1#ifndef _LINUX_HIGHMEM_H
2#define _LINUX_HIGHMEM_H
3
4#include <linux/fs.h>
5#include <linux/mm.h>
6#include <linux/uaccess.h>
7
8#include <asm/cacheflush.h>
9
10#ifndef ARCH_HAS_FLUSH_ANON_PAGE
11static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
12{
13}
14#endif
15
16#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
17static inline void flush_kernel_dcache_page(struct page *page)
18{
19}
20#endif
21
22#ifdef CONFIG_HIGHMEM
23
24#include <asm/highmem.h>
25
26/* declarations for linux/mm/highmem.c */
27unsigned int nr_free_highpages(void);
28extern unsigned long totalhigh_pages;
29
30void kmap_flush_unused(void);
31
32#else /* CONFIG_HIGHMEM */
33
34static inline unsigned int nr_free_highpages(void) { return 0; }
35
36#define totalhigh_pages 0
37
38#ifndef ARCH_HAS_KMAP
39static inline void *kmap(struct page *page)
40{
41	might_sleep();
42	return page_address(page);
43}
44
45#define kunmap(page) do { (void) (page); } while (0)
46
47#include <asm/kmap_types.h>
48
49static inline void *kmap_atomic(struct page *page, enum km_type idx)
50{
51	pagefault_disable();
52	return page_address(page);
53}
54#define kmap_atomic_prot(page, idx, prot)	kmap_atomic(page, idx)
55
56#define kunmap_atomic(addr, idx)	do { pagefault_enable(); } while (0)
57#define kmap_atomic_pfn(pfn, idx)	kmap_atomic(pfn_to_page(pfn), (idx))
58#define kmap_atomic_to_page(ptr)	virt_to_page(ptr)
59#define kmap_atomic_pfn_prot(x, y, z)   ( \
60					 panic("Enable CONFIG_HIGHMEM to use kmap_atomic_pfn_prot!!!\n"), \
61					 NULL)
62
63#define kmap_flush_unused()	do {} while(0)
64#endif
65
66#endif /* CONFIG_HIGHMEM */
67
68/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
69static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
70{
71	void *addr = kmap_atomic(page, KM_USER0);
72	clear_user_page(addr, vaddr, page);
73	kunmap_atomic(addr, KM_USER0);
74	/* Make sure this page is cleared on other CPU's too before using it */
75	smp_wmb();
76}
77
78#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
79static inline struct page *
80alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr)
81{
82	struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr);
83
84	if (page)
85		clear_user_highpage(page, vaddr);
86
87	return page;
88}
89#endif
90
91static inline void clear_highpage(struct page *page)
92{
93	void *kaddr = kmap_atomic(page, KM_USER0);
94	clear_page(kaddr);
95	kunmap_atomic(kaddr, KM_USER0);
96}
97
98/*
99 * Same but also flushes aliased cache contents to RAM.
100 *
101 * This must be a macro because KM_USER0 and friends aren't defined if
102 * !CONFIG_HIGHMEM
103 */
104#define zero_user_page(page, offset, size, km_type)		\
105	do {							\
106		void *kaddr;					\
107								\
108		BUG_ON((offset) + (size) > PAGE_SIZE);		\
109								\
110		kaddr = kmap_atomic(page, km_type);		\
111		memset((char *)kaddr + (offset), 0, (size));	\
112		flush_dcache_page(page);			\
113		kunmap_atomic(kaddr, (km_type));		\
114	} while (0)
115
116static inline void __deprecated memclear_highpage_flush(struct page *page,
117			unsigned int offset, unsigned int size)
118{
119	zero_user_page(page, offset, size, KM_USER0);
120}
121
122#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
123
124static inline void copy_user_highpage(struct page *to, struct page *from,
125	unsigned long vaddr, struct vm_area_struct *vma)
126{
127	char *vfrom, *vto;
128
129	vfrom = kmap_atomic(from, KM_USER0);
130	vto = kmap_atomic(to, KM_USER1);
131	copy_user_page(vto, vfrom, vaddr, to);
132	kunmap_atomic(vfrom, KM_USER0);
133	kunmap_atomic(vto, KM_USER1);
134	/* Make sure this page is cleared on other CPU's too before using it */
135	smp_wmb();
136}
137
138#endif
139
140static inline void copy_highpage(struct page *to, struct page *from)
141{
142	char *vfrom, *vto;
143
144	vfrom = kmap_atomic(from, KM_USER0);
145	vto = kmap_atomic(to, KM_USER1);
146	copy_page(vto, vfrom);
147	kunmap_atomic(vfrom, KM_USER0);
148	kunmap_atomic(vto, KM_USER1);
149}
150
151#endif /* _LINUX_HIGHMEM_H */
152