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/tick.h>
  18 #include <linux/uaccess.h>
  19
  20 #include <asm/unistd.h>
  21 #include <asm/traps.h>
  22 #include <asm/cpuinfo.h>
  23
  24 asmlinkage void ret_from_fork(void);
  25 asmlinkage void ret_from_kernel_thread(void);
  26
  27 void (*pm_power_off)(void) = NULL;
  28 EXPORT_SYMBOL(pm_power_off);
  29
  30 void arch_cpu_idle(void)
  31 {
  32         local_irq_enable();
  33 }
  34
  35 /*
  36  * The development boards have no way to pull a board reset. Just jump to the
  37  * cpu reset address and let the boot loader or the code in head.S take care of
  38  * resetting peripherals.
  39  */
  40 void machine_restart(char *__unused)
  41 {
  42         pr_notice("Machine restart (%08x)...\n", cpuinfo.reset_addr);
  43         local_irq_disable();
  44         __asm__ __volatile__ (
  45         "jmp    %0\n\t"
  46         :
  47         : "r" (cpuinfo.reset_addr)
  48         : "r4");
  49 }
  50
  51 void machine_halt(void)
  52 {
  53         pr_notice("Machine halt...\n");
  54         local_irq_disable();
  55         for (;;)
  56                 ;
  57 }
  58
  59 /*
  60  * There is no way to power off the development boards. So just spin for now. If
  61  * we ever have a way of resetting a board using a GPIO we should add that here.
  62  */
  63 void machine_power_off(void)
  64 {
  65         pr_notice("Machine power off...\n");
  66         local_irq_disable();
  67         for (;;)
  68                 ;
  69 }
  70
  71 void show_regs(struct pt_regs *regs)
  72 {
  73         pr_notice("\n");
  74         show_regs_print_info(KERN_DEFAULT);
  75
  76         pr_notice("r1: %08lx r2: %08lx r3: %08lx r4: %08lx\n",
  77                 regs->r1,  regs->r2,  regs->r3,  regs->r4);
  78
  79         pr_notice("r5: %08lx r6: %08lx r7: %08lx r8: %08lx\n",
  80                 regs->r5,  regs->r6,  regs->r7,  regs->r8);
  81
  82         pr_notice("r9: %08lx r10: %08lx r11: %08lx r12: %08lx\n",
  83                 regs->r9,  regs->r10, regs->r11, regs->r12);
  84
  85         pr_notice("r13: %08lx r14: %08lx r15: %08lx\n",
  86                 regs->r13, regs->r14, regs->r15);
  87
  88         pr_notice("ra: %08lx fp:  %08lx sp: %08lx gp: %08lx\n",
  89                 regs->ra,  regs->fp,  regs->sp,  regs->gp);
  90
  91         pr_notice("ea: %08lx estatus: %08lx\n",
  92                 regs->ea,  regs->estatus);
  93 }
  94
  95 void flush_thread(void)
  96 {
  97         set_fs(USER_DS);
  98 }
  99
 100 int copy_thread(unsigned long clone_flags,
 101                 unsigned long usp, unsigned long arg, struct task_struct *p)
 102 {
 103         struct pt_regs *childregs = task_pt_regs(p);
 104         struct pt_regs *regs;
 105         struct switch_stack *stack;
 106         struct switch_stack *childstack =
 107                 ((struct switch_stack *)childregs) - 1;
 108
 109         if (unlikely(p->flags & PF_KTHREAD)) {
 110                 memset(childstack, 0,
 111                         sizeof(struct switch_stack) + sizeof(struct pt_regs));
 112
 113                 childstack->r16 = usp;          /* fn */
 114                 childstack->r17 = arg;
 115                 childstack->ra = (unsigned long) ret_from_kernel_thread;
 116                 childregs->estatus = STATUS_PIE;
 117                 childregs->sp = (unsigned long) childstack;
 118
 119                 p->thread.ksp = (unsigned long) childstack;
 120                 p->thread.kregs = childregs;
 121                 return 0;
 122         }
 123
 124         regs = current_pt_regs();
 125         *childregs = *regs;
 126         childregs->r2 = 0;      /* Set the return value for the child. */
 127         childregs->r7 = 0;
 128
 129         stack = ((struct switch_stack *) regs) - 1;
 130         *childstack = *stack;
 131         childstack->ra = (unsigned long)ret_from_fork;
 132         p->thread.kregs = childregs;
 133         p->thread.ksp = (unsigned long) childstack;
 134
 135         if (usp)
 136                 childregs->sp = usp;
 137
 138         /* Initialize tls register. */
 139         if (clone_flags & CLONE_SETTLS)
 140                 childstack->r23 = regs->r8;
 141
 142         return 0;
 143 }
 144
 145 /*
 146  *      Generic dumping code. Used for panic and debug.
 147  */
 148 void dump(struct pt_regs *fp)
 149 {
 150         unsigned long   *sp;
 151         unsigned char   *tp;
 152         int             i;
 153
 154         pr_emerg("\nCURRENT PROCESS:\n\n");
 155         pr_emerg("COMM=%s PID=%d\n", current->comm, current->pid);
 156
 157         if (current->mm) {
 158                 pr_emerg("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 159                         (int) current->mm->start_code,
 160                         (int) current->mm->end_code,
 161                         (int) current->mm->start_data,
 162                         (int) current->mm->end_data,
 163                         (int) current->mm->end_data,
 164                         (int) current->mm->brk);
 165                 pr_emerg("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
 166                         (int) current->mm->start_stack,
 167                         (int)(((unsigned long) current) + THREAD_SIZE));
 168         }
 169
 170         pr_emerg("PC: %08lx\n", fp->ea);
 171         pr_emerg("SR: %08lx    SP: %08lx\n",
 172                 (long) fp->estatus, (long) fp);
 173
 174         pr_emerg("r1: %08lx    r2: %08lx    r3: %08lx\n",
 175                 fp->r1, fp->r2, fp->r3);
 176
 177         pr_emerg("r4: %08lx    r5: %08lx    r6: %08lx    r7: %08lx\n",
 178                 fp->r4, fp->r5, fp->r6, fp->r7);
 179         pr_emerg("r8: %08lx    r9: %08lx    r10: %08lx    r11: %08lx\n",
 180                 fp->r8, fp->r9, fp->r10, fp->r11);
 181         pr_emerg("r12: %08lx  r13: %08lx    r14: %08lx    r15: %08lx\n",
 182                 fp->r12, fp->r13, fp->r14, fp->r15);
 183         pr_emerg("or2: %08lx   ra: %08lx     fp: %08lx    sp: %08lx\n",
 184                 fp->orig_r2, fp->ra, fp->fp, fp->sp);
 185         pr_emerg("\nUSP: %08x   TRAPFRAME: %08x\n",
 186                 (unsigned int) fp->sp, (unsigned int) fp);
 187
 188         pr_emerg("\nCODE:");
 189         tp = ((unsigned char *) fp->ea) - 0x20;
 190         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 191                 if ((i % 0x10) == 0)
 192                         pr_emerg("\n%08x: ", (int) (tp + i));
 193                 pr_emerg("%08x ", (int) *sp++);
 194         }
 195         pr_emerg("\n");
 196
 197         pr_emerg("\nKERNEL STACK:");
 198         tp = ((unsigned char *) fp) - 0x40;
 199         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 200                 if ((i % 0x10) == 0)
 201                         pr_emerg("\n%08x: ", (int) (tp + i));
 202                 pr_emerg("%08x ", (int) *sp++);
 203         }
 204         pr_emerg("\n");
 205         pr_emerg("\n");
 206
 207         pr_emerg("\nUSER STACK:");
 208         tp = (unsigned char *) (fp->sp - 0x10);
 209         for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
 210                 if ((i % 0x10) == 0)
 211                         pr_emerg("\n%08x: ", (int) (tp + i));
 212                 pr_emerg("%08x ", (int) *sp++);
 213         }
 214         pr_emerg("\n\n");
 215 }
 216
 217 unsigned long get_wchan(struct task_struct *p)
 218 {
 219         unsigned long fp, pc;
 220         unsigned long stack_page;
 221         int count = 0;
 222
 223         if (!p || p == current || p->state == TASK_RUNNING)
 224                 return 0;
 225
 226         stack_page = (unsigned long)p;
 227         fp = ((struct switch_stack *)p->thread.ksp)->fp;        /* ;dgt2 */
 228         do {
 229                 if (fp < stack_page+sizeof(struct task_struct) ||
 230                         fp >= 8184+stack_page)  /* ;dgt2;tmp */
 231                         return 0;
 232                 pc = ((unsigned long *)fp)[1];
 233                 if (!in_sched_functions(pc))
 234                         return pc;
 235                 fp = *(unsigned long *) fp;
 236         } while (count++ < 16);         /* ;dgt2;tmp */
 237         return 0;
 238 }
 239
 240 /*
 241  * Do necessary setup to start up a newly executed thread.
 242  * Will startup in user mode (status_extension = 0).
 243  */
 244 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
 245 {
 246         memset((void *) regs, 0, sizeof(struct pt_regs));
 247         regs->estatus = ESTATUS_EPIE | ESTATUS_EU;
 248         regs->ea = pc;
 249         regs->sp = sp;
 250 }
 251
 252 #include <linux/elfcore.h>
 253
 254 /* Fill in the FPU structure for a core dump. */
 255 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r)
 256 {
 257         return 0; /* Nios2 has no FPU and thus no FPU registers */
 258 }