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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/include/linux/prefetch.h
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/include/linux/prefetch.h')
-rw-r--r--kernel/include/linux/prefetch.h64
1 files changed, 64 insertions, 0 deletions
diff --git a/kernel/include/linux/prefetch.h b/kernel/include/linux/prefetch.h
new file mode 100644
index 000000000..a3bfbdf63
--- /dev/null
+++ b/kernel/include/linux/prefetch.h
@@ -0,0 +1,64 @@
+/*
+ * Generic cache management functions. Everything is arch-specific,
+ * but this header exists to make sure the defines/functions can be
+ * used in a generic way.
+ *
+ * 2000-11-13 Arjan van de Ven <arjan@fenrus.demon.nl>
+ *
+ */
+
+#ifndef _LINUX_PREFETCH_H
+#define _LINUX_PREFETCH_H
+
+#include <linux/types.h>
+#include <asm/processor.h>
+#include <asm/cache.h>
+
+/*
+ prefetch(x) attempts to pre-emptively get the memory pointed to
+ by address "x" into the CPU L1 cache.
+ prefetch(x) should not cause any kind of exception, prefetch(0) is
+ specifically ok.
+
+ prefetch() should be defined by the architecture, if not, the
+ #define below provides a no-op define.
+
+ There are 3 prefetch() macros:
+
+ prefetch(x) - prefetches the cacheline at "x" for read
+ prefetchw(x) - prefetches the cacheline at "x" for write
+ spin_lock_prefetch(x) - prefetches the spinlock *x for taking
+
+ there is also PREFETCH_STRIDE which is the architecure-preferred
+ "lookahead" size for prefetching streamed operations.
+
+*/
+
+#ifndef ARCH_HAS_PREFETCH
+#define prefetch(x) __builtin_prefetch(x)
+#endif
+
+#ifndef ARCH_HAS_PREFETCHW
+#define prefetchw(x) __builtin_prefetch(x,1)
+#endif
+
+#ifndef ARCH_HAS_SPINLOCK_PREFETCH
+#define spin_lock_prefetch(x) prefetchw(x)
+#endif
+
+#ifndef PREFETCH_STRIDE
+#define PREFETCH_STRIDE (4*L1_CACHE_BYTES)
+#endif
+
+static inline void prefetch_range(void *addr, size_t len)
+{
+#ifdef ARCH_HAS_PREFETCH
+ char *cp;
+ char *end = addr + len;
+
+ for (cp = addr; cp < end; cp += PREFETCH_STRIDE)
+ prefetch(cp);
+#endif
+}
+
+#endif