arch/arm/lib/io-readsb.S

   1 /*
   2  *  linux/arch/arm/lib/io-readsb.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 #include <asm/export.h>
  13
  14 .Linsb_align:   rsb     ip, ip, #4
  15                 cmp     ip, r2
  16                 movgt   ip, r2
  17                 cmp     ip, #2
  18                 ldrb    r3, [r0]
  19                 strb    r3, [r1], #1
  20                 ldrgeb  r3, [r0]
  21                 strgeb  r3, [r1], #1
  22                 ldrgtb  r3, [r0]
  23                 strgtb  r3, [r1], #1
  24                 subs    r2, r2, ip
  25                 bne     .Linsb_aligned
  26
  27 ENTRY(__raw_readsb)
  28                 teq     r2, #0          @ do we have to check for the zero len?
  29                 reteq   lr
  30                 ands    ip, r1, #3
  31                 bne     .Linsb_align
  32
  33 .Linsb_aligned: stmfd   sp!, {r4 - r6, lr}
  34
  35                 subs    r2, r2, #16
  36                 bmi     .Linsb_no_16
  37
  38 .Linsb_16_lp:   ldrb    r3, [r0]
  39                 ldrb    r4, [r0]
  40                 ldrb    r5, [r0]
  41                 mov     r3, r3,     put_byte_0
  42                 ldrb    r6, [r0]
  43                 orr     r3, r3, r4, put_byte_1
  44                 ldrb    r4, [r0]
  45                 orr     r3, r3, r5, put_byte_2
  46                 ldrb    r5, [r0]
  47                 orr     r3, r3, r6, put_byte_3
  48                 ldrb    r6, [r0]
  49                 mov     r4, r4,     put_byte_0
  50                 ldrb    ip, [r0]
  51                 orr     r4, r4, r5, put_byte_1
  52                 ldrb    r5, [r0]
  53                 orr     r4, r4, r6, put_byte_2
  54                 ldrb    r6, [r0]
  55                 orr     r4, r4, ip, put_byte_3
  56                 ldrb    ip, [r0]
  57                 mov     r5, r5,     put_byte_0
  58                 ldrb    lr, [r0]
  59                 orr     r5, r5, r6, put_byte_1
  60                 ldrb    r6, [r0]
  61                 orr     r5, r5, ip, put_byte_2
  62                 ldrb    ip, [r0]
  63                 orr     r5, r5, lr, put_byte_3
  64                 ldrb    lr, [r0]
  65                 mov     r6, r6,     put_byte_0
  66                 orr     r6, r6, ip, put_byte_1
  67                 ldrb    ip, [r0]
  68                 orr     r6, r6, lr, put_byte_2
  69                 orr     r6, r6, ip, put_byte_3
  70                 stmia   r1!, {r3 - r6}
  71
  72                 subs    r2, r2, #16
  73                 bpl     .Linsb_16_lp
  74
  75                 tst     r2, #15
  76                 ldmeqfd sp!, {r4 - r6, pc}
  77
  78 .Linsb_no_16:   tst     r2, #8
  79                 beq     .Linsb_no_8
  80
  81                 ldrb    r3, [r0]
  82                 ldrb    r4, [r0]
  83                 ldrb    r5, [r0]
  84                 mov     r3, r3,     put_byte_0
  85                 ldrb    r6, [r0]
  86                 orr     r3, r3, r4, put_byte_1
  87                 ldrb    r4, [r0]
  88                 orr     r3, r3, r5, put_byte_2
  89                 ldrb    r5, [r0]
  90                 orr     r3, r3, r6, put_byte_3
  91                 ldrb    r6, [r0]
  92                 mov     r4, r4,     put_byte_0
  93                 ldrb    ip, [r0]
  94                 orr     r4, r4, r5, put_byte_1
  95                 orr     r4, r4, r6, put_byte_2
  96                 orr     r4, r4, ip, put_byte_3
  97                 stmia   r1!, {r3, r4}
  98
  99 .Linsb_no_8:    tst     r2, #4
 100                 beq     .Linsb_no_4
 101
 102                 ldrb    r3, [r0]
 103                 ldrb    r4, [r0]
 104                 ldrb    r5, [r0]
 105                 ldrb    r6, [r0]
 106                 mov     r3, r3,     put_byte_0
 107                 orr     r3, r3, r4, put_byte_1
 108                 orr     r3, r3, r5, put_byte_2
 109                 orr     r3, r3, r6, put_byte_3
 110                 str     r3, [r1], #4
 111
 112 .Linsb_no_4:    ands    r2, r2, #3
 113                 ldmeqfd sp!, {r4 - r6, pc}
 114
 115                 cmp     r2, #2
 116                 ldrb    r3, [r0]
 117                 strb    r3, [r1], #1
 118                 ldrgeb  r3, [r0]
 119                 strgeb  r3, [r1], #1
 120                 ldrgtb  r3, [r0]
 121                 strgtb  r3, [r1]
 122
 123                 ldmfd   sp!, {r4 - r6, pc}
 124 ENDPROC(__raw_readsb)
 125 EXPORT_SYMBOL(__raw_readsb)