arch/arm/mm/copypage-fa.c

   1 /*
   2  *  linux/arch/arm/lib/copypage-fa.S
   3  *
   4  *  Copyright (C) 2005 Faraday Corp.
   5  *  Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
   6  *
   7  * Based on copypage-v4wb.S:
   8  *  Copyright (C) 1995-1999 Russell King
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14 #include <linux/init.h>
  15 #include <linux/highmem.h>
  16
  17 /*
  18  * Faraday optimised copy_user_page
  19  */
  20 static void __naked
  21 fa_copy_user_page(void *kto, const void *kfrom)
  22 {
  23         asm("\
  24         stmfd   sp!, {r4, lr}                   @ 2\n\
  25         mov     r2, %0                          @ 1\n\
  26 1:      ldmia   r1!, {r3, r4, ip, lr}           @ 4\n\
  27         stmia   r0, {r3, r4, ip, lr}            @ 4\n\
  28         mcr     p15, 0, r0, c7, c14, 1          @ 1   clean and invalidate D line\n\
  29         add     r0, r0, #16                     @ 1\n\
  30         ldmia   r1!, {r3, r4, ip, lr}           @ 4\n\
  31         stmia   r0, {r3, r4, ip, lr}            @ 4\n\
  32         mcr     p15, 0, r0, c7, c14, 1          @ 1   clean and invalidate D line\n\
  33         add     r0, r0, #16                     @ 1\n\
  34         subs    r2, r2, #1                      @ 1\n\
  35         bne     1b                              @ 1\n\
  36         mcr     p15, 0, r2, c7, c10, 4          @ 1   drain WB\n\
  37         ldmfd   sp!, {r4, pc}                   @ 3"
  38         :
  39         : "I" (PAGE_SIZE / 32));
  40 }
  41
  42 void fa_copy_user_highpage(struct page *to, struct page *from,
  43         unsigned long vaddr)
  44 {
  45         void *kto, *kfrom;
  46
  47         kto = kmap_atomic(to, KM_USER0);
  48         kfrom = kmap_atomic(from, KM_USER1);
  49         fa_copy_user_page(kto, kfrom);
  50         kunmap_atomic(kfrom, KM_USER1);
  51         kunmap_atomic(kto, KM_USER0);
  52 }
  53
  54 /*
  55  * Faraday optimised clear_user_page
  56  *
  57  * Same story as above.
  58  */
  59 void fa_clear_user_highpage(struct page *page, unsigned long vaddr)
  60 {
  61         void *ptr, *kaddr = kmap_atomic(page, KM_USER0);
  62         asm volatile("\
  63         mov     r1, %2                          @ 1\n\
  64         mov     r2, #0                          @ 1\n\
  65         mov     r3, #0                          @ 1\n\
  66         mov     ip, #0                          @ 1\n\
  67         mov     lr, #0                          @ 1\n\
  68 1:      stmia   %0, {r2, r3, ip, lr}            @ 4\n\
  69         mcr     p15, 0, %0, c7, c14, 1          @ 1   clean and invalidate D line\n\
  70         add     %0, %0, #16                     @ 1\n\
  71         stmia   %0, {r2, r3, ip, lr}            @ 4\n\
  72         mcr     p15, 0, %0, c7, c14, 1          @ 1   clean and invalidate D line\n\
  73         add     %0, %0, #16                     @ 1\n\
  74         subs    r1, r1, #1                      @ 1\n\
  75         bne     1b                              @ 1\n\
  76         mcr     p15, 0, r1, c7, c10, 4          @ 1   drain WB"
  77         : "=r" (ptr)
  78         : "0" (kaddr), "I" (PAGE_SIZE / 32)
  79         : "r1", "r2", "r3", "ip", "lr");
  80         kunmap_atomic(kaddr, KM_USER0);
  81 }
  82
  83 struct cpu_user_fns fa_user_fns __initdata = {
  84         .cpu_clear_user_highpage = fa_clear_user_highpage,
  85         .cpu_copy_user_highpage = fa_copy_user_highpage,
  86 };