LXR linux/arch/arm/lib/io-readsw-armv4.S

   1/*
   2 *  linux/arch/arm/lib/io-readsw-armv4.S
   3 *
   4 *  Copyright (C) 1995-2000 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/linkage.h>
  11#include <asm/assembler.h>
  12
  13                .macro  pack, rd, hw1, hw2
  14#ifndef __ARMEB__
  15                orr     \rd, \hw1, \hw2, lsl #16
  16#else
  17                orr     \rd, \hw2, \hw1, lsl #16
  18#endif
  19                .endm
  20
  21.Linsw_align:   movs    ip, r1, lsl #31
  22                bne     .Linsw_noalign
  23                ldrh    ip, [r0]
  24                sub     r2, r2, #1
  25                strh    ip, [r1], #2
  26
  27ENTRY(__raw_readsw)
  28                teq     r2, #0
  29                reteq   lr
  30                tst     r1, #3
  31                bne     .Linsw_align
  32
  33                stmfd   sp!, {r4, r5, lr}
  34
  35                subs    r2, r2, #8
  36                bmi     .Lno_insw_8
  37
  38.Linsw_8_lp:    ldrh    r3, [r0]
  39                ldrh    r4, [r0]
  40                pack    r3, r3, r4
  41
  42                ldrh    r4, [r0]
  43                ldrh    r5, [r0]
  44                pack    r4, r4, r5
  45
  46                ldrh    r5, [r0]
  47                ldrh    ip, [r0]
  48                pack    r5, r5, ip
  49
  50                ldrh    ip, [r0]
  51                ldrh    lr, [r0]
  52                pack    ip, ip, lr
  53
  54                subs    r2, r2, #8
  55                stmia   r1!, {r3 - r5, ip}
  56                bpl     .Linsw_8_lp
  57
  58.Lno_insw_8:    tst     r2, #4
  59                beq     .Lno_insw_4
  60
  61                ldrh    r3, [r0]
  62                ldrh    r4, [r0]
  63                pack    r3, r3, r4
  64
  65                ldrh    r4, [r0]
  66                ldrh    ip, [r0]
  67                pack    r4, r4, ip
  68
  69                stmia   r1!, {r3, r4}
  70
  71.Lno_insw_4:    movs    r2, r2, lsl #31
  72                bcc     .Lno_insw_2
  73
  74                ldrh    r3, [r0]
  75                ldrh    ip, [r0]
  76                pack    r3, r3, ip
  77                str     r3, [r1], #4
  78
  79.Lno_insw_2:    ldrneh  r3, [r0]
  80                strneh  r3, [r1]
  81
  82                ldmfd   sp!, {r4, r5, pc}
  83
  84#ifdef __ARMEB__
  85#define _BE_ONLY_(code...)      code
  86#define _LE_ONLY_(code...)
  87#define push_hbyte0             lsr #8
  88#define pull_hbyte1             lsl #24
  89#else
  90#define _BE_ONLY_(code...)
  91#define _LE_ONLY_(code...) code
  92#define push_hbyte0             lsl #24
  93#define pull_hbyte1             lsr #8
  94#endif
  95
  96.Linsw_noalign: stmfd   sp!, {r4, lr}
  97                ldrccb  ip, [r1, #-1]!
  98                bcc     1f
  99
 100                ldrh    ip, [r0]
 101                sub     r2, r2, #1
 102   _BE_ONLY_(   mov     ip, ip, ror #8          )
 103                strb    ip, [r1], #1
 104   _LE_ONLY_(   mov     ip, ip, lsr #8          )
 105   _BE_ONLY_(   mov     ip, ip, lsr #24         )
 106
 1071:              subs    r2, r2, #2
 108                bmi     3f
 109   _BE_ONLY_(   mov     ip, ip, lsl #24         )
 110
 1112:              ldrh    r3, [r0]
 112                ldrh    r4, [r0]
 113                subs    r2, r2, #2
 114                orr     ip, ip, r3, lsl #8
 115                orr     ip, ip, r4, push_hbyte0
 116                str     ip, [r1], #4
 117                mov     ip, r4, pull_hbyte1
 118                bpl     2b
 119
 120   _BE_ONLY_(   mov     ip, ip, lsr #24         )
 121
 1223:              tst     r2, #1
 123                strb    ip, [r1], #1
 124                ldrneh  ip, [r0]
 125   _BE_ONLY_(   movne   ip, ip, ror #8          )
 126                strneb  ip, [r1], #1
 127   _LE_ONLY_(   movne   ip, ip, lsr #8          )
 128   _BE_ONLY_(   movne   ip, ip, lsr #24         )
 129                strneb  ip, [r1]
 130                ldmfd   sp!, {r4, pc}
 131ENDPROC(__raw_readsw)
 132