * hdr)207 int elf_check_arch(const struct elf32_hdr *hdr)
208 {
209 unsigned long hsr0 = __get_HSR(0);
210 unsigned long psr = __get_PSR();
211
212 if (hdr->e_machine != EM_FRV)
213 return 0;
214
215 switch (hdr->e_flags & EF_FRV_GPR_MASK) {
216 case EF_FRV_GPR64:
217 if ((hsr0 & HSR0_GRN) == HSR0_GRN_32)
218 return 0;
219 case EF_FRV_GPR32:
220 case 0:
221 break;
222 default:
223 return 0;
224 }
225
226 switch (hdr->e_flags & EF_FRV_FPR_MASK) {
227 case EF_FRV_FPR64:
228 if ((hsr0 & HSR0_FRN) == HSR0_FRN_32)
229 return 0;
230 case EF_FRV_FPR32:
231 case EF_FRV_FPR_NONE:
232 case 0:
233 break;
234 default:
235 return 0;
236 }
237
238 if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD)
239 if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
240 PSR_IMPLE(psr) != PSR_IMPLE_FR451)
241 return 0;
242
243 switch (hdr->e_flags & EF_FRV_CPU_MASK) {
244 case EF_FRV_CPU_GENERIC:
245 break;
246 case EF_FRV_CPU_FR300:
247 case EF_FRV_CPU_SIMPLE:
248 case EF_FRV_CPU_TOMCAT:
249 default:
250 return 0;
251 case EF_FRV_CPU_FR400:
252 if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 &&
253 PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
254 PSR_IMPLE(psr) != PSR_IMPLE_FR451 &&
255 PSR_IMPLE(psr) != PSR_IMPLE_FR551)
256 return 0;
257 break;
258 case EF_FRV_CPU_FR450:
259 if (PSR_IMPLE(psr) != PSR_IMPLE_FR451)
260 return 0;
261 break;
262 case EF_FRV_CPU_FR500:
263 if (PSR_IMPLE(psr) != PSR_IMPLE_FR501)
264 return 0;
265 break;
266 case EF_FRV_CPU_FR550:
267 if (PSR_IMPLE(psr) != PSR_IMPLE_FR551)
268 return 0;
269 break;
270 }
271
272 return 1;
273 }
274
dump_fpu(struct pt_regs * regs,elf_fpregset_t * fpregs)275 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
276 {
277 memcpy(fpregs,
278 ¤t->thread.user->f,
279 sizeof(current->thread.user->f));
280 return 1;
281 }
282