1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Copyright (C) 2013 Regents of the University of California
  4 */
  5
  6#include <linux/linkage.h>
  7#include <asm/asm.h>
  8
  9/* void *memcpy(void *, const void *, size_t) */
 10ENTRY(memcpy)
 11	move t6, a0  /* Preserve return value */
 12
 13	/* Defer to byte-oriented copy for small sizes */
 14	sltiu a3, a2, 128
 15	bnez a3, 4f
 16	/* Use word-oriented copy only if low-order bits match */
 17	andi a3, t6, SZREG-1
 18	andi a4, a1, SZREG-1
 19	bne a3, a4, 4f
 20
 21	beqz a3, 2f  /* Skip if already aligned */
 22	/*
 23	 * Round to nearest double word-aligned address
 24	 * greater than or equal to start address
 25	 */
 26	andi a3, a1, ~(SZREG-1)
 27	addi a3, a3, SZREG
 28	/* Handle initial misalignment */
 29	sub a4, a3, a1
 301:
 31	lb a5, 0(a1)
 32	addi a1, a1, 1
 33	sb a5, 0(t6)
 34	addi t6, t6, 1
 35	bltu a1, a3, 1b
 36	sub a2, a2, a4  /* Update count */
 37
 382:
 39	andi a4, a2, ~((16*SZREG)-1)
 40	beqz a4, 4f
 41	add a3, a1, a4
 423:
 43	REG_L a4,       0(a1)
 44	REG_L a5,   SZREG(a1)
 45	REG_L a6, 2*SZREG(a1)
 46	REG_L a7, 3*SZREG(a1)
 47	REG_L t0, 4*SZREG(a1)
 48	REG_L t1, 5*SZREG(a1)
 49	REG_L t2, 6*SZREG(a1)
 50	REG_L t3, 7*SZREG(a1)
 51	REG_L t4, 8*SZREG(a1)
 52	REG_L t5, 9*SZREG(a1)
 53	REG_S a4,       0(t6)
 54	REG_S a5,   SZREG(t6)
 55	REG_S a6, 2*SZREG(t6)
 56	REG_S a7, 3*SZREG(t6)
 57	REG_S t0, 4*SZREG(t6)
 58	REG_S t1, 5*SZREG(t6)
 59	REG_S t2, 6*SZREG(t6)
 60	REG_S t3, 7*SZREG(t6)
 61	REG_S t4, 8*SZREG(t6)
 62	REG_S t5, 9*SZREG(t6)
 63	REG_L a4, 10*SZREG(a1)
 64	REG_L a5, 11*SZREG(a1)
 65	REG_L a6, 12*SZREG(a1)
 66	REG_L a7, 13*SZREG(a1)
 67	REG_L t0, 14*SZREG(a1)
 68	REG_L t1, 15*SZREG(a1)
 69	addi a1, a1, 16*SZREG
 70	REG_S a4, 10*SZREG(t6)
 71	REG_S a5, 11*SZREG(t6)
 72	REG_S a6, 12*SZREG(t6)
 73	REG_S a7, 13*SZREG(t6)
 74	REG_S t0, 14*SZREG(t6)
 75	REG_S t1, 15*SZREG(t6)
 76	addi t6, t6, 16*SZREG
 77	bltu a1, a3, 3b
 78	andi a2, a2, (16*SZREG)-1  /* Update count */
 79
 804:
 81	/* Handle trailing misalignment */
 82	beqz a2, 6f
 83	add a3, a1, a2
 84
 85	/* Use word-oriented copy if co-aligned to word boundary */
 86	or a5, a1, t6
 87	or a5, a5, a3
 88	andi a5, a5, 3
 89	bnez a5, 5f
 907:
 91	lw a4, 0(a1)
 92	addi a1, a1, 4
 93	sw a4, 0(t6)
 94	addi t6, t6, 4
 95	bltu a1, a3, 7b
 96
 97	ret
 98
 995:
100	lb a4, 0(a1)
101	addi a1, a1, 1
102	sb a4, 0(t6)
103	addi t6, t6, 1
104	bltu a1, a3, 5b
1056:
106	ret
107END(memcpy)