summaryrefslogtreecommitdiffstats
path: root/arch/parisc/mm/kmap.c
blob: 4bd5dd4b439a7a93086f726461784fa87aae7999 (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
/*
** Stolen mostly from arch/parisc/kernel/pci-dma.c
*/

#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/pci.h>

#include <linux/slab.h>
#include <linux/vmalloc.h>

#include <asm/uaccess.h>
#include <asm/pgalloc.h>

#include <asm/io.h>
#include <asm/page.h>		/* get_order */

#undef flush_cache_all
#define flush_cache_all flush_all_caches

typedef void (*pte_iterator_t) (pte_t * pte, unsigned long arg);

#if 0
/* XXX This routine could be used with iterate_page() to replace
 * unmap_uncached_page() and save a little code space but I didn't
 * do that since I'm not certain whether this is the right path. -PB
 */
static void unmap_cached_pte(pte_t * pte, unsigned long arg)
{
	pte_t page = *pte;
	pte_clear(pte);
	if (!pte_none(page)) {
		if (pte_present(page)) {
			unsigned long map_nr = pte_pagenr(page);
			if (map_nr < max_mapnr)
				__free_page(mem_map + map_nr);
		} else {
			printk(KERN_CRIT
			       "Whee.. Swapped out page in kernel page table\n");
		}
	}
}
#endif

/* These two routines should probably check a few things... */
static void set_uncached(pte_t * pte, unsigned long arg)
{
	pte_val(*pte) |= _PAGE_NO_CACHE;
}

static void set_cached(pte_t * pte, unsigned long arg)
{
	pte_val(*pte) &= ~_PAGE_NO_CACHE;
}

static inline void iterate_pte(pmd_t * pmd, unsigned long address,
			       unsigned long size, pte_iterator_t op,
			       unsigned long arg)
{
	pte_t *pte;
	unsigned long end;

	if (pmd_none(*pmd))
		return;
	if (pmd_bad(*pmd)) {
		pmd_ERROR(*pmd);
		pmd_clear(pmd);
		return;
	}
	pte = pte_offset(pmd, address);
	address &= ~PMD_MASK;
	end = address + size;
	if (end > PMD_SIZE)
		end = PMD_SIZE;
	do {
		op(pte, arg);
		address += PAGE_SIZE;
		pte++;
	} while (address < end);
}

static inline void iterate_pmd(pgd_t * dir, unsigned long address,
			       unsigned long size, pte_iterator_t op,
			       unsigned long arg)
{
	pmd_t *pmd;
	unsigned long end;

	if (pgd_none(*dir))
		return;
	if (pgd_bad(*dir)) {
		pgd_ERROR(*dir);
		pgd_clear(dir);
		return;
	}
	pmd = pmd_offset(dir, address);
	address &= ~PGDIR_MASK;
	end = address + size;
	if (end > PGDIR_SIZE)
		end = PGDIR_SIZE;
	do {
		iterate_pte(pmd, address, end - address, op, arg);
		address = (address + PMD_SIZE) & PMD_MASK;
		pmd++;
	} while (address < end);
}

static void iterate_pages(unsigned long address, unsigned long size,
			  pte_iterator_t op, unsigned long arg)
{
	pgd_t *dir;
	unsigned long end = address + size;

	dir = pgd_offset_k(address);
	flush_cache_all();
	do {
		iterate_pmd(dir, address, end - address, op, arg);
		address = (address + PGDIR_SIZE) & PGDIR_MASK;
		dir++;
	} while (address && (address < end));
	flush_tlb_all();
}

void
kernel_set_cachemode(unsigned long vaddr, unsigned long size, int what)
{
	switch (what) {
	case IOMAP_FULL_CACHING:
		iterate_pages(vaddr, size, set_cached, 0);
		flush_tlb_range(&init_mm, vaddr, size);
		break;
	case IOMAP_NOCACHE_SER:
		iterate_pages(vaddr, size, set_uncached, 0);
		flush_tlb_range(&init_mm, vaddr, size);
		break;
	default:
		printk(KERN_CRIT
		       "kernel_set_cachemode mode %d not understood\n",
		       what);
		break;
	}
}