diff options
Diffstat (limited to 'arch/avr32/kernel/process.c')
| -rw-r--r-- | arch/avr32/kernel/process.c | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/arch/avr32/kernel/process.c b/arch/avr32/kernel/process.c new file mode 100644 index 000000000000..317dc50945f2 --- /dev/null +++ b/arch/avr32/kernel/process.c @@ -0,0 +1,276 @@ +/* + * Copyright (C) 2004-2006 Atmel Corporation + * + * 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 <linux/sched.h> +#include <linux/module.h> +#include <linux/kallsyms.h> +#include <linux/fs.h> +#include <linux/ptrace.h> +#include <linux/reboot.h> +#include <linux/unistd.h> + +#include <asm/sysreg.h> +#include <asm/ocd.h> + +void (*pm_power_off)(void) = NULL; +EXPORT_SYMBOL(pm_power_off); + +/* + * This file handles the architecture-dependent parts of process handling.. + */ + +void cpu_idle(void) +{ + /* endless idle loop with no priority at all */ + while (1) { + /* TODO: Enter sleep mode */ + while (!need_resched()) + cpu_relax(); + preempt_enable_no_resched(); + schedule(); + preempt_disable(); + } +} + +void machine_halt(void) +{ +} + +void machine_power_off(void) +{ +} + +void machine_restart(char *cmd) +{ + __mtdr(DBGREG_DC, DC_DBE); + __mtdr(DBGREG_DC, DC_RES); + while (1) ; +} + +/* + * PC is actually discarded when returning from a system call -- the + * return address must be stored in LR. This function will make sure + * LR points to do_exit before starting the thread. + * + * Also, when returning from fork(), r12 is 0, so we must copy the + * argument as well. + * + * r0 : The argument to the main thread function + * r1 : The address of do_exit + * r2 : The address of the main thread function + */ +asmlinkage extern void kernel_thread_helper(void); +__asm__(" .type kernel_thread_helper, @function\n" + "kernel_thread_helper:\n" + " mov r12, r0\n" + " mov lr, r2\n" + " mov pc, r1\n" + " .size kernel_thread_helper, . - kernel_thread_helper"); + +int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) +{ + struct pt_regs regs; + + memset(®s, 0, sizeof(regs)); + + regs.r0 = (unsigned long)arg; + regs.r1 = (unsigned long)fn; + regs.r2 = (unsigned long)do_exit; + regs.lr = (unsigned long)kernel_thread_helper; + regs.pc = (unsigned long)kernel_thread_helper; + regs.sr = MODE_SUPERVISOR; + + return do_fork(flags | CLONE_VM | CLONE_UNTRACED, + 0, ®s, 0, NULL, NULL); +} +EXPORT_SYMBOL(kernel_thread); + +/* + * Free current thread data structures etc + */ +void exit_thread(void) +{ + /* nothing to do */ +} + +void flush_thread(void) +{ + /* nothing to do */ +} + +void release_thread(struct task_struct *dead_task) +{ + /* do nothing */ +} + +static const char *cpu_modes[] = { + "Application", "Supervisor", "Interrupt level 0", "Interrupt level 1", + "Interrupt level 2", "Interrupt level 3", "Exception", "NMI" +}; + +void show_regs(struct pt_regs *regs) +{ + unsigned long sp = regs->sp; + unsigned long lr = regs->lr; + unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT; + + if (!user_mode(regs)) + sp = (unsigned long)regs + FRAME_SIZE_FULL; + + print_symbol("PC is at %s\n", instruction_pointer(regs)); + print_symbol("LR is at %s\n", lr); + printk("pc : [<%08lx>] lr : [<%08lx>] %s\n" + "sp : %08lx r12: %08lx r11: %08lx\n", + instruction_pointer(regs), + lr, print_tainted(), sp, regs->r12, regs->r11); + printk("r10: %08lx r9 : %08lx r8 : %08lx\n", + regs->r10, regs->r9, regs->r8); + printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", + regs->r7, regs->r6, regs->r5, regs->r4); + printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", + regs->r3, regs->r2, regs->r1, regs->r0); + printk("Flags: %c%c%c%c%c\n", + regs->sr & SR_Q ? 'Q' : 'q', + regs->sr & SR_V ? 'V' : 'v', + regs->sr & SR_N ? 'N' : 'n', + regs->sr & SR_Z ? 'Z' : 'z', + regs->sr & SR_C ? 'C' : 'c'); + printk("Mode bits: %c%c%c%c%c%c%c%c%c\n", + regs->sr & SR_H ? 'H' : 'h', + regs->sr & SR_R ? 'R' : 'r', + regs->sr & SR_J ? 'J' : 'j', + regs->sr & SR_EM ? 'E' : 'e', + regs->sr & SR_I3M ? '3' : '.', + regs->sr & SR_I2M ? '2' : '.', + regs->sr & SR_I1M ? '1' : '.', + regs->sr & SR_I0M ? '0' : '.', + regs->sr & SR_GM ? 'G' : 'g'); + printk("CPU Mode: %s\n", cpu_modes[mode]); + + show_trace(NULL, (unsigned long *)sp, regs); +} +EXPORT_SYMBOL(show_regs); + +/* Fill in the fpu structure for a core dump. This is easy -- we don't have any */ +int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) +{ + /* Not valid */ + return 0; +} + +asmlinkage void ret_from_fork(void); + +int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, + unsigned long unused, + struct task_struct *p, struct pt_regs *regs) +{ + struct pt_regs *childregs; + + childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long)p->thread_info)) - 1; + *childregs = *regs; + + if (user_mode(regs)) + childregs->sp = usp; + else + childregs->sp = (unsigned long)p->thread_info + THREAD_SIZE; + + childregs->r12 = 0; /* Set return value for child */ + + p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM; + p->thread.cpu_context.ksp = (unsigned long)childregs; + p->thread.cpu_context.pc = (unsigned long)ret_from_fork; + + return 0; +} + +/* r12-r8 are dummy parameters to force the compiler to use the stack */ +asmlinkage int sys_fork(struct pt_regs *regs) +{ + return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL); +} + +asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, + unsigned long parent_tidptr, + unsigned long child_tidptr, struct pt_regs *regs) +{ + if (!newsp) + newsp = regs->sp; + return do_fork(clone_flags, newsp, regs, 0, + (int __user *)parent_tidptr, + (int __user *)child_tidptr); +} + +asmlinkage int sys_vfork(struct pt_regs *regs) +{ + return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, + 0, NULL, NULL); +} + +asmlinkage int sys_execve(char __user *ufilename, char __user *__user *uargv, + char __user *__user *uenvp, struct pt_regs *regs) +{ + int error; + char *filename; + + filename = getname(ufilename); + error = PTR_ERR(filename); + if (IS_ERR(filename)) + goto out; + + error = do_execve(filename, uargv, uenvp, regs); + if (error == 0) + current->ptrace &= ~PT_DTRACE; + putname(filename); + +out: + return error; +} + + +/* + * This function is supposed to answer the question "who called + * schedule()?" + */ +unsigned long get_wchan(struct task_struct *p) +{ + unsigned long pc; + unsigned long stack_page; + + if (!p || p == current || p->state == TASK_RUNNING) + return 0; + + stack_page = (unsigned long)p->thread_info; + BUG_ON(!stack_page); + + /* + * The stored value of PC is either the address right after + * the call to __switch_to() or ret_from_fork. + */ + pc = thread_saved_pc(p); + if (in_sched_functions(pc)) { +#ifdef CONFIG_FRAME_POINTER + unsigned long fp = p->thread.cpu_context.r7; + BUG_ON(fp < stack_page || fp > (THREAD_SIZE + stack_page)); + pc = *(unsigned long *)fp; +#else + /* + * We depend on the frame size of schedule here, which + * is actually quite ugly. It might be possible to + * determine the frame size automatically at build + * time by doing this: + * - compile sched.c + * - disassemble the resulting sched.o + * - look for 'sub sp,??' shortly after '<schedule>:' + */ + unsigned long sp = p->thread.cpu_context.ksp + 16; + BUG_ON(sp < stack_page || sp > (THREAD_SIZE + stack_page)); + pc = *(unsigned long *)sp; +#endif + } + + return pc; +} |