1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * PARISC Architecture-dependent parts of process handling
4 * based on the work for i386
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>
23 #include <linux/elf.h>
24 #include <linux/errno.h>
25 #include <linux/kernel.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>
46 #include <asm/asm-offsets.h>
47 #include <asm/assembly.h>
49 #include <asm/pdc_chassis.h>
50 #include <asm/unwind.h>
51 #include <asm/sections.h>
53 #define COMMAND_GLOBAL F_EXTEND(0xfffe0030)
54 #define CMD_RESET 5 /* reset any module */
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.
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).
68 void machine_restart(char *cmd)
70 #ifdef FASTBOOT_SELFTEST_SUPPORT
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.
76 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
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)
83 pdc_do_firm_test_reset(ftc_bitmap);
86 /* set up a new led state on systems shipped with a LED State panel */
87 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
89 /* "Normal" system reset */
92 /* Nope...box should reset with just CMD_RESET now */
93 gsc_writel(CMD_RESET, COMMAND_GLOBAL);
95 /* Wait for RESET to lay us to rest. */
100 void (*chassis_power_off)(void);
103 * This routine is called from sys_reboot to actually turn off the
106 void machine_power_off(void)
108 /* If there is a registered power off handler, call it. */
109 if (chassis_power_off)
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);
117 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
119 /* ipmi_poweroff may have been installed. */
123 /* It seems we have no way to power the system off via
124 * software. The user has to press the button himself. */
126 printk("Power off or press RETURN to reboot.\n");
128 /* prevent soft lockup/stalled CPU messages for endless loop. */
130 lockup_detector_soft_poweroff();
132 /* reboot if user presses RETURN key */
133 if (pdc_iodc_getc() == 13) {
134 printk("Rebooting...\n");
135 machine_restart(NULL);
140 void (*pm_power_off)(void);
141 EXPORT_SYMBOL(pm_power_off);
143 void machine_halt(void)
148 void flush_thread(void)
150 /* Only needs to handle fpu stuff or perf monitors.
151 ** REVISIT: several arches implement a "lazy fpu state".
155 void release_thread(struct task_struct *dead_task)
160 * Idle thread support
162 * Detect when running on QEMU with SeaBIOS PDC Firmware and let
163 * QEMU idle the host too.
166 int running_on_qemu __ro_after_init;
167 EXPORT_SYMBOL(running_on_qemu);
169 void __cpuidle arch_cpu_idle_dead(void)
171 /* nop on real hardware, qemu will offline CPU. */
172 asm volatile("or %%r31,%%r31,%%r31\n":::);
175 void __cpuidle arch_cpu_idle(void)
177 raw_local_irq_enable();
179 /* nop on real hardware, qemu will idle sleep. */
180 asm volatile("or %%r10,%%r10,%%r10\n":::);
183 static int __init parisc_idle_init(void)
185 if (!running_on_qemu)
186 cpu_idle_poll_ctrl(1);
190 arch_initcall(parisc_idle_init);
193 * Copy architecture-specific thread state
196 copy_thread(unsigned long clone_flags, unsigned long usp,
197 unsigned long kthread_arg, struct task_struct *p, unsigned long tls)
199 struct pt_regs *cregs = &(p->thread.regs);
200 void *stack = task_stack_page(p);
202 /* We have to use void * instead of a function pointer, because
203 * function pointers aren't a pointer to the function on 64-bit.
204 * Make them const so the compiler knows they live in .text */
205 extern void * const ret_from_kernel_thread;
206 extern void * const child_return;
208 if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
210 memset(cregs, 0, sizeof(struct pt_regs));
211 if (!usp) /* idle thread */
213 /* Must exit via ret_from_kernel_thread in order
214 * to call schedule_tail()
216 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
217 cregs->kpc = (unsigned long) &ret_from_kernel_thread;
219 * Copy function and argument to be called from
220 * ret_from_kernel_thread.
223 cregs->gr[27] = ((unsigned long *)usp)[3];
224 cregs->gr[26] = ((unsigned long *)usp)[2];
228 cregs->gr[25] = kthread_arg;
231 /* usp must be word aligned. This also prevents users from
232 * passing in the value 1 (which is the signal for a special
233 * return for a kernel thread) */
239 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
240 cregs->kpc = (unsigned long) &child_return;
242 /* Setup thread TLS area */
243 if (clone_flags & CLONE_SETTLS)
251 get_wchan(struct task_struct *p)
253 struct unwind_frame_info info;
257 if (!p || p == current || p->state == TASK_RUNNING)
261 * These bracket the sleeping functions..
264 unwind_frame_init_from_blocked_task(&info, p);
266 if (unwind_once(&info) < 0)
269 if (!in_sched_functions(ip))
271 } while (count++ < MAX_UNWIND_ENTRIES);
276 void *dereference_function_descriptor(void *ptr)
278 Elf64_Fdesc *desc = ptr;
281 if (!get_kernel_nofault(p, (void *)&desc->addr))
286 void *dereference_kernel_function_descriptor(void *ptr)
288 if (ptr < (void *)__start_opd ||
289 ptr >= (void *)__end_opd)
292 return dereference_function_descriptor(ptr);
296 static inline unsigned long brk_rnd(void)
298 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
301 unsigned long arch_randomize_brk(struct mm_struct *mm)
303 unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());