arm/lib/io-writesw-armv4.S

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  *  linux/arch/arm/lib/io-writesw-armv4.S
0004  *
0005  *  Copyright (C) 1995-2000 Russell King
0006  */
0007 #include <linux/linkage.h>
0008 #include <asm/assembler.h>
0009
0010         .macro  outword, rd
0011 #ifndef __ARMEB__
0012         strh    \rd, [r0]
0013         mov \rd, \rd, lsr #16
0014         strh    \rd, [r0]
0015 #else
0016         mov lr, \rd, lsr #16
0017         strh    lr, [r0]
0018         strh    \rd, [r0]
0019 #endif
0020         .endm
0021
0022 .Loutsw_align:  movs    ip, r1, lsl #31
0023         bne .Loutsw_noalign
0024
0025         ldrh    r3, [r1], #2
0026         sub r2, r2, #1
0027         strh    r3, [r0]
0028
0029 ENTRY(__raw_writesw)
0030         teq r2, #0
0031         reteq   lr
0032         ands    r3, r1, #3
0033         bne .Loutsw_align
0034
0035         stmfd   sp!, {r4, r5, lr}
0036
0037         subs    r2, r2, #8
0038         bmi .Lno_outsw_8
0039
0040 .Loutsw_8_lp:   ldmia   r1!, {r3, r4, r5, ip}
0041         subs    r2, r2, #8
0042         outword r3
0043         outword r4
0044         outword r5
0045         outword ip
0046         bpl .Loutsw_8_lp
0047
0048 .Lno_outsw_8:   tst r2, #4
0049         beq .Lno_outsw_4
0050
0051         ldmia   r1!, {r3, ip}
0052         outword r3
0053         outword ip
0054
0055 .Lno_outsw_4:   movs    r2, r2, lsl #31
0056         bcc .Lno_outsw_2
0057
0058         ldr r3, [r1], #4
0059         outword r3
0060
0061 .Lno_outsw_2:   ldrhne  r3, [r1]
0062         strhne  r3, [r0]
0063
0064         ldmfd   sp!, {r4, r5, pc}
0065
0066 #ifdef __ARMEB__
0067 #define pull_hbyte0 lsl #8
0068 #define push_hbyte1 lsr #24
0069 #else
0070 #define pull_hbyte0 lsr #24
0071 #define push_hbyte1 lsl #8
0072 #endif
0073
0074 .Loutsw_noalign:
0075  ARM(       ldr r3, [r1, -r3]!  )
0076  THUMB(     rsb r3, r3, #0  )
0077  THUMB(     ldr r3, [r1, r3]    )
0078  THUMB(     sub r1, r3      )
0079         subcs   r2, r2, #1
0080         bcs 2f
0081         subs    r2, r2, #2
0082         bmi 3f
0083
0084 1:      mov ip, r3, lsr #8
0085         strh    ip, [r0]
0086 2:      mov ip, r3, pull_hbyte0
0087         ldr r3, [r1, #4]!
0088         subs    r2, r2, #2
0089         orr ip, ip, r3, push_hbyte1
0090         strh    ip, [r0]
0091         bpl 1b
0092
0093         tst r2, #1
0094 3:      movne   ip, r3, lsr #8
0095         strhne  ip, [r0]
0096         ret lr
0097 ENDPROC(__raw_writesw)