diff options
Diffstat (limited to 'arch/unicore32/kernel/process.c')
| -rw-r--r-- | arch/unicore32/kernel/process.c | 389 |
1 files changed, 389 insertions, 0 deletions
diff --git a/arch/unicore32/kernel/process.c b/arch/unicore32/kernel/process.c new file mode 100644 index 0000000..ba401df --- /dev/null +++ b/arch/unicore32/kernel/process.c @@ -0,0 +1,389 @@ +/* + * 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_stop_sched_tick(1); + while (!need_resched()) { + local_irq_disable(); + stop_critical_timings(); + cpu_do_idle(); + local_irq_enable(); + start_critical_timings(); + } + tick_nohz_restart_sched_tick(); + 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_ALWAYSDUMP | VM_RESERVED, + NULL); +} + +const char *arch_vma_name(struct vm_area_struct *vma) +{ + return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL; +} |
