diff options
Diffstat (limited to 'arch/arm/mm/copypage-v6.c')
| -rw-r--r-- | arch/arm/mm/copypage-v6.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c new file mode 100644 index 00000000..bdba6c65 --- /dev/null +++ b/arch/arm/mm/copypage-v6.c @@ -0,0 +1,149 @@ +/* + * linux/arch/arm/mm/copypage-v6.c + * + * Copyright (C) 2002 Deep Blue Solutions Ltd, All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/mm.h> +#include <linux/highmem.h> + +#include <asm/pgtable.h> +#include <asm/shmparam.h> +#include <asm/tlbflush.h> +#include <asm/cacheflush.h> +#include <asm/cachetype.h> + +#include "mm.h" + +#if SHMLBA > 16384 +#error FIX ME +#endif + +#define from_address (0xffff8000) +#define to_address (0xffffc000) + +static DEFINE_SPINLOCK(v6_lock); + +/* + * Copy the user page. No aliasing to deal with so we can just + * attack the kernel's existing mapping of these pages. + */ +static void v6_copy_user_highpage_nonaliasing(struct page *to, + struct page *from, unsigned long vaddr, struct vm_area_struct *vma) +{ + void *kto, *kfrom; + + kfrom = kmap_atomic(from, KM_USER0); + kto = kmap_atomic(to, KM_USER1); + copy_page(kto, kfrom); + __cpuc_flush_dcache_area(kto, PAGE_SIZE); + kunmap_atomic(kto, KM_USER1); + kunmap_atomic(kfrom, KM_USER0); +} + +/* + * Clear the user page. No aliasing to deal with so we can just + * attack the kernel's existing mapping of this page. + */ +static void v6_clear_user_highpage_nonaliasing(struct page *page, unsigned long vaddr) +{ + void *kaddr = kmap_atomic(page, KM_USER0); + clear_page(kaddr); + kunmap_atomic(kaddr, KM_USER0); +} + +/* + * Discard data in the kernel mapping for the new page. + * FIXME: needs this MCRR to be supported. + */ +static void discard_old_kernel_data(void *kto) +{ + __asm__("mcrr p15, 0, %1, %0, c6 @ 0xec401f06" + : + : "r" (kto), + "r" ((unsigned long)kto + PAGE_SIZE - L1_CACHE_BYTES) + : "cc"); +} + +/* + * Copy the page, taking account of the cache colour. + */ +static void v6_copy_user_highpage_aliasing(struct page *to, + struct page *from, unsigned long vaddr, struct vm_area_struct *vma) +{ + unsigned int offset = CACHE_COLOUR(vaddr); + unsigned long kfrom, kto; + + if (!test_and_set_bit(PG_dcache_clean, &from->flags)) + __flush_dcache_page(page_mapping(from), from); + + /* FIXME: not highmem safe */ + discard_old_kernel_data(page_address(to)); + + /* + * Now copy the page using the same cache colour as the + * pages ultimate destination. + */ + spin_lock(&v6_lock); + + set_pte_ext(TOP_PTE(from_address) + offset, pfn_pte(page_to_pfn(from), PAGE_KERNEL), 0); + set_pte_ext(TOP_PTE(to_address) + offset, pfn_pte(page_to_pfn(to), PAGE_KERNEL), 0); + + kfrom = from_address + (offset << PAGE_SHIFT); + kto = to_address + (offset << PAGE_SHIFT); + + flush_tlb_kernel_page(kfrom); + flush_tlb_kernel_page(kto); + + copy_page((void *)kto, (void *)kfrom); + + spin_unlock(&v6_lock); +} + +/* + * Clear the user page. We need to deal with the aliasing issues, + * so remap the kernel page into the same cache colour as the user + * page. + */ +static void v6_clear_user_highpage_aliasing(struct page *page, unsigned long vaddr) +{ + unsigned int offset = CACHE_COLOUR(vaddr); + unsigned long to = to_address + (offset << PAGE_SHIFT); + + /* FIXME: not highmem safe */ + discard_old_kernel_data(page_address(page)); + + /* + * Now clear the page using the same cache colour as + * the pages ultimate destination. + */ + spin_lock(&v6_lock); + + set_pte_ext(TOP_PTE(to_address) + offset, pfn_pte(page_to_pfn(page), PAGE_KERNEL), 0); + flush_tlb_kernel_page(to); + clear_page((void *)to); + + spin_unlock(&v6_lock); +} + +struct cpu_user_fns v6_user_fns __initdata = { + .cpu_clear_user_highpage = v6_clear_user_highpage_nonaliasing, + .cpu_copy_user_highpage = v6_copy_user_highpage_nonaliasing, +}; + +static int __init v6_userpage_init(void) +{ + if (cache_is_vipt_aliasing()) { + cpu_user.cpu_clear_user_highpage = v6_clear_user_highpage_aliasing; + cpu_user.cpu_copy_user_highpage = v6_copy_user_highpage_aliasing; + } + + return 0; +} + +core_initcall(v6_userpage_init); |