Loading...
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) 2001-2007 Helge Deller <deller at parisc-linux.org>
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
52#include <asm/io.h>
53#include <asm/asm-offsets.h>
54#include <asm/pdc.h>
55#include <asm/pdc_chassis.h>
56#include <asm/pgalloc.h>
57#include <asm/unwind.h>
58#include <asm/sections.h>
59
60/*
61 * The idle thread. There's no useful work to be
62 * done, so just try to conserve power and have a
63 * low exit latency (ie sit in a loop waiting for
64 * somebody to say that they'd like to reschedule)
65 */
66void cpu_idle(void)
67{
68 set_thread_flag(TIF_POLLING_NRFLAG);
69
70 /* endless idle loop with no priority at all */
71 while (1) {
72 while (!need_resched())
73 barrier();
74 schedule_preempt_disabled();
75 check_pgt_cache();
76 }
77}
78
79
80#define COMMAND_GLOBAL F_EXTEND(0xfffe0030)
81#define CMD_RESET 5 /* reset any module */
82
83/*
84** The Wright Brothers and Gecko systems have a H/W problem
85** (Lasi...'nuf said) may cause a broadcast reset to lockup
86** the system. An HVERSION dependent PDC call was developed
87** to perform a "safe", platform specific broadcast reset instead
88** of kludging up all the code.
89**
90** Older machines which do not implement PDC_BROADCAST_RESET will
91** return (with an error) and the regular broadcast reset can be
92** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
93** the PDC call will not return (the system will be reset).
94*/
95void machine_restart(char *cmd)
96{
97#ifdef FASTBOOT_SELFTEST_SUPPORT
98 /*
99 ** If user has modified the Firmware Selftest Bitmap,
100 ** run the tests specified in the bitmap after the
101 ** system is rebooted w/PDC_DO_RESET.
102 **
103 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
104 **
105 ** Using "directed resets" at each processor with the MEM_TOC
106 ** vector cleared will also avoid running destructive
107 ** memory self tests. (Not implemented yet)
108 */
109 if (ftc_bitmap) {
110 pdc_do_firm_test_reset(ftc_bitmap);
111 }
112#endif
113 /* set up a new led state on systems shipped with a LED State panel */
114 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
115
116 /* "Normal" system reset */
117 pdc_do_reset();
118
119 /* Nope...box should reset with just CMD_RESET now */
120 gsc_writel(CMD_RESET, COMMAND_GLOBAL);
121
122 /* Wait for RESET to lay us to rest. */
123 while (1) ;
124
125}
126
127void machine_halt(void)
128{
129 /*
130 ** The LED/ChassisCodes are updated by the led_halt()
131 ** function, called by the reboot notifier chain.
132 */
133}
134
135void (*chassis_power_off)(void);
136
137/*
138 * This routine is called from sys_reboot to actually turn off the
139 * machine
140 */
141void machine_power_off(void)
142{
143 /* If there is a registered power off handler, call it. */
144 if (chassis_power_off)
145 chassis_power_off();
146
147 /* Put the soft power button back under hardware control.
148 * If the user had already pressed the power button, the
149 * following call will immediately power off. */
150 pdc_soft_power_button(0);
151
152 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
153
154 /* It seems we have no way to power the system off via
155 * software. The user has to press the button himself. */
156
157 printk(KERN_EMERG "System shut down completed.\n"
158 "Please power this system off now.");
159}
160
161void (*pm_power_off)(void) = machine_power_off;
162EXPORT_SYMBOL(pm_power_off);
163
164/*
165 * Create a kernel thread
166 */
167
168extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
169pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
170{
171
172 /*
173 * FIXME: Once we are sure we don't need any debug here,
174 * kernel_thread can become a #define.
175 */
176
177 return __kernel_thread(fn, arg, flags);
178}
179EXPORT_SYMBOL(kernel_thread);
180
181/*
182 * Free current thread data structures etc..
183 */
184void exit_thread(void)
185{
186}
187
188void flush_thread(void)
189{
190 /* Only needs to handle fpu stuff or perf monitors.
191 ** REVISIT: several arches implement a "lazy fpu state".
192 */
193}
194
195void release_thread(struct task_struct *dead_task)
196{
197}
198
199/*
200 * Fill in the FPU structure for a core dump.
201 */
202
203int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
204{
205 if (regs == NULL)
206 return 0;
207
208 memcpy(r, regs->fr, sizeof *r);
209 return 1;
210}
211
212int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
213{
214 memcpy(r, tsk->thread.regs.fr, sizeof(*r));
215 return 1;
216}
217
218/* Note that "fork()" is implemented in terms of clone, with
219 parameters (SIGCHLD, regs->gr[30], regs). */
220int
221sys_clone(unsigned long clone_flags, unsigned long usp,
222 struct pt_regs *regs)
223{
224 /* Arugments from userspace are:
225 r26 = Clone flags.
226 r25 = Child stack.
227 r24 = parent_tidptr.
228 r23 = Is the TLS storage descriptor
229 r22 = child_tidptr
230
231 However, these last 3 args are only examined
232 if the proper flags are set. */
233 int __user *parent_tidptr = (int __user *)regs->gr[24];
234 int __user *child_tidptr = (int __user *)regs->gr[22];
235
236 /* usp must be word aligned. This also prevents users from
237 * passing in the value 1 (which is the signal for a special
238 * return for a kernel thread) */
239 usp = ALIGN(usp, 4);
240
241 /* A zero value for usp means use the current stack */
242 if (usp == 0)
243 usp = regs->gr[30];
244
245 return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr);
246}
247
248int
249sys_vfork(struct pt_regs *regs)
250{
251 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
252}
253
254int
255copy_thread(unsigned long clone_flags, unsigned long usp,
256 unsigned long unused, /* in ia64 this is "user_stack_size" */
257 struct task_struct * p, struct pt_regs * pregs)
258{
259 struct pt_regs * cregs = &(p->thread.regs);
260 void *stack = task_stack_page(p);
261
262 /* We have to use void * instead of a function pointer, because
263 * function pointers aren't a pointer to the function on 64-bit.
264 * Make them const so the compiler knows they live in .text */
265 extern void * const ret_from_kernel_thread;
266 extern void * const child_return;
267#ifdef CONFIG_HPUX
268 extern void * const hpux_child_return;
269#endif
270
271 *cregs = *pregs;
272
273 /* Set the return value for the child. Note that this is not
274 actually restored by the syscall exit path, but we put it
275 here for consistency in case of signals. */
276 cregs->gr[28] = 0; /* child */
277
278 /*
279 * We need to differentiate between a user fork and a
280 * kernel fork. We can't use user_mode, because the
281 * the syscall path doesn't save iaoq. Right now
282 * We rely on the fact that kernel_thread passes
283 * in zero for usp.
284 */
285 if (usp == 1) {
286 /* kernel thread */
287 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN;
288 /* Must exit via ret_from_kernel_thread in order
289 * to call schedule_tail()
290 */
291 cregs->kpc = (unsigned long) &ret_from_kernel_thread;
292 /*
293 * Copy function and argument to be called from
294 * ret_from_kernel_thread.
295 */
296#ifdef CONFIG_64BIT
297 cregs->gr[27] = pregs->gr[27];
298#endif
299 cregs->gr[26] = pregs->gr[26];
300 cregs->gr[25] = pregs->gr[25];
301 } else {
302 /* user thread */
303 /*
304 * Note that the fork wrappers are responsible
305 * for setting gr[21].
306 */
307
308 /* Use same stack depth as parent */
309 cregs->ksp = (unsigned long)stack
310 + (pregs->gr[21] & (THREAD_SIZE - 1));
311 cregs->gr[30] = usp;
312 if (p->personality == PER_HPUX) {
313#ifdef CONFIG_HPUX
314 cregs->kpc = (unsigned long) &hpux_child_return;
315#else
316 BUG();
317#endif
318 } else {
319 cregs->kpc = (unsigned long) &child_return;
320 }
321 /* Setup thread TLS area from the 4th parameter in clone */
322 if (clone_flags & CLONE_SETTLS)
323 cregs->cr27 = pregs->gr[23];
324
325 }
326
327 return 0;
328}
329
330unsigned long thread_saved_pc(struct task_struct *t)
331{
332 return t->thread.regs.kpc;
333}
334
335/*
336 * sys_execve() executes a new program.
337 */
338
339asmlinkage int sys_execve(struct pt_regs *regs)
340{
341 int error;
342 char *filename;
343
344 filename = getname((const char __user *) regs->gr[26]);
345 error = PTR_ERR(filename);
346 if (IS_ERR(filename))
347 goto out;
348 error = do_execve(filename,
349 (const char __user *const __user *) regs->gr[25],
350 (const char __user *const __user *) regs->gr[24],
351 regs);
352 putname(filename);
353out:
354
355 return error;
356}
357
358extern int __execve(const char *filename,
359 const char *const argv[],
360 const char *const envp[], struct task_struct *task);
361int kernel_execve(const char *filename,
362 const char *const argv[],
363 const char *const envp[])
364{
365 return __execve(filename, argv, envp, current);
366}
367
368unsigned long
369get_wchan(struct task_struct *p)
370{
371 struct unwind_frame_info info;
372 unsigned long ip;
373 int count = 0;
374
375 if (!p || p == current || p->state == TASK_RUNNING)
376 return 0;
377
378 /*
379 * These bracket the sleeping functions..
380 */
381
382 unwind_frame_init_from_blocked_task(&info, p);
383 do {
384 if (unwind_once(&info) < 0)
385 return 0;
386 ip = info.ip;
387 if (!in_sched_functions(ip))
388 return ip;
389 } while (count++ < 16);
390 return 0;
391}
392
393#ifdef CONFIG_64BIT
394void *dereference_function_descriptor(void *ptr)
395{
396 Elf64_Fdesc *desc = ptr;
397 void *p;
398
399 if (!probe_kernel_address(&desc->addr, p))
400 ptr = p;
401 return ptr;
402}
403#endif
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}