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authorYouling Tang <tangyouling@loongson.cn>2023-06-29 20:58:44 +0800
committerHuacai Chen <chenhuacai@loongson.cn>2023-06-29 20:58:44 +0800
commitf02644e32c9e4bd1a9b286dc0b84f9cbe294f4e2 (patch)
tree3742c78f2f4c61b1463b9a40c98835182ed6ac13 /arch/loongarch
parent5d553770409de4a98a8c4f8c014559725dcfaa37 (diff)
LoongArch: Add jump-label implementation
Add support for jump labels based on the ARM64 version. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch')
-rw-r--r--arch/loongarch/Kconfig2
-rw-r--r--arch/loongarch/include/asm/jump_label.h50
-rw-r--r--arch/loongarch/kernel/Makefile2
-rw-r--r--arch/loongarch/kernel/jump_label.c22
4 files changed, 76 insertions, 0 deletions
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 8c7b67eca838..64cdc6802295 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -87,6 +87,8 @@ config LOONGARCH
select GPIOLIB
select HAS_IOPORT
select HAVE_ARCH_AUDITSYSCALL
+ select HAVE_ARCH_JUMP_LABEL
+ select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_MMAP_RND_BITS if MMU
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_TRACEHOOK
diff --git a/arch/loongarch/include/asm/jump_label.h b/arch/loongarch/include/asm/jump_label.h
new file mode 100644
index 000000000000..3cea299a5ef5
--- /dev/null
+++ b/arch/loongarch/include/asm/jump_label.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2023 Loongson Technology Corporation Limited
+ *
+ * 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>
+
+#define JUMP_LABEL_NOP_SIZE 4
+
+#define JUMP_TABLE_ENTRY \
+ ".pushsection __jump_table, \"aw\" \n\t" \
+ ".align 3 \n\t" \
+ ".long 1b - ., %l[l_yes] - . \n\t" \
+ ".quad %0 - . \n\t" \
+ ".popsection \n\t"
+
+static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)
+{
+ asm_volatile_goto(
+ "1: nop \n\t"
+ JUMP_TABLE_ENTRY
+ : : "i"(&((char *)key)[branch]) : : l_yes);
+
+ return false;
+
+l_yes:
+ return true;
+}
+
+static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch)
+{
+ asm_volatile_goto(
+ "1: b %l[l_yes] \n\t"
+ JUMP_TABLE_ENTRY
+ : : "i"(&((char *)key)[branch]) : : l_yes);
+
+ return false;
+
+l_yes:
+ return true;
+}
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_JUMP_LABEL_H */
diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile
index 9a72d91cd104..64ea76f60e2c 100644
--- a/arch/loongarch/kernel/Makefile
+++ b/arch/loongarch/kernel/Makefile
@@ -54,4 +54,6 @@ obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_KPROBES) += kprobes.o kprobes_trampoline.o
+obj-$(CONFIG_JUMP_LABEL) += jump_label.o
+
CPPFLAGS_vmlinux.lds := $(KBUILD_CFLAGS)
diff --git a/arch/loongarch/kernel/jump_label.c b/arch/loongarch/kernel/jump_label.c
new file mode 100644
index 000000000000..31891214b767
--- /dev/null
+++ b/arch/loongarch/kernel/jump_label.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Loongson Technology Corporation Limited
+ *
+ * Based on arch/arm64/kernel/jump_label.c
+ */
+#include <linux/kernel.h>
+#include <linux/jump_label.h>
+#include <asm/inst.h>
+
+void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type)
+{
+ u32 insn;
+ void *addr = (void *)jump_entry_code(entry);
+
+ if (type == JUMP_LABEL_JMP)
+ insn = larch_insn_gen_b(jump_entry_code(entry), jump_entry_target(entry));
+ else
+ insn = larch_insn_gen_nop();
+
+ larch_insn_patch_text(addr, insn);
+}