summaryrefslogtreecommitdiffstats
path: root/kernel/arch/tile/lib/memset_64.c
diff options
context:
space:
mode:
authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/tile/lib/memset_64.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/tile/lib/memset_64.c')
-rw-r--r--kernel/arch/tile/lib/memset_64.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/kernel/arch/tile/lib/memset_64.c b/kernel/arch/tile/lib/memset_64.c
new file mode 100644
index 000000000..03ef69cd7
--- /dev/null
+++ b/kernel/arch/tile/lib/memset_64.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright 2011 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>
+#include "string-endian.h"
+
+void *memset(void *s, int c, size_t n)
+{
+ uint64_t *out64;
+ int n64, to_align64;
+ uint64_t v64;
+ uint8_t *out8 = s;
+
+ /* 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 < 7
+ /* 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 >= 7 so this won't write past the end. */
+ while (((uintptr_t) out8 & 7) != 0) {
+ *out8++ = c;
+ --n;
+ }
+
+ /* Align 'n'. */
+ while (n & 7)
+ out8[--n] = c;
+
+ out64 = (uint64_t *) out8;
+ n64 = n >> 3;
+
+ /* Tile input byte out to 64 bits. */
+ v64 = copy_byte(c);
+
+ /* This must be at least 8 or the following loop doesn't work. */
+#define CACHE_LINE_SIZE_IN_DOUBLEWORDS (CHIP_L2_LINE_SIZE() / 8)
+
+ /* Determine how many words we need to emit before the 'out32'
+ * pointer becomes aligned modulo the cache line size.
+ */
+ to_align64 = (-((uintptr_t)out64 >> 3)) &
+ (CACHE_LINE_SIZE_IN_DOUBLEWORDS - 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_align64 <= n64 - CACHE_LINE_SIZE_IN_DOUBLEWORDS) {
+ int lines_left;
+
+ /* Align out64 mod the cache line size so we can use wh64. */
+ n64 -= to_align64;
+ for (; to_align64 != 0; to_align64--) {
+ *out64 = v64;
+ out64++;
+ }
+
+ /* Use unsigned divide to turn this into a right shift. */
+ lines_left = (unsigned)n64 / CACHE_LINE_SIZE_IN_DOUBLEWORDS;
+
+ 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());
+ uint64_t *wh = out64;
+ int i = x;
+ int j;
+
+ lines_left -= x;
+
+ do {
+ __insn_wh64(wh);
+ wh += CACHE_LINE_SIZE_IN_DOUBLEWORDS;
+ } while (--i);
+
+ for (j = x * (CACHE_LINE_SIZE_IN_DOUBLEWORDS / 4);
+ j != 0; j--) {
+ *out64++ = v64;
+ *out64++ = v64;
+ *out64++ = v64;
+ *out64++ = v64;
+ }
+ } while (lines_left != 0);
+
+ /* We processed all full lines above, so only this many
+ * words remain to be processed.
+ */
+ n64 &= CACHE_LINE_SIZE_IN_DOUBLEWORDS - 1;
+ }
+
+ /* Now handle any leftover values. */
+ if (n64 != 0) {
+ do {
+ *out64 = v64;
+ out64++;
+ } while (--n64 != 0);
+ }
+
+ return s;
+}
+EXPORT_SYMBOL(memset);