aboutsummaryrefslogtreecommitdiff
path: root/arch/mn10300/mm/cache-flush-icache.c
blob: fdb1a9db20f0b168d7b019aa0674e6635269f99b (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
147
148
149
150
151
152
153
154
155
/* Flush dcache and invalidate icache when the dcache is in writeback mode
 *
 * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */
#include <linux/module.h>
#include <linux/mm.h>
#include <asm/cacheflush.h>
#include <asm/smp.h>
#include "cache-smp.h"

/**
 * flush_icache_page - Flush a page from the dcache and invalidate the icache
 * @vma: The VMA the page is part of.
 * @page: The page to be flushed.
 *
 * Write a page back from the dcache and invalidate the icache so that we can
 * run code from it that we've just written into it
 */
void flush_icache_page(struct vm_area_struct *vma, struct page *page)
{
	unsigned long start = page_to_phys(page);
	unsigned long flags;

	flags = smp_lock_cache();

	mn10300_local_dcache_flush_page(start);
	mn10300_local_icache_inv_page(start);

	smp_cache_call(SMP_IDCACHE_INV_FLUSH_RANGE, start, start + PAGE_SIZE);
	smp_unlock_cache(flags);
}
EXPORT_SYMBOL(flush_icache_page);

/**
 * flush_icache_page_range - Flush dcache and invalidate icache for part of a
 *				single page
 * @start: The starting virtual address of the page part.
 * @end: The ending virtual address of the page part.
 *
 * Flush the dcache and invalidate the icache for part of a single page, as
 * determined by the virtual addresses given.  The page must be in the paged
 * area.
 */
static void flush_icache_page_range(unsigned long start, unsigned long end)
{
	unsigned long addr, size, off;
	struct page *page;
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *ppte, pte;

	/* work out how much of the page to flush */
	off = start & ~PAGE_MASK;
	size = end - start;

	/* get the physical address the page is mapped to from the page
	 * tables */
	pgd = pgd_offset(current->mm, start);
	if (!pgd || !pgd_val(*pgd))
		return;

	pud = pud_offset(pgd, start);
	if (!pud || !pud_val(*pud))
		return;

	pmd = pmd_offset(pud, start);
	if (!pmd || !pmd_val(*pmd))
		return;

	ppte = pte_offset_map(pmd, start);
	if (!ppte)
		return;
	pte = *ppte;
	pte_unmap(ppte);

	if (pte_none(pte))
		return;

	page = pte_page(pte);
	if (!page)
		return;

	addr = page_to_phys(page);

	/* flush the dcache and invalidate the icache coverage on that
	 * region */
	mn10300_local_dcache_flush_range2(addr + off, size);
	mn10300_local_icache_inv_range2(addr + off, size);
	smp_cache_call(SMP_IDCACHE_INV_FLUSH_RANGE, start, end);
}

/**
 * flush_icache_range - Globally flush dcache and invalidate icache for region
 * @start: The starting virtual address of the region.
 * @end: The ending virtual address of the region.
 *
 * This is used by the kernel to globally flush some code it has just written
 * from the dcache back to RAM and then to globally invalidate the icache over
 * that region so that that code can be run on all CPUs in the system.
 */
void flush_icache_range(unsigned long start, unsigned long end)
{
	unsigned long start_page, end_page;
	unsigned long flags;

	flags = smp_lock_cache();

	if (end > 0x80000000UL) {
		/* addresses above 0xa0000000 do not go through the cache */
		if (end > 0xa0000000UL) {
			end = 0xa0000000UL;
			if (start >= end)
				goto done;
		}

		/* kernel addresses between 0x80000000 and 0x9fffffff do not
		 * require page tables, so we just map such addresses
		 * directly */
		start_page = (start >= 0x80000000UL) ? start : 0x80000000UL;
		mn10300_local_dcache_flush_range(start_page, end);
		mn10300_local_icache_inv_range(start_page, end);
		smp_cache_call(SMP_IDCACHE_INV_FLUSH_RANGE, start_page, end);
		if (start_page == start)
			goto done;
		end = start_page;
	}

	start_page = start & PAGE_MASK;
	end_page = (end - 1) & PAGE_MASK;

	if (start_page == end_page) {
		/* the first and last bytes are on the same page */
		flush_icache_page_range(start, end);
	} else if (start_page + 1 == end_page) {
		/* split over two virtually contiguous pages */
		flush_icache_page_range(start, end_page);
		flush_icache_page_range(end_page, end);
	} else {
		/* more than 2 pages; just flush the entire cache */
		mn10300_dcache_flush();
		mn10300_icache_inv();
		smp_cache_call(SMP_IDCACHE_INV_FLUSH, 0, 0);
	}

done:
	smp_unlock_cache(flags);
}
EXPORT_SYMBOL(flush_icache_range);