arch/unicore32/kernel/process.c

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