/*
* Derived from "arch/i386/kernel/process.c"
* Copyright (C) 1995 Linus Torvalds
*
* Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
* Paul Mackerras (paulus@cs.anu.edu.au)
*
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* 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.
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/elf.h>
#include <linux/init.h>
#include <linux/prctl.h>
#include <linux/init_task.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/mqueue.h>
#include <linux/hardirq.h>
#include <linux/utsname.h>
#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/mmu.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/time.h>
#include <asm/syscalls.h>
#ifdef CONFIG_PPC64
#include <asm/firmware.h>
#endif
extern unsigned long _get_SP(void);
#ifndef CONFIG_SMP
struct task_struct *last_task_used_math = NULL;
struct task_struct *last_task_used_altivec = NULL;
struct task_struct *last_task_used_spe = NULL;
#endif
/*
* Make sure the floating-point register state in the
* the thread_struct is up to date for task tsk.
*/
void flush_fp_to_thread(struct task_struct *tsk)
{
if (tsk->thread.regs) {
/*
* We need to disable preemption here because if we didn't,
* another process could get scheduled after the regs->msr
* test but before we have finished saving the FP registers
* to the thread_struct. That process could take over the
* FPU, and then when we get scheduled again we would store
* bogus values for the remaining FP registers.
*/
preempt_disable();
if (tsk->thread.regs->msr & MSR_FP) {
#ifdef CONFIG_SMP
/*
* This should only ever be called for current or
* for a stopped child process. Since we save away
* the FP register state on context switch on SMP,
* there is something wrong if a stopped child appears
* to still have its FP state in the CPU registers.
*/
BUG_ON(tsk != current);
#endif
giveup_fpu(tsk);
}
preempt_enable();
}
}
void enable_kernel_fp(void)
{
WARN_ON(preemptible());
#ifdef CONFIG_SMP
if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
giveup_fpu(current);
else
giveup_fpu(NULL); /* just enables FP for kernel */
#else
giveup_fpu(last_task_used_math);
#endif /* CONFIG_SMP */
}
EXPORT_SYMBOL(enable_kernel_fp);
int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
{
if (!tsk->thread.regs)
return 0;
flush_fp_to_thread(current);
memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
return 1;
}
#ifdef CONFIG_ALTIVEC
void enable_kernel_altivec(void)
{
WARN_ON(preemptible());
#ifdef CONFIG_SMP
if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
giveup_altivec(current);
else
giveup_altivec(NULL); /* just enable AltiVec for kernel - force */
#else
giveup_altivec(last_task_used_altivec);
#endif /* CONFIG_SMP */
}
EXPORT_SYMBOL(enable_kernel_altivec);
/*
* Make sure the VMX/Altivec register state in the
* the thread_struct is up to date for task tsk.
*/
void flush_altivec_to_thread(struct task_struct *tsk)
{
if (tsk->thread.regs) {
preempt_disable();
if (tsk->thread.regs->msr & MSR_VEC) {
#ifdef CONFIG_SMP
BUG_ON(tsk != current);
#endif
giveup_altivec(tsk);
}
preempt_enable();
}
}
int dump_task_altivec(struct task_struct *tsk, elf_vrregset_t *vrregs)
{
/* ELF_NVRREG includes the VSCR and VRSAVE which we need to save
* separately, see below */
const int nregs = ELF_NVRREG - 2;
elf_vrreg_t *reg;
u32 *dest;
if (tsk == current)
flush_altivec_to_thread(tsk);
reg = (elf_vrreg_t *)vrregs;
/* copy the 32 vr registers */
memcpy(reg, &tsk->thread.vr[0], nregs * sizeof(*reg));
reg += nregs;
/* copy the vscr */
memcpy(reg, &tsk->thread.vscr, sizeof(*reg));
reg++;
/* vrsave is stored in the high 32bit slot of the final 128bits */
memset(reg, 0, sizeof(*reg));
dest = (u32 *)reg;
*dest = tsk->thread.vrsave;
return 1;
}
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_SPE
void enable_kernel_spe(v