From patchwork Thu May 27 12:51:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Quentin Perret X-Patchwork-Id: 12284081 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=-17.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 B0FAAC4707F for ; Thu, 27 May 2021 12:55:35 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7C3FE613CA for ; Thu, 27 May 2021 12:55:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7C3FE613CA Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:From:Subject:References: Mime-Version:Message-Id:In-Reply-To:Date:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=ukiihvqmCdtYpsUH3gPWRr17pd5JoVWSf8++uOSDJFw=; b=GboIki8h9A52i+rU8mpzX3Lpzl 4Gt17WvQ3Hp5SORI2w3fBHZBJOfQYeLtrYlwx9HQmGv2pnGNuJQ2E3TFTDrLQyag3w//h3pEKugNw JaF+xEF0gNa7nf86cr877SszjLLzs7cFkPNfS/F2F2b7bO7v/i82gxnIWUQ73RHHQZRbsUR08NxJa 453lnSgoCei9VWpVQ4KdGsjHTsDF/RCL3SospMX4AOw95x4BDJzykjz4QdQDKJ1za9R9Ezm+SHdyM qpqQdz+j97X5hRqkVShXk//rwCIi8LfHxtCiN5njCM7T+W7x+aZ5XhYjLJgW1mr3kFXfHNg1jPEIZ bAbASpnA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lmFVQ-005u1C-7g; Thu, 27 May 2021 12:52:56 +0000 Received: from mail-ed1-x549.google.com ([2a00:1450:4864:20::549]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lmFUH-005tRg-IX for linux-arm-kernel@lists.infradead.org; Thu, 27 May 2021 12:51:47 +0000 Received: by mail-ed1-x549.google.com with SMTP id x3-20020a50ba830000b029038caed0dd2eso266856ede.7 for ; Thu, 27 May 2021 05:51:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=gi5cRmDtyloWJMITCIj/sPnhDqshqX/If7D8pZ+Fco8=; b=DMh/PwjeROpCuIsXL8vRKNGEi9sHS19ekOOPLJW/yYZpcAXKCDh4kFuF6iI/aU1kMl Gd3tI584HoLn+kctQ7quFOApvKA4kHemuJ26RXQjx3fbsek7WyRVBTy4z/hDTF8/7CEL zxQX0nPp35II7RVacLFWT/l/To+3fVcczDHqZzs1XFABFaNr9SgLwX30EBRUuUMGhiEz 5euHTt9w+mN6fCrPAsZ1YWV8quDogTUAATc6+C9p/KeVUkcsAtPRHini8QK1D0L79neA NUHURMi7p+5iRahsNBMDoS6FlUOqIo57NM1IYG8tkhwHWec9RAnj7z1x/hxWSkIx0PPp axhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=gi5cRmDtyloWJMITCIj/sPnhDqshqX/If7D8pZ+Fco8=; b=rwiqyhFTIh8vS73Cb4nNeU02za83VT3r3vQI2gI0rw1JwOW1Tdljw67K+Sn3CdfXe+ 73b8SVnpz31F/LxZHOmHbYKdzxLn0agzNXgLf08ymrBetQ7pybmkOwMufhp3f/yV99An Bggf5AQ5sd0vtXJJF9V8a4LTyRBqirJZBi3OfToeNmB+pSTilGDB1nt/Yen/msi2mFgn Jo74Y/hyAxsrf85JD2pJ40iUBiDgahXNS4+xi0K3OWww++6uneu+2icJiMfYPGaski+i SvIxiOFkO5GAQ4CzZcLfRpvv3dUlmcAw1Ye7KuahqaOS522kCmznC1sb+A+tYJtmlT3a 1FAg== X-Gm-Message-State: AOAM530yQuQ2lSmJcR5DzdUuSrj+/090eC2BeLG64mqQyDNwjX3YDazz vVOvcK3eXItwPmlxS5Z107CNmpuzQtyC X-Google-Smtp-Source: ABdhPJwlv3mU0dZTO0kFr4Yy4f9wIZtT5gFLjr+4vvIMhKkBy7e5WNSw28epAMZVLsvaNdTluQlcqCDUf204 X-Received: from r2d2-qp.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:1652]) (user=qperret job=sendgmr) by 2002:a17:907:770a:: with SMTP id kw10mr3675153ejc.213.1622119903222; Thu, 27 May 2021 05:51:43 -0700 (PDT) Date: Thu, 27 May 2021 12:51:30 +0000 In-Reply-To: <20210527125134.2116404-1-qperret@google.com> Message-Id: <20210527125134.2116404-4-qperret@google.com> Mime-Version: 1.0 References: <20210527125134.2116404-1-qperret@google.com> X-Mailer: git-send-email 2.31.1.818.g46aad6cb9e-goog Subject: [PATCH 3/7] KVM: arm64: Remove list_head from hyp_page From: Quentin Perret To: maz@kernel.org, will@kernel.org, james.morse@arm.com, alexandru.elisei@arm.com, catalin.marinas@arm.com, suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kernel-team@android.com, linux-kernel@vger.kernel.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210527_055145_662943_3E5F19EE X-CRM114-Status: GOOD ( 19.57 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The list_head member of struct hyp_page is only needed when the page is attached to a free-list, which by definition implies the page is free. As such, nothing prevents us from using the page itself to store the list_head, hence reducing the size of the vmemmap. Signed-off-by: Quentin Perret --- arch/arm64/kvm/hyp/include/nvhe/memory.h | 1 - arch/arm64/kvm/hyp/nvhe/page_alloc.c | 39 ++++++++++++++++++++---- 2 files changed, 33 insertions(+), 7 deletions(-) diff --git a/arch/arm64/kvm/hyp/include/nvhe/memory.h b/arch/arm64/kvm/hyp/include/nvhe/memory.h index fd78bde939ee..7691ab495eb4 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/memory.h +++ b/arch/arm64/kvm/hyp/include/nvhe/memory.h @@ -12,7 +12,6 @@ struct hyp_page { unsigned int refcount; unsigned int order; struct hyp_pool *pool; - struct list_head node; }; extern u64 __hyp_vmemmap; diff --git a/arch/arm64/kvm/hyp/nvhe/page_alloc.c b/arch/arm64/kvm/hyp/nvhe/page_alloc.c index 7ee882f36767..ce7379f1480b 100644 --- a/arch/arm64/kvm/hyp/nvhe/page_alloc.c +++ b/arch/arm64/kvm/hyp/nvhe/page_alloc.c @@ -62,6 +62,34 @@ static struct hyp_page *__find_buddy_avail(struct hyp_pool *pool, } +/* + * Pages that are available for allocation are tracked in free-lists, so we use + * the pages themselves to store the list nodes to avoid wasting space. As the + * allocator always returns zeroed pages (which are zeroed on the hyp_put_page() + * path to optimize allocation speed), we also need to clean-up the list node in + * each page when we take it out of the list. + */ +static inline void page_remove_from_list(struct hyp_page *p) +{ + struct list_head *node = (struct list_head *)hyp_page_to_virt(p); + + __list_del_entry(node); + memset(node, 0, sizeof(*node)); +} + +static inline void page_add_to_list(struct hyp_page *p, struct list_head *head) +{ + struct list_head *node = (struct list_head *)hyp_page_to_virt(p); + + INIT_LIST_HEAD(node); + list_add_tail(node, head); +} + +static inline struct hyp_page *node_to_page(struct list_head *node) +{ + return (struct hyp_page *)hyp_virt_to_page(node); +} + static void __hyp_attach_page(struct hyp_pool *pool, struct hyp_page *p) { @@ -83,14 +111,14 @@ static void __hyp_attach_page(struct hyp_pool *pool, break; /* Take the buddy out of its list, and coallesce with @p */ - list_del_init(&buddy->node); + page_remove_from_list(buddy); buddy->order = HYP_NO_ORDER; p = min(p, buddy); } /* Mark the new head, and insert it */ p->order = order; - list_add_tail(&p->node, &pool->free_area[order]); + page_add_to_list(p, &pool->free_area[order]); } static struct hyp_page *__hyp_extract_page(struct hyp_pool *pool, @@ -99,7 +127,7 @@ static struct hyp_page *__hyp_extract_page(struct hyp_pool *pool, { struct hyp_page *buddy; - list_del_init(&p->node); + page_remove_from_list(p); while (p->order > order) { /* * The buddy of order n - 1 currently has HYP_NO_ORDER as it @@ -110,7 +138,7 @@ static struct hyp_page *__hyp_extract_page(struct hyp_pool *pool, p->order--; buddy = __find_buddy_nocheck(pool, p, p->order); buddy->order = p->order; - list_add_tail(&buddy->node, &pool->free_area[buddy->order]); + page_add_to_list(buddy, &pool->free_area[buddy->order]); } return p; @@ -158,7 +186,7 @@ void *hyp_alloc_pages(struct hyp_pool *pool, unsigned int order) } /* Extract it from the tree at the right order */ - p = list_first_entry(&pool->free_area[i], struct hyp_page, node); + p = node_to_page(pool->free_area[i].next); p = __hyp_extract_page(pool, p, order); hyp_set_page_refcounted(p); @@ -186,7 +214,6 @@ int hyp_pool_init(struct hyp_pool *pool, u64 pfn, unsigned int nr_pages, for (i = 0; i < nr_pages; i++) { p[i].pool = pool; p[i].order = 0; - INIT_LIST_HEAD(&p[i].node); hyp_set_page_refcounted(&p[i]); }