#include <linux/mm.h>#include <linux/kernel.h>#include <linux/slab.h>#include <linux/sched.h> struct kmem_cache *task_xstate_cachep = NULL;unsigned int xstate_size; int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src){	*dst = *src; 	if (src->thread.xstate) {		dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep,						      GFP_KERNEL);		if (!dst->thread.xstate)			return -ENOMEM;		memcpy(dst->thread.xstate, src->thread.xstate, xstate_size);	} 	return 0;} void free_thread_xstate(struct task_struct *tsk){	if (tsk->thread.xstate) {		kmem_cache_free(task_xstate_cachep, tsk->thread.xstate);		tsk->thread.xstate = NULL;	}} #if THREAD_SHIFT < PAGE_SHIFTstatic struct kmem_cache *thread_info_cache; struct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node){	struct thread_info *ti;#ifdef CONFIG_DEBUG_STACK_USAGE	gfp_t mask = GFP_KERNEL | __GFP_ZERO;#else	gfp_t mask = GFP_KERNEL;#endif 	ti = kmem_cache_alloc_node(thread_info_cache, mask, node);	return ti;} void free_thread_info(struct thread_info *ti){	free_thread_xstate(ti->task);	kmem_cache_free(thread_info_cache, ti);} void thread_info_cache_init(void){	thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,					      THREAD_SIZE, SLAB_PANIC, NULL);}#elsestruct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node){#ifdef CONFIG_DEBUG_STACK_USAGE	gfp_t mask = GFP_KERNEL | __GFP_ZERO;#else	gfp_t mask = GFP_KERNEL;#endif	struct page *page = alloc_pages_node(node, mask, THREAD_SIZE_ORDER); 	return page ? page_address(page) : NULL;} void free_thread_info(struct thread_info *ti){	free_thread_xstate(ti->task);	free_pages((unsigned long)ti, THREAD_SIZE_ORDER);}#endif /* THREAD_SHIFT < PAGE_SHIFT */ void arch_task_cache_init(void){	if (!xstate_size)		return; 	task_xstate_cachep = kmem_cache_create("task_xstate", xstate_size,					       __alignof__(union thread_xstate),					       SLAB_PANIC | SLAB_NOTRACK, NULL);} #ifdef CONFIG_SH_FPU_EMU# define HAVE_SOFTFP	1#else# define HAVE_SOFTFP	0#endif void __cpuinit init_thread_xstate(void){	if (boot_cpu_data.flags & CPU_HAS_FPU)		xstate_size = sizeof(struct sh_fpu_hard_struct);	else if (HAVE_SOFTFP)		xstate_size = sizeof(struct sh_fpu_soft_struct);	else		xstate_size = 0;}