linux/arch/nios2/kernel/process.c
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   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
  28asmlinkage void ret_from_fork(void);
  29asmlinkage void ret_from_kernel_thread(void);
  30
  31void (*pm_power_off)(void) = NULL;
  32EXPORT_SYMBOL(pm_power_off);
  33
  34void 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 */
  44void 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
  55void 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 */
  67void machine_power_off(void)
  68{
  69        pr_notice("Machine power off...\n");
  70        local_irq_disable();
  71        for (;;)
  72                ;
  73}
  74
  75void 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
  99void flush_thread(void)
 100{
 101}
 102
 103int 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 | PF_IO_WORKER))) {
 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 */
 151void 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
 220unsigned 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 */
 247void 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
 255asmlinkage 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}
 271