diff options
Diffstat (limited to 'arch/arm26/kernel/process.c')
| -rw-r--r-- | arch/arm26/kernel/process.c | 401 |
1 files changed, 401 insertions, 0 deletions
diff --git a/arch/arm26/kernel/process.c b/arch/arm26/kernel/process.c new file mode 100644 index 000000000000..46aea6ac194d --- /dev/null +++ b/arch/arm26/kernel/process.c @@ -0,0 +1,401 @@ +/* + * linux/arch/arm26/kernel/process.c + * + * Copyright (C) 2003 Ian Molton - adapted for ARM26 + * Copyright (C) 1996-2000 Russell King - Converted to ARM. + * Origional Copyright (C) 1995 Linus Torvalds + * + * 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/config.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/ptrace.h> +#include <linux/slab.h> +#include <linux/user.h> +#include <linux/a.out.h> +#include <linux/delay.h> +#include <linux/reboot.h> +#include <linux/interrupt.h> +#include <linux/init.h> + +#include <asm/system.h> +#include <asm/io.h> +#include <asm/leds.h> +#include <asm/processor.h> +#include <asm/uaccess.h> + +extern const char *processor_modes[]; +extern void setup_mm_for_reboot(char mode); + +static volatile int hlt_counter; + +void disable_hlt(void) +{ + hlt_counter++; +} + +EXPORT_SYMBOL(disable_hlt); + +void enable_hlt(void) +{ + hlt_counter--; +} + +EXPORT_SYMBOL(enable_hlt); + +static int __init nohlt_setup(char *__unused) +{ + hlt_counter = 1; + return 1; +} + +static int __init hlt_setup(char *__unused) +{ + hlt_counter = 0; + return 1; +} + +__setup("nohlt", nohlt_setup); +__setup("hlt", hlt_setup); + +/* + * This is our default idle handler. We need to disable + * interrupts here to ensure we don't miss a wakeup call. + */ +void cpu_idle(void) +{ + /* endless idle loop with no priority at all */ + preempt_disable(); + while (1) { + while (!need_resched()) { + local_irq_disable(); + if (!need_resched() && !hlt_counter) + local_irq_enable(); + } + } + schedule(); +} + +static char reboot_mode = 'h'; + +int __init reboot_setup(char *str) +{ + reboot_mode = str[0]; + return 1; +} + +__setup("reboot=", reboot_setup); + +/* ARM26 cant do these but we still need to define them. */ +void machine_halt(void) +{ +} +void machine_power_off(void) +{ +} + +EXPORT_SYMBOL(machine_halt); +EXPORT_SYMBOL(machine_power_off); + +void machine_restart(char * __unused) +{ + /* + * Clean and disable cache, and turn off interrupts + */ + cpu_proc_fin(); + + /* + * 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); + + /* + * copy branch instruction to reset location and call it + */ + + *(unsigned long *)0 = *(unsigned long *)0x03800000; + ((void(*)(void))0)(); + + /* + * Whoops - the architecture was unable to reboot. + * Tell the user! Should never happen... + */ + mdelay(1000); + printk("Reboot failed -- System halted\n"); + while (1); +} + +EXPORT_SYMBOL(machine_restart); + +void show_regs(struct pt_regs * regs) +{ + unsigned long flags; + + flags = condition_codes(regs); + + printk("pc : [<%08lx>] lr : [<%08lx>] %s\n" + "sp : %08lx ip : %08lx fp : %08lx\n", + instruction_pointer(regs), + regs->ARM_lr, print_tainted(), regs->ARM_sp, + regs->ARM_ip, regs->ARM_fp); + printk("r10: %08lx r9 : %08lx r8 : %08lx\n", + regs->ARM_r10, regs->ARM_r9, + regs->ARM_r8); + printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", + regs->ARM_r7, regs->ARM_r6, + regs->ARM_r5, regs->ARM_r4); + printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", + regs->ARM_r3, regs->ARM_r2, + regs->ARM_r1, regs->ARM_r0); + printk("Flags: %c%c%c%c", + flags & PSR_N_BIT ? 'N' : 'n', + flags & PSR_Z_BIT ? 'Z' : 'z', + flags & PSR_C_BIT ? 'C' : 'c', + flags & PSR_V_BIT ? 'V' : 'v'); + printk(" IRQs o%s FIQs o%s Mode %s Segment %s\n", + interrupts_enabled(regs) ? "n" : "ff", + fast_interrupts_enabled(regs) ? "n" : "ff", + processor_modes[processor_mode(regs)], + get_fs() == get_ds() ? "kernel" : "user"); +} + +void show_fpregs(struct user_fp *regs) +{ + int i; + + for (i = 0; i < 8; i++) { + unsigned long *p; + char type; + + p = (unsigned long *)(regs->fpregs + i); + + switch (regs->ftype[i]) { + case 1: type = 'f'; break; + case 2: type = 'd'; break; + case 3: type = 'e'; break; + default: type = '?'; break; + } + if (regs->init_flag) + type = '?'; + + printk(" f%d(%c): %08lx %08lx %08lx%c", + i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); + } + + + printk("FPSR: %08lx FPCR: %08lx\n", + (unsigned long)regs->fpsr, + (unsigned long)regs->fpcr); +} + +/* + * Task structure and kernel stack allocation. + */ +static unsigned long *thread_info_head; +static unsigned int nr_thread_info; + +extern unsigned long get_page_8k(int priority); +extern void free_page_8k(unsigned long page); + +// FIXME - is this valid? +#define EXTRA_TASK_STRUCT 0 +#define ll_alloc_task_struct() ((struct thread_info *)get_page_8k(GFP_KERNEL)) +#define ll_free_task_struct(p) free_page_8k((unsigned long)(p)) + +//FIXME - do we use *task param below looks like we dont, which is ok? +//FIXME - if EXTRA_TASK_STRUCT is zero we can optimise the below away permanently. *IF* its supposed to be zero. +struct thread_info *alloc_thread_info(struct task_struct *task) +{ + struct thread_info *thread = NULL; + + if (EXTRA_TASK_STRUCT) { + unsigned long *p = thread_info_head; + + if (p) { + thread_info_head = (unsigned long *)p[0]; + nr_thread_info -= 1; + } + thread = (struct thread_info *)p; + } + + if (!thread) + thread = ll_alloc_task_struct(); + +#ifdef CONFIG_MAGIC_SYSRQ + /* + * The stack must be cleared if you want SYSRQ-T to + * give sensible stack usage information + */ + if (thread) { + char *p = (char *)thread; + memzero(p+KERNEL_STACK_SIZE, KERNEL_STACK_SIZE); + } +#endif + return thread; +} + +void free_thread_info(struct thread_info *thread) +{ + if (EXTRA_TASK_STRUCT && nr_thread_info < EXTRA_TASK_STRUCT) { + unsigned long *p = (unsigned long *)thread; + p[0] = (unsigned long)thread_info_head; + thread_info_head = p; + nr_thread_info += 1; + } else + ll_free_task_struct(thread); +} + +/* + * 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(&tsk->thread.debug, 0, sizeof(struct debug_info)); + memset(&thread->fpstate, 0, sizeof(union fp_state)); + + clear_used_math(); +} + +void release_thread(struct task_struct *dead_task) +{ +} + +asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); + +int +copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, + unsigned long unused, struct task_struct *p, struct pt_regs *regs) +{ + struct thread_info *thread = p->thread_info; + struct pt_regs *childregs; + + childregs = __get_user_regs(thread); + *childregs = *regs; + childregs->ARM_r0 = 0; + childregs->ARM_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 | MODE_SVC26 | PSR_I_BIT; + + return 0; +} + +/* + * fill in the fpe structure for a core dump... + */ +int dump_fpu (struct pt_regs *regs, struct user_fp *fp) +{ + struct thread_info *thread = current_thread_info(); + int used_math = !!used_math(); + + if (used_math) + memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); + + return used_math; +} + +/* + * fill in the user structure for a core dump.. + */ +void dump_thread(struct pt_regs * regs, struct user * dump) +{ + struct task_struct *tsk = current; + + dump->magic = CMAGIC; + dump->start_code = tsk->mm->start_code; + dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1); + + dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT; + dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT; + dump->u_ssize = 0; + + dump->u_debugreg[0] = tsk->thread.debug.bp[0].address; + dump->u_debugreg[1] = tsk->thread.debug.bp[1].address; + dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn; + dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn; + dump->u_debugreg[4] = tsk->thread.debug.nsaved; + + if (dump->start_stack < 0x04000000) + dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT; + + dump->regs = *regs; + dump->u_fpvalid = dump_fpu (regs, &dump->u_fp); +} + +/* + * 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. + * FIXME - make sure this is right - the older code used to zero fp + * and cause the parent to call sys_exit (do_exit in this version) + */ +extern void kernel_thread_helper(void); + +asm( ".section .text\n" +" .align\n" +" .type kernel_thread_helper, #function\n" +"kernel_thread_helper:\n" +" mov r0, r1\n" +" mov lr, r3\n" +" mov pc, r2\n" +" .size kernel_thread_helper, . - kernel_thread_helper\n" +" .previous"); + +/* + * 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.ARM_r1 = (unsigned long)arg; + regs.ARM_r2 = (unsigned long)fn; + regs.ARM_r3 = (unsigned long)do_exit; + regs.ARM_pc = (unsigned long)kernel_thread_helper | MODE_SVC26; + + 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) +{ + unsigned long fp, lr; + unsigned long stack_page; + int count = 0; + if (!p || p == current || p->state == TASK_RUNNING) + return 0; + + stack_page = 4096 + (unsigned long)p; + fp = thread_saved_fp(p); + do { + if (fp < stack_page || fp > 4092+stack_page) + return 0; + lr = pc_pointer (((unsigned long *)fp)[-1]); + if (!in_sched_functions(lr)) + return lr; + fp = *(unsigned long *) (fp - 12); + } while (count ++ < 16); + return 0; +} |