tile/jump_label: add jump label support for TILE-Gx

Add the arch-specific code to support jump label for TILE-Gx. This
code shares NOP instruction with ftrace, so we move it to a common
header file.

Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Signed-off-by: Zhigang Lu <zlu@ezchip.com>
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/arch/tile/include/asm/jump_label.h b/arch/tile/include/asm/jump_label.h
new file mode 100644
index 0000000..cde7573
--- /dev/null
+++ b/arch/tile/include/asm/jump_label.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2015 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.
+ */
+
+#ifndef _ASM_TILE_JUMP_LABEL_H
+#define _ASM_TILE_JUMP_LABEL_H
+
+#include <arch/opcode.h>
+
+#define JUMP_LABEL_NOP_SIZE	TILE_BUNDLE_SIZE_IN_BYTES
+
+static __always_inline bool arch_static_branch(struct static_key *key,
+					       bool branch)
+{
+	asm_volatile_goto("1:\n\t"
+		"nop" "\n\t"
+		".pushsection __jump_table,  \"aw\"\n\t"
+		".quad 1b, %l[l_yes], %0 + %1 \n\t"
+		".popsection\n\t"
+		: :  "i" (key), "i" (branch) : : l_yes);
+	return false;
+l_yes:
+	return true;
+}
+
+static __always_inline bool arch_static_branch_jump(struct static_key *key,
+						    bool branch)
+{
+	asm_volatile_goto("1:\n\t"
+		"j %l[l_yes]" "\n\t"
+		".pushsection __jump_table,  \"aw\"\n\t"
+		".quad 1b, %l[l_yes], %0 + %1 \n\t"
+		".popsection\n\t"
+		: :  "i" (key), "i" (branch) : : l_yes);
+	return false;
+l_yes:
+	return true;
+}
+
+typedef u64 jump_label_t;
+
+struct jump_entry {
+	jump_label_t code;
+	jump_label_t target;
+	jump_label_t key;
+};
+
+#endif /* _ASM_TILE_JUMP_LABEL_H */