arch/nios2/kernel/process.c

   1 /*
   2  * Architecture-dependent parts of process handling.
   3  *
   4  * Copyright (C) 2013 Altera Corporation
   5  * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
   6  * Copyright (C) 2009 Wind River Systems Inc
   7  *   Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
   8  * Copyright (C) 2004 Microtronix Datacom Ltd
   9  *
  10  * This file is subject to the terms and conditions of the GNU General Public
  11  * License.  See the file "COPYING" in the main directory of this archive
  12  * for more details.
  13  */
  14
  15 #include <linux/export.h>
  16 #include <linux/sched.h>
  17 #include <linux/sched/debug.h>
  18 #include <linux/sched/task.h>
  19 #include <linux/sched/task_stack.h>
  20 #include <linux/mm_types.h>
  21 #include <linux/tick.h>
  22 #include <linux/uaccess.h>
  23
  24 #include <asm/unistd.h>
  25 #include <asm/traps.h>
  26 #include <asm/cpuinfo.h>
  27
  28 asmlinkage void ret_from_fork(void);
  29 asmlinkage void ret_from_kernel_thread(void);
  30
  31 void (*pm_power_off)(void) = NULL;
  32 EXPORT_SYMBOL(pm_power_off);
  33
  34 void arch_cpu_idle(void)
  35 {
  36 }
  37
  38 /*
  39  * The development boards have no way to pull a board reset. Just jump to the
  40  * cpu reset address and let the boot loader or the code in head.S take care of
  41  * resetting peripherals.
  42  */
  43 void machine_restart(char *__unused)
  44 {
  45         pr_notice("Machine restart (%08x)...\n", cpuinfo.reset_addr);
  46         local_irq_disable();
  47         __asm__ __volatile__ (
  48         "jmp    %0\n\t"
  49         :
  50         : "r" (cpuinfo.reset_addr)
  51         : "r4");
  52 }
  53
  54 void machine_halt(void)
  55 {
  56         pr_notice("Machine halt...\n");
  57         local_irq_disable();
  58         for (;;)
  59                 ;
  60 }
  61
  62 /*
  63  * There is no way to power off the development boards. So just spin for now. If
  64  * we ever have a way of resetting a board using a GPIO we should add that here.
  65  */
  66 void machine_power_off(void)
  67 {
  68         pr_notice("Machine power off...\n");
  69         local_irq_disable();
  70         for (;;)
  71                 ;
  72 }
  73
  74 void show_regs(struct pt_regs *regs)
  75 {
  76         pr_notice("\n");
  77         show_regs_print_info(KERN_DEFAULT);
  78
  79         pr_notice("r1: %08lx r2: %08lx r3: %08lx r4: %08lx\n",
  80                 regs->r1,  regs->r2,  regs->r3,  regs->r4);
  81
  82         pr_notice("r5: %08lx r6: %08lx r7: %08lx r8: %08lx\n",
  83                 regs->r5,  regs->r6,  regs->r7,  regs->r8);
  84
  85         pr_notice("r9: %08lx r10: %08lx r11: %08lx r12: %08lx\n",
  86                 regs->r9,  regs->r10, regs->r11, regs->r12);
  87
  88         pr_notice("r13: %08lx r14: %08lx r15: %08lx\n",
  89                 regs->r13, regs->r14, regs->r15);
  90
  91         pr_notice("ra: %08lx fp:  %08lx sp: %08lx gp: %08lx\n",
  92                 regs->ra,  regs->fp,  regs->sp,  regs->gp);
  93
  94         pr_notice("ea: %08lx estatus: %08lx\n",
  95                 regs->ea,  regs->estatus);
  96 }
  97
  98 void flush_thread(void)
  99 {
 100 }
 101
 102 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 103 {
 104         unsigned long clone_flags = args->flags;
 105         unsigned long usp = args->stack;
 106         unsigned long tls = args->tls;
 107         struct pt_regs *childregs = task_pt_regs(p);
 108         struct pt_regs *regs;
 109         struct switch_stack *stack;
 110         struct switch_stack *childstack =
 111                 ((struct switch_stack *)childregs) - 1;
 112
 113         if (unlikely(args->fn)) {
 114                 memset(childstack, 0,
 115                         sizeof(struct switch_stack) + sizeof(struct pt_regs));
 116
 117                 childstack->r16 = (unsigned long) args->fn;
 118                 childstack->r17 = (unsigned long) args->fn_arg;
 119                 childstack->ra = (unsigned long) ret_from_kernel_thread;
 120                 childregs->estatus = STATUS_PIE;
 121                 childregs->sp = (unsigned long) childstack;
 122
 123                 p->thread.ksp = (unsigned long) childstack;
 124                 p->thread.kregs = childregs;
 125                 return 0;
 126         }
 127
 128         regs = current_pt_regs();
 129         *childregs = *regs;
 130         childregs->r2 = 0;      /* Set the return value for the child. */
 131         childregs->r7 = 0;
 132
 133         stack = ((struct switch_stack *) regs) - 1;
 134         *childstack = *stack;
 135         childstack->ra = (unsigned long)ret_from_fork;
 136         p->thread.kregs = childregs;
 137         p->thread.ksp = (unsigned long) childstack;
 138
 139         if (usp)
 140                 childregs->sp = usp;
 141
 142         /* Initialize tls register. */
 143         if (clone_flags & CLONE_SETTLS)
 144                 childstack->r23 = tls;
 145
 146         return 0;
 147 }
 148
 149 /*
 150  *      Generic dumping code. Used for panic and debug.
 151  */
 152 void dump(struct pt_regs *fp)
 153 {
 154         unsigned long   *sp;
 155         unsigned char   *tp;
 156         int             i;
 157
 158         pr_emerg("\nCURRENT PROCESS:\n\n");
 159         pr_emerg("COMM=%s PID=%d\n", current->comm, current->pid);
 160
 161         if (current->mm) {
 162                 pr_emerg("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 163                         (int) current->mm->start_code,
 164                         (int) current->mm->end_code,
 165                         (int) current->mm->start_data,
 166                         (int) current->mm->end_data,
 167                         (int) current->mm->end_data,
 168                         (int) current->mm->brk);
 169                 pr_emerg("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
 170                         (int) current->mm->start_stack,
 171                         (int)(((unsigned long) current) + THREAD_SIZE));
 172         }
 173
 174         pr_emerg("PC: %08lx\n", fp->ea);
 175         pr_emerg("SR: %08lx    SP: %08lx\n",
 176                 (long) fp->estatus, (long) fp);
 177
 178         pr_emerg("r1: %08lx    r2: %08lx    r3: %08lx\n",
 179                 fp->r1, fp->r2, fp->r3);
 180
 181         pr_emerg("r4: %08lx    r5: %08lx    r6: %08lx    r7: %08lx\n",
 182                 fp->r4, fp->r5, fp->r6, fp->r7);
 183         pr_emerg("r8: %08lx    r9: %08lx    r10: %08lx    r11: %08lx\n",
 184                 fp->r8, fp->r9, fp->r10, fp->r11);
 185         pr_emerg("r12: %08lx  r13: %08lx    r14: %08lx    r15: %08lx\n",
 186                 fp->r12, fp->r13, fp->r14, fp->r15);
 187         pr_emerg("or2: %08lx   ra: %08lx     fp: %08lx    sp: %08lx\n",
 188                 fp->orig_r2, fp->ra, fp->fp, fp->sp);
 189         pr_emerg("\nUSP: %08x   TRAPFRAME: %08x\n",
 190                 (unsigned int) fp->sp, (unsigned int) fp);
 191
 192         pr_emerg("\nCODE:");
 193         tp = ((unsigned char *) fp->ea) - 0x20;
 194         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 195                 if ((i % 0x10) == 0)
 196                         pr_emerg("\n%08x: ", (int) (tp + i));
 197                 pr_emerg("%08x ", (int) *sp++);
 198         }
 199         pr_emerg("\n");
 200
 201         pr_emerg("\nKERNEL STACK:");
 202         tp = ((unsigned char *) fp) - 0x40;
 203         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 204                 if ((i % 0x10) == 0)
 205                         pr_emerg("\n%08x: ", (int) (tp + i));
 206                 pr_emerg("%08x ", (int) *sp++);
 207         }
 208         pr_emerg("\n");
 209         pr_emerg("\n");
 210
 211         pr_emerg("\nUSER STACK:");
 212         tp = (unsigned char *) (fp->sp - 0x10);
 213         for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
 214                 if ((i % 0x10) == 0)
 215                         pr_emerg("\n%08x: ", (int) (tp + i));
 216                 pr_emerg("%08x ", (int) *sp++);
 217         }
 218         pr_emerg("\n\n");
 219 }
 220
 221 unsigned long __get_wchan(struct task_struct *p)
 222 {
 223         unsigned long fp, pc;
 224         unsigned long stack_page;
 225         int count = 0;
 226
 227         stack_page = (unsigned long)p;
 228         fp = ((struct switch_stack *)p->thread.ksp)->fp;        /* ;dgt2 */
 229         do {
 230                 if (fp < stack_page+sizeof(struct task_struct) ||
 231                         fp >= 8184+stack_page)  /* ;dgt2;tmp */
 232                         return 0;
 233                 pc = ((unsigned long *)fp)[1];
 234                 if (!in_sched_functions(pc))
 235                         return pc;
 236                 fp = *(unsigned long *) fp;
 237         } while (count++ < 16);         /* ;dgt2;tmp */
 238         return 0;
 239 }
 240
 241 /*
 242  * Do necessary setup to start up a newly executed thread.
 243  * Will startup in user mode (status_extension = 0).
 244  */
 245 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
 246 {
 247         memset((void *) regs, 0, sizeof(struct pt_regs));
 248         regs->estatus = ESTATUS_EPIE | ESTATUS_EU;
 249         regs->ea = pc;
 250         regs->sp = sp;
 251 }
 252
 253 asmlinkage int nios2_clone(unsigned long clone_flags, unsigned long newsp,
 254                            int __user *parent_tidptr, int __user *child_tidptr,
 255                            unsigned long tls)
 256 {
 257         struct kernel_clone_args args = {
 258                 .flags          = (lower_32_bits(clone_flags) & ~CSIGNAL),
 259                 .pidfd          = parent_tidptr,
 260                 .child_tid      = child_tidptr,
 261                 .parent_tid     = parent_tidptr,
 262                 .exit_signal    = (lower_32_bits(clone_flags) & CSIGNAL),
 263                 .stack          = newsp,
 264                 .tls            = tls,
 265         };
 266
 267         return kernel_clone(&args);
 268 }