linux/arch/arm/mm/copypage-xsc3.c
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   1/*
   2 *  linux/arch/arm/mm/copypage-xsc3.S
   3 *
   4 *  Copyright (C) 2004 Intel Corp.
   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 * Adapted for 3rd gen XScale core, no more mini-dcache
  11 * Author: Matt Gilbert (matthew.m.gilbert@intel.com)
  12 */
  13#include <linux/init.h>
  14#include <linux/highmem.h>
  15
  16/*
  17 * General note:
  18 *  We don't really want write-allocate cache behaviour for these functions
  19 *  since that will just eat through 8K of the cache.
  20 */
  21
  22/*
  23 * XSC3 optimised copy_user_highpage
  24 *  r0 = destination
  25 *  r1 = source
  26 *
  27 * The source page may have some clean entries in the cache already, but we
  28 * can safely ignore them - break_cow() will flush them out of the cache
  29 * if we eventually end up using our copied page.
  30 *
  31 */
  32static void __naked
  33xsc3_mc_copy_user_page(void *kto, const void *kfrom)
  34{
  35        asm("\
  36        stmfd   sp!, {r4, r5, lr}               \n\
  37        mov     lr, %2                          \n\
  38                                                \n\
  39        pld     [r1, #0]                        \n\
  40        pld     [r1, #32]                       \n\
  411:      pld     [r1, #64]                       \n\
  42        pld     [r1, #96]                       \n\
  43                                                \n\
  442:      ldrd    r2, [r1], #8                    \n\
  45        mov     ip, r0                          \n\
  46        ldrd    r4, [r1], #8                    \n\
  47        mcr     p15, 0, ip, c7, c6, 1           @ invalidate\n\
  48        strd    r2, [r0], #8                    \n\
  49        ldrd    r2, [r1], #8                    \n\
  50        strd    r4, [r0], #8                    \n\
  51        ldrd    r4, [r1], #8                    \n\
  52        strd    r2, [r0], #8                    \n\
  53        strd    r4, [r0], #8                    \n\
  54        ldrd    r2, [r1], #8                    \n\
  55        mov     ip, r0                          \n\
  56        ldrd    r4, [r1], #8                    \n\
  57        mcr     p15, 0, ip, c7, c6, 1           @ invalidate\n\
  58        strd    r2, [r0], #8                    \n\
  59        ldrd    r2, [r1], #8                    \n\
  60        subs    lr, lr, #1                      \n\
  61        strd    r4, [r0], #8                    \n\
  62        ldrd    r4, [r1], #8                    \n\
  63        strd    r2, [r0], #8                    \n\
  64        strd    r4, [r0], #8                    \n\
  65        bgt     1b                              \n\
  66        beq     2b                              \n\
  67                                                \n\
  68        ldmfd   sp!, {r4, r5, pc}"
  69        :
  70        : "r" (kto), "r" (kfrom), "I" (PAGE_SIZE / 64 - 1));
  71}
  72
  73void xsc3_mc_copy_user_highpage(struct page *to, struct page *from,
  74        unsigned long vaddr, struct vm_area_struct *vma)
  75{
  76        void *kto, *kfrom;
  77
  78        kto = kmap_atomic(to, KM_USER0);
  79        kfrom = kmap_atomic(from, KM_USER1);
  80        flush_cache_page(vma, vaddr, page_to_pfn(from));
  81        xsc3_mc_copy_user_page(kto, kfrom);
  82        kunmap_atomic(kfrom, KM_USER1);
  83        kunmap_atomic(kto, KM_USER0);
  84}
  85
  86/*
  87 * XScale optimised clear_user_page
  88 *  r0 = destination
  89 *  r1 = virtual user address of ultimate destination page
  90 */
  91void xsc3_mc_clear_user_highpage(struct page *page, unsigned long vaddr)
  92{
  93        void *ptr, *kaddr = kmap_atomic(page, KM_USER0);
  94        asm volatile ("\
  95        mov     r1, %2                          \n\
  96        mov     r2, #0                          \n\
  97        mov     r3, #0                          \n\
  981:      mcr     p15, 0, %0, c7, c6, 1           @ invalidate line\n\
  99        strd    r2, [%0], #8                    \n\
 100        strd    r2, [%0], #8                    \n\
 101        strd    r2, [%0], #8                    \n\
 102        strd    r2, [%0], #8                    \n\
 103        subs    r1, r1, #1                      \n\
 104        bne     1b"
 105        : "=r" (ptr)
 106        : "0" (kaddr), "I" (PAGE_SIZE / 32)
 107        : "r1", "r2", "r3");
 108        kunmap_atomic(kaddr, KM_USER0);
 109}
 110
 111struct cpu_user_fns xsc3_mc_user_fns __initdata = {
 112        .cpu_clear_user_highpage = xsc3_mc_clear_user_highpage,
 113        .cpu_copy_user_highpage = xsc3_mc_copy_user_highpage,
 114};
 115
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