release/src-rt-6.x.4708/linux/linux-2.6.36/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
   6 struct kmem_cache *task_xstate_cachep = NULL;
   7 unsigned int xstate_size;
   8
   9 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
  10 {
  11         *dst = *src;
  12
  13         if (src->thread.xstate) {
  14                 dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
  15                                                       GFP_KERNEL);
  16                 if (!dst->thread.xstate)
  17                         return -ENOMEM;
  18                 memcpy(dst->thread.xstate, src->thread.xstate, xstate_size);
  19         }
  20
  21         return 0;
  22 }
  23
  24 void free_thread_xstate(struct task_struct *tsk)
  25 {
  26         if (tsk->thread.xstate) {
  27                 kmem_cache_free(task_xstate_cachep, tsk->thread.xstate);
  28                 tsk->thread.xstate = NULL;
  29         }
  30 }
  31
  32 #if THREAD_SHIFT < PAGE_SHIFT
  33 static struct kmem_cache *thread_info_cache;
  34
  35 struct thread_info *alloc_thread_info(struct task_struct *tsk)
  36 {
  37         struct thread_info *ti;
  38
  39         ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL);
  40         if (unlikely(ti == NULL))
  41                 return NULL;
  42 #ifdef CONFIG_DEBUG_STACK_USAGE
  43         memset(ti, 0, THREAD_SIZE);
  44 #endif
  45         return ti;
  46 }
  47
  48 void free_thread_info(struct thread_info *ti)
  49 {
  50         free_thread_xstate(ti->task);
  51         kmem_cache_free(thread_info_cache, ti);
  52 }
  53
  54 void thread_info_cache_init(void)
  55 {
  56         thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
  57                                               THREAD_SIZE, SLAB_PANIC, NULL);
  58 }
  59 #else
  60 struct thread_info *alloc_thread_info(struct task_struct *tsk)
  61 {
  62 #ifdef CONFIG_DEBUG_STACK_USAGE
  63         gfp_t mask = GFP_KERNEL | __GFP_ZERO;
  64 #else
  65         gfp_t mask = GFP_KERNEL;
  66 #endif
  67         return (struct thread_info *)__get_free_pages(mask, THREAD_SIZE_ORDER);
  68 }
  69
  70 void free_thread_info(struct thread_info *ti)
  71 {
  72         free_thread_xstate(ti->task);
  73         free_pages((unsigned long)ti, THREAD_SIZE_ORDER);
  74 }
  75 #endif /* THREAD_SHIFT < PAGE_SHIFT */
  76
  77 void arch_task_cache_init(void)
  78 {
  79         if (!xstate_size)
  80                 return;
  81
  82         task_xstate_cachep = kmem_cache_create("task_xstate", xstate_size,
  83                                                __alignof__(union thread_xstate),
  84                                                SLAB_PANIC | SLAB_NOTRACK, NULL);
  85 }
  86
  87 #ifdef CONFIG_SH_FPU_EMU
  88 # define HAVE_SOFTFP    1
  89 #else
  90 # define HAVE_SOFTFP    0
  91 #endif
  92
  93 void __cpuinit init_thread_xstate(void)
  94 {
  95         if (boot_cpu_data.flags & CPU_HAS_FPU)
  96                 xstate_size = sizeof(struct sh_fpu_hard_struct);
  97         else if (HAVE_SOFTFP)
  98                 xstate_size = sizeof(struct sh_fpu_soft_struct);
  99         else
 100                 xstate_size = 0;
 101 }