From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8FB50C433DF for ; Thu, 2 Jul 2020 20:07:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FD9E2088E for ; Thu, 2 Jul 2020 20:07:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UwA+SCdq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726074AbgGBUHn (ORCPT ); Thu, 2 Jul 2020 16:07:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725915AbgGBUHm (ORCPT ); Thu, 2 Jul 2020 16:07:42 -0400 Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0EE02C08C5C1 for ; Thu, 2 Jul 2020 13:07:42 -0700 (PDT) Received: by mail-wm1-x341.google.com with SMTP id l17so28749696wmj.0 for ; Thu, 02 Jul 2020 13:07:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=dwcOL44/6/46bE3/0vVlUgkMmYErY370J4sDOgg59nk=; b=UwA+SCdqUguWwxxLckgnzNztsdeZeLfjkurpCiyiRk1X1kD6IHn76V5vHvpE5o48Yc AkNrUoJ7i9npVnssaVzLY7P3EER6cUYBDho+siALS7Wg+S/qb0c9VtDSvOSgqCk7vu5n 96VNdLAcbAzoWZqDZl6O5Bu4ZN5FFZQeeYvJ+xUV4o+NPM6OBsJW6OghiLq47/4z4bIG rlopFHv4JOHS1zP4dWGApHMoIkuWMH52wKT7zKNWZVs5tqJs2FeN7H/HnsdZdbQSgijY FkUgGl0I2pge5Dj4oz9Ok3WgUPMOxWzWVk8XHemO5iV13ZxmQI6RffLSfogdTf0IIYT1 GrTg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=dwcOL44/6/46bE3/0vVlUgkMmYErY370J4sDOgg59nk=; b=bc0rh1OT4Iec43uyXgcIiTODMD7D/o2c7hwFXFE68vCs/ATzBNUx5lKCP53X6n6msx qu3zcI9ga1bD74H4kz+MNOUMlD1TNIhgGYnpPVi3x7reQH8+b7i/x5IJfT8VvLP5+FJJ rhZEeT3yoP8a3LVBTPiCAFXlsJ9jRY+RchvC86buxjB/7tWW+I6F4o/Cnyouq+CTiCYd 0HZ2hu10IB34xWuh8J6m+vrpkzIP/nGt1qzVJDWcb80YkQ+breAKm4v7QZnc3cc/wyZJ Z5wCjOgC2sfpkmoBq8iUs3B9u/ppa8LEr4jZxOTUu5RqNf2CgdDqiOSOik5ZpGVd/ZTK kf4A== X-Gm-Message-State: AOAM5317B0YRHgWdFZsns3tk3qs0yQlbChD9A/pts33scTkYJmzmJMco 4BrLwEvkjNTwUjdbXO3sRzYMXEg4V+I= X-Google-Smtp-Source: ABdhPJzFARY6FE78ZvF/8RPjaMM8SxlV/4oa1w6Phs+euFFJvB8dZKlxPA66UHi/PKGIWpD0qKf35A== X-Received: by 2002:a1c:a7ca:: with SMTP id q193mr33537422wme.69.1593720460773; Thu, 02 Jul 2020 13:07:40 -0700 (PDT) Received: from localhost.localdomain ([80.71.140.73]) by smtp.gmail.com with ESMTPSA id t15sm11699463wmj.14.2020.07.02.13.07.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Jul 2020 13:07:40 -0700 (PDT) From: Emil Renner Berthing To: linux-riscv@lists.infradead.org Cc: Emil Renner Berthing , Palmer Dabbelt , Paul Walmsley , Anup Patel , Atish Patra , linux-kernel@vger.kernel.org Subject: [RFC] riscv: Add jump-label implementation Date: Thu, 2 Jul 2020 22:07:27 +0200 Message-Id: <20200702200727.239348-1-kernel@esmil.dk> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add basic jump-label implementation heavily based on the ARM64 version. Tested on the HiFive Unleashed. Signed-off-by: Emil Renner Berthing --- This seems to work on my HiFive Unleashed. At least boots, runs fine and the static key self-tests doesn't complain, but I'm sure I've missed something, so I'm sending this as an RFC. /Emil .../core/jump-labels/arch-support.txt | 2 +- arch/riscv/Kconfig | 2 + arch/riscv/include/asm/jump_label.h | 59 +++++++++++++++++++ arch/riscv/kernel/Makefile | 2 + arch/riscv/kernel/jump_label.c | 44 ++++++++++++++ 5 files changed, 108 insertions(+), 1 deletion(-) create mode 100644 arch/riscv/include/asm/jump_label.h create mode 100644 arch/riscv/kernel/jump_label.c diff --git a/Documentation/features/core/jump-labels/arch-support.txt b/Documentation/features/core/jump-labels/arch-support.txt index 632a1c7aefa2..760243d18ed7 100644 --- a/Documentation/features/core/jump-labels/arch-support.txt +++ b/Documentation/features/core/jump-labels/arch-support.txt @@ -23,7 +23,7 @@ | openrisc: | TODO | | parisc: | ok | | powerpc: | ok | - | riscv: | TODO | + | riscv: | ok | | s390: | ok | | sh: | TODO | | sparc: | ok | diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index fd639937e251..d2f5c53fdc19 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -46,6 +46,8 @@ config RISCV select GENERIC_TIME_VSYSCALL if MMU && 64BIT select HANDLE_DOMAIN_IRQ select HAVE_ARCH_AUDITSYSCALL + select HAVE_ARCH_JUMP_LABEL + select HAVE_ARCH_JUMP_LABEL_RELATIVE select HAVE_ARCH_KASAN if MMU && 64BIT select HAVE_ARCH_KGDB select HAVE_ARCH_KGDB_QXFER_PKT diff --git a/arch/riscv/include/asm/jump_label.h b/arch/riscv/include/asm/jump_label.h new file mode 100644 index 000000000000..29be6d351866 --- /dev/null +++ b/arch/riscv/include/asm/jump_label.h @@ -0,0 +1,59 @@ +/* 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 + +#define JUMP_LABEL_NOP_SIZE 4 + +static __always_inline bool arch_static_branch(struct static_key *key, + bool branch) +{ + asm_volatile_goto( + " .option push \n\n" + " .option norelax \n\n" + " .option norvc \n\n" + "1: nop \n\t" + " .option pop \n\n" + " .pushsection __jump_table, \"aw\" \n\t" + " .align 3 \n\t" + " .long 1b - ., %l[l_yes] - . \n\t" + " .quad %0 - . \n\t" + " .popsection \n\t" + : : "i"(&((char *)key)[branch ? 1 : 0]) : : l_yes); + + return false; +l_yes: + return true; +} + +static __always_inline bool arch_static_branch_jump(struct static_key *key, + bool branch) +{ + asm_volatile_goto( + " .option push \n\n" + " .option norelax \n\n" + " .option norvc \n\n" + "1: jal zero, %l[l_yes] \n\t" + " .option pop \n\n" + " .pushsection __jump_table, \"aw\" \n\t" + " .align 3 \n\t" + " .long 1b - ., %l[l_yes] - . \n\t" + " .quad %0 - . \n\t" + " .popsection \n\t" + : : "i"(&((char *)key)[branch ? 1 : 0]) : : l_yes); + + return false; +l_yes: + return true; +} + +#endif /* __ASSEMBLY__ */ +#endif /* __ASM_JUMP_LABEL_H */ diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index b355cf485671..a5287ab9f7f2 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -53,4 +53,6 @@ endif obj-$(CONFIG_HOTPLUG_CPU) += cpu-hotplug.o obj-$(CONFIG_KGDB) += kgdb.o +obj-$(CONFIG_JUMP_LABEL) += jump_label.o + clean: diff --git a/arch/riscv/kernel/jump_label.c b/arch/riscv/kernel/jump_label.c new file mode 100644 index 000000000000..55b2d742efe1 --- /dev/null +++ b/arch/riscv/kernel/jump_label.c @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Emil Renner Berthing + * + * Based on arch/arm64/kernel/jump_label.c + */ +#include +#include +#include + +#define RISCV_INSN_NOP 0x00000013 +#define RISCV_INSN_JAL 0x0000006f + +void arch_jump_label_transform(struct jump_entry *entry, + enum jump_label_type type) +{ + void *addr = (void *)jump_entry_code(entry); + u32 insn; + + if (type == JUMP_LABEL_JMP) { + u32 offset = jump_entry_target(entry) - jump_entry_code(entry); + + insn = RISCV_INSN_JAL | + ((offset & GENMASK(19, 12)) << (12 - 12)) | + ((offset & GENMASK(11, 11)) << (20 - 11)) | + ((offset & GENMASK(10, 1)) << (21 - 1)) | + ((offset & GENMASK(20, 20)) << (31 - 20)); + } else + insn = RISCV_INSN_NOP; + + patch_text_nosync(addr, &insn, sizeof(insn)); +} + +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. + */ +} -- 2.27.0