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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 853B4CD342C for ; Wed, 6 May 2026 14:51:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=oQpUzOuM6UHL5MR8Yl9UG08QHq3QgEJ/816hCLFUfBw=; b=z6kJXogDQQHa0hkO8PYMjDnZHe /vDI6nyiJqd3bp/c0yOtRLfmgHU9UoTCthIssIWGS049StcMN3O0tM7YXcsa45yNmlwHrjUCXNiGz 8oFw6e9yFk0FSpXzKHqIpxcW4r342cELE+MqtXZFOQbiVDHnDb0Eom0CW3Ox/+w7pE7OTRsT/NNyz EwFJjekFmEmJP3HxhO2CRct0TRh+uyVdfoV6R31GbiMLQ7q1TOkccu7ELyvFodXsGnTWeiCPBmnoa z23vZ+ZjPZV8aPqKBBfelgX2vsAamq6/i0rbaMCoa5R5vbtZig1WMsQmQjGp4zao0Id9b5yYd/ZCl 7ReCL2uQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wKdaT-00000001AeD-1XgS; Wed, 06 May 2026 14:50:57 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wKdaR-00000001AdE-1Tuu; Wed, 06 May 2026 14:50:55 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id C95D360139; Wed, 6 May 2026 14:50:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B0ADC2BCB0; Wed, 6 May 2026 14:50:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778079024; bh=CZrArw/oj5KuHDK0tXBG7dLbv82g9Q+f39sVJuaaXGo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Y6TUxV34XzI+ncRRf/mLg+KIaFrcYHGltCpfI6F9PLZtKGMDFzHlEA+6uzHO1W/Ff PuipwjSYswUif3oyWQyRzZ985ozzFxYPVJAr7+dWyHDP2Am/kO0owTKxjP1hGgUlJ8 f5IfHPQOEbID0Ndb0UdMoS35ufyK8ucGEdz6QhylU9g+1Bhsc2ThDYKGw5ncod6vRB 5Mxxaqvg8h705i+G0A9OldBOWs/rtfAoxjWdFtOKLb21H8M+6dC1GP9zhEyFJoYOjS 4rImJsWyBPDPqBkbm22VTED8BEP8k8B/Ttl9xuhcH887xrMHSQ6OuJAZTqRv1rUxjh tmx8iwFEkEJvA== Date: Wed, 6 May 2026 09:50:22 -0500 From: Rob Herring To: Chen Wandun Cc: kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, akpm@linux-foundation.org, bhe@redhat.com, rppt@kernel.org, pasha.tatashin@soleen.com, pratyush@kernel.org, ruirui.yang@linux.dev, corbet@lwn.net, skhan@linuxfoundation.org, catalin.marinas@arm.com, will@kernel.org, chenhuacai@kernel.org, kernel@xen0n.name, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, saravanak@kernel.org, chenwandun@lixiang.com, zhaomeijing@lixiang.com, everyzhao@126.com Subject: Re: [PATCH 07/11] of: reserved_mem: add no-dump crash_mem exclusion helpers Message-ID: <20260506145022.GA2084721-robh@kernel.org> References: <20260429065831.1510858-1-chenwandun@lixiang.com> <20260429065831.1510858-8-chenwandun@lixiang.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260429065831.1510858-8-chenwandun@lixiang.com> 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 On Wed, Apr 29, 2026 at 02:58:27PM +0800, Chen Wandun wrote: > Provide two kdump-oriented helpers so that arch kexec_file code does > not have to open-code the no-dump filtering loop: > > - of_reserved_mem_no_dump_nr_ranges() returns the number of reserved > regions flagged with linux,no-dump. Each exclusion may split one > existing crash_mem range into two, so callers use this count to > pre-size their crash_mem allocation. > > - of_reserved_mem_exclude_no_dump() walks the reserved_mem[] array > and calls crash_exclude_mem_range() for each no-dump region. > > Both helpers are guarded by CONFIG_KEXEC_FILE; empty inline stubs are > provided for the !KEXEC_FILE case so architecture code can call them > unconditionally. > > The consumers are added in the following arm64, riscv and loongarch > patches in this series. > > Signed-off-by: Chen Wandun > Tested-by: Zhao Meijing > --- > drivers/of/of_reserved_mem.c | 54 +++++++++++++++++++++++++++++++++ > include/linux/of_reserved_mem.h | 15 +++++++++ > 2 files changed, 69 insertions(+) > > diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c > index 4b80420da2d2..038056a6408a 100644 > --- a/drivers/of/of_reserved_mem.c > +++ b/drivers/of/of_reserved_mem.c > @@ -27,6 +27,10 @@ > > #include "of_private.h" > > +#ifdef CONFIG_KEXEC_FILE > +#include > +#endif You shouldn't need ifdef around includes. > + > static struct reserved_mem reserved_mem_array[MAX_RESERVED_REGIONS] __initdata; > static struct reserved_mem *reserved_mem __refdata = reserved_mem_array; > static int total_reserved_mem_cnt = MAX_RESERVED_REGIONS; > @@ -916,6 +920,56 @@ struct reserved_mem *of_reserved_mem_lookup(struct device_node *np) > } > EXPORT_SYMBOL_GPL(of_reserved_mem_lookup); > > +#ifdef CONFIG_KEXEC_FILE Use 'if (IS_ENABLED())' within the function. > +/** > + * of_reserved_mem_no_dump_nr_ranges() - count reserved regions flagged > + * with the linux,no-dump property. > + * > + * Each such region may split an existing crash_mem range into two when > + * it is excluded, so callers can use this count to pre-size their > + * crash_mem allocation. > + */ > +unsigned int of_reserved_mem_no_dump_nr_ranges(void) > +{ > + unsigned int i, n = 0; > + > + for (i = 0; i < reserved_mem_count; i++) > + if (reserved_mem[i].no_dump) > + n++; > + return n; > +} > + > +/** > + * of_reserved_mem_exclude_no_dump() - exclude no-dump reserved regions > + * from a crash_mem list. > + * @cmem: crash memory list to modify > + * > + * Walks the reserved_mem[] array and calls crash_exclude_mem_range() for > + * every region with no_dump set. Intended to be called from arch kdump > + * code when constructing the elfcorehdr. > + * > + * Returns 0 on success, or a negative error returned by > + * crash_exclude_mem_range() on the first failure. > + */ > +int of_reserved_mem_exclude_no_dump(struct crash_mem *cmem) > +{ > + unsigned int i; > + int ret; > + > + for (i = 0; i < reserved_mem_count; i++) { > + struct reserved_mem *r = &reserved_mem[i]; > + > + if (!r->no_dump || !r->size) > + continue; > + ret = crash_exclude_mem_range(cmem, r->base, > + r->base + r->size - 1); > + if (ret) > + return ret; > + } > + return 0; > +} > +#endif /* CONFIG_KEXEC_FILE */