arch/arm/lib/io-readsl.S

   1 /*
   2  *  linux/arch/arm/lib/io-readsl.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 ENTRY(__raw_readsl)
  14                 teq     r2, #0          @ do we have to check for the zero len?
  15                 moveq   pc, lr
  16                 ands    ip, r1, #3
  17                 bne     3f
  18
  19                 subs    r2, r2, #4
  20                 bmi     2f
  21                 stmfd   sp!, {r4, lr}
  22 1:              ldr     r3, [r0, #0]
  23                 ldr     r4, [r0, #0]
  24                 ldr     ip, [r0, #0]
  25                 ldr     lr, [r0, #0]
  26                 subs    r2, r2, #4
  27                 stmia   r1!, {r3, r4, ip, lr}
  28                 bpl     1b
  29                 ldmfd   sp!, {r4, lr}
  30 2:              movs    r2, r2, lsl #31
  31                 ldrcs   r3, [r0, #0]
  32                 ldrcs   ip, [r0, #0]
  33                 stmcsia r1!, {r3, ip}
  34                 ldrne   r3, [r0, #0]
  35                 strne   r3, [r1, #0]
  36                 mov     pc, lr
  37
  38 3:              ldr     r3, [r0]
  39                 cmp     ip, #2
  40                 mov     ip, r3, get_byte_0
  41                 strb    ip, [r1], #1
  42                 bgt     6f
  43                 mov     ip, r3, get_byte_1
  44                 strb    ip, [r1], #1
  45                 beq     5f
  46                 mov     ip, r3, get_byte_2
  47                 strb    ip, [r1], #1
  48
  49 4:              subs    r2, r2, #1
  50                 mov     ip, r3, pull #24
  51                 ldrne   r3, [r0]
  52                 orrne   ip, ip, r3, push #8
  53                 strne   ip, [r1], #4
  54                 bne     4b
  55                 b       8f
  56
  57 5:              subs    r2, r2, #1
  58                 mov     ip, r3, pull #16
  59                 ldrne   r3, [r0]
  60                 orrne   ip, ip, r3, push #16
  61                 strne   ip, [r1], #4
  62                 bne     5b
  63                 b       7f
  64
  65 6:              subs    r2, r2, #1
  66                 mov     ip, r3, pull #8
  67                 ldrne   r3, [r0]
  68                 orrne   ip, ip, r3, push #24
  69                 strne   ip, [r1], #4
  70                 bne     6b
  71
  72                 mov     r3, ip, get_byte_2
  73                 strb    r3, [r1, #2]
  74 7:              mov     r3, ip, get_byte_1
  75                 strb    r3, [r1, #1]
  76 8:              mov     r3, ip, get_byte_0
  77                 strb    r3, [r1, #0]
  78                 mov     pc, lr