From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754779Ab1CQQnM (ORCPT ); Thu, 17 Mar 2011 12:43:12 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.123]:64339 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937Ab1CQQmZ (ORCPT ); Thu, 17 Mar 2011 12:42:25 -0400 X-Authority-Analysis: v=1.1 cv=qyUSAyc82z9xLljZQc9ErY9Tl2GSEfqK/XYZS35I9d8= c=1 sm=0 a=djBn2BlVee0A:10 a=bbbx4UPp9XUA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=VnNF1IyMAAAA:8 a=20KFwNOVAAAA:8 a=meVymXHHAAAA:8 a=Mc-_X80uJyPRC93ysRcA:9 a=MsmttncK34YbfjpuqkAA:7 a=N_9okJ8NxBtNaBSf5o2L6EyLEr4A:4 a=jEp0ucaQiEUA:10 a=jeBq3FmKZ4MA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Message-Id: <20110317164223.734998786@goodmis.org> User-Agent: quilt/0.48-1 Date: Thu, 17 Mar 2011 12:41:52 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Peter Zijlstra , Frederic Weisbecker , Jan Glauber , Martin Schwidefsky Subject: [PATCH 4/4] jump label: Add s390 support References: <20110317164148.550876008@goodmis.org> Content-Disposition: inline; filename=0004-jump-label-Add-s390-support.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jan Glauber Implement the architecture backend for jump label support on s390. For a shared kernel booted from a NSS silently disable jump labels because the NSS is read-only. Therefore jump labels will be disabled in a shared kernel and can't be activated. Signed-off-by: Jan Glauber LKML-Reference: <6935d2c41ce111e1719176ed4bbd3dbe4de80855.1300299760.git.jbaron@redhat.com> Signed-off-by: Martin Schwidefsky Signed-off-by: Steven Rostedt --- arch/s390/Kconfig | 1 + arch/s390/include/asm/jump_label.h | 37 ++++++++++++++++++++++ arch/s390/kernel/Makefile | 2 +- arch/s390/kernel/jump_label.c | 59 ++++++++++++++++++++++++++++++++++++ 4 files changed, 98 insertions(+), 1 deletions(-) create mode 100644 arch/s390/include/asm/jump_label.h create mode 100644 arch/s390/kernel/jump_label.c diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 636bcb8..0739c8b 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -87,6 +87,7 @@ config S390 select HAVE_KERNEL_LZO 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 diff --git a/arch/s390/include/asm/jump_label.h b/arch/s390/include/asm/jump_label.h new file mode 100644 index 0000000..95a6cf2 --- /dev/null +++ b/arch/s390/include/asm/jump_label.h @@ -0,0 +1,37 @@ +#ifndef _ASM_S390_JUMP_LABEL_H +#define _ASM_S390_JUMP_LABEL_H + +#include + +#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 diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index 64230bc..5ff15da 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -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) diff --git a/arch/s390/kernel/jump_label.c b/arch/s390/kernel/jump_label.c new file mode 100644 index 0000000..44cc06b --- /dev/null +++ b/arch/s390/kernel/jump_label.c @@ -0,0 +1,59 @@ +/* + * Jump label s390 support + * + * Copyright IBM Corp. 2011 + * Author(s): Jan Glauber + */ +#include +#include +#include +#include +#include + +#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 -- 1.7.2.3