From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752106AbeCVDhq (ORCPT ); Wed, 21 Mar 2018 23:37:46 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:39792 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751728AbeCVDhm (ORCPT ); Wed, 21 Mar 2018 23:37:42 -0400 From: Baoquan He To: linux-kernel@vger.kernel.org Cc: kexec@lists.infradead.org, akpm@linux-foundation.org, takahiro.akashi@linaro.org, ebiederm@xmission.com, vgoyal@redhat.com, dyoung@redhat.com, prudo@linux.vnet.ibm.com, Baoquan He Subject: [PATCH 1/2] resource: add walk_system_ram_res_rev() Date: Thu, 22 Mar 2018 11:37:21 +0800 Message-Id: <20180322033722.9279-2-bhe@redhat.com> In-Reply-To: <20180322033722.9279-1-bhe@redhat.com> References: <20180322033722.9279-1-bhe@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: AKASHI Takahiro 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: AKASHI Takahiro Signed-off-by: Baoquan He --- include/linux/ioport.h | 3 +++ kernel/resource.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 66 insertions(+) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index da0ebaec25f0..f12d95fe038b 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -277,6 +277,9 @@ 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 e270b5048988..f456fc95f1b2 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -23,6 +23,8 @@ #include #include #include +#include +#include #include @@ -470,6 +472,67 @@ 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 *)) +{ + struct resource res, *rams; + int rams_size = 16, i; + int ret = -1; + + /* create a list */ + rams = vmalloc(sizeof(struct resource) * rams_size); + if (!rams) + return ret; + + res.start = start; + res.end = end; + res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + i = 0; + while ((res.start < res.end) && + (!find_next_iomem_res(&res, IORES_DESC_NONE, true))) { + if (i >= rams_size) { + /* re-alloc */ + struct resource *rams_new; + int rams_new_size; + + rams_new_size = rams_size + 16; + rams_new = vmalloc(sizeof(struct resource) + * rams_new_size); + if (!rams_new) + goto out; + + memcpy(rams_new, rams, + sizeof(struct resource) * rams_size); + vfree(rams); + rams = rams_new; + rams_size = rams_new_size; + } + + rams[i].start = res.start; + rams[i++].end = res.end; + + res.start = res.end + 1; + res.end = end; + } + + /* go reverse */ + for (i--; i >= 0; i--) { + ret = (*func)(&rams[i], arg); + if (ret) + break; + } + +out: + vfree(rams); + 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