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 .insw_bad_alignment:
  22                 adr     r0, .insw_bad_align_msg
  23                 mov     r2, lr
  24                 b       panic
  25 .insw_bad_align_msg:
  26                 .asciz  "insw: bad buffer alignment (0x%p, lr=0x%08lX)\n"
  27                 .align
  28
  29 .insw_align:    tst     r1, #1
  30                 bne     .insw_bad_alignment
  31
  32                 ldrh    r3, [r0]
  33                 strh    r3, [r1], #2
  34
  35                 subs    r2, r2, #1
  36                 RETINSTR(moveq, pc, lr)
  37
  38 ENTRY(__raw_readsw)
  39                 teq     r2, #0          @ do we have to check for the zero len?
  40                 moveq   pc, lr
  41                 tst     r1, #3
  42                 bne     .insw_align
  43
  44                 stmfd   sp!, {r4, r5, lr}
  45
  46                 subs    r2, r2, #8
  47                 bmi     .no_insw_8
  48
  49 .insw_8_lp:     ldrh    r3, [r0]
  50                 ldrh    r4, [r0]
  51                 pack    r3, r3, r4
  52
  53                 ldrh    r4, [r0]
  54                 ldrh    r5, [r0]
  55                 pack    r4, r4, r5
  56
  57                 ldrh    r5, [r0]
  58                 ldrh    ip, [r0]
  59                 pack    r5, r5, ip
  60
  61                 ldrh    ip, [r0]
  62                 ldrh    lr, [r0]
  63                 pack    ip, ip, lr
  64
  65                 stmia   r1!, {r3 - r5, ip}
  66
  67                 subs    r2, r2, #8
  68                 bpl     .insw_8_lp
  69
  70                 tst     r2, #7
  71                 LOADREGS(eqfd, sp!, {r4, r5, pc})
  72
  73 .no_insw_8:     tst     r2, #4
  74                 beq     .no_insw_4
  75
  76                 ldrh    r3, [r0]
  77                 ldrh    r4, [r0]
  78                 pack    r3, r3, r4
  79
  80                 ldrh    r4, [r0]
  81                 ldrh    ip, [r0]
  82                 pack    r4, r4, ip
  83
  84                 stmia   r1!, {r3, r4}
  85
  86 .no_insw_4:     tst     r2, #2
  87                 beq     .no_insw_2
  88
  89                 ldrh    r3, [r0]
  90                 ldrh    ip, [r0]
  91                 pack    r3, r3, ip
  92
  93                 str     r3, [r1], #4
  94
  95 .no_insw_2:     tst     r2, #1
  96                 ldrneh  r3, [r0]
  97                 strneh  r3, [r1]
  98
  99                 LOADREGS(fd, sp!, {r4, r5, pc})