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/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
  44 static 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
  51 void arch_cpu_idle(void)
  52 {
  53         cpu_do_idle();
  54         local_irq_enable();
  55 }
  56
  57 void machine_halt(void)
  58 {
  59         gpio_set_value(GPO_SOFT_OFF, 0);
  60 }
  61
  62 /*
  63  * Function pointers to optional machine specific functions
  64  */
  65 void (*pm_power_off)(void) = NULL;
  66 EXPORT_SYMBOL(pm_power_off);
  67
  68 void machine_power_off(void)
  69 {
  70         if (pm_power_off)
  71                 pm_power_off();
  72         machine_halt();
  73 }
  74
  75 void 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
 136 void __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
 198 void 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
 207 void 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
 219 void release_thread(struct task_struct *dead_task)
 220 {
 221 }
 222
 223 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 224 asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
 225
 226 int
 227 copy_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  */
 256 int 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  */
 265 int 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 }
 276 EXPORT_SYMBOL(dump_fpu);
 277
 278 unsigned 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
 299 unsigned 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
 310 int 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
 320 const char *arch_vma_name(struct vm_area_struct *vma)
 321 {
 322         return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
 323 }