1 /*
2 * PARISC Architecture-dependent parts of process handling
3 * based on the work for i386
4 *
5 * Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
6 * Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
7 * Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
8 * Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org>
9 * Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
10 * Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
11 * Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com>
12 * Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
13 * Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
14 * Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org>
15 * Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
16 * Copyright (C) 2001-2014 Helge Deller <deller@gmx.de>
17 * Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
18 *
19 *
20 * This program is free software; you can redistribute it and/or modify
21 * it under the terms of the GNU General Public License as published by
22 * the Free Software Foundation; either version 2 of the License, or
23 * (at your option) any later version.
24 *
25 * This program is distributed in the hope that it will be useful,
26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
28 * GNU General Public License for more details.
29 *
30 * You should have received a copy of the GNU General Public License
31 * along with this program; if not, write to the Free Software
32 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
33 */
34
35 #include <stdarg.h>
36
37 #include <linux/elf.h>
38 #include <linux/errno.h>
39 #include <linux/kernel.h>
40 #include <linux/mm.h>
41 #include <linux/fs.h>
42 #include <linux/module.h>
43 #include <linux/personality.h>
44 #include <linux/ptrace.h>
45 #include <linux/sched.h>
46 #include <linux/slab.h>
47 #include <linux/stddef.h>
48 #include <linux/unistd.h>
49 #include <linux/kallsyms.h>
50 #include <linux/uaccess.h>
51 #include <linux/rcupdate.h>
52 #include <linux/random.h>
53
54 #include <asm/io.h>
55 #include <asm/asm-offsets.h>
56 #include <asm/assembly.h>
57 #include <asm/pdc.h>
58 #include <asm/pdc_chassis.h>
59 #include <asm/pgalloc.h>
60 #include <asm/unwind.h>
61 #include <asm/sections.h>
62
63 #define COMMAND_GLOBAL F_EXTEND(0xfffe0030)
64 #define CMD_RESET 5 /* reset any module */
65
66 /*
67 ** The Wright Brothers and Gecko systems have a H/W problem
68 ** (Lasi...'nuf said) may cause a broadcast reset to lockup
69 ** the system. An HVERSION dependent PDC call was developed
70 ** to perform a "safe", platform specific broadcast reset instead
71 ** of kludging up all the code.
72 **
73 ** Older machines which do not implement PDC_BROADCAST_RESET will
74 ** return (with an error) and the regular broadcast reset can be
75 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
76 ** the PDC call will not return (the system will be reset).
77 */
machine_restart(char * cmd)78 void machine_restart(char *cmd)
79 {
80 #ifdef FASTBOOT_SELFTEST_SUPPORT
81 /*
82 ** If user has modified the Firmware Selftest Bitmap,
83 ** run the tests specified in the bitmap after the
84 ** system is rebooted w/PDC_DO_RESET.
85 **
86 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
87 **
88 ** Using "directed resets" at each processor with the MEM_TOC
89 ** vector cleared will also avoid running destructive
90 ** memory self tests. (Not implemented yet)
91 */
92 if (ftc_bitmap) {
93 pdc_do_firm_test_reset(ftc_bitmap);
94 }
95 #endif
96 /* set up a new led state on systems shipped with a LED State panel */
97 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
98
99 /* "Normal" system reset */
100 pdc_do_reset();
101
102 /* Nope...box should reset with just CMD_RESET now */
103 gsc_writel(CMD_RESET, COMMAND_GLOBAL);
104
105 /* Wait for RESET to lay us to rest. */
106 while (1) ;
107
108 }
109
machine_halt(void)110 void machine_halt(void)
111 {
112 /*
113 ** The LED/ChassisCodes are updated by the led_halt()
114 ** function, called by the reboot notifier chain.
115 */
116 }
117
118 void (*chassis_power_off)(void);
119
120 /*
121 * This routine is called from sys_reboot to actually turn off the
122 * machine
123 */
machine_power_off(void)124 void machine_power_off(void)
125 {
126 /* If there is a registered power off handler, call it. */
127 if (chassis_power_off)
128 chassis_power_off();
129
130 /* Put the soft power button back under hardware control.
131 * If the user had already pressed the power button, the
132 * following call will immediately power off. */
133 pdc_soft_power_button(0);
134
135 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
136
137 /* It seems we have no way to power the system off via
138 * software. The user has to press the button himself. */
139
140 printk(KERN_EMERG "System shut down completed.\n"
141 "Please power this system off now.");
142 }
143
144 void (*pm_power_off)(void) = machine_power_off;
145 EXPORT_SYMBOL(pm_power_off);
146
flush_thread(void)147 void flush_thread(void)
148 {
149 /* Only needs to handle fpu stuff or perf monitors.
150 ** REVISIT: several arches implement a "lazy fpu state".
151 */
152 }
153
release_thread(struct task_struct * dead_task)154 void release_thread(struct task_struct *dead_task)
155 {
156 }
157
158 /*
159 * Fill in the FPU structure for a core dump.
160 */
161
dump_fpu(struct pt_regs * regs,elf_fpregset_t * r)162 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
163 {
164 if (regs == NULL)
165 return 0;
166
167 memcpy(r, regs->fr, sizeof *r);
168 return 1;
169 }
170
dump_task_fpu(struct task_struct * tsk,elf_fpregset_t * r)171 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
172 {
173 memcpy(r, tsk->thread.regs.fr, sizeof(*r));
174 return 1;
175 }
176
177 /*
178 * Copy architecture-specific thread state
179 */
180 int
copy_thread(unsigned long clone_flags,unsigned long usp,unsigned long kthread_arg,struct task_struct * p)181 copy_thread(unsigned long clone_flags, unsigned long usp,
182 unsigned long kthread_arg, struct task_struct *p)
183 {
184 struct pt_regs *cregs = &(p->thread.regs);
185 void *stack = task_stack_page(p);
186
187 /* We have to use void * instead of a function pointer, because
188 * function pointers aren't a pointer to the function on 64-bit.
189 * Make them const so the compiler knows they live in .text */
190 extern void * const ret_from_kernel_thread;
191 extern void * const child_return;
192
193 if (unlikely(p->flags & PF_KTHREAD)) {
194 /* kernel thread */
195 memset(cregs, 0, sizeof(struct pt_regs));
196 if (!usp) /* idle thread */
197 return 0;
198 /* Must exit via ret_from_kernel_thread in order
199 * to call schedule_tail()
200 */
201 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
202 cregs->kpc = (unsigned long) &ret_from_kernel_thread;
203 /*
204 * Copy function and argument to be called from
205 * ret_from_kernel_thread.
206 */
207 #ifdef CONFIG_64BIT
208 cregs->gr[27] = ((unsigned long *)usp)[3];
209 cregs->gr[26] = ((unsigned long *)usp)[2];
210 #else
211 cregs->gr[26] = usp;
212 #endif
213 cregs->gr[25] = kthread_arg;
214 } else {
215 /* user thread */
216 /* usp must be word aligned. This also prevents users from
217 * passing in the value 1 (which is the signal for a special
218 * return for a kernel thread) */
219 if (usp) {
220 usp = ALIGN(usp, 4);
221 if (likely(usp))
222 cregs->gr[30] = usp;
223 }
224 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
225 cregs->kpc = (unsigned long) &child_return;
226
227 /* Setup thread TLS area from the 4th parameter in clone */
228 if (clone_flags & CLONE_SETTLS)
229 cregs->cr27 = cregs->gr[23];
230 }
231
232 return 0;
233 }
234
thread_saved_pc(struct task_struct * t)235 unsigned long thread_saved_pc(struct task_struct *t)
236 {
237 return t->thread.regs.kpc;
238 }
239
240 unsigned long
get_wchan(struct task_struct * p)241 get_wchan(struct task_struct *p)
242 {
243 struct unwind_frame_info info;
244 unsigned long ip;
245 int count = 0;
246
247 if (!p || p == current || p->state == TASK_RUNNING)
248 return 0;
249
250 /*
251 * These bracket the sleeping functions..
252 */
253
254 unwind_frame_init_from_blocked_task(&info, p);
255 do {
256 if (unwind_once(&info) < 0)
257 return 0;
258 ip = info.ip;
259 if (!in_sched_functions(ip))
260 return ip;
261 } while (count++ < 16);
262 return 0;
263 }
264
265 #ifdef CONFIG_64BIT
dereference_function_descriptor(void * ptr)266 void *dereference_function_descriptor(void *ptr)
267 {
268 Elf64_Fdesc *desc = ptr;
269 void *p;
270
271 if (!probe_kernel_address(&desc->addr, p))
272 ptr = p;
273 return ptr;
274 }
275 #endif
276
brk_rnd(void)277 static inline unsigned long brk_rnd(void)
278 {
279 /* 8MB for 32bit, 1GB for 64bit */
280 if (is_32bit_task())
281 return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;
282 else
283 return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;
284 }
285
arch_randomize_brk(struct mm_struct * mm)286 unsigned long arch_randomize_brk(struct mm_struct *mm)
287 {
288 unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
289
290 if (ret < mm->brk)
291 return mm->brk;
292 return ret;
293 }
294