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/cpu.h>
43 #include <linux/module.h>
44 #include <linux/personality.h>
45 #include <linux/ptrace.h>
46 #include <linux/sched.h>
47 #include <linux/sched/debug.h>
48 #include <linux/sched/task.h>
49 #include <linux/sched/task_stack.h>
50 #include <linux/slab.h>
51 #include <linux/stddef.h>
52 #include <linux/unistd.h>
53 #include <linux/kallsyms.h>
54 #include <linux/uaccess.h>
55 #include <linux/rcupdate.h>
56 #include <linux/random.h>
57 #include <linux/nmi.h>
58
59 #include <asm/io.h>
60 #include <asm/asm-offsets.h>
61 #include <asm/assembly.h>
62 #include <asm/pdc.h>
63 #include <asm/pdc_chassis.h>
64 #include <asm/pgalloc.h>
65 #include <asm/unwind.h>
66 #include <asm/sections.h>
67
68 #define COMMAND_GLOBAL F_EXTEND(0xfffe0030)
69 #define CMD_RESET 5 /* reset any module */
70
71 /*
72 ** The Wright Brothers and Gecko systems have a H/W problem
73 ** (Lasi...'nuf said) may cause a broadcast reset to lockup
74 ** the system. An HVERSION dependent PDC call was developed
75 ** to perform a "safe", platform specific broadcast reset instead
76 ** of kludging up all the code.
77 **
78 ** Older machines which do not implement PDC_BROADCAST_RESET will
79 ** return (with an error) and the regular broadcast reset can be
80 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
81 ** the PDC call will not return (the system will be reset).
82 */
machine_restart(char * cmd)83 void machine_restart(char *cmd)
84 {
85 #ifdef FASTBOOT_SELFTEST_SUPPORT
86 /*
87 ** If user has modified the Firmware Selftest Bitmap,
88 ** run the tests specified in the bitmap after the
89 ** system is rebooted w/PDC_DO_RESET.
90 **
91 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
92 **
93 ** Using "directed resets" at each processor with the MEM_TOC
94 ** vector cleared will also avoid running destructive
95 ** memory self tests. (Not implemented yet)
96 */
97 if (ftc_bitmap) {
98 pdc_do_firm_test_reset(ftc_bitmap);
99 }
100 #endif
101 /* set up a new led state on systems shipped with a LED State panel */
102 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
103
104 /* "Normal" system reset */
105 pdc_do_reset();
106
107 /* Nope...box should reset with just CMD_RESET now */
108 gsc_writel(CMD_RESET, COMMAND_GLOBAL);
109
110 /* Wait for RESET to lay us to rest. */
111 while (1) ;
112
113 }
114
machine_halt(void)115 void machine_halt(void)
116 {
117 /*
118 ** The LED/ChassisCodes are updated by the led_halt()
119 ** function, called by the reboot notifier chain.
120 */
121 }
122
123 void (*chassis_power_off)(void);
124
125 /*
126 * This routine is called from sys_reboot to actually turn off the
127 * machine
128 */
machine_power_off(void)129 void machine_power_off(void)
130 {
131 /* If there is a registered power off handler, call it. */
132 if (chassis_power_off)
133 chassis_power_off();
134
135 /* Put the soft power button back under hardware control.
136 * If the user had already pressed the power button, the
137 * following call will immediately power off. */
138 pdc_soft_power_button(0);
139
140 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
141
142 /* It seems we have no way to power the system off via
143 * software. The user has to press the button himself. */
144
145 printk(KERN_EMERG "System shut down completed.\n"
146 "Please power this system off now.");
147
148 /* prevent soft lockup/stalled CPU messages for endless loop. */
149 rcu_sysrq_start();
150 lockup_detector_soft_poweroff();
151 for (;;);
152 }
153
154 void (*pm_power_off)(void) = machine_power_off;
155 EXPORT_SYMBOL(pm_power_off);
156
flush_thread(void)157 void flush_thread(void)
158 {
159 /* Only needs to handle fpu stuff or perf monitors.
160 ** REVISIT: several arches implement a "lazy fpu state".
161 */
162 }
163
release_thread(struct task_struct * dead_task)164 void release_thread(struct task_struct *dead_task)
165 {
166 }
167
168 /*
169 * Fill in the FPU structure for a core dump.
170 */
171
dump_fpu(struct pt_regs * regs,elf_fpregset_t * r)172 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
173 {
174 if (regs == NULL)
175 return 0;
176
177 memcpy(r, regs->fr, sizeof *r);
178 return 1;
179 }
180
dump_task_fpu(struct task_struct * tsk,elf_fpregset_t * r)181 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
182 {
183 memcpy(r, tsk->thread.regs.fr, sizeof(*r));
184 return 1;
185 }
186
187 /*
188 * Idle thread support
189 *
190 * Detect when running on QEMU with SeaBIOS PDC Firmware and let
191 * QEMU idle the host too.
192 */
193
194 int running_on_qemu __read_mostly;
195 EXPORT_SYMBOL(running_on_qemu);
196
arch_cpu_idle_dead(void)197 void __cpuidle arch_cpu_idle_dead(void)
198 {
199 /* nop on real hardware, qemu will offline CPU. */
200 asm volatile("or %%r31,%%r31,%%r31\n":::);
201 }
202
arch_cpu_idle(void)203 void __cpuidle arch_cpu_idle(void)
204 {
205 local_irq_enable();
206
207 /* nop on real hardware, qemu will idle sleep. */
208 asm volatile("or %%r10,%%r10,%%r10\n":::);
209 }
210
parisc_idle_init(void)211 static int __init parisc_idle_init(void)
212 {
213 if (!running_on_qemu)
214 cpu_idle_poll_ctrl(1);
215
216 return 0;
217 }
218 arch_initcall(parisc_idle_init);
219
220 /*
221 * Copy architecture-specific thread state
222 */
223 int
copy_thread(unsigned long clone_flags,unsigned long usp,unsigned long kthread_arg,struct task_struct * p)224 copy_thread(unsigned long clone_flags, unsigned long usp,
225 unsigned long kthread_arg, struct task_struct *p)
226 {
227 struct pt_regs *cregs = &(p->thread.regs);
228 void *stack = task_stack_page(p);
229
230 /* We have to use void * instead of a function pointer, because
231 * function pointers aren't a pointer to the function on 64-bit.
232 * Make them const so the compiler knows they live in .text */
233 extern void * const ret_from_kernel_thread;
234 extern void * const child_return;
235
236 if (unlikely(p->flags & PF_KTHREAD)) {
237 /* kernel thread */
238 memset(cregs, 0, sizeof(struct pt_regs));
239 if (!usp) /* idle thread */
240 return 0;
241 /* Must exit via ret_from_kernel_thread in order
242 * to call schedule_tail()
243 */
244 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
245 cregs->kpc = (unsigned long) &ret_from_kernel_thread;
246 /*
247 * Copy function and argument to be called from
248 * ret_from_kernel_thread.
249 */
250 #ifdef CONFIG_64BIT
251 cregs->gr[27] = ((unsigned long *)usp)[3];
252 cregs->gr[26] = ((unsigned long *)usp)[2];
253 #else
254 cregs->gr[26] = usp;
255 #endif
256 cregs->gr[25] = kthread_arg;
257 } else {
258 /* user thread */
259 /* usp must be word aligned. This also prevents users from
260 * passing in the value 1 (which is the signal for a special
261 * return for a kernel thread) */
262 if (usp) {
263 usp = ALIGN(usp, 4);
264 if (likely(usp))
265 cregs->gr[30] = usp;
266 }
267 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
268 cregs->kpc = (unsigned long) &child_return;
269
270 /* Setup thread TLS area from the 4th parameter in clone */
271 if (clone_flags & CLONE_SETTLS)
272 cregs->cr27 = cregs->gr[23];
273 }
274
275 return 0;
276 }
277
278 unsigned long
get_wchan(struct task_struct * p)279 get_wchan(struct task_struct *p)
280 {
281 struct unwind_frame_info info;
282 unsigned long ip;
283 int count = 0;
284
285 if (!p || p == current || p->state == TASK_RUNNING)
286 return 0;
287
288 /*
289 * These bracket the sleeping functions..
290 */
291
292 unwind_frame_init_from_blocked_task(&info, p);
293 do {
294 if (unwind_once(&info) < 0)
295 return 0;
296 ip = info.ip;
297 if (!in_sched_functions(ip))
298 return ip;
299 } while (count++ < 16);
300 return 0;
301 }
302
303 #ifdef CONFIG_64BIT
dereference_function_descriptor(void * ptr)304 void *dereference_function_descriptor(void *ptr)
305 {
306 Elf64_Fdesc *desc = ptr;
307 void *p;
308
309 if (!probe_kernel_address(&desc->addr, p))
310 ptr = p;
311 return ptr;
312 }
313 #endif
314
brk_rnd(void)315 static inline unsigned long brk_rnd(void)
316 {
317 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
318 }
319
arch_randomize_brk(struct mm_struct * mm)320 unsigned long arch_randomize_brk(struct mm_struct *mm)
321 {
322 unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
323
324 if (ret < mm->brk)
325 return mm->brk;
326 return ret;
327 }
328