aboutsummaryrefslogtreecommitdiffstats
path: root/arch/sh/mm/pg-sh4.c
blob: 2fe14da1f83909826d352249ba849488103fb4c2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/*
 * arch/sh/mm/pg-sh4.c
 *
 * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
 * Copyright (C) 2002 - 2007  Paul Mundt
 *
 * Released under the terms of the GNU GPL v2.0.
 */
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/fs.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>

#define CACHE_ALIAS (current_cpu_data.dcache.alias_mask)

#define kmap_get_fixmap_pte(vaddr)                                     \
	pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))

static pte_t *kmap_coherent_pte;

void __init kmap_coherent_init(void)
{
	unsigned long vaddr;

	/* cache the first coherent kmap pte */
	vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
	kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
}

static inline void *kmap_coherent(struct page *page, unsigned long addr)
{
	enum fixed_addresses idx;
	unsigned long vaddr, flags;
	pte_t pte;

	inc_preempt_count();

	idx = (addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT;
	vaddr = __fix_to_virt(FIX_CMAP_END - idx);
	pte = mk_pte(page, PAGE_KERNEL);

	local_irq_save(flags);
	flush_tlb_one(get_asid(), vaddr);
	local_irq_restore(flags);

	update_mmu_cache(NULL, vaddr, pte);

	set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);

	return (void *)vaddr;
}

static inline void kunmap_coherent(struct page *page)
{
	dec_preempt_count();
	preempt_check_resched();
}

/*
 * clear_user_page
 * @to: P1 address
 * @address: U0 address to be mapped
 * @page: page (virt_to_page(to))
 */
void clear_user_page(void *to, unsigned long address, struct page *page)
{
	__set_bit(PG_mapped, &page->flags);

	clear_page(to);
	if ((((address & PAGE_MASK) ^ (unsigned long)to) & CACHE_ALIAS))
		__flush_wback_region(to, PAGE_SIZE);
}

void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
		       unsigned long vaddr, void *dst, const void *src,
		       unsigned long len)
{
	void *vto;

	__set_bit(PG_mapped, &page->flags);

	vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
	memcpy(vto, src, len);
	kunmap_coherent(vto);

	if (vma->vm_flags & VM_EXEC)
		flush_cache_page(vma, vaddr, page_to_pfn(page));
}

void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
			 unsigned long vaddr, void *dst, const void *src,
			 unsigned long len)
{
	void *vfrom;

	__set_bit(PG_mapped, &page->flags);

	vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
	memcpy(dst, vfrom, len);
	kunmap_coherent(vfrom);
}

void copy_user_highpage(struct page *to, struct page *from,
			unsigned long vaddr, struct vm_area_struct *vma)
{
	void *vfrom, *vto;

	__set_bit(PG_mapped, &to->flags);

	vto = kmap_atomic(to, KM_USER1);
	vfrom = kmap_coherent(from, vaddr);
	copy_page(vto, vfrom);
	kunmap_coherent(vfrom);

	if (((vaddr ^ (unsigned long)vto) & CACHE_ALIAS))
		__flush_wback_region(vto, PAGE_SIZE);

	kunmap_atomic(vto, KM_USER1);
	/* Make sure this page is cleared on other CPU's too before using it */
	smp_wmb();
}
EXPORT_SYMBOL(copy_user_highpage);

/*
 * For SH-4, we have our own implementation for ptep_get_and_clear
 */
pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
	pte_t pte = *ptep;

	pte_clear(mm, addr, ptep);
	if (!pte_not_present(pte)) {
		unsigned long pfn = pte_pfn(pte);
		if (pfn_valid(pfn)) {
			struct page *page = pfn_to_page(pfn);
			struct address_space *mapping = page_mapping(page);
			if (!mapping || !mapping_writably_mapped(mapping))
				__clear_bit(PG_mapped, &page->flags);
		}
	}
	return pte;
}