| /* |
| * linux/arch/unicore32/kernel/process.c |
| * |
| * Code specific to PKUnity SoC and UniCore ISA |
| * |
| * Copyright (C) 2001-2010 GUAN Xue-tao |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| #include <stdarg.h> |
| |
| #include <linux/module.h> |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/stddef.h> |
| #include <linux/unistd.h> |
| #include <linux/delay.h> |
| #include <linux/reboot.h> |
| #include <linux/interrupt.h> |
| #include <linux/kallsyms.h> |
| #include <linux/init.h> |
| #include <linux/cpu.h> |
| #include <linux/elfcore.h> |
| #include <linux/pm.h> |
| #include <linux/tick.h> |
| #include <linux/utsname.h> |
| #include <linux/uaccess.h> |
| #include <linux/random.h> |
| #include <linux/gpio.h> |
| #include <linux/stacktrace.h> |
| |
| #include <asm/cacheflush.h> |
| #include <asm/processor.h> |
| #include <asm/system.h> |
| #include <asm/stacktrace.h> |
| |
| #include "setup.h" |
| |
| static const char * const processor_modes[] = { |
| "UK00", "UK01", "UK02", "UK03", "UK04", "UK05", "UK06", "UK07", |
| "UK08", "UK09", "UK0A", "UK0B", "UK0C", "UK0D", "UK0E", "UK0F", |
| "USER", "REAL", "INTR", "PRIV", "UK14", "UK15", "UK16", "ABRT", |
| "UK18", "UK19", "UK1A", "EXTN", "UK1C", "UK1D", "UK1E", "SUSR" |
| }; |
| |
| /* |
| * The idle thread, has rather strange semantics for calling pm_idle, |
| * but this is what x86 does and we need to do the same, so that |
| * things like cpuidle get called in the same way. |
| */ |
| void cpu_idle(void) |
| { |
| /* endless idle loop with no priority at all */ |
| while (1) { |
| tick_nohz_idle_enter(); |
| rcu_idle_enter(); |
| while (!need_resched()) { |
| local_irq_disable(); |
| stop_critical_timings(); |
| cpu_do_idle(); |
| local_irq_enable(); |
| start_critical_timings(); |
| } |
| rcu_idle_exit(); |
| tick_nohz_idle_exit(); |
| preempt_enable_no_resched(); |
| schedule(); |
| preempt_disable(); |
| } |
| } |
| |
| static char reboot_mode = 'h'; |
| |
| int __init reboot_setup(char *str) |
| { |
| reboot_mode = str[0]; |
| return 1; |
| } |
| |
| __setup("reboot=", reboot_setup); |
| |
| void machine_halt(void) |
| { |
| gpio_set_value(GPO_SOFT_OFF, 0); |
| } |
| |
| /* |
| * Function pointers to optional machine specific functions |
| */ |
| void (*pm_power_off)(void) = NULL; |
| |
| void machine_power_off(void) |
| { |
| if (pm_power_off) |
| pm_power_off(); |
| machine_halt(); |
| } |
| |
| void machine_restart(char *cmd) |
| { |
| /* Disable interrupts first */ |
| local_irq_disable(); |
| |
| /* |
| * Tell the mm system that we are going to reboot - |
| * we may need it to insert some 1:1 mappings so that |
| * soft boot works. |
| */ |
| setup_mm_for_reboot(reboot_mode); |
| |
| /* Clean and invalidate caches */ |
| flush_cache_all(); |
| |
| /* Turn off caching */ |
| cpu_proc_fin(); |
| |
| /* Push out any further dirty data, and ensure cache is empty */ |
| flush_cache_all(); |
| |
| /* |
| * Now handle reboot code. |
| */ |
| if (reboot_mode == 's') { |
| /* Jump into ROM at address 0xffff0000 */ |
| cpu_reset(VECTORS_BASE); |
| } else { |
| writel(0x00002001, PM_PLLSYSCFG); /* cpu clk = 250M */ |
| writel(0x00100800, PM_PLLDDRCFG); /* ddr clk = 44M */ |
| writel(0x00002001, PM_PLLVGACFG); /* vga clk = 250M */ |
| |
| /* Use on-chip reset capability */ |
| /* following instructions must be in one icache line */ |
| __asm__ __volatile__( |
| " .align 5\n\t" |
| " stw %1, [%0]\n\t" |
| "201: ldw r0, [%0]\n\t" |
| " cmpsub.a r0, #0\n\t" |
| " bne 201b\n\t" |
| " stw %3, [%2]\n\t" |
| " nop; nop; nop\n\t" |
| /* prefetch 3 instructions at most */ |
| : |
| : "r" (PM_PMCR), |
| "r" (PM_PMCR_CFBSYS | PM_PMCR_CFBDDR |
| | PM_PMCR_CFBVGA), |
| "r" (RESETC_SWRR), |
| "r" (RESETC_SWRR_SRB) |
| : "r0", "memory"); |
| } |
| |
| /* |
| * Whoops - the architecture was unable to reboot. |
| * Tell the user! |
| */ |
| mdelay(1000); |
| printk(KERN_EMERG "Reboot failed -- System halted\n"); |
| do { } while (1); |
| } |
| |
| void __show_regs(struct pt_regs *regs) |
| { |
| unsigned long flags; |
| char buf[64]; |
| |
| printk(KERN_DEFAULT "CPU: %d %s (%s %.*s)\n", |
| raw_smp_processor_id(), print_tainted(), |
| init_utsname()->release, |
| (int)strcspn(init_utsname()->version, " "), |
| init_utsname()->version); |
| print_symbol("PC is at %s\n", instruction_pointer(regs)); |
| print_symbol("LR is at %s\n", regs->UCreg_lr); |
| printk(KERN_DEFAULT "pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n" |
| "sp : %08lx ip : %08lx fp : %08lx\n", |
| regs->UCreg_pc, regs->UCreg_lr, regs->UCreg_asr, |
| regs->UCreg_sp, regs->UCreg_ip, regs->UCreg_fp); |
| printk(KERN_DEFAULT "r26: %08lx r25: %08lx r24: %08lx\n", |
| regs->UCreg_26, regs->UCreg_25, |
| regs->UCreg_24); |
| printk(KERN_DEFAULT "r23: %08lx r22: %08lx r21: %08lx r20: %08lx\n", |
| regs->UCreg_23, regs->UCreg_22, |
| regs->UCreg_21, regs->UCreg_20); |
| printk(KERN_DEFAULT "r19: %08lx r18: %08lx r17: %08lx r16: %08lx\n", |
| regs->UCreg_19, regs->UCreg_18, |
| regs->UCreg_17, regs->UCreg_16); |
| printk(KERN_DEFAULT "r15: %08lx r14: %08lx r13: %08lx r12: %08lx\n", |
| regs->UCreg_15, regs->UCreg_14, |
| regs->UCreg_13, regs->UCreg_12); |
| printk(KERN_DEFAULT "r11: %08lx r10: %08lx r9 : %08lx r8 : %08lx\n", |
| regs->UCreg_11, regs->UCreg_10, |
| regs->UCreg_09, regs->UCreg_08); |
| printk(KERN_DEFAULT "r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", |
| regs->UCreg_07, regs->UCreg_06, |
| regs->UCreg_05, regs->UCreg_04); |
| printk(KERN_DEFAULT "r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", |
| regs->UCreg_03, regs->UCreg_02, |
| regs->UCreg_01, regs->UCreg_00); |
| |
| flags = regs->UCreg_asr; |
| buf[0] = flags & PSR_S_BIT ? 'S' : 's'; |
| buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z'; |
| buf[2] = flags & PSR_C_BIT ? 'C' : 'c'; |
| buf[3] = flags & PSR_V_BIT ? 'V' : 'v'; |
| buf[4] = '\0'; |
| |
| printk(KERN_DEFAULT "Flags: %s INTR o%s REAL o%s Mode %s Segment %s\n", |
| buf, interrupts_enabled(regs) ? "n" : "ff", |
| fast_interrupts_enabled(regs) ? "n" : "ff", |
| processor_modes[processor_mode(regs)], |
| segment_eq(get_fs(), get_ds()) ? "kernel" : "user"); |
| { |
| unsigned int ctrl; |
| |
| buf[0] = '\0'; |
| { |
| unsigned int transbase; |
| asm("movc %0, p0.c2, #0\n" |
| : "=r" (transbase)); |
| snprintf(buf, sizeof(buf), " Table: %08x", transbase); |
| } |
| asm("movc %0, p0.c1, #0\n" : "=r" (ctrl)); |
| |
| printk(KERN_DEFAULT "Control: %08x%s\n", ctrl, buf); |
| } |
| } |
| |
| void show_regs(struct pt_regs *regs) |
| { |
| printk(KERN_DEFAULT "\n"); |
| printk(KERN_DEFAULT "Pid: %d, comm: %20s\n", |
| task_pid_nr(current), current->comm); |
| __show_regs(regs); |
| __backtrace(); |
| } |
| |
| /* |
| * Free current thread data structures etc.. |
| */ |
| void exit_thread(void) |
| { |
| } |
| |
| void flush_thread(void) |
| { |
| struct thread_info *thread = current_thread_info(); |
| struct task_struct *tsk = current; |
| |
| memset(thread->used_cp, 0, sizeof(thread->used_cp)); |
| memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); |
| #ifdef CONFIG_UNICORE_FPU_F64 |
| memset(&thread->fpstate, 0, sizeof(struct fp_state)); |
| #endif |
| } |
| |
| void release_thread(struct task_struct *dead_task) |
| { |
| } |
| |
| asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); |
| |
| int |
| copy_thread(unsigned long clone_flags, unsigned long stack_start, |
| unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) |
| { |
| struct thread_info *thread = task_thread_info(p); |
| struct pt_regs *childregs = task_pt_regs(p); |
| |
| *childregs = *regs; |
| childregs->UCreg_00 = 0; |
| childregs->UCreg_sp = stack_start; |
| |
| memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); |
| thread->cpu_context.sp = (unsigned long)childregs; |
| thread->cpu_context.pc = (unsigned long)ret_from_fork; |
| |
| if (clone_flags & CLONE_SETTLS) |
| childregs->UCreg_16 = regs->UCreg_03; |
| |
| return 0; |
| } |
| |
| /* |
| * Fill in the task's elfregs structure for a core dump. |
| */ |
| int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs) |
| { |
| elf_core_copy_regs(elfregs, task_pt_regs(t)); |
| return 1; |
| } |
| |
| /* |
| * fill in the fpe structure for a core dump... |
| */ |
| int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fp) |
| { |
| struct thread_info *thread = current_thread_info(); |
| int used_math = thread->used_cp[1] | thread->used_cp[2]; |
| |
| #ifdef CONFIG_UNICORE_FPU_F64 |
| if (used_math) |
| memcpy(fp, &thread->fpstate, sizeof(*fp)); |
| #endif |
| return used_math != 0; |
| } |
| EXPORT_SYMBOL(dump_fpu); |
| |
| /* |
| * Shuffle the argument into the correct register before calling the |
| * thread function. r1 is the thread argument, r2 is the pointer to |
| * the thread function, and r3 points to the exit function. |
| */ |
| asm(".pushsection .text\n" |
| " .align\n" |
| " .type kernel_thread_helper, #function\n" |
| "kernel_thread_helper:\n" |
| " mov.a asr, r7\n" |
| " mov r0, r4\n" |
| " mov lr, r6\n" |
| " mov pc, r5\n" |
| " .size kernel_thread_helper, . - kernel_thread_helper\n" |
| " .popsection"); |
| |
| /* |
| * Create a kernel thread. |
| */ |
| pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) |
| { |
| struct pt_regs regs; |
| |
| memset(®s, 0, sizeof(regs)); |
| |
| regs.UCreg_04 = (unsigned long)arg; |
| regs.UCreg_05 = (unsigned long)fn; |
| regs.UCreg_06 = (unsigned long)do_exit; |
| regs.UCreg_07 = PRIV_MODE; |
| regs.UCreg_pc = (unsigned long)kernel_thread_helper; |
| regs.UCreg_asr = regs.UCreg_07 | PSR_I_BIT; |
| |
| return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); |
| } |
| EXPORT_SYMBOL(kernel_thread); |
| |
| unsigned long get_wchan(struct task_struct *p) |
| { |
| struct stackframe frame; |
| int count = 0; |
| if (!p || p == current || p->state == TASK_RUNNING) |
| return 0; |
| |
| frame.fp = thread_saved_fp(p); |
| frame.sp = thread_saved_sp(p); |
| frame.lr = 0; /* recovered from the stack */ |
| frame.pc = thread_saved_pc(p); |
| do { |
| int ret = unwind_frame(&frame); |
| if (ret < 0) |
| return 0; |
| if (!in_sched_functions(frame.pc)) |
| return frame.pc; |
| } while ((count++) < 16); |
| return 0; |
| } |
| |
| unsigned long arch_randomize_brk(struct mm_struct *mm) |
| { |
| unsigned long range_end = mm->brk + 0x02000000; |
| return randomize_range(mm->brk, range_end, 0) ? : mm->brk; |
| } |
| |
| /* |
| * The vectors page is always readable from user space for the |
| * atomic helpers and the signal restart code. Let's declare a mapping |
| * for it so it is visible through ptrace and /proc/<pid>/mem. |
| */ |
| |
| int vectors_user_mapping(void) |
| { |
| struct mm_struct *mm = current->mm; |
| return install_special_mapping(mm, 0xffff0000, PAGE_SIZE, |
| VM_READ | VM_EXEC | |
| VM_MAYREAD | VM_MAYEXEC | |
| VM_RESERVED, |
| NULL); |
| } |
| |
| const char *arch_vma_name(struct vm_area_struct *vma) |
| { |
| return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL; |
| } |