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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm/mm/copypage-v6.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/mm/copypage-v6.c')
-rw-r--r-- | arch/arm/mm/copypage-v6.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c new file mode 100644 index 000000000..d8a115de5 --- /dev/null +++ b/arch/arm/mm/copypage-v6.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/arch/arm/mm/copypage-v6.c + * + * Copyright (C) 2002 Deep Blue Solutions Ltd, All Rights Reserved. + */ +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/mm.h> +#include <linux/highmem.h> +#include <linux/pagemap.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 + +static DEFINE_RAW_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); + kto = kmap_atomic(to); + copy_page(kto, kfrom); + kunmap_atomic(kto); + kunmap_atomic(kfrom); +} + +/* + * 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); + clear_page(kaddr); + kunmap_atomic(kaddr); +} + +/* + * 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 - 1) + : "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_file(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. + */ + raw_spin_lock(&v6_lock); + + kfrom = COPYPAGE_V6_FROM + (offset << PAGE_SHIFT); + kto = COPYPAGE_V6_TO + (offset << PAGE_SHIFT); + + set_top_pte(kfrom, mk_pte(from, PAGE_KERNEL)); + set_top_pte(kto, mk_pte(to, PAGE_KERNEL)); + + copy_page((void *)kto, (void *)kfrom); + + raw_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 long to = COPYPAGE_V6_TO + (CACHE_COLOUR(vaddr) << 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. + */ + raw_spin_lock(&v6_lock); + + set_top_pte(to, mk_pte(page, PAGE_KERNEL)); + clear_page((void *)to); + + raw_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); |