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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 8F244C47247 for ; Tue, 5 May 2020 14:21:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 75F6320675 for ; Tue, 5 May 2020 14:21:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729970AbgEEOVe (ORCPT ); Tue, 5 May 2020 10:21:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1729802AbgEEOPW (ORCPT ); Tue, 5 May 2020 10:15:22 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D50B4C061A0F for ; Tue, 5 May 2020 07:15:21 -0700 (PDT) Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jVyLf-0001MU-N7; Tue, 05 May 2020 16:15:03 +0200 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id 3C564FFC8D; Tue, 5 May 2020 16:15:03 +0200 (CEST) Message-Id: <20200505134904.273363275@linutronix.de> User-Agent: quilt/0.65 Date: Tue, 05 May 2020 15:44:04 +0200 From: Thomas Gleixner To: LKML Cc: x86@kernel.org, "Paul E. McKenney" , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon Subject: [patch V4 part 3 10/29] x86/idtentry: Provide macros to define/declare IDT entry points References: <20200505134354.774943181@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-transfer-encoding: 8-bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Provide DECLARE/DEFINE_IDTENTRY() macros. DEFINE_IDTENTRY() provides a wrapper which acts as the function definition. The exception handler body is just appended to it with curly brackets. The entry point is marked notrace/noprobe so that irq tracing and the enter_from_user_mode() can be moved into the C-entry point. As all C-entries use the same macro (or a later variant) the necessary entry handling can be implemented at one central place. DECLARE_IDTENTRY() provides the function prototypes: - The C entry point cfunc - The ASM entry point asm_cfunc - The XEN/PV entry point xen_asm_cfunc They all follow the same naming convention. When included from ASM code DECLARE_IDTENTRY() is a macro which emits the low level entry point in assembly by instantiating idtentry. IDTENTRY is the simplest variant which just has a pt_regs argument. It's going to be used for all exceptions which have no error code. Signed-off-by: Thomas Gleixner Reviewed-by: Alexandre Chartre --- V2: Add comments to explain the C vs. ASM variants --- arch/x86/entry/entry_32.S | 6 +++ arch/x86/entry/entry_64.S | 6 +++ arch/x86/include/asm/idtentry.h | 67 ++++++++++++++++++++++++++++++++++++++++ arch/x86/include/asm/traps.h | 2 - 4 files changed, 80 insertions(+), 1 deletion(-) --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -753,6 +753,12 @@ SYM_CODE_END(\asmsym) .endm /* + * Include the defines which emit the idt entries which are shared + * shared between 32 and 64 bit. + */ +#include + +/* * %eax: prev task * %edx: next task */ --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -700,6 +700,12 @@ SYM_CODE_END(\asmsym) .endm /* + * Include the defines which emit the idt entries which are shared + * shared between 32 and 64 bit. + */ +#include + +/* * Interrupt entry helper function. * * Entry runs with interrupts off. Stack layout at entry: --- /dev/null +++ b/arch/x86/include/asm/idtentry.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_IDTENTRY_H +#define _ASM_X86_IDTENTRY_H + +/* Interrupts/Exceptions */ +#include + +#ifndef __ASSEMBLY__ + +/** + * DECLARE_IDTENTRY - Declare functions for simple IDT entry points + * No error code pushed by hardware + * @vector: Vector number (ignored for C) + * @func: Function name of the entry point + * + * Declares three functions: + * - The ASM entry point: asm_##func + * - The XEN PV trap entry point: xen_##func (maybe unused) + * - The C handler called from the ASM entry point + * + * Note: This is the C variant of DECLARE_IDTENTRY(). As the name says it + * declares the entry points for usage in C code. There is an ASM variant + * as well which is used to emit the entry stubs in entry_32/64.S. + */ +#define DECLARE_IDTENTRY(vector, func) \ + asmlinkage void asm_##func(void); \ + asmlinkage void xen_asm_##func(void); \ + __visible void func(struct pt_regs *regs) + +/** + * DEFINE_IDTENTRY - Emit code for simple IDT entry points + * @func: Function name of the entry point + * + * @func is called from ASM entry code with interrupts disabled. + * + * The macro is written so it acts as function definition. Append the + * body with a pair of curly brackets. + * + * idtentry_enter() contains common code which has to be invoked before + * arbitrary code in the body. idtentry_exit() contains common code + * which has to run before returning to the low level assembly code. + */ +#define DEFINE_IDTENTRY(func) \ +static __always_inline void __##func(struct pt_regs *regs); \ + \ +__visible noinstr void func(struct pt_regs *regs) \ +{ \ + idtentry_enter(regs); \ + instr_begin(); \ + __##func (regs); \ + instr_end(); \ + idtentry_exit(regs); \ +} \ + \ +static __always_inline void __##func(struct pt_regs *regs) + +#else /* !__ASSEMBLY__ */ + +/* + * The ASM variants for DECLARE_IDTENTRY*() which emit the ASM entry stubs. + */ +#define DECLARE_IDTENTRY(vector, func) \ + idtentry vector asm_##func func has_error_code=0 sane=1 + +#endif /* __ASSEMBLY__ */ + +#endif --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -6,8 +6,8 @@ #include #include +#include #include /* TRAP_TRACE, ... */ -#include #define dotraplinkage __visible