jump label: Add s390 support (5373db88) · Commits · 戴 / test

arch/s390/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -88,6 +88,7 @@ config S390
		select HAVE_KERNEL_XZ
		select HAVE_GET_USER_PAGES_FAST
		select HAVE_ARCH_MUTEX_CPU_RELAX
		select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
		select ARCH_INLINE_SPIN_TRYLOCK
		select ARCH_INLINE_SPIN_TRYLOCK_BH
		select ARCH_INLINE_SPIN_LOCK

0 → 100644

+37 −0

Original line number	Diff line number	Diff line
		#ifndef _ASM_S390_JUMP_LABEL_H
		#define _ASM_S390_JUMP_LABEL_H

		#include <linux/types.h>

		#define JUMP_LABEL_NOP_SIZE 6

		#ifdef CONFIG_64BIT
		#define ASM_PTR ".quad"
		#define ASM_ALIGN ".balign 8"
		#else
		#define ASM_PTR ".long"
		#define ASM_ALIGN ".balign 4"
		#endif

		static __always_inline bool arch_static_branch(struct jump_label_key *key)
		{
		asm goto("0: brcl 0,0\n"
		".pushsection __jump_table, \"aw\"\n"
		ASM_ALIGN "\n"
		ASM_PTR " 0b, %l[label], %0\n"
		".popsection\n"
		: : "X" (key) : : label);
		return false;
		label:
		return true;
		}

		typedef unsigned long jump_label_t;

		struct jump_entry {
		jump_label_t code;
		jump_label_t target;
		jump_label_t key;
		};

		#endif

+1 −1

Original line number	Diff line number	Diff line
		@@ -23,7 +23,7 @@ CFLAGS_sysinfo.o += -Iinclude/math-emu -Iarch/s390/math-emu -w
		obj-y := bitmap.o traps.o time.o process.o base.o early.o setup.o \
		processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o \
		s390_ext.o debug.o irq.o ipl.o dis.o diag.o mem_detect.o \
		vdso.o vtime.o sysinfo.o nmi.o sclp.o
		vdso.o vtime.o sysinfo.o nmi.o sclp.o jump_label.o

		obj-y += $(if $(CONFIG_64BIT),entry64.o,entry.o)
		obj-y += $(if $(CONFIG_64BIT),reipl64.o,reipl.o)

0 → 100644

+59 −0

Original line number	Diff line number	Diff line
		/*
		* Jump label s390 support
		*
		* Copyright IBM Corp. 2011
		* Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
		*/
		#include <linux/module.h>
		#include <linux/uaccess.h>
		#include <linux/stop_machine.h>
		#include <linux/jump_label.h>
		#include <asm/ipl.h>

		#ifdef HAVE_JUMP_LABEL

		struct insn {
		u16 opcode;
		s32 offset;
		} __packed;

		struct insn_args {
		unsigned long *target;
		struct insn *insn;
		ssize_t size;
		};

		static int __arch_jump_label_transform(void *data)
		{
		struct insn_args *args = data;
		int rc;

		rc = probe_kernel_write(args->target, args->insn, args->size);
		WARN_ON_ONCE(rc < 0);
		return 0;
		}

		void arch_jump_label_transform(struct jump_entry *entry,
		enum jump_label_type type)
		{
		struct insn_args args;
		struct insn insn;

		if (type == JUMP_LABEL_ENABLE) {
		/* brcl 15,offset */
		insn.opcode = 0xc0f4;
		insn.offset = (entry->target - entry->code) >> 1;
		} else {
		/* brcl 0,0 */
		insn.opcode = 0xc004;
		insn.offset = 0;
		}

		args.target = (void *) entry->code;
		args.insn = &insn;
		args.size = JUMP_LABEL_NOP_SIZE;

		stop_machine(__arch_jump_label_transform, &args, NULL);
		}

		#endif