arch/parisc/kernel/process.c

   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 #include <linux/rcupdate.h>
  52
  53 #include <asm/io.h>
  54 #include <asm/asm-offsets.h>
  55 #include <asm/assembly.h>
  56 #include <asm/pdc.h>
  57 #include <asm/pdc_chassis.h>
  58 #include <asm/pgalloc.h>
  59 #include <asm/unwind.h>
  60 #include <asm/sections.h>
  61
  62 #define COMMAND_GLOBAL  F_EXTEND(0xfffe0030)
  63 #define CMD_RESET       5       /* reset any module */
  64
  65 /*
  66 ** The Wright Brothers and Gecko systems have a H/W problem
  67 ** (Lasi...'nuf said) may cause a broadcast reset to lockup
  68 ** the system. An HVERSION dependent PDC call was developed
  69 ** to perform a "safe", platform specific broadcast reset instead
  70 ** of kludging up all the code.
  71 **
  72 ** Older machines which do not implement PDC_BROADCAST_RESET will
  73 ** return (with an error) and the regular broadcast reset can be
  74 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
  75 ** the PDC call will not return (the system will be reset).
  76 */
  77 void machine_restart(char *cmd)
  78 {
  79 #ifdef FASTBOOT_SELFTEST_SUPPORT
  80         /*
  81          ** If user has modified the Firmware Selftest Bitmap,
  82          ** run the tests specified in the bitmap after the
  83          ** system is rebooted w/PDC_DO_RESET.
  84          **
  85          ** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
  86          **
  87          ** Using "directed resets" at each processor with the MEM_TOC
  88          ** vector cleared will also avoid running destructive
  89          ** memory self tests. (Not implemented yet)
  90          */
  91         if (ftc_bitmap) {
  92                 pdc_do_firm_test_reset(ftc_bitmap);
  93         }
  94 #endif
  95         /* set up a new led state on systems shipped with a LED State panel */
  96         pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
  97
  98         /* "Normal" system reset */
  99         pdc_do_reset();
 100
 101         /* Nope...box should reset with just CMD_RESET now */
 102         gsc_writel(CMD_RESET, COMMAND_GLOBAL);
 103
 104         /* Wait for RESET to lay us to rest. */
 105         while (1) ;
 106
 107 }
 108
 109 void machine_halt(void)
 110 {
 111         /*
 112         ** The LED/ChassisCodes are updated by the led_halt()
 113         ** function, called by the reboot notifier chain.
 114         */
 115 }
 116
 117 void (*chassis_power_off)(void);
 118
 119 /*
 120  * This routine is called from sys_reboot to actually turn off the
 121  * machine
 122  */
 123 void machine_power_off(void)
 124 {
 125         /* If there is a registered power off handler, call it. */
 126         if (chassis_power_off)
 127                 chassis_power_off();
 128
 129         /* Put the soft power button back under hardware control.
 130          * If the user had already pressed the power button, the
 131          * following call will immediately power off. */
 132         pdc_soft_power_button(0);
 133
 134         pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
 135
 136         /* It seems we have no way to power the system off via
 137          * software. The user has to press the button himself. */
 138
 139         printk(KERN_EMERG "System shut down completed.\n"
 140                "Please power this system off now.");
 141 }
 142
 143 void (*pm_power_off)(void) = machine_power_off;
 144 EXPORT_SYMBOL(pm_power_off);
 145
 146 /*
 147  * Free current thread data structures etc..
 148  */
 149 void exit_thread(void)
 150 {
 151 }
 152
 153 void flush_thread(void)
 154 {
 155         /* Only needs to handle fpu stuff or perf monitors.
 156         ** REVISIT: several arches implement a "lazy fpu state".
 157         */
 158 }
 159
 160 void release_thread(struct task_struct *dead_task)
 161 {
 162 }
 163
 164 /*
 165  * Fill in the FPU structure for a core dump.
 166  */
 167
 168 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
 169 {
 170         if (regs == NULL)
 171                 return 0;
 172
 173         memcpy(r, regs->fr, sizeof *r);
 174         return 1;
 175 }
 176
 177 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
 178 {
 179         memcpy(r, tsk->thread.regs.fr, sizeof(*r));
 180         return 1;
 181 }
 182
 183 int
 184 copy_thread(unsigned long clone_flags, unsigned long usp,
 185             unsigned long arg, struct task_struct *p)
 186 {
 187         struct pt_regs *cregs = &(p->thread.regs);
 188         void *stack = task_stack_page(p);
 189
 190         /* We have to use void * instead of a function pointer, because
 191          * function pointers aren't a pointer to the function on 64-bit.
 192          * Make them const so the compiler knows they live in .text */
 193         extern void * const ret_from_kernel_thread;
 194         extern void * const child_return;
 195 #ifdef CONFIG_HPUX
 196         extern void * const hpux_child_return;
 197 #endif
 198         if (unlikely(p->flags & PF_KTHREAD)) {
 199                 memset(cregs, 0, sizeof(struct pt_regs));
 200                 if (!usp) /* idle thread */
 201                         return 0;
 202
 203                 /* kernel thread */
 204                 /* Must exit via ret_from_kernel_thread in order
 205                  * to call schedule_tail()
 206                  */
 207                 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
 208                 cregs->kpc = (unsigned long) &ret_from_kernel_thread;
 209                 /*
 210                  * Copy function and argument to be called from
 211                  * ret_from_kernel_thread.
 212                  */
 213 #ifdef CONFIG_64BIT
 214                 cregs->gr[27] = ((unsigned long *)usp)[3];
 215                 cregs->gr[26] = ((unsigned long *)usp)[2];
 216 #else
 217                 cregs->gr[26] = usp;
 218 #endif
 219                 cregs->gr[25] = arg;
 220         } else {
 221                 /* user thread */
 222                 /* usp must be word aligned.  This also prevents users from
 223                  * passing in the value 1 (which is the signal for a special
 224                  * return for a kernel thread) */
 225                 if (usp) {
 226                         usp = ALIGN(usp, 4);
 227                         if (likely(usp))
 228                                 cregs->gr[30] = usp;
 229                 }
 230                 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
 231                 if (personality(p->personality) == PER_HPUX) {
 232 #ifdef CONFIG_HPUX
 233                         cregs->kpc = (unsigned long) &hpux_child_return;
 234 #else
 235                         BUG();
 236 #endif
 237                 } else {
 238                         cregs->kpc = (unsigned long) &child_return;
 239                 }
 240                 /* Setup thread TLS area from the 4th parameter in clone */
 241                 if (clone_flags & CLONE_SETTLS)
 242                         cregs->cr27 = cregs->gr[23];
 243         }
 244
 245         return 0;
 246 }
 247
 248 unsigned long thread_saved_pc(struct task_struct *t)
 249 {
 250         return t->thread.regs.kpc;
 251 }
 252
 253 unsigned long
 254 get_wchan(struct task_struct *p)
 255 {
 256         struct unwind_frame_info info;
 257         unsigned long ip;
 258         int count = 0;
 259
 260         if (!p || p == current || p->state == TASK_RUNNING)
 261                 return 0;
 262
 263         /*
 264          * These bracket the sleeping functions..
 265          */
 266
 267         unwind_frame_init_from_blocked_task(&info, p);
 268         do {
 269                 if (unwind_once(&info) < 0)
 270                         return 0;
 271                 ip = info.ip;
 272                 if (!in_sched_functions(ip))
 273                         return ip;
 274         } while (count++ < 16);
 275         return 0;
 276 }
 277
 278 #ifdef CONFIG_64BIT
 279 void *dereference_function_descriptor(void *ptr)
 280 {
 281         Elf64_Fdesc *desc = ptr;
 282         void *p;
 283
 284         if (!probe_kernel_address(&desc->addr, p))
 285                 ptr = p;
 286         return ptr;
 287 }
 288 #endif