417 lines
11 KiB
C
417 lines
11 KiB
C
/*
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* arch/s390/kernel/process.c
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*
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* S390 version
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* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
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* Hartmut Penner (hp@de.ibm.com),
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* Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
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*
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* Derived from "arch/i386/kernel/process.c"
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* Copyright (C) 1995, Linus Torvalds
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*/
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/*
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* This file handles the architecture-dependent parts of process handling..
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*/
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#include <linux/config.h>
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#include <linux/compiler.h>
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#include <linux/cpu.h>
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/smp_lock.h>
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#include <linux/stddef.h>
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#include <linux/unistd.h>
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#include <linux/ptrace.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/user.h>
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#include <linux/a.out.h>
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#include <linux/interrupt.h>
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#include <linux/delay.h>
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#include <linux/reboot.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/notifier.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <asm/system.h>
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#include <asm/io.h>
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#include <asm/processor.h>
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#include <asm/irq.h>
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#include <asm/timer.h>
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asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
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/*
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* Return saved PC of a blocked thread. used in kernel/sched.
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* resume in entry.S does not create a new stack frame, it
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* just stores the registers %r6-%r15 to the frame given by
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* schedule. We want to return the address of the caller of
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* schedule, so we have to walk the backchain one time to
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* find the frame schedule() store its return address.
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*/
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unsigned long thread_saved_pc(struct task_struct *tsk)
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{
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struct stack_frame *sf;
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sf = (struct stack_frame *) tsk->thread.ksp;
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sf = (struct stack_frame *) sf->back_chain;
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return sf->gprs[8];
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}
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/*
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* Need to know about CPUs going idle?
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*/
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static struct notifier_block *idle_chain;
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int register_idle_notifier(struct notifier_block *nb)
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{
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return notifier_chain_register(&idle_chain, nb);
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}
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EXPORT_SYMBOL(register_idle_notifier);
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int unregister_idle_notifier(struct notifier_block *nb)
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{
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return notifier_chain_unregister(&idle_chain, nb);
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}
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EXPORT_SYMBOL(unregister_idle_notifier);
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void do_monitor_call(struct pt_regs *regs, long interruption_code)
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{
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/* disable monitor call class 0 */
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__ctl_clear_bit(8, 15);
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notifier_call_chain(&idle_chain, CPU_NOT_IDLE,
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(void *)(long) smp_processor_id());
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}
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/*
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* The idle loop on a S390...
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*/
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void default_idle(void)
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{
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psw_t wait_psw;
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unsigned long reg;
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int cpu, rc;
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local_irq_disable();
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if (need_resched()) {
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local_irq_enable();
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schedule();
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return;
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}
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/* CPU is going idle. */
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cpu = smp_processor_id();
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rc = notifier_call_chain(&idle_chain, CPU_IDLE, (void *)(long) cpu);
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if (rc != NOTIFY_OK && rc != NOTIFY_DONE)
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BUG();
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if (rc != NOTIFY_OK) {
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local_irq_enable();
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return;
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}
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/* enable monitor call class 0 */
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__ctl_set_bit(8, 15);
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#ifdef CONFIG_HOTPLUG_CPU
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if (cpu_is_offline(smp_processor_id()))
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cpu_die();
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#endif
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/*
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* Wait for external, I/O or machine check interrupt and
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* switch off machine check bit after the wait has ended.
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*/
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wait_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK | PSW_MASK_WAIT |
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PSW_MASK_IO | PSW_MASK_EXT;
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#ifndef CONFIG_ARCH_S390X
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asm volatile (
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" basr %0,0\n"
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"0: la %0,1f-0b(%0)\n"
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" st %0,4(%1)\n"
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" oi 4(%1),0x80\n"
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" lpsw 0(%1)\n"
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"1: la %0,2f-1b(%0)\n"
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" st %0,4(%1)\n"
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" oi 4(%1),0x80\n"
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" ni 1(%1),0xf9\n"
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" lpsw 0(%1)\n"
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"2:"
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: "=&a" (reg) : "a" (&wait_psw) : "memory", "cc" );
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#else /* CONFIG_ARCH_S390X */
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asm volatile (
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" larl %0,0f\n"
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" stg %0,8(%1)\n"
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" lpswe 0(%1)\n"
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"0: larl %0,1f\n"
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" stg %0,8(%1)\n"
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" ni 1(%1),0xf9\n"
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" lpswe 0(%1)\n"
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"1:"
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: "=&a" (reg) : "a" (&wait_psw) : "memory", "cc" );
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#endif /* CONFIG_ARCH_S390X */
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}
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void cpu_idle(void)
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{
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for (;;)
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default_idle();
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}
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void show_regs(struct pt_regs *regs)
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{
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struct task_struct *tsk = current;
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printk("CPU: %d %s\n", tsk->thread_info->cpu, print_tainted());
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printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
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current->comm, current->pid, (void *) tsk,
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(void *) tsk->thread.ksp);
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show_registers(regs);
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/* Show stack backtrace if pt_regs is from kernel mode */
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if (!(regs->psw.mask & PSW_MASK_PSTATE))
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show_trace(0,(unsigned long *) regs->gprs[15]);
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}
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extern void kernel_thread_starter(void);
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__asm__(".align 4\n"
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"kernel_thread_starter:\n"
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" la 2,0(10)\n"
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" basr 14,9\n"
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" la 2,0\n"
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" br 11\n");
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int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
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{
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struct pt_regs regs;
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memset(®s, 0, sizeof(regs));
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regs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_IO | PSW_MASK_EXT;
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regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE;
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regs.gprs[9] = (unsigned long) fn;
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regs.gprs[10] = (unsigned long) arg;
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regs.gprs[11] = (unsigned long) do_exit;
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regs.orig_gpr2 = -1;
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/* Ok, create the new process.. */
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return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
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0, ®s, 0, NULL, NULL);
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}
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/*
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* Free current thread data structures etc..
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*/
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void exit_thread(void)
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{
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}
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void flush_thread(void)
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{
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clear_used_math();
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clear_tsk_thread_flag(current, TIF_USEDFPU);
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}
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void release_thread(struct task_struct *dead_task)
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{
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}
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int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp,
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unsigned long unused,
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struct task_struct * p, struct pt_regs * regs)
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{
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struct fake_frame
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{
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struct stack_frame sf;
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struct pt_regs childregs;
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} *frame;
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frame = ((struct fake_frame *)
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(THREAD_SIZE + (unsigned long) p->thread_info)) - 1;
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p->thread.ksp = (unsigned long) frame;
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/* Store access registers to kernel stack of new process. */
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frame->childregs = *regs;
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frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
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frame->childregs.gprs[15] = new_stackp;
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frame->sf.back_chain = 0;
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/* new return point is ret_from_fork */
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frame->sf.gprs[8] = (unsigned long) ret_from_fork;
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/* fake return stack for resume(), don't go back to schedule */
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frame->sf.gprs[9] = (unsigned long) frame;
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/* Save access registers to new thread structure. */
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save_access_regs(&p->thread.acrs[0]);
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#ifndef CONFIG_ARCH_S390X
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/*
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* save fprs to current->thread.fp_regs to merge them with
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* the emulated registers and then copy the result to the child.
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*/
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save_fp_regs(¤t->thread.fp_regs);
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memcpy(&p->thread.fp_regs, ¤t->thread.fp_regs,
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sizeof(s390_fp_regs));
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p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _SEGMENT_TABLE;
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/* Set a new TLS ? */
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if (clone_flags & CLONE_SETTLS)
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p->thread.acrs[0] = regs->gprs[6];
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#else /* CONFIG_ARCH_S390X */
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/* Save the fpu registers to new thread structure. */
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save_fp_regs(&p->thread.fp_regs);
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p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _REGION_TABLE;
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/* Set a new TLS ? */
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if (clone_flags & CLONE_SETTLS) {
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if (test_thread_flag(TIF_31BIT)) {
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p->thread.acrs[0] = (unsigned int) regs->gprs[6];
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} else {
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p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32);
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p->thread.acrs[1] = (unsigned int) regs->gprs[6];
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}
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}
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#endif /* CONFIG_ARCH_S390X */
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/* start new process with ar4 pointing to the correct address space */
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p->thread.mm_segment = get_fs();
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/* Don't copy debug registers */
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memset(&p->thread.per_info,0,sizeof(p->thread.per_info));
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return 0;
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}
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asmlinkage long sys_fork(struct pt_regs regs)
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{
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return do_fork(SIGCHLD, regs.gprs[15], ®s, 0, NULL, NULL);
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}
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asmlinkage long sys_clone(struct pt_regs regs)
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{
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unsigned long clone_flags;
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unsigned long newsp;
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int __user *parent_tidptr, *child_tidptr;
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clone_flags = regs.gprs[3];
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newsp = regs.orig_gpr2;
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parent_tidptr = (int __user *) regs.gprs[4];
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child_tidptr = (int __user *) regs.gprs[5];
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if (!newsp)
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newsp = regs.gprs[15];
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return do_fork(clone_flags, newsp, ®s, 0,
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parent_tidptr, child_tidptr);
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}
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/*
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* This is trivial, and on the face of it looks like it
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* could equally well be done in user mode.
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*
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* Not so, for quite unobvious reasons - register pressure.
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* In user mode vfork() cannot have a stack frame, and if
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* done by calling the "clone()" system call directly, you
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* do not have enough call-clobbered registers to hold all
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* the information you need.
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*/
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asmlinkage long sys_vfork(struct pt_regs regs)
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{
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return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
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regs.gprs[15], ®s, 0, NULL, NULL);
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}
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/*
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* sys_execve() executes a new program.
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*/
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asmlinkage long sys_execve(struct pt_regs regs)
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{
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int error;
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char * filename;
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filename = getname((char __user *) regs.orig_gpr2);
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error = PTR_ERR(filename);
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if (IS_ERR(filename))
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goto out;
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error = do_execve(filename, (char __user * __user *) regs.gprs[3],
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(char __user * __user *) regs.gprs[4], ®s);
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if (error == 0) {
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task_lock(current);
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current->ptrace &= ~PT_DTRACE;
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task_unlock(current);
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current->thread.fp_regs.fpc = 0;
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if (MACHINE_HAS_IEEE)
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asm volatile("sfpc %0,%0" : : "d" (0));
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}
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putname(filename);
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out:
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return error;
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}
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/*
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* fill in the FPU structure for a core dump.
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*/
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int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
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{
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#ifndef CONFIG_ARCH_S390X
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/*
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* save fprs to current->thread.fp_regs to merge them with
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* the emulated registers and then copy the result to the dump.
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*/
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save_fp_regs(¤t->thread.fp_regs);
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memcpy(fpregs, ¤t->thread.fp_regs, sizeof(s390_fp_regs));
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#else /* CONFIG_ARCH_S390X */
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save_fp_regs(fpregs);
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#endif /* CONFIG_ARCH_S390X */
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return 1;
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}
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/*
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* fill in the user structure for a core dump..
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*/
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void dump_thread(struct pt_regs * regs, struct user * dump)
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{
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/* changed the size calculations - should hopefully work better. lbt */
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dump->magic = CMAGIC;
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dump->start_code = 0;
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dump->start_stack = regs->gprs[15] & ~(PAGE_SIZE - 1);
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dump->u_tsize = current->mm->end_code >> PAGE_SHIFT;
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dump->u_dsize = (current->mm->brk + PAGE_SIZE - 1) >> PAGE_SHIFT;
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dump->u_dsize -= dump->u_tsize;
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dump->u_ssize = 0;
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if (dump->start_stack < TASK_SIZE)
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dump->u_ssize = (TASK_SIZE - dump->start_stack) >> PAGE_SHIFT;
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memcpy(&dump->regs, regs, sizeof(s390_regs));
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dump_fpu (regs, &dump->regs.fp_regs);
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dump->regs.per_info = current->thread.per_info;
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}
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unsigned long get_wchan(struct task_struct *p)
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{
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struct stack_frame *sf, *low, *high;
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unsigned long return_address;
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int count;
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if (!p || p == current || p->state == TASK_RUNNING || !p->thread_info)
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return 0;
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low = (struct stack_frame *) p->thread_info;
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high = (struct stack_frame *)
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((unsigned long) p->thread_info + THREAD_SIZE) - 1;
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sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);
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if (sf <= low || sf > high)
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return 0;
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for (count = 0; count < 16; count++) {
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sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
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if (sf <= low || sf > high)
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return 0;
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return_address = sf->gprs[8] & PSW_ADDR_INSN;
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if (!in_sched_functions(return_address))
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return return_address;
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}
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return 0;
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}
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