1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-or-later */ 2*4882a593Smuzhiyun #include <linux/types.h> 3*4882a593Smuzhiyun #include <asm/string.h> 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun #define OPSIZ (BITS_PER_LONG/8) 6*4882a593Smuzhiyun typedef unsigned long op_t; 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun void * memset(void * dstpp,int sc,size_t len)9*4882a593Smuzhiyunmemset (void *dstpp, int sc, size_t len) 10*4882a593Smuzhiyun { 11*4882a593Smuzhiyun unsigned int c = sc; 12*4882a593Smuzhiyun long int dstp = (long int) dstpp; 13*4882a593Smuzhiyun 14*4882a593Smuzhiyun if (len >= 8) 15*4882a593Smuzhiyun { 16*4882a593Smuzhiyun size_t xlen; 17*4882a593Smuzhiyun op_t cccc; 18*4882a593Smuzhiyun 19*4882a593Smuzhiyun cccc = (unsigned char) c; 20*4882a593Smuzhiyun cccc |= cccc << 8; 21*4882a593Smuzhiyun cccc |= cccc << 16; 22*4882a593Smuzhiyun if (OPSIZ > 4) 23*4882a593Smuzhiyun /* Do the shift in two steps to avoid warning if long has 32 bits. */ 24*4882a593Smuzhiyun cccc |= (cccc << 16) << 16; 25*4882a593Smuzhiyun 26*4882a593Smuzhiyun /* There are at least some bytes to set. 27*4882a593Smuzhiyun No need to test for LEN == 0 in this alignment loop. */ 28*4882a593Smuzhiyun while (dstp % OPSIZ != 0) 29*4882a593Smuzhiyun { 30*4882a593Smuzhiyun ((unsigned char *) dstp)[0] = c; 31*4882a593Smuzhiyun dstp += 1; 32*4882a593Smuzhiyun len -= 1; 33*4882a593Smuzhiyun } 34*4882a593Smuzhiyun 35*4882a593Smuzhiyun /* Write 8 `op_t' per iteration until less than 8 `op_t' remain. */ 36*4882a593Smuzhiyun xlen = len / (OPSIZ * 8); 37*4882a593Smuzhiyun while (xlen > 0) 38*4882a593Smuzhiyun { 39*4882a593Smuzhiyun ((op_t *) dstp)[0] = cccc; 40*4882a593Smuzhiyun ((op_t *) dstp)[1] = cccc; 41*4882a593Smuzhiyun ((op_t *) dstp)[2] = cccc; 42*4882a593Smuzhiyun ((op_t *) dstp)[3] = cccc; 43*4882a593Smuzhiyun ((op_t *) dstp)[4] = cccc; 44*4882a593Smuzhiyun ((op_t *) dstp)[5] = cccc; 45*4882a593Smuzhiyun ((op_t *) dstp)[6] = cccc; 46*4882a593Smuzhiyun ((op_t *) dstp)[7] = cccc; 47*4882a593Smuzhiyun dstp += 8 * OPSIZ; 48*4882a593Smuzhiyun xlen -= 1; 49*4882a593Smuzhiyun } 50*4882a593Smuzhiyun len %= OPSIZ * 8; 51*4882a593Smuzhiyun 52*4882a593Smuzhiyun /* Write 1 `op_t' per iteration until less than OPSIZ bytes remain. */ 53*4882a593Smuzhiyun xlen = len / OPSIZ; 54*4882a593Smuzhiyun while (xlen > 0) 55*4882a593Smuzhiyun { 56*4882a593Smuzhiyun ((op_t *) dstp)[0] = cccc; 57*4882a593Smuzhiyun dstp += OPSIZ; 58*4882a593Smuzhiyun xlen -= 1; 59*4882a593Smuzhiyun } 60*4882a593Smuzhiyun len %= OPSIZ; 61*4882a593Smuzhiyun } 62*4882a593Smuzhiyun 63*4882a593Smuzhiyun /* Write the last few bytes. */ 64*4882a593Smuzhiyun while (len > 0) 65*4882a593Smuzhiyun { 66*4882a593Smuzhiyun ((unsigned char *) dstp)[0] = c; 67*4882a593Smuzhiyun dstp += 1; 68*4882a593Smuzhiyun len -= 1; 69*4882a593Smuzhiyun } 70*4882a593Smuzhiyun 71*4882a593Smuzhiyun return dstpp; 72*4882a593Smuzhiyun } 73