Commit 4e8bb4ba authored by Guo Ren's avatar Guo Ren
Browse files

csky: Add jump-label implementation 



Add jump-label implementation for static branch

Signed-off-by: default avatarGuo Ren <guoren@linux.alibaba.com>
Signed-off-by: default avatarGuo Ren <guoren@kernel.org>
parent 01ab4649

arch/csky/Kconfig

+2 −0
Original line number Original line Diff line number Diff line
@@ -40,6 +40,8 @@ config CSKY 
	select GX6605S_TIMER if CPU_CK610

	select GX6605S_TIMER if CPU_CK610

	select HAVE_ARCH_TRACEHOOK

	select HAVE_ARCH_TRACEHOOK

	select HAVE_ARCH_AUDITSYSCALL

	select HAVE_ARCH_AUDITSYSCALL

	select HAVE_ARCH_JUMP_LABEL if !CPU_CK610

	select HAVE_ARCH_JUMP_LABEL_RELATIVE

	select HAVE_ARCH_MMAP_RND_BITS

	select HAVE_ARCH_MMAP_RND_BITS

	select HAVE_ARCH_SECCOMP_FILTER

	select HAVE_ARCH_SECCOMP_FILTER

	select HAVE_CONTEXT_TRACKING

	select HAVE_CONTEXT_TRACKING

arch/csky/include/asm/jump_label.h

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/* SPDX-License-Identifier: GPL-2.0-only */



#ifndef __ASM_CSKY_JUMP_LABEL_H

#define __ASM_CSKY_JUMP_LABEL_H



#ifndef __ASSEMBLY__



#include <linux/types.h>



#define JUMP_LABEL_NOP_SIZE 4



static __always_inline bool arch_static_branch(struct static_key *key,

					       bool branch)

{

	asm_volatile_goto(

		"1:	nop32					\n"

		"	.pushsection	__jump_table, \"aw\"	\n"

		"	.align		2			\n"

		"	.long		1b - ., %l[label] - .	\n"

		"	.long		%0 - .			\n"

		"	.popsection				\n"

		:  :  "i"(&((char *)key)[branch]) :  : label);



	return false;

label:

	return true;

}



static __always_inline bool arch_static_branch_jump(struct static_key *key,

						    bool branch)

{

	asm_volatile_goto(

		"1:	bsr32		%l[label]		\n"

		"	.pushsection	__jump_table, \"aw\"	\n"

		"	.align		2			\n"

		"	.long		1b - ., %l[label] - .	\n"

		"	.long		%0 - .			\n"

		"	.popsection				\n"

		:  :  "i"(&((char *)key)[branch]) :  : label);



	return false;

label:

	return true;

}



#endif  /* __ASSEMBLY__ */

#endif	/* __ASM_CSKY_JUMP_LABEL_H */

arch/csky/kernel/Makefile

+1 −0
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@@ -13,6 +13,7 @@ obj-$(CONFIG_STACKTRACE) += stacktrace.o 
obj-$(CONFIG_CSKY_PMU_V1)		+= perf_event.o

obj-$(CONFIG_CSKY_PMU_V1)		+= perf_event.o

obj-$(CONFIG_PERF_EVENTS)		+= perf_callchain.o

obj-$(CONFIG_PERF_EVENTS)		+= perf_callchain.o

obj-$(CONFIG_HAVE_PERF_REGS)            += perf_regs.o

obj-$(CONFIG_HAVE_PERF_REGS)            += perf_regs.o

obj-$(CONFIG_JUMP_LABEL)		+= jump_label.o





ifdef CONFIG_FUNCTION_TRACER

ifdef CONFIG_FUNCTION_TRACER

CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)

CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)

arch/csky/kernel/jump_label.c

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// SPDX-License-Identifier: GPL-2.0-only



#include <linux/jump_label.h>

#include <linux/kernel.h>

#include <linux/memory.h>

#include <linux/mutex.h>

#include <linux/uaccess.h>

#include <asm/cacheflush.h>



#define NOP32_HI	0xc400

#define NOP32_LO	0x4820

#define BSR_LINK	0xe000



void arch_jump_label_transform(struct jump_entry *entry,

			       enum jump_label_type type)

{

	unsigned long addr = jump_entry_code(entry);

	u16 insn[2];

	int ret = 0;



	if (type == JUMP_LABEL_JMP) {

		long offset = jump_entry_target(entry) - jump_entry_code(entry);



		if (WARN_ON(offset & 1 || offset < -67108864 || offset >= 67108864))

			return;



		offset = offset >> 1;



		insn[0] = BSR_LINK |

			((uint16_t)((unsigned long) offset >> 16) & 0x3ff);

		insn[1] = (uint16_t)((unsigned long) offset & 0xffff);

	} else {

		insn[0] = NOP32_HI;

		insn[1] = NOP32_LO;

	}



	ret = copy_to_kernel_nofault((void *)addr, insn, 4);

	WARN_ON(ret);



	flush_icache_range(addr, addr + 4);

}



void arch_jump_label_transform_static(struct jump_entry *entry,

				      enum jump_label_type type)

{

	/*

	 * We use the same instructions in the arch_static_branch and

	 * arch_static_branch_jump inline functions, so there's no

	 * need to patch them up here.

	 * The core will call arch_jump_label_transform  when those

	 * instructions need to be replaced.

	 */

	arch_jump_label_transform(entry, type);

}