arch/arm/mm/copypage-v3.c

   1 /*
   2  *  linux/arch/arm/mm/copypage-v3.c
   3  *
   4  *  Copyright (C) 1995-1999 Russell King
   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 #include <linux/init.h>
  11 #include <linux/highmem.h>
  12
  13 /*
  14  * ARMv3 optimised copy_user_highpage
  15  *
  16  * FIXME: do we need to handle cache stuff...
  17  */
  18 static void __naked
  19 v3_copy_user_page(void *kto, const void *kfrom)
  20 {
  21         asm("\n\
  22         stmfd   sp!, {r4, lr}                   @       2\n\
  23         mov     r2, %2                          @       1\n\
  24         ldmia   %0!, {r3, r4, ip, lr}           @       4+1\n\
  25 1:      stmia   %1!, {r3, r4, ip, lr}           @       4\n\
  26         ldmia   %0!, {r3, r4, ip, lr}           @       4+1\n\
  27         stmia   %1!, {r3, r4, ip, lr}           @       4\n\
  28         ldmia   %0!, {r3, r4, ip, lr}           @       4+1\n\
  29         stmia   %1!, {r3, r4, ip, lr}           @       4\n\
  30         ldmia   %0!, {r3, r4, ip, lr}           @       4\n\
  31         subs    r2, r2, #1                      @       1\n\
  32         stmia   %1!, {r3, r4, ip, lr}           @       4\n\
  33         ldmneia %0!, {r3, r4, ip, lr}           @       4\n\
  34         bne     1b                              @       1\n\
  35         ldmfd   sp!, {r4, pc}                   @       3"
  36         :
  37         : "r" (kfrom), "r" (kto), "I" (PAGE_SIZE / 64));
  38 }
  39
  40 void v3_copy_user_highpage(struct page *to, struct page *from,
  41         unsigned long vaddr)
  42 {
  43         void *kto, *kfrom;
  44
  45         kto = kmap_atomic(to, KM_USER0);
  46         kfrom = kmap_atomic(from, KM_USER1);
  47         v3_copy_user_page(kto, kfrom);
  48         kunmap_atomic(kfrom, KM_USER1);
  49         kunmap_atomic(kto, KM_USER0);
  50 }
  51
  52 /*
  53  * ARMv3 optimised clear_user_page
  54  *
  55  * FIXME: do we need to handle cache stuff...
  56  */
  57 void v3_clear_user_highpage(struct page *page, unsigned long vaddr)
  58 {
  59         void *ptr, *kaddr = kmap_atomic(page, KM_USER0);
  60         asm volatile("\n\
  61         mov     r1, %2                          @ 1\n\
  62         mov     r2, #0                          @ 1\n\
  63         mov     r3, #0                          @ 1\n\
  64         mov     ip, #0                          @ 1\n\
  65         mov     lr, #0                          @ 1\n\
  66 1:      stmia   %0!, {r2, r3, ip, lr}           @ 4\n\
  67         stmia   %0!, {r2, r3, ip, lr}           @ 4\n\
  68         stmia   %0!, {r2, r3, ip, lr}           @ 4\n\
  69         stmia   %0!, {r2, r3, ip, lr}           @ 4\n\
  70         subs    r1, r1, #1                      @ 1\n\
  71         bne     1b                              @ 1"
  72         : "=r" (ptr)
  73         : "0" (kaddr), "I" (PAGE_SIZE / 64)
  74         : "r1", "r2", "r3", "ip", "lr");
  75         kunmap_atomic(kaddr, KM_USER0);
  76 }
  77
  78 struct cpu_user_fns v3_user_fns __initdata = {
  79         .cpu_clear_user_highpage = v3_clear_user_highpage,
  80         .cpu_copy_user_highpage = v3_copy_user_highpage,
  81 };