|  | /* | 
|  | * This file is subject to the terms and conditions of the GNU General Public | 
|  | * License.  See the file "COPYING" in the main directory of this archive | 
|  | * for more details. | 
|  | */ | 
|  | #include <linux/export.h> | 
|  | #include <linux/mm.h> | 
|  | #include <linux/string.h> | 
|  | #include <asm/pgalloc.h> | 
|  |  | 
|  | pgd_t *pgd_alloc(struct mm_struct *mm) | 
|  | { | 
|  | pgd_t *ret, *init; | 
|  |  | 
|  | ret = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_ORDER); | 
|  | if (ret) { | 
|  | init = pgd_offset(&init_mm, 0UL); | 
|  | pgd_init((unsigned long)ret); | 
|  | memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD, | 
|  | (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); | 
|  | } | 
|  |  | 
|  | return ret; | 
|  | } | 
|  | EXPORT_SYMBOL_GPL(pgd_alloc); |