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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * PARISC Architecture-dependent parts of process handling
4 * based on the work for i386
5 *
6 * Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
7 * Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
8 * Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
9 * Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org>
10 * Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
11 * Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
12 * Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com>
13 * Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
14 * Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
15 * Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org>
16 * Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
17 * Copyright (C) 2001-2014 Helge Deller <deller@gmx.de>
18 * Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
19 */
20#include <linux/elf.h>
21#include <linux/errno.h>
22#include <linux/kernel.h>
23#include <linux/mm.h>
24#include <linux/fs.h>
25#include <linux/cpu.h>
26#include <linux/module.h>
27#include <linux/personality.h>
28#include <linux/ptrace.h>
29#include <linux/reboot.h>
30#include <linux/sched.h>
31#include <linux/sched/debug.h>
32#include <linux/sched/task.h>
33#include <linux/sched/task_stack.h>
34#include <linux/slab.h>
35#include <linux/stddef.h>
36#include <linux/unistd.h>
37#include <linux/kallsyms.h>
38#include <linux/uaccess.h>
39#include <linux/rcupdate.h>
40#include <linux/random.h>
41#include <linux/nmi.h>
42#include <linux/sched/hotplug.h>
43
44#include <asm/io.h>
45#include <asm/asm-offsets.h>
46#include <asm/assembly.h>
47#include <asm/pdc.h>
48#include <asm/pdc_chassis.h>
49#include <asm/unwind.h>
50#include <asm/sections.h>
51#include <asm/cacheflush.h>
52
53#define COMMAND_GLOBAL F_EXTEND(0xfffe0030)
54#define CMD_RESET 5 /* reset any module */
55
56/*
57** The Wright Brothers and Gecko systems have a H/W problem
58** (Lasi...'nuf said) may cause a broadcast reset to lockup
59** the system. An HVERSION dependent PDC call was developed
60** to perform a "safe", platform specific broadcast reset instead
61** of kludging up all the code.
62**
63** Older machines which do not implement PDC_BROADCAST_RESET will
64** return (with an error) and the regular broadcast reset can be
65** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
66** the PDC call will not return (the system will be reset).
67*/
68void machine_restart(char *cmd)
69{
70#ifdef FASTBOOT_SELFTEST_SUPPORT
71 /*
72 ** If user has modified the Firmware Selftest Bitmap,
73 ** run the tests specified in the bitmap after the
74 ** system is rebooted w/PDC_DO_RESET.
75 **
76 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
77 **
78 ** Using "directed resets" at each processor with the MEM_TOC
79 ** vector cleared will also avoid running destructive
80 ** memory self tests. (Not implemented yet)
81 */
82 if (ftc_bitmap) {
83 pdc_do_firm_test_reset(ftc_bitmap);
84 }
85#endif
86 /* set up a new led state on systems shipped with a LED State panel */
87 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
88
89 /* "Normal" system reset */
90 pdc_do_reset();
91
92 /* Nope...box should reset with just CMD_RESET now */
93 gsc_writel(CMD_RESET, COMMAND_GLOBAL);
94
95 /* Wait for RESET to lay us to rest. */
96 while (1) ;
97
98}
99
100/*
101 * This routine is called from sys_reboot to actually turn off the
102 * machine
103 */
104void machine_power_off(void)
105{
106 /* Put the soft power button back under hardware control.
107 * If the user had already pressed the power button, the
108 * following call will immediately power off. */
109 pdc_soft_power_button(0);
110
111 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
112
113 /* ipmi_poweroff may have been installed. */
114 do_kernel_power_off();
115
116 /* It seems we have no way to power the system off via
117 * software. The user has to press the button himself. */
118
119 printk("Power off or press RETURN to reboot.\n");
120
121 /* prevent soft lockup/stalled CPU messages for endless loop. */
122 rcu_sysrq_start();
123 lockup_detector_soft_poweroff();
124 while (1) {
125 /* reboot if user presses RETURN key */
126 if (pdc_iodc_getc() == 13) {
127 printk("Rebooting...\n");
128 machine_restart(NULL);
129 }
130 }
131}
132
133void (*pm_power_off)(void);
134EXPORT_SYMBOL(pm_power_off);
135
136void machine_halt(void)
137{
138 machine_power_off();
139}
140
141void flush_thread(void)
142{
143 /* Only needs to handle fpu stuff or perf monitors.
144 ** REVISIT: several arches implement a "lazy fpu state".
145 */
146}
147
148/*
149 * Idle thread support
150 *
151 * Detect when running on QEMU with SeaBIOS PDC Firmware and let
152 * QEMU idle the host too.
153 */
154
155int running_on_qemu __ro_after_init;
156EXPORT_SYMBOL(running_on_qemu);
157
158/*
159 * Called from the idle thread for the CPU which has been shutdown.
160 */
161void __noreturn arch_cpu_idle_dead(void)
162{
163#ifdef CONFIG_HOTPLUG_CPU
164 idle_task_exit();
165
166 local_irq_disable();
167
168 /* Tell the core that this CPU is now safe to dispose of. */
169 cpuhp_ap_report_dead();
170
171 /* Ensure that the cache lines are written out. */
172 flush_cache_all_local();
173 flush_tlb_all_local(NULL);
174
175 /* Let PDC firmware put CPU into firmware idle loop. */
176 __pdc_cpu_rendezvous();
177
178 pr_warn("PDC does not provide rendezvous function.\n");
179#endif
180 while (1);
181}
182
183void __cpuidle arch_cpu_idle(void)
184{
185 /* nop on real hardware, qemu will idle sleep. */
186 asm volatile("or %%r10,%%r10,%%r10\n":::);
187}
188
189static int __init parisc_idle_init(void)
190{
191 if (!running_on_qemu)
192 cpu_idle_poll_ctrl(1);
193
194 return 0;
195}
196arch_initcall(parisc_idle_init);
197
198/*
199 * Copy architecture-specific thread state
200 */
201int
202copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
203{
204 unsigned long clone_flags = args->flags;
205 unsigned long usp = args->stack;
206 unsigned long tls = args->tls;
207 struct pt_regs *cregs = &(p->thread.regs);
208 void *stack = task_stack_page(p);
209
210 /* We have to use void * instead of a function pointer, because
211 * function pointers aren't a pointer to the function on 64-bit.
212 * Make them const so the compiler knows they live in .text */
213 extern void * const ret_from_kernel_thread;
214 extern void * const child_return;
215
216 if (unlikely(args->fn)) {
217 /* kernel thread */
218 memset(cregs, 0, sizeof(struct pt_regs));
219 if (args->idle) /* idle thread */
220 return 0;
221 /* Must exit via ret_from_kernel_thread in order
222 * to call schedule_tail()
223 */
224 cregs->ksp = (unsigned long) stack + FRAME_SIZE + PT_SZ_ALGN;
225 cregs->kpc = (unsigned long) &ret_from_kernel_thread;
226 /*
227 * Copy function and argument to be called from
228 * ret_from_kernel_thread.
229 */
230#ifdef CONFIG_64BIT
231 cregs->gr[27] = ((unsigned long *)args->fn)[3];
232 cregs->gr[26] = ((unsigned long *)args->fn)[2];
233#else
234 cregs->gr[26] = (unsigned long) args->fn;
235#endif
236 cregs->gr[25] = (unsigned long) args->fn_arg;
237 } else {
238 /* user thread */
239 /* usp must be word aligned. This also prevents users from
240 * passing in the value 1 (which is the signal for a special
241 * return for a kernel thread) */
242 if (usp) {
243 usp = ALIGN(usp, 4);
244 if (likely(usp))
245 cregs->gr[30] = usp;
246 }
247 cregs->ksp = (unsigned long) stack + FRAME_SIZE;
248 cregs->kpc = (unsigned long) &child_return;
249
250 /* Setup thread TLS area */
251 if (clone_flags & CLONE_SETTLS)
252 cregs->cr27 = tls;
253 }
254
255 return 0;
256}
257
258unsigned long
259__get_wchan(struct task_struct *p)
260{
261 struct unwind_frame_info info;
262 unsigned long ip;
263 int count = 0;
264
265 /*
266 * These bracket the sleeping functions..
267 */
268
269 unwind_frame_init_from_blocked_task(&info, p);
270 do {
271 if (unwind_once(&info) < 0)
272 return 0;
273 if (task_is_running(p))
274 return 0;
275 ip = info.ip;
276 if (!in_sched_functions(ip))
277 return ip;
278 } while (count++ < MAX_UNWIND_ENTRIES);
279 return 0;
280}
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*/
78void 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
110void 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
118void (*chassis_power_off)(void);
119
120/*
121 * This routine is called from sys_reboot to actually turn off the
122 * machine
123 */
124void 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 /* prevent soft lockup/stalled CPU messages for endless loop. */
144 rcu_sysrq_start();
145 for (;;);
146}
147
148void (*pm_power_off)(void) = machine_power_off;
149EXPORT_SYMBOL(pm_power_off);
150
151void flush_thread(void)
152{
153 /* Only needs to handle fpu stuff or perf monitors.
154 ** REVISIT: several arches implement a "lazy fpu state".
155 */
156}
157
158void release_thread(struct task_struct *dead_task)
159{
160}
161
162/*
163 * Fill in the FPU structure for a core dump.
164 */
165
166int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
167{
168 if (regs == NULL)
169 return 0;
170
171 memcpy(r, regs->fr, sizeof *r);
172 return 1;
173}
174
175int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
176{
177 memcpy(r, tsk->thread.regs.fr, sizeof(*r));
178 return 1;
179}
180
181/*
182 * Copy architecture-specific thread state
183 */
184int
185copy_thread(unsigned long clone_flags, unsigned long usp,
186 unsigned long kthread_arg, struct task_struct *p)
187{
188 struct pt_regs *cregs = &(p->thread.regs);
189 void *stack = task_stack_page(p);
190
191 /* We have to use void * instead of a function pointer, because
192 * function pointers aren't a pointer to the function on 64-bit.
193 * Make them const so the compiler knows they live in .text */
194 extern void * const ret_from_kernel_thread;
195 extern void * const child_return;
196
197 if (unlikely(p->flags & PF_KTHREAD)) {
198 /* kernel thread */
199 memset(cregs, 0, sizeof(struct pt_regs));
200 if (!usp) /* idle thread */
201 return 0;
202 /* Must exit via ret_from_kernel_thread in order
203 * to call schedule_tail()
204 */
205 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
206 cregs->kpc = (unsigned long) &ret_from_kernel_thread;
207 /*
208 * Copy function and argument to be called from
209 * ret_from_kernel_thread.
210 */
211#ifdef CONFIG_64BIT
212 cregs->gr[27] = ((unsigned long *)usp)[3];
213 cregs->gr[26] = ((unsigned long *)usp)[2];
214#else
215 cregs->gr[26] = usp;
216#endif
217 cregs->gr[25] = kthread_arg;
218 } else {
219 /* user thread */
220 /* usp must be word aligned. This also prevents users from
221 * passing in the value 1 (which is the signal for a special
222 * return for a kernel thread) */
223 if (usp) {
224 usp = ALIGN(usp, 4);
225 if (likely(usp))
226 cregs->gr[30] = usp;
227 }
228 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
229 cregs->kpc = (unsigned long) &child_return;
230
231 /* Setup thread TLS area from the 4th parameter in clone */
232 if (clone_flags & CLONE_SETTLS)
233 cregs->cr27 = cregs->gr[23];
234 }
235
236 return 0;
237}
238
239unsigned long thread_saved_pc(struct task_struct *t)
240{
241 return t->thread.regs.kpc;
242}
243
244unsigned long
245get_wchan(struct task_struct *p)
246{
247 struct unwind_frame_info info;
248 unsigned long ip;
249 int count = 0;
250
251 if (!p || p == current || p->state == TASK_RUNNING)
252 return 0;
253
254 /*
255 * These bracket the sleeping functions..
256 */
257
258 unwind_frame_init_from_blocked_task(&info, p);
259 do {
260 if (unwind_once(&info) < 0)
261 return 0;
262 ip = info.ip;
263 if (!in_sched_functions(ip))
264 return ip;
265 } while (count++ < 16);
266 return 0;
267}
268
269#ifdef CONFIG_64BIT
270void *dereference_function_descriptor(void *ptr)
271{
272 Elf64_Fdesc *desc = ptr;
273 void *p;
274
275 if (!probe_kernel_address(&desc->addr, p))
276 ptr = p;
277 return ptr;
278}
279#endif
280
281static inline unsigned long brk_rnd(void)
282{
283 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
284}
285
286unsigned 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}