linux/arch/unicore32/kernel/process.c
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   1/*
   2 * linux/arch/unicore32/kernel/process.c
   3 *
   4 * Code specific to PKUnity SoC and UniCore ISA
   5 *
   6 * Copyright (C) 2001-2010 GUAN Xue-tao
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 */
  12#include <stdarg.h>
  13
  14#include <linux/module.h>
  15#include <linux/sched.h>
  16#include <linux/kernel.h>
  17#include <linux/mm.h>
  18#include <linux/stddef.h>
  19#include <linux/unistd.h>
  20#include <linux/delay.h>
  21#include <linux/reboot.h>
  22#include <linux/interrupt.h>
  23#include <linux/kallsyms.h>
  24#include <linux/init.h>
  25#include <linux/cpu.h>
  26#include <linux/elfcore.h>
  27#include <linux/pm.h>
  28#include <linux/tick.h>
  29#include <linux/utsname.h>
  30#include <linux/uaccess.h>
  31#include <linux/random.h>
  32#include <linux/gpio.h>
  33#include <linux/stacktrace.h>
  34
  35#include <asm/cacheflush.h>
  36#include <asm/processor.h>
  37#include <asm/stacktrace.h>
  38
  39#include "setup.h"
  40
  41static const char * const processor_modes[] = {
  42        "UK00", "UK01", "UK02", "UK03", "UK04", "UK05", "UK06", "UK07",
  43        "UK08", "UK09", "UK0A", "UK0B", "UK0C", "UK0D", "UK0E", "UK0F",
  44        "USER", "REAL", "INTR", "PRIV", "UK14", "UK15", "UK16", "ABRT",
  45        "UK18", "UK19", "UK1A", "EXTN", "UK1C", "UK1D", "UK1E", "SUSR"
  46};
  47
  48void arch_cpu_idle(void)
  49{
  50        cpu_do_idle();
  51        local_irq_enable();
  52}
  53
  54void machine_halt(void)
  55{
  56        gpio_set_value(GPO_SOFT_OFF, 0);
  57}
  58
  59/*
  60 * Function pointers to optional machine specific functions
  61 */
  62void (*pm_power_off)(void) = NULL;
  63EXPORT_SYMBOL(pm_power_off);
  64
  65void machine_power_off(void)
  66{
  67        if (pm_power_off)
  68                pm_power_off();
  69        machine_halt();
  70}
  71
  72void machine_restart(char *cmd)
  73{
  74        /* Disable interrupts first */
  75        local_irq_disable();
  76
  77        /*
  78         * Tell the mm system that we are going to reboot -
  79         * we may need it to insert some 1:1 mappings so that
  80         * soft boot works.
  81         */
  82        setup_mm_for_reboot();
  83
  84        /* Clean and invalidate caches */
  85        flush_cache_all();
  86
  87        /* Turn off caching */
  88        cpu_proc_fin();
  89
  90        /* Push out any further dirty data, and ensure cache is empty */
  91        flush_cache_all();
  92
  93        /*
  94         * Now handle reboot code.
  95         */
  96        if (reboot_mode == REBOOT_SOFT) {
  97                /* Jump into ROM at address 0xffff0000 */
  98                cpu_reset(VECTORS_BASE);
  99        } else {
 100                writel(0x00002001, PM_PLLSYSCFG); /* cpu clk = 250M */
 101                writel(0x00100800, PM_PLLDDRCFG); /* ddr clk =  44M */
 102                writel(0x00002001, PM_PLLVGACFG); /* vga clk = 250M */
 103
 104                /* Use on-chip reset capability */
 105                /* following instructions must be in one icache line */
 106                __asm__ __volatile__(
 107                        "       .align 5\n\t"
 108                        "       stw     %1, [%0]\n\t"
 109                        "201:   ldw     r0, [%0]\n\t"
 110                        "       cmpsub.a        r0, #0\n\t"
 111                        "       bne     201b\n\t"
 112                        "       stw     %3, [%2]\n\t"
 113                        "       nop; nop; nop\n\t"
 114                        /* prefetch 3 instructions at most */
 115                        :
 116                        : "r" (PM_PMCR),
 117                          "r" (PM_PMCR_CFBSYS | PM_PMCR_CFBDDR
 118                                | PM_PMCR_CFBVGA),
 119                          "r" (RESETC_SWRR),
 120                          "r" (RESETC_SWRR_SRB)
 121                        : "r0", "memory");
 122        }
 123
 124        /*
 125         * Whoops - the architecture was unable to reboot.
 126         * Tell the user!
 127         */
 128        mdelay(1000);
 129        printk(KERN_EMERG "Reboot failed -- System halted\n");
 130        do { } while (1);
 131}
 132
 133void __show_regs(struct pt_regs *regs)
 134{
 135        unsigned long flags;
 136        char buf[64];
 137
 138        show_regs_print_info(KERN_DEFAULT);
 139        print_symbol("PC is at %s\n", instruction_pointer(regs));
 140        print_symbol("LR is at %s\n", regs->UCreg_lr);
 141        printk(KERN_DEFAULT "pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n"
 142               "sp : %08lx  ip : %08lx  fp : %08lx\n",
 143                regs->UCreg_pc, regs->UCreg_lr, regs->UCreg_asr,
 144                regs->UCreg_sp, regs->UCreg_ip, regs->UCreg_fp);
 145        printk(KERN_DEFAULT "r26: %08lx  r25: %08lx  r24: %08lx\n",
 146                regs->UCreg_26, regs->UCreg_25,
 147                regs->UCreg_24);
 148        printk(KERN_DEFAULT "r23: %08lx  r22: %08lx  r21: %08lx  r20: %08lx\n",
 149                regs->UCreg_23, regs->UCreg_22,
 150                regs->UCreg_21, regs->UCreg_20);
 151        printk(KERN_DEFAULT "r19: %08lx  r18: %08lx  r17: %08lx  r16: %08lx\n",
 152                regs->UCreg_19, regs->UCreg_18,
 153                regs->UCreg_17, regs->UCreg_16);
 154        printk(KERN_DEFAULT "r15: %08lx  r14: %08lx  r13: %08lx  r12: %08lx\n",
 155                regs->UCreg_15, regs->UCreg_14,
 156                regs->UCreg_13, regs->UCreg_12);
 157        printk(KERN_DEFAULT "r11: %08lx  r10: %08lx  r9 : %08lx  r8 : %08lx\n",
 158                regs->UCreg_11, regs->UCreg_10,
 159                regs->UCreg_09, regs->UCreg_08);
 160        printk(KERN_DEFAULT "r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
 161                regs->UCreg_07, regs->UCreg_06,
 162                regs->UCreg_05, regs->UCreg_04);
 163        printk(KERN_DEFAULT "r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 164                regs->UCreg_03, regs->UCreg_02,
 165                regs->UCreg_01, regs->UCreg_00);
 166
 167        flags = regs->UCreg_asr;
 168        buf[0] = flags & PSR_S_BIT ? 'S' : 's';
 169        buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
 170        buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
 171        buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
 172        buf[4] = '\0';
 173
 174        printk(KERN_DEFAULT "Flags: %s  INTR o%s  REAL o%s  Mode %s  Segment %s\n",
 175                buf, interrupts_enabled(regs) ? "n" : "ff",
 176                fast_interrupts_enabled(regs) ? "n" : "ff",
 177                processor_modes[processor_mode(regs)],
 178                segment_eq(get_fs(), get_ds()) ? "kernel" : "user");
 179        {
 180                unsigned int ctrl;
 181
 182                buf[0] = '\0';
 183                {
 184                        unsigned int transbase;
 185                        asm("movc %0, p0.c2, #0\n"
 186                            : "=r" (transbase));
 187                        snprintf(buf, sizeof(buf), "  Table: %08x", transbase);
 188                }
 189                asm("movc %0, p0.c1, #0\n" : "=r" (ctrl));
 190
 191                printk(KERN_DEFAULT "Control: %08x%s\n", ctrl, buf);
 192        }
 193}
 194
 195void show_regs(struct pt_regs *regs)
 196{
 197        printk(KERN_DEFAULT "\n");
 198        printk(KERN_DEFAULT "Pid: %d, comm: %20s\n",
 199                        task_pid_nr(current), current->comm);
 200        __show_regs(regs);
 201        __backtrace();
 202}
 203
 204/*
 205 * Free current thread data structures etc..
 206 */
 207void exit_thread(void)
 208{
 209}
 210
 211void flush_thread(void)
 212{
 213        struct thread_info *thread = current_thread_info();
 214        struct task_struct *tsk = current;
 215
 216        memset(thread->used_cp, 0, sizeof(thread->used_cp));
 217        memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 218#ifdef CONFIG_UNICORE_FPU_F64
 219        memset(&thread->fpstate, 0, sizeof(struct fp_state));
 220#endif
 221}
 222
 223void release_thread(struct task_struct *dead_task)
 224{
 225}
 226
 227asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 228asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
 229
 230int
 231copy_thread(unsigned long clone_flags, unsigned long stack_start,
 232            unsigned long stk_sz, struct task_struct *p)
 233{
 234        struct thread_info *thread = task_thread_info(p);
 235        struct pt_regs *childregs = task_pt_regs(p);
 236
 237        memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
 238        thread->cpu_context.sp = (unsigned long)childregs;
 239        if (unlikely(p->flags & PF_KTHREAD)) {
 240                thread->cpu_context.pc = (unsigned long)ret_from_kernel_thread;
 241                thread->cpu_context.r4 = stack_start;
 242                thread->cpu_context.r5 = stk_sz;
 243                memset(childregs, 0, sizeof(struct pt_regs));
 244        } else {
 245                thread->cpu_context.pc = (unsigned long)ret_from_fork;
 246                *childregs = *current_pt_regs();
 247                childregs->UCreg_00 = 0;
 248                if (stack_start)
 249                        childregs->UCreg_sp = stack_start;
 250
 251                if (clone_flags & CLONE_SETTLS)
 252                        childregs->UCreg_16 = childregs->UCreg_03;
 253        }
 254        return 0;
 255}
 256
 257/*
 258 * Fill in the task's elfregs structure for a core dump.
 259 */
 260int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
 261{
 262        elf_core_copy_regs(elfregs, task_pt_regs(t));
 263        return 1;
 264}
 265
 266/*
 267 * fill in the fpe structure for a core dump...
 268 */
 269int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fp)
 270{
 271        struct thread_info *thread = current_thread_info();
 272        int used_math = thread->used_cp[1] | thread->used_cp[2];
 273
 274#ifdef CONFIG_UNICORE_FPU_F64
 275        if (used_math)
 276                memcpy(fp, &thread->fpstate, sizeof(*fp));
 277#endif
 278        return used_math != 0;
 279}
 280EXPORT_SYMBOL(dump_fpu);
 281
 282unsigned long get_wchan(struct task_struct *p)
 283{
 284        struct stackframe frame;
 285        int count = 0;
 286        if (!p || p == current || p->state == TASK_RUNNING)
 287                return 0;
 288
 289        frame.fp = thread_saved_fp(p);
 290        frame.sp = thread_saved_sp(p);
 291        frame.lr = 0;                   /* recovered from the stack */
 292        frame.pc = thread_saved_pc(p);
 293        do {
 294                int ret = unwind_frame(&frame);
 295                if (ret < 0)
 296                        return 0;
 297                if (!in_sched_functions(frame.pc))
 298                        return frame.pc;
 299        } while ((count++) < 16);
 300        return 0;
 301}
 302
 303unsigned long arch_randomize_brk(struct mm_struct *mm)
 304{
 305        unsigned long range_end = mm->brk + 0x02000000;
 306        return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
 307}
 308
 309/*
 310 * The vectors page is always readable from user space for the
 311 * atomic helpers and the signal restart code.  Let's declare a mapping
 312 * for it so it is visible through ptrace and /proc/<pid>/mem.
 313 */
 314
 315int vectors_user_mapping(void)
 316{
 317        struct mm_struct *mm = current->mm;
 318        return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
 319                                       VM_READ | VM_EXEC |
 320                                       VM_MAYREAD | VM_MAYEXEC |
 321                                       VM_DONTEXPAND | VM_DONTDUMP,
 322                                       NULL);
 323}
 324
 325const char *arch_vma_name(struct vm_area_struct *vma)
 326{
 327        return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
 328}
 329