LXR linux/arch/sh/kernel/process.c

   1#include <linux/mm.h>
   2#include <linux/kernel.h>
   3#include <linux/slab.h>
   4#include <linux/sched.h>
   5#include <linux/export.h>
   6#include <linux/stackprotector.h>
   7#include <asm/fpu.h>
   8
   9struct kmem_cache *task_xstate_cachep = NULL;
  10unsigned int xstate_size;
  11
  12#ifdef CONFIG_CC_STACKPROTECTOR
  13unsigned long __stack_chk_guard __read_mostly;
  14EXPORT_SYMBOL(__stack_chk_guard);
  15#endif
  16
  17/*
  18 * this gets called so that we can store lazy state into memory and copy the
  19 * current task into the new thread.
  20 */
  21int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
  22{
  23#ifdef CONFIG_SUPERH32
  24        unlazy_fpu(src, task_pt_regs(src));
  25#endif
  26        *dst = *src;
  27
  28        if (src->thread.xstate) {
  29                dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
  30                                                      GFP_KERNEL);
  31                if (!dst->thread.xstate)
  32                        return -ENOMEM;
  33                memcpy(dst->thread.xstate, src->thread.xstate, xstate_size);
  34        }
  35
  36        return 0;
  37}
  38
  39void free_thread_xstate(struct task_struct *tsk)
  40{
  41        if (tsk->thread.xstate) {
  42                kmem_cache_free(task_xstate_cachep, tsk->thread.xstate);
  43                tsk->thread.xstate = NULL;
  44        }
  45}
  46
  47void arch_release_task_struct(struct task_struct *tsk)
  48{
  49        free_thread_xstate(tsk);
  50}
  51
  52void arch_task_cache_init(void)
  53{
  54        if (!xstate_size)
  55                return;
  56
  57        task_xstate_cachep = kmem_cache_create("task_xstate", xstate_size,
  58                                               __alignof__(union thread_xstate),
  59                                               SLAB_PANIC | SLAB_NOTRACK, NULL);
  60}
  61
  62#ifdef CONFIG_SH_FPU_EMU
  63# define HAVE_SOFTFP    1
  64#else
  65# define HAVE_SOFTFP    0
  66#endif
  67
  68void __cpuinit init_thread_xstate(void)
  69{
  70        if (boot_cpu_data.flags & CPU_HAS_FPU)
  71                xstate_size = sizeof(struct sh_fpu_hard_struct);
  72        else if (HAVE_SOFTFP)
  73                xstate_size = sizeof(struct sh_fpu_soft_struct);
  74        else
  75                xstate_size = 0;
  76}
  77