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-rw-r--r--arch/arm/mm/minicache.c73
1 files changed, 0 insertions, 73 deletions
diff --git a/arch/arm/mm/minicache.c b/arch/arm/mm/minicache.c
index dedf2ab01b2a..e69de29bb2d1 100644
--- a/arch/arm/mm/minicache.c
+++ b/arch/arm/mm/minicache.c
@@ -1,73 +0,0 @@
1/*
2 * linux/arch/arm/mm/minicache.c
3 *
4 * Copyright (C) 2001 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This handles the mini data cache, as found on SA11x0 and XScale
11 * processors. When we copy a user page page, we map it in such a way
12 * that accesses to this page will not touch the main data cache, but
13 * will be cached in the mini data cache. This prevents us thrashing
14 * the main data cache on page faults.
15 */
16#include <linux/init.h>
17#include <linux/mm.h>
18
19#include <asm/page.h>
20#include <asm/pgtable.h>
21#include <asm/tlbflush.h>
22
23/*
24 * 0xffff8000 to 0xffffffff is reserved for any ARM architecture
25 * specific hacks for copying pages efficiently.
26 */
27#define minicache_address (0xffff8000)
28#define minicache_pgprot __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | \
29 L_PTE_CACHEABLE)
30
31static pte_t *minicache_pte;
32
33/*
34 * Note that this is intended to be called only from the copy_user_page
35 * asm code; anything else will require special locking to prevent the
36 * mini-cache space being re-used. (Note: probably preempt unsafe).
37 *
38 * We rely on the fact that the minicache is 2K, and we'll be pushing
39 * 4K of data through it, so we don't actually have to specifically
40 * flush the minicache when we change the mapping.
41 *
42 * Note also: assert(PAGE_OFFSET <= virt < high_memory).
43 * Unsafe: preempt, kmap.
44 */
45unsigned long map_page_minicache(unsigned long virt)
46{
47 set_pte(minicache_pte, pfn_pte(__pa(virt) >> PAGE_SHIFT, minicache_pgprot));
48 flush_tlb_kernel_page(minicache_address);
49
50 return minicache_address;
51}
52
53static int __init minicache_init(void)
54{
55 pgd_t *pgd;
56 pmd_t *pmd;
57
58 spin_lock(&init_mm.page_table_lock);
59
60 pgd = pgd_offset_k(minicache_address);
61 pmd = pmd_alloc(&init_mm, pgd, minicache_address);
62 if (!pmd)
63 BUG();
64 minicache_pte = pte_alloc_kernel(&init_mm, pmd, minicache_address);
65 if (!minicache_pte)
66 BUG();
67
68 spin_unlock(&init_mm.page_table_lock);
69
70 return 0;
71}
72
73core_initcall(minicache_init);