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
144void (*pm_power_off)(void) = machine_power_off;
145EXPORT_SYMBOL(pm_power_off);
146
147/*
148 * Free current thread data structures etc..
149 */
150void exit_thread(void)
151{
152}
153
154void flush_thread(void)
155{
156	/* Only needs to handle fpu stuff or perf monitors.
157	** REVISIT: several arches implement a "lazy fpu state".
158	*/
159}
160
161void release_thread(struct task_struct *dead_task)
162{
163}
164
165/*
166 * Fill in the FPU structure for a core dump.
167 */
168
169int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
170{
171	if (regs == NULL)
172		return 0;
173
174	memcpy(r, regs->fr, sizeof *r);
175	return 1;
176}
177
178int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
179{
180	memcpy(r, tsk->thread.regs.fr, sizeof(*r));
181	return 1;
182}
183
184/*
185 * Copy architecture-specific thread state
186 */
187int
188copy_thread(unsigned long clone_flags, unsigned long usp,
189	    unsigned long kthread_arg, struct task_struct *p)
190{
191	struct pt_regs *cregs = &(p->thread.regs);
192	void *stack = task_stack_page(p);
193
194	/* We have to use void * instead of a function pointer, because
195	 * function pointers aren't a pointer to the function on 64-bit.
196	 * Make them const so the compiler knows they live in .text */
197	extern void * const ret_from_kernel_thread;
198	extern void * const child_return;
199
200	if (unlikely(p->flags & PF_KTHREAD)) {
201		/* kernel thread */
202		memset(cregs, 0, sizeof(struct pt_regs));
203		if (!usp) /* idle thread */
204			return 0;
205		/* Must exit via ret_from_kernel_thread in order
206		 * to call schedule_tail()
207		 */
208		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
209		cregs->kpc = (unsigned long) &ret_from_kernel_thread;
210		/*
211		 * Copy function and argument to be called from
212		 * ret_from_kernel_thread.
213		 */
214#ifdef CONFIG_64BIT
215		cregs->gr[27] = ((unsigned long *)usp)[3];
216		cregs->gr[26] = ((unsigned long *)usp)[2];
217#else
218		cregs->gr[26] = usp;
219#endif
220		cregs->gr[25] = kthread_arg;
221	} else {
222		/* user thread */
223		/* usp must be word aligned.  This also prevents users from
224		 * passing in the value 1 (which is the signal for a special
225		 * return for a kernel thread) */
226		if (usp) {
227			usp = ALIGN(usp, 4);
228			if (likely(usp))
229				cregs->gr[30] = usp;
230		}
231		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
232		cregs->kpc = (unsigned long) &child_return;
233
234		/* Setup thread TLS area from the 4th parameter in clone */
235		if (clone_flags & CLONE_SETTLS)
236			cregs->cr27 = cregs->gr[23];
237	}
238
239	return 0;
240}
241
242unsigned long thread_saved_pc(struct task_struct *t)
243{
244	return t->thread.regs.kpc;
245}
246
247unsigned long
248get_wchan(struct task_struct *p)
249{
250	struct unwind_frame_info info;
251	unsigned long ip;
252	int count = 0;
253
254	if (!p || p == current || p->state == TASK_RUNNING)
255		return 0;
256
257	/*
258	 * These bracket the sleeping functions..
259	 */
260
261	unwind_frame_init_from_blocked_task(&info, p);
262	do {
263		if (unwind_once(&info) < 0)
264			return 0;
265		ip = info.ip;
266		if (!in_sched_functions(ip))
267			return ip;
268	} while (count++ < 16);
269	return 0;
270}
271
272#ifdef CONFIG_64BIT
273void *dereference_function_descriptor(void *ptr)
274{
275	Elf64_Fdesc *desc = ptr;
276	void *p;
277
278	if (!probe_kernel_address(&desc->addr, p))
279		ptr = p;
280	return ptr;
281}
282#endif
283
284static inline unsigned long brk_rnd(void)
285{
286	/* 8MB for 32bit, 1GB for 64bit */
287	if (is_32bit_task())
288		return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;
289	else
290		return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;
291}
292
293unsigned long arch_randomize_brk(struct mm_struct *mm)
294{
295	unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
296
297	if (ret < mm->brk)
298		return mm->brk;
299	return ret;
300}
301