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