LXR linux/arch/cris/arch-v32/kernel/process.c

   1/*
   2 *  Copyright (C) 2000-2003  Axis Communications AB
   3 *
   4 *  Authors:   Bjorn Wesen (bjornw@axis.com)
   5 *             Mikael Starvik (starvik@axis.com)
   6 *             Tobias Anderberg (tobiasa@axis.com), CRISv32 port.
   7 *
   8 * This file handles the architecture-dependent parts of process handling..
   9 */
  10
  11#include <linux/sched.h>
  12#include <linux/slab.h>
  13#include <linux/err.h>
  14#include <linux/fs.h>
  15#include <hwregs/reg_rdwr.h>
  16#include <hwregs/reg_map.h>
  17#include <hwregs/timer_defs.h>
  18#include <hwregs/intr_vect_defs.h>
  19#include <linux/ptrace.h>
  20
  21extern void stop_watchdog(void);
  22
  23/* We use this if we don't have any better idle routine. */
  24void default_idle(void)
  25{
  26        /* Halt until exception. */
  27        __asm__ volatile("ei    \n\t"
  28                         "halt      ");
  29}
  30
  31/*
  32 * Free current thread data structures etc..
  33 */
  34
  35extern void deconfigure_bp(long pid);
  36void exit_thread(void)
  37{
  38        deconfigure_bp(current->pid);
  39}
  40
  41/*
  42 * If the watchdog is enabled, disable interrupts and enter an infinite loop.
  43 * The watchdog will reset the CPU after 0.1s. If the watchdog isn't enabled
  44 * then enable it and wait.
  45 */
  46extern void arch_enable_nmi(void);
  47
  48void
  49hard_reset_now(void)
  50{
  51        /*
  52         * Don't declare this variable elsewhere.  We don't want any other
  53         * code to know about it than the watchdog handler in entry.S and
  54         * this code, implementing hard reset through the watchdog.
  55         */
  56#if defined(CONFIG_ETRAX_WATCHDOG)
  57        extern int cause_of_death;
  58#endif
  59
  60        printk("*** HARD RESET ***\n");
  61        local_irq_disable();
  62
  63#if defined(CONFIG_ETRAX_WATCHDOG)
  64        cause_of_death = 0xbedead;
  65#else
  66{
  67        reg_timer_rw_wd_ctrl wd_ctrl = {0};
  68
  69        stop_watchdog();
  70
  71        wd_ctrl.key = 16;       /* Arbitrary key. */
  72        wd_ctrl.cnt = 1;        /* Minimum time. */
  73        wd_ctrl.cmd = regk_timer_start;
  74
  75        arch_enable_nmi();
  76        REG_WR(timer, regi_timer0, rw_wd_ctrl, wd_ctrl);
  77}
  78#endif
  79
  80        while (1)
  81                ; /* Wait for reset. */
  82}
  83
  84/*
  85 * Return saved PC of a blocked thread.
  86 */
  87unsigned long thread_saved_pc(struct task_struct *t)
  88{
  89        return task_pt_regs(t)->erp;
  90}
  91
  92/*
  93 * Setup the child's kernel stack with a pt_regs and call switch_stack() on it.
  94 * It will be unnested during _resume and _ret_from_sys_call when the new thread
  95 * is scheduled.
  96 *
  97 * Also setup the thread switching structure which is used to keep
  98 * thread-specific data during _resumes.
  99 */
 100
 101extern asmlinkage void ret_from_fork(void);
 102extern asmlinkage void ret_from_kernel_thread(void);
 103
 104int
 105copy_thread(unsigned long clone_flags, unsigned long usp,
 106        unsigned long arg, struct task_struct *p)
 107{
 108        struct pt_regs *childregs = task_pt_regs(p);
 109        struct switch_stack *swstack = ((struct switch_stack *) childregs) - 1;
 110
 111        /*
 112         * Put the pt_regs structure at the end of the new kernel stack page and
 113         * fix it up. Note: the task_struct doubles as the kernel stack for the
 114         * task.
 115         */
 116        if (unlikely(p->flags & PF_KTHREAD)) {
 117                memset(swstack, 0,
 118                        sizeof(struct switch_stack) + sizeof(struct pt_regs));
 119                swstack->r1 = usp;
 120                swstack->r2 = arg;
 121                childregs->ccs = 1 << (I_CCS_BITNR + CCS_SHIFT);
 122                swstack->return_ip = (unsigned long) ret_from_kernel_thread;
 123                p->thread.ksp = (unsigned long) swstack;
 124                p->thread.usp = 0;
 125                return 0;
 126        }
 127        *childregs = *current_pt_regs();        /* Struct copy of pt_regs. */
 128        childregs->r10 = 0;     /* Child returns 0 after a fork/clone. */
 129
 130        /* Set a new TLS ?
 131         * The TLS is in $mof because it is the 5th argument to sys_clone.
 132         */
 133        if (p->mm && (clone_flags & CLONE_SETTLS)) {
 134                task_thread_info(p)->tls = childregs->mof;
 135        }
 136
 137        /* Put the switch stack right below the pt_regs. */
 138
 139        /* Parameter to ret_from_sys_call. 0 is don't restart the syscall. */
 140        swstack->r9 = 0;
 141
 142        /*
 143         * We want to return into ret_from_sys_call after the _resume.
 144         * ret_from_fork will call ret_from_sys_call.
 145         */
 146        swstack->return_ip = (unsigned long) ret_from_fork;
 147
 148        /* Fix the user-mode and kernel-mode stackpointer. */
 149        p->thread.usp = usp ?: rdusp();
 150        p->thread.ksp = (unsigned long) swstack;
 151
 152        return 0;
 153}
 154
 155unsigned long
 156get_wchan(struct task_struct *p)
 157{
 158        /* TODO */
 159        return 0;
 160}
 161#undef last_sched
 162#undef first_sched
 163
 164void show_regs(struct pt_regs * regs)
 165{
 166        unsigned long usp = rdusp();
 167
 168        show_regs_print_info(KERN_DEFAULT);
 169
 170        printk("ERP: %08lx SRP: %08lx  CCS: %08lx USP: %08lx MOF: %08lx\n",
 171                regs->erp, regs->srp, regs->ccs, usp, regs->mof);
 172
 173        printk(" r0: %08lx  r1: %08lx   r2: %08lx  r3: %08lx\n",
 174                regs->r0, regs->r1, regs->r2, regs->r3);
 175
 176        printk(" r4: %08lx  r5: %08lx   r6: %08lx  r7: %08lx\n",
 177                regs->r4, regs->r5, regs->r6, regs->r7);
 178
 179        printk(" r8: %08lx  r9: %08lx  r10: %08lx r11: %08lx\n",
 180                regs->r8, regs->r9, regs->r10, regs->r11);
 181
 182        printk("r12: %08lx r13: %08lx oR10: %08lx\n",
 183                regs->r12, regs->r13, regs->orig_r10);
 184}
 185