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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
21#include <stdarg.h>
22
23#include <linux/elf.h>
24#include <linux/errno.h>
25#include <linux/kernel.h>
26#include <linux/mm.h>
27#include <linux/fs.h>
28#include <linux/cpu.h>
29#include <linux/module.h>
30#include <linux/personality.h>
31#include <linux/ptrace.h>
32#include <linux/sched.h>
33#include <linux/sched/debug.h>
34#include <linux/sched/task.h>
35#include <linux/sched/task_stack.h>
36#include <linux/slab.h>
37#include <linux/stddef.h>
38#include <linux/unistd.h>
39#include <linux/kallsyms.h>
40#include <linux/uaccess.h>
41#include <linux/rcupdate.h>
42#include <linux/random.h>
43#include <linux/nmi.h>
44
45#include <asm/io.h>
46#include <asm/asm-offsets.h>
47#include <asm/assembly.h>
48#include <asm/pdc.h>
49#include <asm/pdc_chassis.h>
50#include <asm/unwind.h>
51#include <asm/sections.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
100void (*chassis_power_off)(void);
101
102/*
103 * This routine is called from sys_reboot to actually turn off the
104 * machine
105 */
106void machine_power_off(void)
107{
108 /* If there is a registered power off handler, call it. */
109 if (chassis_power_off)
110 chassis_power_off();
111
112 /* Put the soft power button back under hardware control.
113 * If the user had already pressed the power button, the
114 * following call will immediately power off. */
115 pdc_soft_power_button(0);
116
117 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
118
119 /* ipmi_poweroff may have been installed. */
120 if (pm_power_off)
121 pm_power_off();
122
123 /* It seems we have no way to power the system off via
124 * software. The user has to press the button himself. */
125
126 printk(KERN_EMERG "System shut down completed.\n"
127 "Please power this system off now.");
128
129 /* prevent soft lockup/stalled CPU messages for endless loop. */
130 rcu_sysrq_start();
131 lockup_detector_soft_poweroff();
132 for (;;);
133}
134
135void (*pm_power_off)(void);
136EXPORT_SYMBOL(pm_power_off);
137
138void machine_halt(void)
139{
140 machine_power_off();
141}
142
143void flush_thread(void)
144{
145 /* Only needs to handle fpu stuff or perf monitors.
146 ** REVISIT: several arches implement a "lazy fpu state".
147 */
148}
149
150void release_thread(struct task_struct *dead_task)
151{
152}
153
154/*
155 * Idle thread support
156 *
157 * Detect when running on QEMU with SeaBIOS PDC Firmware and let
158 * QEMU idle the host too.
159 */
160
161int running_on_qemu __ro_after_init;
162EXPORT_SYMBOL(running_on_qemu);
163
164void __cpuidle arch_cpu_idle_dead(void)
165{
166 /* nop on real hardware, qemu will offline CPU. */
167 asm volatile("or %%r31,%%r31,%%r31\n":::);
168}
169
170void __cpuidle arch_cpu_idle(void)
171{
172 local_irq_enable();
173
174 /* nop on real hardware, qemu will idle sleep. */
175 asm volatile("or %%r10,%%r10,%%r10\n":::);
176}
177
178static int __init parisc_idle_init(void)
179{
180 if (!running_on_qemu)
181 cpu_idle_poll_ctrl(1);
182
183 return 0;
184}
185arch_initcall(parisc_idle_init);
186
187/*
188 * Copy architecture-specific thread state
189 */
190int
191copy_thread(unsigned long clone_flags, unsigned long usp,
192 unsigned long kthread_arg, struct task_struct *p, unsigned long tls)
193{
194 struct pt_regs *cregs = &(p->thread.regs);
195 void *stack = task_stack_page(p);
196
197 /* We have to use void * instead of a function pointer, because
198 * function pointers aren't a pointer to the function on 64-bit.
199 * Make them const so the compiler knows they live in .text */
200 extern void * const ret_from_kernel_thread;
201 extern void * const child_return;
202
203 if (unlikely(p->flags & PF_KTHREAD)) {
204 /* kernel thread */
205 memset(cregs, 0, sizeof(struct pt_regs));
206 if (!usp) /* idle thread */
207 return 0;
208 /* Must exit via ret_from_kernel_thread in order
209 * to call schedule_tail()
210 */
211 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
212 cregs->kpc = (unsigned long) &ret_from_kernel_thread;
213 /*
214 * Copy function and argument to be called from
215 * ret_from_kernel_thread.
216 */
217#ifdef CONFIG_64BIT
218 cregs->gr[27] = ((unsigned long *)usp)[3];
219 cregs->gr[26] = ((unsigned long *)usp)[2];
220#else
221 cregs->gr[26] = usp;
222#endif
223 cregs->gr[25] = kthread_arg;
224 } else {
225 /* user thread */
226 /* usp must be word aligned. This also prevents users from
227 * passing in the value 1 (which is the signal for a special
228 * return for a kernel thread) */
229 if (usp) {
230 usp = ALIGN(usp, 4);
231 if (likely(usp))
232 cregs->gr[30] = usp;
233 }
234 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
235 cregs->kpc = (unsigned long) &child_return;
236
237 /* Setup thread TLS area */
238 if (clone_flags & CLONE_SETTLS)
239 cregs->cr27 = tls;
240 }
241
242 return 0;
243}
244
245unsigned long
246get_wchan(struct task_struct *p)
247{
248 struct unwind_frame_info info;
249 unsigned long ip;
250 int count = 0;
251
252 if (!p || p == current || p->state == TASK_RUNNING)
253 return 0;
254
255 /*
256 * These bracket the sleeping functions..
257 */
258
259 unwind_frame_init_from_blocked_task(&info, p);
260 do {
261 if (unwind_once(&info) < 0)
262 return 0;
263 ip = info.ip;
264 if (!in_sched_functions(ip))
265 return ip;
266 } while (count++ < MAX_UNWIND_ENTRIES);
267 return 0;
268}
269
270#ifdef CONFIG_64BIT
271void *dereference_function_descriptor(void *ptr)
272{
273 Elf64_Fdesc *desc = ptr;
274 void *p;
275
276 if (!get_kernel_nofault(p, (void *)&desc->addr))
277 ptr = p;
278 return ptr;
279}
280
281void *dereference_kernel_function_descriptor(void *ptr)
282{
283 if (ptr < (void *)__start_opd ||
284 ptr >= (void *)__end_opd)
285 return ptr;
286
287 return dereference_function_descriptor(ptr);
288}
289#endif
290
291static inline unsigned long brk_rnd(void)
292{
293 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
294}
295
296unsigned long arch_randomize_brk(struct mm_struct *mm)
297{
298 unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
299
300 if (ret < mm->brk)
301 return mm->brk;
302 return ret;
303}
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}