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=-17.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,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 4BF0CC47088 for ; Wed, 26 May 2021 20:11:57 +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 113C96109F for ; Wed, 26 May 2021 20:11:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 113C96109F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=T+/mnH/EEozShtpcPYeVmDOZlRIvoTnkUSboGV6EPD0=; b=MYKWfYqKW/9Ufc B90p8CXmd+voF9Rs/G5I7+sYdkNnZPWI576Z9qQ4T0m/NtuMV0VLeaz3kXp3oZe9QiQvP8Df959iP EZAFLNuBkXpMDSf7ypuWH+yvvRfrP+PHi3dLv2748QSPDqeh90etfk1VqLSV/imc9E5zuHvATE5wO BfSk7EdfhQCV60Qx9Lf39kKKCd7FE5qYPaR8h3sbCuRw/p7aLrudKwJOC6YfpioN4DOGc1FUO7GxY 8EwHXFnOZQu7yLA2eLFXt85BR8Pub3B8OdC2RTPHlbu9aGB1QQuhmfhI6dcqkBBDDK5pryoWjRCuh Oijqf20VMgGBa7+d8y+Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1llzqp-00HGys-QS; Wed, 26 May 2021 20:10:00 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1llyqg-00GoOq-T0; Wed, 26 May 2021 19:05:49 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 807CB613CC; Wed, 26 May 2021 19:05:46 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1llyqe-003o26-RV; Wed, 26 May 2021 20:05:44 +0100 From: Marc Zyngier To: kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Ard Biesheuvel , Mark Rutland , James Morse , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Eric Biederman , Bhupesh SHARMA , AKASHI Takahiro , Dave Young , Moritz Fischer , kernel-team@android.com Subject: [PATCH 3/4] kernel/resource: Add walk_excluding_child_res() helper Date: Wed, 26 May 2021 20:05:30 +0100 Message-Id: <20210526190531.62751-4-maz@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210526190531.62751-1-maz@kernel.org> References: <20210526190531.62751-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, ardb@kernel.org, mark.rutland@arm.com, james.morse@arm.com, lorenzo.pieralisi@arm.com, guohanjun@huawei.com, sudeep.holla@arm.com, ebiederm@xmission.com, bhupesh.sharma@linaro.org, takahiro.akashi@linaro.org, dyoung@redhat.com, mdf@kernel.org, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210526_120547_054031_63D072AA X-CRM114-Status: GOOD ( 21.64 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Once we have obtained a resource of a certain type from find_next_iomem_res(), it doesn't necessarily mean that the whole resource is usable, and we have cases where a child resource denotes an exclusion in the initial resource. Provide a new walker that deals with this exact case, and calls a callback on each resource fragment that doesn't have a child. Signed-off-by: Marc Zyngier --- include/linux/ioport.h | 4 +++ kernel/resource.c | 80 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 84 insertions(+) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 8359c50f9988..526314a42ad2 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -323,6 +323,10 @@ extern int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end, void *arg, int (*func)(struct resource *, void *)); +extern int +walk_excluding_child_res(struct resource *res, void *arg, + int (*func)(struct resource *, void *)); + struct resource *devm_request_free_mem_region(struct device *dev, struct resource *base, unsigned long size); struct resource *request_free_mem_region(struct resource *base, diff --git a/kernel/resource.c b/kernel/resource.c index 311b8d2c9957..1d9b5f653938 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -318,6 +318,86 @@ int release_resource(struct resource *old) EXPORT_SYMBOL(release_resource); +/** + * walk_excluding_child_res - call a callback function on each fragment of + * a resource that do not have a child resource + * + * @res: the root resource containing the initial range + * @arg: function argument for the callback @func + * @func: callback function that is called for each qualifying resource area + * + * For a given resource, remove all the child resources and feed the + * resulting fragments to kexec_locate_mem_hole_callback(). + */ +int walk_excluding_child_res(struct resource *res, void *arg, + int (*func)(struct resource *, void *)) +{ + struct resource *tmp, cursor; + int ret = 0; + + cursor = *res; + + /* Use .child for the head of the list, .sibling for the tail */ + cursor.child = cursor.sibling = NULL; + + read_lock(&resource_lock); + + for (tmp = res->child; tmp; tmp = tmp->sibling) { + struct resource *new; + + if (cursor.start < tmp->start) { + new = kmalloc(sizeof(*new), GFP_KERNEL); + if (!new) + goto cleanup; + + *new = (struct resource) { + .start = cursor.start, + .end = tmp->start - 1, + .flags = res->flags, + .desc = res->desc, + .parent = res->parent, + }; + + if (!cursor.child) + cursor.child = new; + if (cursor.sibling) + cursor.sibling->sibling = new; + cursor.sibling = new; + } + + /* + * This may result in a resource with a negative size + * at the very end of the loop. + */ + cursor.start = tmp->end + 1; + } + + read_unlock(&resource_lock); + + /* + * At this stage, the list pointed to by cursor.child contains + * every non-reserved blocks, completed by 'cursor' which + * contains the potential last block (may be empty). + */ + for (tmp = cursor.child; tmp; tmp = tmp->sibling) { + ret = func(tmp, arg); + if (ret) + break; + } + + if (!ret && cursor.start <= cursor.end) + ret = func(&cursor, tmp); + +cleanup: + while (cursor.child) { + tmp = cursor.child; + cursor.child = cursor.child->sibling; + kfree(tmp); + } + + return ret; +} + /** * find_next_iomem_res - Finds the lowest iomem resource that covers part of * [@start..@end]. -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel