arch/arm/lib/io-readsw-armv3.S

   1 /*
   2  *  linux/arch/arm/lib/io-readsw-armv3.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 .Linsw_bad_alignment:
  14                 adr     r0, .Linsw_bad_align_msg
  15                 mov     r2, lr
  16                 b       panic
  17 .Linsw_bad_align_msg:
  18                 .asciz  "insw: bad buffer alignment (0x%p, lr=0x%08lX)\n"
  19                 .align
  20
  21 .Linsw_align:   tst     r1, #1
  22                 bne     .Linsw_bad_alignment
  23
  24                 ldr     r3, [r0]
  25                 strb    r3, [r1], #1
  26                 mov     r3, r3, lsr #8
  27                 strb    r3, [r1], #1
  28
  29                 subs    r2, r2, #1
  30                 reteq   lr
  31
  32 ENTRY(__raw_readsw)
  33                 teq     r2, #0          @ do we have to check for the zero len?
  34                 reteq   lr
  35                 tst     r1, #3
  36                 bne     .Linsw_align
  37
  38 .Linsw_aligned: mov     ip, #0xff
  39                 orr     ip, ip, ip, lsl #8
  40                 stmfd   sp!, {r4, r5, r6, lr}
  41
  42                 subs    r2, r2, #8
  43                 bmi     .Lno_insw_8
  44
  45 .Linsw_8_lp:    ldr     r3, [r0]
  46                 and     r3, r3, ip
  47                 ldr     r4, [r0]
  48                 orr     r3, r3, r4, lsl #16
  49
  50                 ldr     r4, [r0]
  51                 and     r4, r4, ip
  52                 ldr     r5, [r0]
  53                 orr     r4, r4, r5, lsl #16
  54
  55                 ldr     r5, [r0]
  56                 and     r5, r5, ip
  57                 ldr     r6, [r0]
  58                 orr     r5, r5, r6, lsl #16
  59
  60                 ldr     r6, [r0]
  61                 and     r6, r6, ip
  62                 ldr     lr, [r0]
  63                 orr     r6, r6, lr, lsl #16
  64
  65                 stmia   r1!, {r3 - r6}
  66
  67                 subs    r2, r2, #8
  68                 bpl     .Linsw_8_lp
  69
  70                 tst     r2, #7
  71                 ldmeqfd sp!, {r4, r5, r6, pc}
  72
  73 .Lno_insw_8:    tst     r2, #4
  74                 beq     .Lno_insw_4
  75
  76                 ldr     r3, [r0]
  77                 and     r3, r3, ip
  78                 ldr     r4, [r0]
  79                 orr     r3, r3, r4, lsl #16
  80
  81                 ldr     r4, [r0]
  82                 and     r4, r4, ip
  83                 ldr     r5, [r0]
  84                 orr     r4, r4, r5, lsl #16
  85
  86                 stmia   r1!, {r3, r4}
  87
  88 .Lno_insw_4:    tst     r2, #2
  89                 beq     .Lno_insw_2
  90
  91                 ldr     r3, [r0]
  92                 and     r3, r3, ip
  93                 ldr     r4, [r0]
  94                 orr     r3, r3, r4, lsl #16
  95
  96                 str     r3, [r1], #4
  97
  98 .Lno_insw_2:    tst     r2, #1
  99                 ldrne   r3, [r0]
 100                 strneb  r3, [r1], #1
 101                 movne   r3, r3, lsr #8
 102                 strneb  r3, [r1]
 103
 104                 ldmfd   sp!, {r4, r5, r6, pc}
 105
 106