From patchwork Tue Sep 7 22:00:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Packard X-Patchwork-Id: 12479429 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=-16.0 required=3.0 tests=BAYES_00,DKIM_ADSP_ALL, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 70EE0C43217 for ; Tue, 7 Sep 2021 22:00:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1C83D61103 for ; Tue, 7 Sep 2021 22:00:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 1C83D61103 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id B53EE6B0072; Tue, 7 Sep 2021 18:00:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B2A3A6B0073; Tue, 7 Sep 2021 18:00:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9C8456B0074; Tue, 7 Sep 2021 18:00:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0045.hostedemail.com [216.40.44.45]) by kanga.kvack.org (Postfix) with ESMTP id 7FCDC6B0073 for ; Tue, 7 Sep 2021 18:00:45 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 2F11C181DF776 for ; Tue, 7 Sep 2021 22:00:45 +0000 (UTC) X-FDA: 78562147650.17.0512A2F Received: from elaine.keithp.com (home.keithp.com [63.227.221.253]) by imf08.hostedemail.com (Postfix) with ESMTP id D04DF30000B6 for ; Tue, 7 Sep 2021 22:00:44 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by elaine.keithp.com (Postfix) with ESMTP id 136533F30867; Tue, 7 Sep 2021 15:00:19 -0700 (PDT) X-Virus-Scanned: Debian amavisd-new at keithp.com Received: from elaine.keithp.com ([127.0.0.1]) by localhost (elaine.keithp.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id LYoWbEmDiZX3; Tue, 7 Sep 2021 15:00:18 -0700 (PDT) Received: from keithp.com (168-103-156-98.tukw.qwest.net [168.103.156.98]) by elaine.keithp.com (Postfix) with ESMTPSA id A3F673F30861; Tue, 7 Sep 2021 15:00:18 -0700 (PDT) Received: by keithp.com (Postfix, from userid 1000) id D854B1E6013A; Tue, 7 Sep 2021 15:00:40 -0700 (PDT) From: Keith Packard To: linux-kernel@vger.kernel.org Cc: Abbott Liu , Andrew Morton , Andrey Ryabinin , Anshuman Khandual , Ard Biesheuvel , Arnd Bergmann , Bjorn Andersson , Christoph Lameter , Dennis Zhou , Geert Uytterhoeven , Jens Axboe , Joe Perches , Kees Cook , Keith Packard , Krzysztof Kozlowski , Linus Walleij , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, Manivannan Sadhasivam , Marc Zyngier , Masahiro Yamada , Mike Rapoport , Nathan Chancellor , Nick Desaulniers , Nick Desaulniers , Nicolas Pitre , Russell King , Tejun Heo , Thomas Gleixner , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Valentin Schneider , Viresh Kumar , "Wolfram Sang (Renesas)" , YiFei Zhu Subject: [PATCH 4/7] ARM: Use hack from powerpc to get current cpu number Date: Tue, 7 Sep 2021 15:00:35 -0700 Message-Id: <20210907220038.91021-5-keithpac@amazon.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210907220038.91021-1-keithpac@amazon.com> References: <20210904060908.1310204-1-keithp@keithp.com> <20210907220038.91021-1-keithpac@amazon.com> MIME-Version: 1.0 Authentication-Results: imf08.hostedemail.com; dkim=none; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=amazon.com (policy=quarantine); spf=pass (imf08.hostedemail.com: domain of keithp@keithp.com designates 63.227.221.253 as permitted sender) smtp.mailfrom=keithp@keithp.com X-Stat-Signature: ubwgighwg1s1u4bnhpeirs8o1cxmu1np X-Rspamd-Queue-Id: D04DF30000B6 X-Rspamd-Server: rspam04 X-Rspam: Yes X-HE-Tag: 1631052044-178941 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: When we enable THREAD_INFO_IN_TASK, the cpu number will disappear from thread_info and reappear in task_struct. As we cannot include linux/sched.h in asm/smp.h, there's no way to use that struct type in the raw_smp_processor_id macro. Instead, a hack from the powerpc code is used. This pulls the TI_CPU offset out of asm-offsets.h and uses that to find the cpu value. Signed-off-by: Keith Packard --- arch/arm/Makefile | 8 ++++++++ arch/arm/include/asm/smp.h | 18 +++++++++++++++++- 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 415c3514573a..6752995d2914 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -284,6 +284,14 @@ stack_protector_prepare: prepare0 $(eval GCC_PLUGINS_CFLAGS += $(SSP_PLUGIN_CFLAGS)) endif +ifdef CONFIG_SMP +prepare: task_cpu_prepare + +PHONY += task_cpu_prepare +task_cpu_prepare: prepare0 + $(eval KBUILD_CFLAGS += -D_TI_CPU=$(shell awk '{if ($$2 == "TI_CPU") print $$3;}' include/generated/asm-offsets.h)) +endif + all: $(notdir $(KBUILD_IMAGE)) diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index d43b64635d77..f77ba3753bc4 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -15,7 +15,23 @@ # error " included in non-SMP build" #endif -#define raw_smp_processor_id() (current_thread_info()->cpu) +/* + * This is particularly ugly: it appears we can't actually get the + * definition of task_struct here, but we need access to the CPU this + * task is running on, which is stored in task_struct when + * THREAD_INFO_IN_TASK is set. Instead of using task_struct we're + * using TI_CPU which is extracted from asm-offsets.h by kbuild to get + * the current processor ID. + * + * This also needs to be safeguarded when building asm-offsets.s + * because at that time TI_CPU is not defined yet. + */ +#ifndef _TI_CPU +#define raw_smp_processor_id() (0) +#else +#define raw_smp_processor_id() \ + (*(unsigned int *)((void *)current_thread_info() + _TI_CPU)) +#endif struct seq_file;