arch/arm/mm/copypage-v4wt.S

   1 /*
   2  *  linux/arch/arm/lib/copypage-v4.S
   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  *  ASM optimised string functions
  11  *
  12  *  This is for CPUs with a writethrough cache and 'flush ID cache' is
  13  *  the only supported cache operation.
  14  */
  15 #include <linux/linkage.h>
  16 #include <linux/init.h>
  17 #include <asm/constants.h>
  18
  19         .text
  20         .align  5
  21 /*
  22  * ARMv4 optimised copy_user_page
  23  *
  24  * Since we have writethrough caches, we don't have to worry about
  25  * dirty data in the cache.  However, we do have to ensure that
  26  * subsequent reads are up to date.
  27  */
  28 ENTRY(v4wt_copy_user_page)
  29         stmfd   sp!, {r4, lr}                   @ 2
  30         mov     r2, #PAGE_SZ/64                 @ 1
  31         ldmia   r1!, {r3, r4, ip, lr}           @ 4
  32 1:      stmia   r0!, {r3, r4, ip, lr}           @ 4
  33         ldmia   r1!, {r3, r4, ip, lr}           @ 4+1
  34         stmia   r0!, {r3, r4, ip, lr}           @ 4
  35         ldmia   r1!, {r3, r4, ip, lr}           @ 4
  36         stmia   r0!, {r3, r4, ip, lr}           @ 4
  37         ldmia   r1!, {r3, r4, ip, lr}           @ 4
  38         subs    r2, r2, #1                      @ 1
  39         stmia   r0!, {r3, r4, ip, lr}           @ 4
  40         ldmneia r1!, {r3, r4, ip, lr}           @ 4
  41         bne     1b                              @ 1
  42         mcr     p15, 0, r2, c7, c7, 0           @ flush ID cache
  43         ldmfd   sp!, {r4, pc}                   @ 3
  44
  45         .align  5
  46 /*
  47  * ARMv4 optimised clear_user_page
  48  *
  49  * Same story as above.
  50  */
  51 ENTRY(v4wt_clear_user_page)
  52         str     lr, [sp, #-4]!
  53         mov     r1, #PAGE_SZ/64                 @ 1
  54         mov     r2, #0                          @ 1
  55         mov     r3, #0                          @ 1
  56         mov     ip, #0                          @ 1
  57         mov     lr, #0                          @ 1
  58 1:      stmia   r0!, {r2, r3, ip, lr}           @ 4
  59         stmia   r0!, {r2, r3, ip, lr}           @ 4
  60         stmia   r0!, {r2, r3, ip, lr}           @ 4
  61         stmia   r0!, {r2, r3, ip, lr}           @ 4
  62         subs    r1, r1, #1                      @ 1
  63         bne     1b                              @ 1
  64         mcr     p15, 0, r2, c7, c7, 0           @ flush ID cache
  65         ldr     pc, [sp], #4
  66
  67         __INITDATA
  68
  69         .type   v4wt_user_fns, #object
  70 ENTRY(v4wt_user_fns)
  71         .long   v4wt_clear_user_page
  72         .long   v4wt_copy_user_page
  73         .size   v4wt_user_fns, . - v4wt_user_fns