You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
143 lines
3.4 KiB
143 lines
3.4 KiB
/*
|
|
* Copyright 2010 Tilera Corporation. All Rights Reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation, version 2.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
|
|
* NON INFRINGEMENT. See the GNU General Public License for
|
|
* more details.
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/string.h>
|
|
#include <linux/module.h>
|
|
#include <arch/chip.h>
|
|
|
|
void *memset(void *s, int c, size_t n)
|
|
{
|
|
uint32_t *out32;
|
|
int n32;
|
|
uint32_t v16, v32;
|
|
uint8_t *out8 = s;
|
|
int to_align32;
|
|
|
|
/* Experimentation shows that a trivial tight loop is a win up until
|
|
* around a size of 20, where writing a word at a time starts to win.
|
|
*/
|
|
#define BYTE_CUTOFF 20
|
|
|
|
#if BYTE_CUTOFF < 3
|
|
/* This must be at least at least this big, or some code later
|
|
* on doesn't work.
|
|
*/
|
|
#error "BYTE_CUTOFF is too small"
|
|
#endif
|
|
|
|
if (n < BYTE_CUTOFF) {
|
|
/* Strangely, this turns out to be the tightest way to
|
|
* write this loop.
|
|
*/
|
|
if (n != 0) {
|
|
do {
|
|
/* Strangely, combining these into one line
|
|
* performs worse.
|
|
*/
|
|
*out8 = c;
|
|
out8++;
|
|
} while (--n != 0);
|
|
}
|
|
|
|
return s;
|
|
}
|
|
|
|
/* Align 'out8'. We know n >= 3 so this won't write past the end. */
|
|
while (((uintptr_t) out8 & 3) != 0) {
|
|
*out8++ = c;
|
|
--n;
|
|
}
|
|
|
|
/* Align 'n'. */
|
|
while (n & 3)
|
|
out8[--n] = c;
|
|
|
|
out32 = (uint32_t *) out8;
|
|
n32 = n >> 2;
|
|
|
|
/* Tile input byte out to 32 bits. */
|
|
v16 = __insn_intlb(c, c);
|
|
v32 = __insn_intlh(v16, v16);
|
|
|
|
/* This must be at least 8 or the following loop doesn't work. */
|
|
#define CACHE_LINE_SIZE_IN_WORDS (CHIP_L2_LINE_SIZE() / 4)
|
|
|
|
/* Determine how many words we need to emit before the 'out32'
|
|
* pointer becomes aligned modulo the cache line size.
|
|
*/
|
|
to_align32 =
|
|
(-((uintptr_t)out32 >> 2)) & (CACHE_LINE_SIZE_IN_WORDS - 1);
|
|
|
|
/* Only bother aligning and using wh64 if there is at least
|
|
* one full cache line to process. This check also prevents
|
|
* overrunning the end of the buffer with alignment words.
|
|
*/
|
|
if (to_align32 <= n32 - CACHE_LINE_SIZE_IN_WORDS) {
|
|
int lines_left;
|
|
|
|
/* Align out32 mod the cache line size so we can use wh64. */
|
|
n32 -= to_align32;
|
|
for (; to_align32 != 0; to_align32--) {
|
|
*out32 = v32;
|
|
out32++;
|
|
}
|
|
|
|
/* Use unsigned divide to turn this into a right shift. */
|
|
lines_left = (unsigned)n32 / CACHE_LINE_SIZE_IN_WORDS;
|
|
|
|
do {
|
|
/* Only wh64 a few lines at a time, so we don't
|
|
* exceed the maximum number of victim lines.
|
|
*/
|
|
int x = ((lines_left < CHIP_MAX_OUTSTANDING_VICTIMS())
|
|
? lines_left
|
|
: CHIP_MAX_OUTSTANDING_VICTIMS());
|
|
uint32_t *wh = out32;
|
|
int i = x;
|
|
int j;
|
|
|
|
lines_left -= x;
|
|
|
|
do {
|
|
__insn_wh64(wh);
|
|
wh += CACHE_LINE_SIZE_IN_WORDS;
|
|
} while (--i);
|
|
|
|
for (j = x * (CACHE_LINE_SIZE_IN_WORDS / 4);
|
|
j != 0; j--) {
|
|
*out32++ = v32;
|
|
*out32++ = v32;
|
|
*out32++ = v32;
|
|
*out32++ = v32;
|
|
}
|
|
} while (lines_left != 0);
|
|
|
|
/* We processed all full lines above, so only this many
|
|
* words remain to be processed.
|
|
*/
|
|
n32 &= CACHE_LINE_SIZE_IN_WORDS - 1;
|
|
}
|
|
|
|
/* Now handle any leftover values. */
|
|
if (n32 != 0) {
|
|
do {
|
|
*out32 = v32;
|
|
out32++;
|
|
} while (--n32 != 0);
|
|
}
|
|
|
|
return s;
|
|
}
|
|
EXPORT_SYMBOL(memset);
|
|
|