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-rw-r--r--arch/riscv/include/asm/jump_label.h62
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/jump_label.h b/arch/riscv/include/asm/jump_label.h
new file mode 100644
index 000000000..14a5ea8d8
--- /dev/null
+++ b/arch/riscv/include/asm/jump_label.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 Emil Renner Berthing
+ *
+ * Based on arch/arm64/include/asm/jump_label.h
+ */
+#ifndef __ASM_JUMP_LABEL_H
+#define __ASM_JUMP_LABEL_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+#include <asm/asm.h>
+
+#define JUMP_LABEL_NOP_SIZE 4
+
+static __always_inline bool arch_static_branch(struct static_key * const key,
+ const bool branch)
+{
+ asm_volatile_goto(
+ " .align 2 \n\t"
+ " .option push \n\t"
+ " .option norelax \n\t"
+ " .option norvc \n\t"
+ "1: nop \n\t"
+ " .option pop \n\t"
+ " .pushsection __jump_table, \"aw\" \n\t"
+ " .align " RISCV_LGPTR " \n\t"
+ " .long 1b - ., %l[label] - . \n\t"
+ " " RISCV_PTR " %0 - . \n\t"
+ " .popsection \n\t"
+ : : "i"(&((char *)key)[branch]) : : label);
+
+ return false;
+label:
+ return true;
+}
+
+static __always_inline bool arch_static_branch_jump(struct static_key * const key,
+ const bool branch)
+{
+ asm_volatile_goto(
+ " .align 2 \n\t"
+ " .option push \n\t"
+ " .option norelax \n\t"
+ " .option norvc \n\t"
+ "1: jal zero, %l[label] \n\t"
+ " .option pop \n\t"
+ " .pushsection __jump_table, \"aw\" \n\t"
+ " .align " RISCV_LGPTR " \n\t"
+ " .long 1b - ., %l[label] - . \n\t"
+ " " RISCV_PTR " %0 - . \n\t"
+ " .popsection \n\t"
+ : : "i"(&((char *)key)[branch]) : : label);
+
+ return false;
+label:
+ return true;
+}
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_JUMP_LABEL_H */