4 * Linux architectural port borrowing liberally from similar works of
5 * others. All original copyrights apply as per the original source
8 * Modifications for the OpenRISC architecture:
9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
17 * This file handles the architecture-dependent parts of process handling...
20 #define __KERNEL_SYSCALLS__
23 #include <linux/errno.h>
24 #include <linux/sched.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
28 #include <linux/stddef.h>
29 #include <linux/unistd.h>
30 #include <linux/ptrace.h>
31 #include <linux/slab.h>
32 #include <linux/elfcore.h>
33 #include <linux/interrupt.h>
34 #include <linux/delay.h>
35 #include <linux/init_task.h>
36 #include <linux/mqueue.h>
39 #include <asm/uaccess.h>
40 #include <asm/pgtable.h>
42 #include <asm/processor.h>
43 #include <asm/spr_defs.h>
45 #include <linux/smp.h>
48 * Pointer to Current thread info structure.
50 * Used at user space -> kernel transitions.
52 struct thread_info *current_thread_info_set[NR_CPUS] = { &init_thread_info, };
54 void machine_restart(void)
56 printk(KERN_INFO "*** MACHINE RESTART ***\n");
61 * Similar to machine_power_off, but don't shut off power. Add code
62 * here to freeze the system for e.g. post-mortem debug purpose when
63 * possible. This halt has nothing to do with the idle halt.
65 void machine_halt(void)
67 printk(KERN_INFO "*** MACHINE HALT ***\n");
71 /* If or when software power-off is implemented, add code here. */
72 void machine_power_off(void)
74 printk(KERN_INFO "*** MACHINE POWER OFF ***\n");
78 void (*pm_power_off) (void) = machine_power_off;
81 * When a process does an "exec", machine state like FPU and debug
82 * registers need to be reset. This is a hook function for that.
83 * Currently we don't have any such state to reset, so this is empty.
85 void flush_thread(void)
89 void show_regs(struct pt_regs *regs)
91 extern void show_registers(struct pt_regs *regs);
93 /* __PHX__ cleanup this mess */
97 unsigned long thread_saved_pc(struct task_struct *t)
99 return (unsigned long)user_regs(t->stack)->pc;
102 void release_thread(struct task_struct *dead_task)
107 * Copy the thread-specific (arch specific) info from the current
108 * process to the new one p
110 extern asmlinkage void ret_from_fork(void);
113 copy_thread(unsigned long clone_flags, unsigned long usp,
114 unsigned long unused, struct task_struct *p, struct pt_regs *regs)
116 struct pt_regs *childregs;
117 struct pt_regs *kregs;
118 unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
119 struct thread_info *ti;
120 unsigned long top_of_kernel_stack;
122 top_of_kernel_stack = sp;
124 p->set_child_tid = p->clear_child_tid = NULL;
128 sp -= STACK_FRAME_OVERHEAD;
129 sp -= sizeof(struct pt_regs);
130 childregs = (struct pt_regs *)sp;
132 /* Copy parent registers */
135 if ((childregs->sr & SPR_SR_SM) == 1) {
136 /* for kernel thread, set `current_thread_info'
137 * and stackptr in new task
139 childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
140 childregs->gpr[10] = (unsigned long)task_thread_info(p);
145 childregs->gpr[11] = 0; /* Result from fork() */
148 * The way this works is that at some point in the future
149 * some task will call _switch to switch to the new task.
150 * That will pop off the stack frame created below and start
151 * the new task running at ret_from_fork. The new task will
152 * do some house keeping and then return from the fork or clone
153 * system call, using the stack frame created above.
156 sp -= STACK_FRAME_OVERHEAD;
157 sp -= sizeof(struct pt_regs);
158 kregs = (struct pt_regs *)sp;
160 ti = task_thread_info(p);
163 /* kregs->sp must store the location of the 'pre-switch' kernel stack
164 * pointer... for a newly forked process, this is simply the top of
167 kregs->sp = top_of_kernel_stack;
168 kregs->gpr[3] = (unsigned long)current; /* arg to schedule_tail */
169 kregs->gpr[10] = (unsigned long)task_thread_info(p);
170 kregs->gpr[9] = (unsigned long)ret_from_fork;
176 * Set up a thread for executing a new program
178 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
180 unsigned long sr = regs->sr & ~SPR_SR_SM;
183 memset(regs->gpr, 0, sizeof(regs->gpr));
189 /* printk("start thread, ksp = %lx\n", current_thread_info()->ksp);*/
192 /* Fill in the fpu structure for a core dump. */
193 int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu)
199 extern struct thread_info *_switch(struct thread_info *old_ti,
200 struct thread_info *new_ti);
202 struct task_struct *__switch_to(struct task_struct *old,
203 struct task_struct *new)
205 struct task_struct *last;
206 struct thread_info *new_ti, *old_ti;
209 local_irq_save(flags);
211 /* current_set is an array of saved current pointers
212 * (one for each cpu). we need them at user->kernel transition,
213 * while we save them at kernel->user transition
218 current_thread_info_set[smp_processor_id()] = new_ti;
219 last = (_switch(old_ti, new_ti))->task;
221 local_irq_restore(flags);
227 * Write out registers in core dump format, as defined by the
228 * struct user_regs_struct
230 void dump_elf_thread(elf_greg_t *dest, struct pt_regs* regs)
232 dest[0] = 0; /* r0 */
233 memcpy(dest+1, regs->gpr+1, 31*sizeof(unsigned long));
240 extern void _kernel_thread_helper(void);
242 void __noreturn kernel_thread_helper(int (*fn) (void *), void *arg)
248 * Create a kernel thread.
250 int kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
254 memset(®s, 0, sizeof(regs));
256 regs.gpr[20] = (unsigned long)fn;
257 regs.gpr[22] = (unsigned long)arg;
258 regs.sr = mfspr(SPR_SR);
259 regs.pc = (unsigned long)_kernel_thread_helper;
261 return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
262 0, ®s, 0, NULL, NULL);
266 * sys_execve() executes a new program.
268 asmlinkage long _sys_execve(const char __user *name,
269 const char __user * const __user *argv,
270 const char __user * const __user *envp,
271 struct pt_regs *regs)
276 filename = getname(name);
277 error = PTR_ERR(filename);
279 if (IS_ERR(filename))
282 error = do_execve(filename, argv, envp, regs);
289 unsigned long get_wchan(struct task_struct *p)
296 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
298 register long __res asm("r11") = __NR_execve;
299 register long __a asm("r3") = (long)(filename);
300 register long __b asm("r4") = (long)(argv);
301 register long __c asm("r5") = (long)(envp);
302 __asm__ volatile ("l.sys 1"
303 : "=r" (__res), "=r"(__a), "=r"(__b), "=r"(__c)
304 : "0"(__res), "1"(__a), "2"(__b), "3"(__c)
305 : "r6", "r7", "r8", "r12", "r13", "r15",
306 "r17", "r19", "r21", "r23", "r25", "r27",
308 __asm__ volatile ("l.nop");