From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753197AbeDSATX (ORCPT ); Wed, 18 Apr 2018 20:19:23 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:37228 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753065AbeDSATW (ORCPT ); Wed, 18 Apr 2018 20:19:22 -0400 From: Baoquan He To: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, robh+dt@kernel.org, dan.j.williams@intel.com, nicolas.pitre@linaro.org, josh@joshtriplett.org Cc: Baoquan He , Thomas Gleixner , Brijesh Singh , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Borislav Petkov , Tom Lendacky , Wei Yang Subject: [PATCH v3 2/3] resource: add walk_system_ram_res_rev() Date: Thu, 19 Apr 2018 08:18:47 +0800 Message-Id: <20180419001848.3041-3-bhe@redhat.com> In-Reply-To: <20180419001848.3041-1-bhe@redhat.com> References: <20180419001848.3041-1-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This function, being a variant of walk_system_ram_res() introduced in commit 8c86e70acead ("resource: provide new functions to walk through resources"), walks through a list of all the resources of System RAM in reversed order, i.e., from higher to lower. It will be used in kexec_file code. Signed-off-by: Baoquan He Cc: Andrew Morton Cc: Thomas Gleixner Cc: Brijesh Singh Cc: "Jérôme Glisse" Cc: Borislav Petkov Cc: Tom Lendacky Cc: Wei Yang --- include/linux/ioport.h | 3 +++ kernel/resource.c | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 225d13d3500a..5f2cfb460a14 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -278,6 +278,9 @@ extern int walk_system_ram_res(u64 start, u64 end, void *arg, int (*func)(struct resource *, void *)); extern int +walk_system_ram_res_rev(u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)); +extern int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end, void *arg, int (*func)(struct resource *, void *)); diff --git a/kernel/resource.c b/kernel/resource.c index 4f560991c130..6c519b06e3d6 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -23,6 +23,8 @@ #include #include #include +#include +#include #include @@ -475,6 +477,44 @@ int walk_system_ram_res(u64 start, u64 end, void *arg, } /* + * This function, being a variant of walk_system_ram_res(), calls the @func + * callback against all memory ranges of type System RAM which are marked as + * IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY in reversed order, i.e., from + * higher to lower. + */ +int walk_system_ram_res_rev(u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)) +{ + unsigned long flags; + struct resource *res; + int ret = -1; + + flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + + read_lock(&resource_lock); + list_for_each_entry_reverse(res, &iomem_resource.child, sibling) { + if (start >= end) + break; + if ((res->flags & flags) != flags) + continue; + if (res->desc != IORES_DESC_NONE) + continue; + if (res->end < start) + break; + + if ((res->end >= start) && (res->start < end)) { + ret = (*func)(res, arg); + if (ret) + break; + } + end = res->start - 1; + + } + read_unlock(&resource_lock); + return ret; +} + +/* * This function calls the @func callback against all memory ranges, which * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY. */ -- 2.13.6