From patchwork Sat Sep 10 15:49:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 12972575 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 58DE2C6FA82 for ; Sat, 10 Sep 2022 15:50:29 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.404810.647428 (Exim 4.92) (envelope-from ) id 1oX2kP-0005Vh-7q; Sat, 10 Sep 2022 15:50:21 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 404810.647428; Sat, 10 Sep 2022 15:50:21 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oX2kP-0005VU-4l; Sat, 10 Sep 2022 15:50:21 +0000 Received: by outflank-mailman (input) for mailman id 404810; Sat, 10 Sep 2022 15:50:20 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oX2kO-0004BJ-As for xen-devel@lists.xenproject.org; Sat, 10 Sep 2022 15:50:20 +0000 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 4598fd20-3120-11ed-9760-273f2230c3a0; Sat, 10 Sep 2022 17:50:19 +0200 (CEST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 64A0621B67; Sat, 10 Sep 2022 15:50:19 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 2835C13441; Sat, 10 Sep 2022 15:50:19 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id SHyYCDuyHGNqZAAAMHmgww (envelope-from ); Sat, 10 Sep 2022 15:50:19 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 4598fd20-3120-11ed-9760-273f2230c3a0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1662825019; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HT/7IdQpKAQmA1bHFNkUTH+SSUmzVBMKCGG4nyC9O9s=; b=jz/mSRYOdzK5Rz8l4vKVkSxHUEgyJJvXeZvo62ktJg4xGVarCKlv5fs43igPIMlKhkKYCr 8MseAgKGswoK1fuT9PgS92W0QgQC1NGthqZiTkx3WHw8Yl6ac6z144K0Jc47QEnUE3iVGm XqM4wRxsVcicQV2bue67pHS947cm5hU= From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross , Andrew Cooper , George Dunlap , Jan Beulich , Julien Grall , Stefano Stabellini , Wei Liu Subject: [RFC PATCH 3/3] xen/spinlock: support higher number of cpus Date: Sat, 10 Sep 2022 17:49:59 +0200 Message-Id: <20220910154959.15971-4-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220910154959.15971-1-jgross@suse.com> References: <20220910154959.15971-1-jgross@suse.com> MIME-Version: 1.0 There is no real reason why the cpu fields of struct spinlock should be limited to 12 bits, now that there is a 2 byte padding hole after those fields. Make the related structures a little bit larger allowing 16 bits per cpu number, which is the limit imposed by spinlock_tickets_t. Signed-off-by: Juergen Gross --- xen/common/spinlock.c | 1 + xen/include/xen/spinlock.h | 18 +++++++++--------- 2 files changed, 10 insertions(+), 9 deletions(-) diff --git a/xen/common/spinlock.c b/xen/common/spinlock.c index a48ed17ac6..5509e4b79a 100644 --- a/xen/common/spinlock.c +++ b/xen/common/spinlock.c @@ -303,6 +303,7 @@ int _spin_trylock_recursive(struct spinlock_recursive *lock) /* Don't allow overflow of recurse_cpu field. */ BUILD_BUG_ON(NR_CPUS > SPINLOCK_NO_CPU); + BUILD_BUG_ON(SPINLOCK_CPU_BITS > sizeof(lock->recurse_cpu) * 8); BUILD_BUG_ON(SPINLOCK_RECURSE_BITS < 3); check_lock(&lock->lock.debug, true); diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h index d0cfb4c524..e157b12f6e 100644 --- a/xen/include/xen/spinlock.h +++ b/xen/include/xen/spinlock.h @@ -6,16 +6,16 @@ #include #include -#define SPINLOCK_CPU_BITS 12 +#define SPINLOCK_CPU_BITS 16 #ifdef CONFIG_DEBUG_LOCKS union lock_debug { - uint16_t val; -#define LOCK_DEBUG_INITVAL 0xffff + uint32_t val; +#define LOCK_DEBUG_INITVAL 0xffffffff struct { - uint16_t cpu:SPINLOCK_CPU_BITS; -#define LOCK_DEBUG_PAD_BITS (14 - SPINLOCK_CPU_BITS) - uint16_t :LOCK_DEBUG_PAD_BITS; + uint32_t cpu:SPINLOCK_CPU_BITS; +#define LOCK_DEBUG_PAD_BITS (30 - SPINLOCK_CPU_BITS) + uint32_t :LOCK_DEBUG_PAD_BITS; bool irq_safe:1; bool unseen:1; }; @@ -173,10 +173,10 @@ typedef struct spinlock { struct spinlock_recursive { struct spinlock lock; - u16 recurse_cpu:SPINLOCK_CPU_BITS; + uint16_t recurse_cpu; #define SPINLOCK_NO_CPU ((1u << SPINLOCK_CPU_BITS) - 1) -#define SPINLOCK_RECURSE_BITS (16 - SPINLOCK_CPU_BITS) - u16 recurse_cnt:SPINLOCK_RECURSE_BITS; +#define SPINLOCK_RECURSE_BITS 8 + uint8_t recurse_cnt; #define SPINLOCK_MAX_RECURSE ((1u << SPINLOCK_RECURSE_BITS) - 1) };