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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/arch/xtensa/include/uapi/asm/swab.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/arch/xtensa/include/uapi/asm/swab.h')
-rw-r--r--kernel/arch/xtensa/include/uapi/asm/swab.h70
1 files changed, 70 insertions, 0 deletions
diff --git a/kernel/arch/xtensa/include/uapi/asm/swab.h b/kernel/arch/xtensa/include/uapi/asm/swab.h
new file mode 100644
index 000000000..226a39162
--- /dev/null
+++ b/kernel/arch/xtensa/include/uapi/asm/swab.h
@@ -0,0 +1,70 @@
+/*
+ * include/asm-xtensa/swab.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2005 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_SWAB_H
+#define _XTENSA_SWAB_H
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+
+#define __SWAB_64_THRU_32__
+
+static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
+{
+ __u32 res;
+ /* instruction sequence from Xtensa ISA release 2/2000 */
+ __asm__("ssai 8 \n\t"
+ "srli %0, %1, 16 \n\t"
+ "src %0, %0, %1 \n\t"
+ "src %0, %0, %0 \n\t"
+ "src %0, %1, %0 \n"
+ : "=&a" (res)
+ : "a" (x)
+ );
+ return res;
+}
+#define __arch_swab32 __arch_swab32
+
+static inline __attribute_const__ __u16 __arch_swab16(__u16 x)
+{
+ /* Given that 'short' values are signed (i.e., can be negative),
+ * we cannot assume that the upper 16-bits of the register are
+ * zero. We are careful to mask values after shifting.
+ */
+
+ /* There exists an anomaly between xt-gcc and xt-xcc. xt-gcc
+ * inserts an extui instruction after putting this function inline
+ * to ensure that it uses only the least-significant 16 bits of
+ * the result. xt-xcc doesn't use an extui, but assumes the
+ * __asm__ macro follows convention that the upper 16 bits of an
+ * 'unsigned short' result are still zero. This macro doesn't
+ * follow convention; indeed, it leaves garbage in the upport 16
+ * bits of the register.
+
+ * Declaring the temporary variables 'res' and 'tmp' to be 32-bit
+ * types while the return type of the function is a 16-bit type
+ * forces both compilers to insert exactly one extui instruction
+ * (or equivalent) to mask off the upper 16 bits. */
+
+ __u32 res;
+ __u32 tmp;
+
+ __asm__("extui %1, %2, 8, 8\n\t"
+ "slli %0, %2, 8 \n\t"
+ "or %0, %0, %1 \n"
+ : "=&a" (res), "=&a" (tmp)
+ : "a" (x)
+ );
+
+ return res;
+}
+#define __arch_swab16 __arch_swab16
+
+#endif /* _XTENSA_SWAB_H */