[PATCH] Move hugetlb declarations into their own header

From Bill Irwin

Move hugetlb and hugetlbfs declarations into a dedicated header file.

Hugetlb's big #ifdeffed block in mm.h got a lot bigger with hugetlbfs.
This patch basically attempts to remove the noise from mm.h by simply
rearranging it into a new header, and fixing all users of hugetlb.

arch/i386/kernel/sys_i386.c

@@ -9,6 +9,7 @@
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/smp.h>
 #include <linux/smp_lock.h>
 #include <linux/sem.h>

arch/i386/mm/hugetlbpage.c

@@ -8,6 +8,7 @@
 #include <linux/init.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/pagemap.h>
 #include <linux/smp_lock.h>
 #include <linux/slab.h>
@@ -356,7 +357,6 @@ alloc_shared_hugetlb_pages(int key, unsigned long addr, unsigned long len,
 	struct vm_area_struct *vma;
 	struct inode *inode;
 	struct address_space *mapping;
-	struct page *page;
 	int idx;
 	int retval = -ENOMEM;
 	int newalloc = 0;

arch/i386/mm/init.c

@@ -16,6 +16,7 @@
 #include <linux/ptrace.h>
 #include <linux/mman.h>
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/swap.h>
 #include <linux/smp.h>
 #include <linux/init.h>

arch/ia64/kernel/sys_ia64.c

@@ -9,6 +9,7 @@
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/mman.h>
 #include <linux/sched.h>
 #include <linux/file.h>		/* doh, must come after sched.h... */

arch/ia64/mm/hugetlbpage.c

@@ -8,6 +8,7 @@
 #include <linux/init.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/pagemap.h>
 #include <linux/smp_lock.h>
 #include <linux/slab.h>

arch/sparc64/kernel/sys_sparc.c

@@ -13,6 +13,7 @@
 #include <linux/fs.h>
 #include <linux/file.h>
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/sem.h>
 #include <linux/msg.h>
 #include <linux/shm.h>

arch/sparc64/mm/hugetlbpage.c

@@ -8,6 +8,7 @@
 #include <linux/init.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/pagemap.h>
 #include <linux/smp_lock.h>
 #include <linux/slab.h>

arch/sparc64/mm/init.c

@@ -12,6 +12,7 @@
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/slab.h>
 #include <linux/blk.h>
 #include <linux/swap.h>

fs/proc/array.c

@@ -64,6 +64,7 @@
 #include <linux/proc_fs.h>
 #include <linux/ioport.h>
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/pagemap.h>
 #include <linux/swap.h>
 #include <linux/slab.h>

include/linux/hugetlb.h

+#ifndef _LINUX_HUGETLB_H
+#define _LINUX_HUGETLB_H
+
+#ifdef CONFIG_HUGETLB_PAGE
+static inline int is_vm_hugetlb_page(struct vm_area_struct *vma)
+{
+	return vma->vm_flags & VM_HUGETLB;
+}
+
+int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
+int follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,
+		struct page **, struct vm_area_struct **, unsigned long *, int *, int);
+int free_hugepages(struct vm_area_struct *);
+int hugetlb_prefault(struct address_space *, struct vm_area_struct *);
+#else /* !CONFIG_HUGETLB_PAGE */
+static inline int is_vm_hugetlb_page(struct vm_area_struct *vma)
+{
+	return 0;
+}
+
+static inline int
+copy_hugetlb_page_range(struct mm_struct *src, struct mm_struct *dst,
+			struct vm_area_struct *vma)
+{
+	return -ENOSYS;
+}
+
+static inline int
+follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
+		struct page **pages, struct vm_area_struct **vmas,
+		unsigned long *start, int *len, int i)
+{
+	return -ENOSYS;
+}
+
+static inline int free_hugepages(struct vm_area_struct *vma)
+{
+	return -EINVAL;
+}
+
+static inline int
+hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma)
+{
+	return -ENOSYS;
+}
+#endif /* !CONFIG_HUGETLB_PAGE */
+
+#ifdef CONFIG_HUGETLBFS
+extern struct file_operations hugetlbfs_file_operations;
+extern struct vm_operations_struct hugetlb_vm_ops;
+struct file *hugetlb_zero_setup(size_t);
+
+static inline int is_file_hugetlb_page(struct file *file)
+{
+	return file->f_op == &hugetlbfs_file_operations;
+}
+
+static inline void set_file_hugetlb_page(struct file *file)
+{
+	file->f_op = &hugetlbfs_file_operations;
+}
+#else /* !CONFIG_HUGETLBFS */
+static inline int is_file_hugetlb_page(struct file *file)
+{
+	return 0;
+}
+
+static inline void set_file_hugetlb_page(struct file *file)
+{
+}
+
+static inline struct file *hugetlb_zero_setup(size_t size)
+{
+	return ERR_PTR(-ENOSYS);
+}
+#endif /* !CONFIG_HUGETLBFS */
+
+#endif /* _LINUX_HUGETLB_H */

include/linux/mm.h

@@ -376,20 +376,6 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long
 int __set_page_dirty_buffers(struct page *page);
 int __set_page_dirty_nobuffers(struct page *page);
 
-#ifdef CONFIG_HUGETLB_PAGE
-#define is_vm_hugetlb_page(vma) (vma->vm_flags & VM_HUGETLB)
-extern int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
-extern int follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *, struct page **, struct vm_area_struct **, unsigned long *, int *, int);
-extern	int free_hugepages(struct vm_area_struct *);
-extern int hugetlb_prefault(struct address_space *, struct vm_area_struct *);
-#else
-#define is_vm_hugetlb_page(vma) (0)
-#define follow_hugetlb_page(mm, vma, pages, vmas, start, len, i) (0)
-#define copy_hugetlb_page_range(dst, src, vma) (0)
-#define free_hugepages(mpnt)  do { } while(0)
-#endif
-
-
 /*
  * Prototype to add a shrinker callback for ageable caches.
  * 

mm/memory.c

@@ -38,6 +38,7 @@
 
 #include <linux/kernel_stat.h>
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/mman.h>
 #include <linux/swap.h>
 #include <linux/highmem.h>

mm/mmap.c

@@ -16,6 +16,7 @@
 #include <linux/fs.h>
 #include <linux/personality.h>
 #include <linux/security.h>
+#include <linux/hugetlb.h>
 #include <linux/profile.h>
 
 #include <asm/uaccess.h>

mm/mprotect.c

@@ -9,6 +9,7 @@
  */
 
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/slab.h>
 #include <linux/shm.h>
 #include <linux/mman.h>

mm/mremap.c

@@ -8,6 +8,7 @@
  */
 
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/slab.h>
 #include <linux/shm.h>
 #include <linux/mman.h>