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         raw_local_irq_enable();
  37 }
  38
  39 /*
  40  * The development boards have no way to pull a board reset. Just jump to the
  41  * cpu reset address and let the boot loader or the code in head.S take care of
  42  * resetting peripherals.
  43  */
  44 void machine_restart(char *__unused)
  45 {
  46         pr_notice("Machine restart (%08x)...\n", cpuinfo.reset_addr);
  47         local_irq_disable();
  48         __asm__ __volatile__ (
  49         "jmp    %0\n\t"
  50         :
  51         : "r" (cpuinfo.reset_addr)
  52         : "r4");
  53 }
  54
  55 void machine_halt(void)
  56 {
  57         pr_notice("Machine halt...\n");
  58         local_irq_disable();
  59         for (;;)
  60                 ;
  61 }
  62
  63 /*
  64  * There is no way to power off the development boards. So just spin for now. If
  65  * we ever have a way of resetting a board using a GPIO we should add that here.
  66  */
  67 void machine_power_off(void)
  68 {
  69         pr_notice("Machine power off...\n");
  70         local_irq_disable();
  71         for (;;)
  72                 ;
  73 }
  74
  75 void show_regs(struct pt_regs *regs)
  76 {
  77         pr_notice("\n");
  78         show_regs_print_info(KERN_DEFAULT);
  79
  80         pr_notice("r1: %08lx r2: %08lx r3: %08lx r4: %08lx\n",
  81                 regs->r1,  regs->r2,  regs->r3,  regs->r4);
  82
  83         pr_notice("r5: %08lx r6: %08lx r7: %08lx r8: %08lx\n",
  84                 regs->r5,  regs->r6,  regs->r7,  regs->r8);
  85
  86         pr_notice("r9: %08lx r10: %08lx r11: %08lx r12: %08lx\n",
  87                 regs->r9,  regs->r10, regs->r11, regs->r12);
  88
  89         pr_notice("r13: %08lx r14: %08lx r15: %08lx\n",
  90                 regs->r13, regs->r14, regs->r15);
  91
  92         pr_notice("ra: %08lx fp:  %08lx sp: %08lx gp: %08lx\n",
  93                 regs->ra,  regs->fp,  regs->sp,  regs->gp);
  94
  95         pr_notice("ea: %08lx estatus: %08lx\n",
  96                 regs->ea,  regs->estatus);
  97 }
  98
  99 void flush_thread(void)
 100 {
 101 }
 102
 103 int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
 104                 struct task_struct *p, unsigned long tls)
 105 {
 106         struct pt_regs *childregs = task_pt_regs(p);
 107         struct pt_regs *regs;
 108         struct switch_stack *stack;
 109         struct switch_stack *childstack =
 110                 ((struct switch_stack *)childregs) - 1;
 111
 112         if (unlikely(p->flags & PF_KTHREAD)) {
 113                 memset(childstack, 0,
 114                         sizeof(struct switch_stack) + sizeof(struct pt_regs));
 115
 116                 childstack->r16 = usp;          /* fn */
 117                 childstack->r17 = arg;
 118                 childstack->ra = (unsigned long) ret_from_kernel_thread;
 119                 childregs->estatus = STATUS_PIE;
 120                 childregs->sp = (unsigned long) childstack;
 121
 122                 p->thread.ksp = (unsigned long) childstack;
 123                 p->thread.kregs = childregs;
 124                 return 0;
 125         }
 126
 127         regs = current_pt_regs();
 128         *childregs = *regs;
 129         childregs->r2 = 0;      /* Set the return value for the child. */
 130         childregs->r7 = 0;
 131
 132         stack = ((struct switch_stack *) regs) - 1;
 133         *childstack = *stack;
 134         childstack->ra = (unsigned long)ret_from_fork;
 135         p->thread.kregs = childregs;
 136         p->thread.ksp = (unsigned long) childstack;
 137
 138         if (usp)
 139                 childregs->sp = usp;
 140
 141         /* Initialize tls register. */
 142         if (clone_flags & CLONE_SETTLS)
 143                 childstack->r23 = tls;
 144
 145         return 0;
 146 }
 147
 148 /*
 149  *      Generic dumping code. Used for panic and debug.
 150  */
 151 void dump(struct pt_regs *fp)
 152 {
 153         unsigned long   *sp;
 154         unsigned char   *tp;
 155         int             i;
 156
 157         pr_emerg("\nCURRENT PROCESS:\n\n");
 158         pr_emerg("COMM=%s PID=%d\n", current->comm, current->pid);
 159
 160         if (current->mm) {
 161                 pr_emerg("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 162                         (int) current->mm->start_code,
 163                         (int) current->mm->end_code,
 164                         (int) current->mm->start_data,
 165                         (int) current->mm->end_data,
 166                         (int) current->mm->end_data,
 167                         (int) current->mm->brk);
 168                 pr_emerg("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
 169                         (int) current->mm->start_stack,
 170                         (int)(((unsigned long) current) + THREAD_SIZE));
 171         }
 172
 173         pr_emerg("PC: %08lx\n", fp->ea);
 174         pr_emerg("SR: %08lx    SP: %08lx\n",
 175                 (long) fp->estatus, (long) fp);
 176
 177         pr_emerg("r1: %08lx    r2: %08lx    r3: %08lx\n",
 178                 fp->r1, fp->r2, fp->r3);
 179
 180         pr_emerg("r4: %08lx    r5: %08lx    r6: %08lx    r7: %08lx\n",
 181                 fp->r4, fp->r5, fp->r6, fp->r7);
 182         pr_emerg("r8: %08lx    r9: %08lx    r10: %08lx    r11: %08lx\n",
 183                 fp->r8, fp->r9, fp->r10, fp->r11);
 184         pr_emerg("r12: %08lx  r13: %08lx    r14: %08lx    r15: %08lx\n",
 185                 fp->r12, fp->r13, fp->r14, fp->r15);
 186         pr_emerg("or2: %08lx   ra: %08lx     fp: %08lx    sp: %08lx\n",
 187                 fp->orig_r2, fp->ra, fp->fp, fp->sp);
 188         pr_emerg("\nUSP: %08x   TRAPFRAME: %08x\n",
 189                 (unsigned int) fp->sp, (unsigned int) fp);
 190
 191         pr_emerg("\nCODE:");
 192         tp = ((unsigned char *) fp->ea) - 0x20;
 193         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 194                 if ((i % 0x10) == 0)
 195                         pr_emerg("\n%08x: ", (int) (tp + i));
 196                 pr_emerg("%08x ", (int) *sp++);
 197         }
 198         pr_emerg("\n");
 199
 200         pr_emerg("\nKERNEL STACK:");
 201         tp = ((unsigned char *) fp) - 0x40;
 202         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 203                 if ((i % 0x10) == 0)
 204                         pr_emerg("\n%08x: ", (int) (tp + i));
 205                 pr_emerg("%08x ", (int) *sp++);
 206         }
 207         pr_emerg("\n");
 208         pr_emerg("\n");
 209
 210         pr_emerg("\nUSER STACK:");
 211         tp = (unsigned char *) (fp->sp - 0x10);
 212         for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
 213                 if ((i % 0x10) == 0)
 214                         pr_emerg("\n%08x: ", (int) (tp + i));
 215                 pr_emerg("%08x ", (int) *sp++);
 216         }
 217         pr_emerg("\n\n");
 218 }
 219
 220 unsigned long get_wchan(struct task_struct *p)
 221 {
 222         unsigned long fp, pc;
 223         unsigned long stack_page;
 224         int count = 0;
 225
 226         if (!p || p == current || p->state == TASK_RUNNING)
 227                 return 0;
 228
 229         stack_page = (unsigned long)p;
 230         fp = ((struct switch_stack *)p->thread.ksp)->fp;        /* ;dgt2 */
 231         do {
 232                 if (fp < stack_page+sizeof(struct task_struct) ||
 233                         fp >= 8184+stack_page)  /* ;dgt2;tmp */
 234                         return 0;
 235                 pc = ((unsigned long *)fp)[1];
 236                 if (!in_sched_functions(pc))
 237                         return pc;
 238                 fp = *(unsigned long *) fp;
 239         } while (count++ < 16);         /* ;dgt2;tmp */
 240         return 0;
 241 }
 242
 243 /*
 244  * Do necessary setup to start up a newly executed thread.
 245  * Will startup in user mode (status_extension = 0).
 246  */
 247 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
 248 {
 249         memset((void *) regs, 0, sizeof(struct pt_regs));
 250         regs->estatus = ESTATUS_EPIE | ESTATUS_EU;
 251         regs->ea = pc;
 252         regs->sp = sp;
 253 }
 254
 255 asmlinkage int nios2_clone(unsigned long clone_flags, unsigned long newsp,
 256                            int __user *parent_tidptr, int __user *child_tidptr,
 257                            unsigned long tls)
 258 {
 259         struct kernel_clone_args args = {
 260                 .flags          = (lower_32_bits(clone_flags) & ~CSIGNAL),
 261                 .pidfd          = parent_tidptr,
 262                 .child_tid      = child_tidptr,
 263                 .parent_tid     = parent_tidptr,
 264                 .exit_signal    = (lower_32_bits(clone_flags) & CSIGNAL),
 265                 .stack          = newsp,
 266                 .tls            = tls,
 267         };
 268
 269         return kernel_clone(&args);
 270 }