1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * linux/arch/arm/lib/io-writesb.S 4 * 5 * Copyright (C) 1995-2000 Russell King 6 */ 7 #include <linux/linkage.h> 8 #include <asm/assembler.h> 9 10 .macro outword, rd 11 #ifndef __ARMEB__ 12 strb \rd, [r0] 13 mov \rd, \rd, lsr #8 14 strb \rd, [r0] 15 mov \rd, \rd, lsr #8 16 strb \rd, [r0] 17 mov \rd, \rd, lsr #8 18 strb \rd, [r0] 19 #else 20 mov lr, \rd, lsr #24 21 strb lr, [r0] 22 mov lr, \rd, lsr #16 23 strb lr, [r0] 24 mov lr, \rd, lsr #8 25 strb lr, [r0] 26 strb \rd, [r0] 27 #endif 28 .endm 29 30 .Loutsb_align: rsb ip, ip, #4 31 cmp ip, r2 32 movgt ip, r2 33 cmp ip, #2 34 ldrb r3, [r1], #1 35 strb r3, [r0] 36 ldrbge r3, [r1], #1 37 strbge r3, [r0] 38 ldrbgt r3, [r1], #1 39 strbgt r3, [r0] 40 subs r2, r2, ip 41 bne .Loutsb_aligned 42 43 ENTRY(__raw_writesb) 44 teq r2, #0 @ do we have to check for the zero len? 45 reteq lr 46 ands ip, r1, #3 47 bne .Loutsb_align 48 49 .Loutsb_aligned: 50 stmfd sp!, {r4, r5, lr} 51 52 subs r2, r2, #16 53 bmi .Loutsb_no_16 54 55 .Loutsb_16_lp: ldmia r1!, {r3, r4, r5, ip} 56 outword r3 57 outword r4 58 outword r5 59 outword ip 60 subs r2, r2, #16 61 bpl .Loutsb_16_lp 62 63 tst r2, #15 64 ldmfdeq sp!, {r4, r5, pc} 65 66 .Loutsb_no_16: tst r2, #8 67 beq .Loutsb_no_8 68 69 ldmia r1!, {r3, r4} 70 outword r3 71 outword r4 72 73 .Loutsb_no_8: tst r2, #4 74 beq .Loutsb_no_4 75 76 ldr r3, [r1], #4 77 outword r3 78 79 .Loutsb_no_4: ands r2, r2, #3 80 ldmfdeq sp!, {r4, r5, pc} 81 82 cmp r2, #2 83 ldrb r3, [r1], #1 84 strb r3, [r0] 85 ldrbge r3, [r1], #1 86 strbge r3, [r0] 87 ldrbgt r3, [r1] 88 strbgt r3, [r0] 89 90 ldmfd sp!, {r4, r5, pc} 91 ENDPROC(__raw_writesb) 92