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

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  *  linux/arch/arm/lib/io-readsw-armv3.S
   4  *
   5  *  Copyright (C) 1995-2000 Russell King
   6  */
   7 #include <linux/linkage.h>
   8 #include <asm/assembler.h>
   9
  10 .Linsw_bad_alignment:
  11                 adr     r0, .Linsw_bad_align_msg
  12                 mov     r2, lr
  13                 b       panic
  14 .Linsw_bad_align_msg:
  15                 .asciz  "insw: bad buffer alignment (0x%p, lr=0x%08lX)\n"
  16                 .align
  17
  18 .Linsw_align:   tst     r1, #1
  19                 bne     .Linsw_bad_alignment
  20
  21                 ldr     r3, [r0]
  22                 strb    r3, [r1], #1
  23                 mov     r3, r3, lsr #8
  24                 strb    r3, [r1], #1
  25
  26                 subs    r2, r2, #1
  27                 reteq   lr
  28
  29 ENTRY(__raw_readsw)
  30                 teq     r2, #0          @ do we have to check for the zero len?
  31                 reteq   lr
  32                 tst     r1, #3
  33                 bne     .Linsw_align
  34
  35 .Linsw_aligned: mov     ip, #0xff
  36                 orr     ip, ip, ip, lsl #8
  37                 stmfd   sp!, {r4, r5, r6, lr}
  38
  39                 subs    r2, r2, #8
  40                 bmi     .Lno_insw_8
  41
  42 .Linsw_8_lp:    ldr     r3, [r0]
  43                 and     r3, r3, ip
  44                 ldr     r4, [r0]
  45                 orr     r3, r3, r4, lsl #16
  46
  47                 ldr     r4, [r0]
  48                 and     r4, r4, ip
  49                 ldr     r5, [r0]
  50                 orr     r4, r4, r5, lsl #16
  51
  52                 ldr     r5, [r0]
  53                 and     r5, r5, ip
  54                 ldr     r6, [r0]
  55                 orr     r5, r5, r6, lsl #16
  56
  57                 ldr     r6, [r0]
  58                 and     r6, r6, ip
  59                 ldr     lr, [r0]
  60                 orr     r6, r6, lr, lsl #16
  61
  62                 stmia   r1!, {r3 - r6}
  63
  64                 subs    r2, r2, #8
  65                 bpl     .Linsw_8_lp
  66
  67                 tst     r2, #7
  68                 ldmfdeq sp!, {r4, r5, r6, pc}
  69
  70 .Lno_insw_8:    tst     r2, #4
  71                 beq     .Lno_insw_4
  72
  73                 ldr     r3, [r0]
  74                 and     r3, r3, ip
  75                 ldr     r4, [r0]
  76                 orr     r3, r3, r4, lsl #16
  77
  78                 ldr     r4, [r0]
  79                 and     r4, r4, ip
  80                 ldr     r5, [r0]
  81                 orr     r4, r4, r5, lsl #16
  82
  83                 stmia   r1!, {r3, r4}
  84
  85 .Lno_insw_4:    tst     r2, #2
  86                 beq     .Lno_insw_2
  87
  88                 ldr     r3, [r0]
  89                 and     r3, r3, ip
  90                 ldr     r4, [r0]
  91                 orr     r3, r3, r4, lsl #16
  92
  93                 str     r3, [r1], #4
  94
  95 .Lno_insw_2:    tst     r2, #1
  96                 ldrne   r3, [r0]
  97                 strbne  r3, [r1], #1
  98                 movne   r3, r3, lsr #8
  99                 strbne  r3, [r1]
 100
 101                 ldmfd   sp!, {r4, r5, r6, pc}
 102
 103