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063b0a4207
We used to override the copy_user_page() function. However, this is not only inefficient, it also causes additional complexity for highmem support, since we convert from a struct page to a kernel direct mapped address and back to a struct page again. Moreover, with highmem support, we end up pointlessly setting up kmap entries for pages which we're going to remap. So, push the kmapping down into the copypage implementation files where it's required. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
80 lines
2 KiB
C
80 lines
2 KiB
C
/*
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* linux/arch/arm/mm/copypage-v3.c
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*
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* Copyright (C) 1995-1999 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/init.h>
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#include <linux/highmem.h>
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/*
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* ARMv3 optimised copy_user_highpage
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*
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* FIXME: do we need to handle cache stuff...
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*/
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static void __attribute__((naked))
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v3_copy_user_page(void *kto, const void *kfrom)
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{
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asm("\n\
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stmfd sp!, {r4, lr} @ 2\n\
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mov r2, %2 @ 1\n\
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ldmia %0!, {r3, r4, ip, lr} @ 4+1\n\
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1: stmia %1!, {r3, r4, ip, lr} @ 4\n\
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ldmia %0!, {r3, r4, ip, lr} @ 4+1\n\
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stmia %1!, {r3, r4, ip, lr} @ 4\n\
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ldmia %0!, {r3, r4, ip, lr} @ 4+1\n\
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stmia %1!, {r3, r4, ip, lr} @ 4\n\
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ldmia %0!, {r3, r4, ip, lr} @ 4\n\
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subs r2, r2, #1 @ 1\n\
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stmia %1!, {r3, r4, ip, lr} @ 4\n\
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ldmneia %0!, {r3, r4, ip, lr} @ 4\n\
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bne 1b @ 1\n\
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ldmfd sp!, {r4, pc} @ 3"
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:
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: "r" (kfrom), "r" (kto), "I" (PAGE_SIZE / 64));
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}
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void v3_copy_user_highpage(struct page *to, struct page *from,
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unsigned long vaddr)
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{
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void *kto, *kfrom;
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kto = kmap_atomic(to, KM_USER0);
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kfrom = kmap_atomic(from, KM_USER1);
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v3_copy_user_page(kto, kfrom);
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kunmap_atomic(kfrom, KM_USER1);
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kunmap_atomic(kto, KM_USER0);
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}
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/*
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* ARMv3 optimised clear_user_page
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*
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* FIXME: do we need to handle cache stuff...
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*/
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void __attribute__((naked)) v3_clear_user_page(void *kaddr, unsigned long vaddr)
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{
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asm("\n\
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str lr, [sp, #-4]!\n\
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mov r1, %1 @ 1\n\
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mov r2, #0 @ 1\n\
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mov r3, #0 @ 1\n\
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mov ip, #0 @ 1\n\
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mov lr, #0 @ 1\n\
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1: stmia %0!, {r2, r3, ip, lr} @ 4\n\
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stmia %0!, {r2, r3, ip, lr} @ 4\n\
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stmia %0!, {r2, r3, ip, lr} @ 4\n\
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stmia %0!, {r2, r3, ip, lr} @ 4\n\
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subs r1, r1, #1 @ 1\n\
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bne 1b @ 1\n\
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ldr pc, [sp], #4"
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:
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: "r" (kaddr), "I" (PAGE_SIZE / 64));
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}
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struct cpu_user_fns v3_user_fns __initdata = {
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.cpu_clear_user_page = v3_clear_user_page,
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.cpu_copy_user_highpage = v3_copy_user_highpage,
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};
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