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author | Jonas Bonn <jonas@southpole.se> | 2011-06-04 22:30:12 +0300 |
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committer | Jonas Bonn <jonas@southpole.se> | 2011-07-22 18:46:36 +0200 |
commit | 88ef7f3f130ddd37f72bc919865eeefe1d437787 (patch) | |
tree | ff9db1bacc192f7a7efabda5415616f0f3b01f2e /arch/openrisc/kernel | |
parent | 2a7be1160a7ccc8b53693ef793fccb4ad2e75bbc (diff) | |
download | linux-88ef7f3f130ddd37f72bc919865eeefe1d437787.tar.bz2 |
OpenRISC: Scheduling/Process management
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/openrisc/kernel')
-rw-r--r-- | arch/openrisc/kernel/process.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c new file mode 100644 index 000000000000..e4209af879ec --- /dev/null +++ b/arch/openrisc/kernel/process.c @@ -0,0 +1,311 @@ +/* + * OpenRISC process.c + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * Modifications for the OpenRISC architecture: + * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> + * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * This file handles the architecture-dependent parts of process handling... + */ + +#define __KERNEL_SYSCALLS__ +#include <stdarg.h> + +#include <linux/errno.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/stddef.h> +#include <linux/unistd.h> +#include <linux/ptrace.h> +#include <linux/slab.h> +#include <linux/elfcore.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/init_task.h> +#include <linux/mqueue.h> +#include <linux/fs.h> + +#include <asm/uaccess.h> +#include <asm/pgtable.h> +#include <asm/system.h> +#include <asm/io.h> +#include <asm/processor.h> +#include <asm/spr_defs.h> + +#include <linux/smp.h> + +/* + * Pointer to Current thread info structure. + * + * Used at user space -> kernel transitions. + */ +struct thread_info *current_thread_info_set[NR_CPUS] = { &init_thread_info, }; + +void machine_restart(void) +{ + printk(KERN_INFO "*** MACHINE RESTART ***\n"); + __asm__("l.nop 1"); +} + +/* + * Similar to machine_power_off, but don't shut off power. Add code + * here to freeze the system for e.g. post-mortem debug purpose when + * possible. This halt has nothing to do with the idle halt. + */ +void machine_halt(void) +{ + printk(KERN_INFO "*** MACHINE HALT ***\n"); + __asm__("l.nop 1"); +} + +/* If or when software power-off is implemented, add code here. */ +void machine_power_off(void) +{ + printk(KERN_INFO "*** MACHINE POWER OFF ***\n"); + __asm__("l.nop 1"); +} + +void (*pm_power_off) (void) = machine_power_off; + +/* + * When a process does an "exec", machine state like FPU and debug + * registers need to be reset. This is a hook function for that. + * Currently we don't have any such state to reset, so this is empty. + */ +void flush_thread(void) +{ +} + +void show_regs(struct pt_regs *regs) +{ + extern void show_registers(struct pt_regs *regs); + + /* __PHX__ cleanup this mess */ + show_registers(regs); +} + +unsigned long thread_saved_pc(struct task_struct *t) +{ + return (unsigned long)user_regs(t->stack)->pc; +} + +void release_thread(struct task_struct *dead_task) +{ +} + +/* + * Copy the thread-specific (arch specific) info from the current + * process to the new one p + */ +extern asmlinkage void ret_from_fork(void); + +int +copy_thread(unsigned long clone_flags, unsigned long usp, + unsigned long unused, struct task_struct *p, struct pt_regs *regs) +{ + struct pt_regs *childregs; + struct pt_regs *kregs; + unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; + struct thread_info *ti; + unsigned long top_of_kernel_stack; + + top_of_kernel_stack = sp; + + p->set_child_tid = p->clear_child_tid = NULL; + + /* Copy registers */ + /* redzone */ + sp -= STACK_FRAME_OVERHEAD; + sp -= sizeof(struct pt_regs); + childregs = (struct pt_regs *)sp; + + /* Copy parent registers */ + *childregs = *regs; + + if ((childregs->sr & SPR_SR_SM) == 1) { + /* for kernel thread, set `current_thread_info' + * and stackptr in new task + */ + childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; + childregs->gpr[10] = (unsigned long)task_thread_info(p); + } else { + childregs->sp = usp; + } + + childregs->gpr[11] = 0; /* Result from fork() */ + + /* + * The way this works is that at some point in the future + * some task will call _switch to switch to the new task. + * That will pop off the stack frame created below and start + * the new task running at ret_from_fork. The new task will + * do some house keeping and then return from the fork or clone + * system call, using the stack frame created above. + */ + /* redzone */ + sp -= STACK_FRAME_OVERHEAD; + sp -= sizeof(struct pt_regs); + kregs = (struct pt_regs *)sp; + + ti = task_thread_info(p); + ti->ksp = sp; + + /* kregs->sp must store the location of the 'pre-switch' kernel stack + * pointer... for a newly forked process, this is simply the top of + * the kernel stack. + */ + kregs->sp = top_of_kernel_stack; + kregs->gpr[3] = (unsigned long)current; /* arg to schedule_tail */ + kregs->gpr[10] = (unsigned long)task_thread_info(p); + kregs->gpr[9] = (unsigned long)ret_from_fork; + + return 0; +} + +/* + * Set up a thread for executing a new program + */ +void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) +{ + unsigned long sr = regs->sr & ~SPR_SR_SM; + + set_fs(USER_DS); + memset(regs->gpr, 0, sizeof(regs->gpr)); + + regs->pc = pc; + regs->sr = sr; + regs->sp = sp; + +/* printk("start thread, ksp = %lx\n", current_thread_info()->ksp);*/ +} + +/* Fill in the fpu structure for a core dump. */ +int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu) +{ + /* TODO */ + return 0; +} + +extern struct thread_info *_switch(struct thread_info *old_ti, + struct thread_info *new_ti); + +struct task_struct *__switch_to(struct task_struct *old, + struct task_struct *new) +{ + struct task_struct *last; + struct thread_info *new_ti, *old_ti; + unsigned long flags; + + local_irq_save(flags); + + /* current_set is an array of saved current pointers + * (one for each cpu). we need them at user->kernel transition, + * while we save them at kernel->user transition + */ + new_ti = new->stack; + old_ti = old->stack; + + current_thread_info_set[smp_processor_id()] = new_ti; + last = (_switch(old_ti, new_ti))->task; + + local_irq_restore(flags); + + return last; +} + +/* + * Write out registers in core dump format, as defined by the + * struct user_regs_struct + */ +void dump_elf_thread(elf_greg_t *dest, struct pt_regs* regs) +{ + dest[0] = 0; /* r0 */ + memcpy(dest+1, regs->gpr+1, 31*sizeof(unsigned long)); + dest[32] = regs->pc; + dest[33] = regs->sr; + dest[34] = 0; + dest[35] = 0; +} + +extern void _kernel_thread_helper(void); + +void __noreturn kernel_thread_helper(int (*fn) (void *), void *arg) +{ + do_exit(fn(arg)); +} + +/* + * Create a kernel thread. + */ +int kernel_thread(int (*fn) (void *), void *arg, unsigned long flags) +{ + struct pt_regs regs; + + memset(®s, 0, sizeof(regs)); + + regs.gpr[20] = (unsigned long)fn; + regs.gpr[22] = (unsigned long)arg; + regs.sr = mfspr(SPR_SR); + regs.pc = (unsigned long)_kernel_thread_helper; + + return do_fork(flags | CLONE_VM | CLONE_UNTRACED, + 0, ®s, 0, NULL, NULL); +} + +/* + * sys_execve() executes a new program. + */ +asmlinkage long _sys_execve(const char __user *name, + const char __user * const __user *argv, + const char __user * const __user *envp, + struct pt_regs *regs) +{ + int error; + char *filename; + + filename = getname(name); + error = PTR_ERR(filename); + + if (IS_ERR(filename)) + goto out; + + error = do_execve(filename, argv, envp, regs); + putname(filename); + +out: + return error; +} + +unsigned long get_wchan(struct task_struct *p) +{ + /* TODO */ + + return 0; +} + +int kernel_execve(const char *filename, char *const argv[], char *const envp[]) +{ + register long __res asm("r11") = __NR_execve; + register long __a asm("r3") = (long)(filename); + register long __b asm("r4") = (long)(argv); + register long __c asm("r5") = (long)(envp); + __asm__ volatile ("l.sys 1" + : "=r" (__res), "=r"(__a), "=r"(__b), "=r"(__c) + : "0"(__res), "1"(__a), "2"(__b), "3"(__c) + : "r6", "r7", "r8", "r12", "r13", "r15", + "r17", "r19", "r21", "r23", "r25", "r27", + "r29", "r31"); + __asm__ volatile ("l.nop"); + return __res; +} |