4 files changed, 112 insertions, 0 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 249acb9da4e3..dd4327f09ba4 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -25,6 +25,7 @@ config ARM64
         select GENERIC_STRNLEN_USER
         select GENERIC_TIME_VSYSCALL
         select HARDIRQS_SW_RESEND
+        select HAVE_ARCH_JUMP_LABEL
         select HAVE_ARCH_TRACEHOOK
         select HAVE_DEBUG_BUGVERBOSE
         select HAVE_DEBUG_KMEMLEAK
diff --git a/arch/arm64/include/asm/jump_label.h b/arch/arm64/include/asm/jump_label.h
new file mode 100644
index 000000000000..076a1c714049
--- /dev/null
+++ b/arch/arm64/include/asm/jump_label.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2013 Huawei Ltd.
+ * Author: Jiang Liu <liuj97@gmail.com>
+ *
+ * Based on arch/arm/include/asm/jump_label.h
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_JUMP_LABEL_H
+#define __ASM_JUMP_LABEL_H
+#include <linux/types.h>
+#include <asm/insn.h>
+
+#ifdef __KERNEL__
+
+#define JUMP_LABEL_NOP_SIZE             AARCH64_INSN_SIZE
+
+static __always_inline bool arch_static_branch(struct static_key *key)
+{
+        asm goto("1: nop\n\t"
+                 ".pushsection __jump_table,  \"aw\"\n\t"
+                 ".align 3\n\t"
+                 ".quad 1b, %l[l_yes], %c0\n\t"
+                 ".popsection\n\t"
+                 :  :  "i"(key) :  : l_yes);
+
+        return false;
+l_yes:
+        return true;
+}
+
+#endif /* __KERNEL__ */
+
+typedef u64 jump_label_t;
+
+struct jump_entry {
+        jump_label_t code;
+        jump_label_t target;
+        jump_label_t key;
+};
+
+#endif  /* __ASM_JUMP_LABEL_H */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 1ea7221f8853..2d4554b13410 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -19,6 +19,7 @@ arm64-obj-$(CONFIG_HW_PERF_EVENTS)	+= perf_event.o
 arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)+= hw_breakpoint.o
 arm64-obj-$(CONFIG_EARLY_PRINTK)        += early_printk.o
 arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND)   += sleep.o suspend.o
+arm64-obj-$(CONFIG_JUMP_LABEL)          += jump_label.o
 
 obj-y                                   += $(arm64-obj-y) vdso/
 obj-m                                   += $(arm64-obj-m)
diff --git a/arch/arm64/kernel/jump_label.c b/arch/arm64/kernel/jump_label.c
new file mode 100644
index 000000000000..263a166291fb
--- /dev/null
+++ b/arch/arm64/kernel/jump_label.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2013 Huawei Ltd.
+ * Author: Jiang Liu <liuj97@gmail.com>
+ *
+ * Based on arch/arm/kernel/jump_label.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/kernel.h>
+#include <linux/jump_label.h>
+#include <asm/insn.h>
+
+#ifdef HAVE_JUMP_LABEL
+
+static void __arch_jump_label_transform(struct jump_entry *entry,
+                                        enum jump_label_type type,
+                                        bool is_static)
+{
+        void *addr = (void *)entry->code;
+        u32 insn;
+
+        if (type == JUMP_LABEL_ENABLE) {
+                insn = aarch64_insn_gen_branch_imm(entry->code,
+                                                   entry->target,
+                                                   AARCH64_INSN_BRANCH_NOLINK);
+        } else {
+                insn = aarch64_insn_gen_nop();
+        }
+
+        if (is_static)
+                aarch64_insn_patch_text_nosync(addr, insn);
+        else
+                aarch64_insn_patch_text(&addr, &insn, 1);
+}
+
+void arch_jump_label_transform(struct jump_entry *entry,
+                               enum jump_label_type type)
+{
+        __arch_jump_label_transform(entry, type, false);
+}
+
+void arch_jump_label_transform_static(struct jump_entry *entry,
+                                      enum jump_label_type type)
+{
+        __arch_jump_label_transform(entry, type, true);
+}
+
+#endif  /* HAVE_JUMP_LABEL */