cache.c revision 57cf4f78c6266d5a6e5de5485065d4015b84bb30 
1/* MN10300 Cache flushing routines
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11#include <linux/module.h>
12#include <linux/mm.h>
13#include <linux/mman.h>
14#include <linux/threads.h>
15#include <asm/page.h>
16#include <asm/pgtable.h>
17#include <asm/processor.h>
18#include <asm/cacheflush.h>
19#include <asm/io.h>
20#include <asm/uaccess.h>
21
22EXPORT_SYMBOL(mn10300_icache_inv);
23EXPORT_SYMBOL(mn10300_dcache_inv);
24EXPORT_SYMBOL(mn10300_dcache_inv_range);
25EXPORT_SYMBOL(mn10300_dcache_inv_range2);
26EXPORT_SYMBOL(mn10300_dcache_inv_page);
27
28#ifdef CONFIG_MN10300_CACHE_WBACK
29EXPORT_SYMBOL(mn10300_dcache_flush);
30EXPORT_SYMBOL(mn10300_dcache_flush_inv);
31EXPORT_SYMBOL(mn10300_dcache_flush_inv_range);
32EXPORT_SYMBOL(mn10300_dcache_flush_inv_range2);
33EXPORT_SYMBOL(mn10300_dcache_flush_inv_page);
34EXPORT_SYMBOL(mn10300_dcache_flush_range);
35EXPORT_SYMBOL(mn10300_dcache_flush_range2);
36EXPORT_SYMBOL(mn10300_dcache_flush_page);
37#endif
38
39/*
40 * write a page back from the dcache and invalidate the icache so that we can
41 * run code from it that we've just written into it
42 */
43void flush_icache_page(struct vm_area_struct *vma, struct page *page)
44{
45	mn10300_dcache_flush_page(page_to_phys(page));
46	mn10300_icache_inv();
47}
48EXPORT_SYMBOL(flush_icache_page);
49
50/*
51 * write some code we've just written back from the dcache and invalidate the
52 * icache so that we can run that code
53 */
54void flush_icache_range(unsigned long start, unsigned long end)
55{
56#ifdef CONFIG_MN10300_CACHE_WBACK
57	unsigned long addr, size, base, off;
58	struct page *page;
59	pgd_t *pgd;
60	pud_t *pud;
61	pmd_t *pmd;
62	pte_t *ppte, pte;
63
64	if (end > 0x80000000UL) {
65		/* addresses above 0xa0000000 do not go through the cache */
66		if (end > 0xa0000000UL) {
67			end = 0xa0000000UL;
68			if (start >= end)
69				return;
70		}
71
72		/* kernel addresses between 0x80000000 and 0x9fffffff do not
73		 * require page tables, so we just map such addresses directly */
74		base = (start >= 0x80000000UL) ? start : 0x80000000UL;
75		mn10300_dcache_flush_range(base, end);
76		if (base == start)
77			goto invalidate;
78		end = base;
79	}
80
81	for (; start < end; start += size) {
82		/* work out how much of the page to flush */
83		off = start & (PAGE_SIZE - 1);
84
85		size = end - start;
86		if (size > PAGE_SIZE - off)
87			size = PAGE_SIZE - off;
88
89		/* get the physical address the page is mapped to from the page
90		 * tables */
91		pgd = pgd_offset(current->mm, start);
92		if (!pgd || !pgd_val(*pgd))
93			continue;
94
95		pud = pud_offset(pgd, start);
96		if (!pud || !pud_val(*pud))
97			continue;
98
99		pmd = pmd_offset(pud, start);
100		if (!pmd || !pmd_val(*pmd))
101			continue;
102
103		ppte = pte_offset_map(pmd, start);
104		if (!ppte)
105			continue;
106		pte = *ppte;
107		pte_unmap(ppte);
108
109		if (pte_none(pte))
110			continue;
111
112		page = pte_page(pte);
113		if (!page)
114			continue;
115
116		addr = page_to_phys(page);
117
118		/* flush the dcache and invalidate the icache coverage on that
119		 * region */
120		mn10300_dcache_flush_range2(addr + off, size);
121	}
122#endif
123
124invalidate:
125	mn10300_icache_inv();
126}
127EXPORT_SYMBOL(flush_icache_range);
128
129/*
130 * allow userspace to flush the instruction cache
131 */
132asmlinkage long sys_cacheflush(unsigned long start, unsigned long end)
133{
134	if (end < start)
135		return -EINVAL;
136
137	flush_icache_range(start, end);
138	return 0;
139}
140