1/* 2 * linux/arch/arm/mm/copypage-v6.c 3 * 4 * Copyright (C) 2002 Deep Blue Solutions Ltd, All Rights Reserved. 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#include <linux/init.h> 11#include <linux/spinlock.h> 12#include <linux/mm.h> 13#include <linux/highmem.h> 14 15#include <asm/pgtable.h> 16#include <asm/shmparam.h> 17#include <asm/tlbflush.h> 18#include <asm/cacheflush.h> 19#include <asm/cachetype.h> 20 21#include "mm.h" 22 23#if SHMLBA > 16384 24#error FIX ME 25#endif 26 27#define from_address (0xffff8000) 28#define to_address (0xffffc000) 29 30static DEFINE_SPINLOCK(v6_lock); 31 32/* 33 * Copy the user page. No aliasing to deal with so we can just 34 * attack the kernel's existing mapping of these pages. 35 */ 36static void v6_copy_user_highpage_nonaliasing(struct page *to, 37 struct page *from, unsigned long vaddr, struct vm_area_struct *vma) 38{ 39 void *kto, *kfrom; 40 41 kfrom = kmap_atomic(from, KM_USER0); 42 kto = kmap_atomic(to, KM_USER1); 43 copy_page(kto, kfrom); 44 __cpuc_flush_dcache_area(kto, PAGE_SIZE); 45 kunmap_atomic(kto, KM_USER1); 46 kunmap_atomic(kfrom, KM_USER0); 47} 48 49/* 50 * Clear the user page. No aliasing to deal with so we can just 51 * attack the kernel's existing mapping of this page. 52 */ 53static void v6_clear_user_highpage_nonaliasing(struct page *page, unsigned long vaddr) 54{ 55 void *kaddr = kmap_atomic(page, KM_USER0); 56 clear_page(kaddr); 57 kunmap_atomic(kaddr, KM_USER0); 58} 59 60static void discard_old_kernel_data(void *kto) 61{ 62 __asm__("mcrr p15, 0, %1, %0, c6 @ 0xec401f06" 63 : 64 : "r" (kto), 65 "r" ((unsigned long)kto + PAGE_SIZE - L1_CACHE_BYTES) 66 : "cc"); 67} 68 69/* 70 * Copy the page, taking account of the cache colour. 71 */ 72static void v6_copy_user_highpage_aliasing(struct page *to, 73 struct page *from, unsigned long vaddr, struct vm_area_struct *vma) 74{ 75 unsigned int offset = CACHE_COLOUR(vaddr); 76 unsigned long kfrom, kto; 77 78#ifdef CONFIG_BCM47XX 79 /* Merged from Linux-2.6.37 */ 80 if (!test_and_set_bit(PG_dcache_clean, &from->flags)) 81#else 82 if (test_and_clear_bit(PG_dcache_dirty, &from->flags)) 83#endif /* CONFIG_BCM47XX */ 84 __flush_dcache_page(page_mapping(from), from); 85 86 discard_old_kernel_data(page_address(to)); 87 88 /* 89 * Now copy the page using the same cache colour as the 90 * pages ultimate destination. 91 */ 92 spin_lock(&v6_lock); 93 94 set_pte_ext(TOP_PTE(from_address) + offset, pfn_pte(page_to_pfn(from), PAGE_KERNEL), 0); 95 set_pte_ext(TOP_PTE(to_address) + offset, pfn_pte(page_to_pfn(to), PAGE_KERNEL), 0); 96 97 kfrom = from_address + (offset << PAGE_SHIFT); 98 kto = to_address + (offset << PAGE_SHIFT); 99 100 flush_tlb_kernel_page(kfrom); 101 flush_tlb_kernel_page(kto); 102 103 copy_page((void *)kto, (void *)kfrom); 104 105 spin_unlock(&v6_lock); 106} 107 108/* 109 * Clear the user page. We need to deal with the aliasing issues, 110 * so remap the kernel page into the same cache colour as the user 111 * page. 112 */ 113static void v6_clear_user_highpage_aliasing(struct page *page, unsigned long vaddr) 114{ 115 unsigned int offset = CACHE_COLOUR(vaddr); 116 unsigned long to = to_address + (offset << PAGE_SHIFT); 117 118 discard_old_kernel_data(page_address(page)); 119 120 /* 121 * Now clear the page using the same cache colour as 122 * the pages ultimate destination. 123 */ 124 spin_lock(&v6_lock); 125 126 set_pte_ext(TOP_PTE(to_address) + offset, pfn_pte(page_to_pfn(page), PAGE_KERNEL), 0); 127 flush_tlb_kernel_page(to); 128 clear_page((void *)to); 129 130 spin_unlock(&v6_lock); 131} 132 133struct cpu_user_fns v6_user_fns __initdata = { 134 .cpu_clear_user_highpage = v6_clear_user_highpage_nonaliasing, 135 .cpu_copy_user_highpage = v6_copy_user_highpage_nonaliasing, 136}; 137 138static int __init v6_userpage_init(void) 139{ 140 if (cache_is_vipt_aliasing()) { 141 cpu_user.cpu_clear_user_highpage = v6_clear_user_highpage_aliasing; 142 cpu_user.cpu_copy_user_highpage = v6_copy_user_highpage_aliasing; 143 } 144 145 return 0; 146} 147 148core_initcall(v6_userpage_init); 149