From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753921AbbINCYx (ORCPT ); Sun, 13 Sep 2015 22:24:53 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:14273 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752698AbbINCYw (ORCPT ); Sun, 13 Sep 2015 22:24:52 -0400 Message-ID: <55F62FA2.8000006@huawei.com> Date: Mon, 14 Sep 2015 10:23:30 +0800 From: Tan Xiaojun User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: CC: , Subject: Re: [PATCH] CMA: fix CONFIG_CMA_SIZE_MBYTES overflow in 64bit References: <1441599672-1360-1-git-send-email-tanxiaojun@huawei.com> In-Reply-To: <1441599672-1360-1-git-send-email-tanxiaojun@huawei.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.19.0] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, please review and give some suggestions. Any suggestion by anyone is fine to me. Thanks Xiaojun On 2015/9/7 12:21, Tan Xiaojun wrote: > In 64bit system, if you set CONFIG_CMA_SIZE_MBYTES>=2048, it will > overflow and size_bytes will be a big wrong number. > > Set CONFIG_CMA_SIZE_MBYTES=2048 and you will get an info below > during system boot: > > ********* > cma: Failed to reserve 17592186042368 MiB > ********* > > Signed-off-by: Tan Xiaojun > --- > drivers/base/dma-contiguous.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c > index 950fff9..426ba27 100644 > --- a/drivers/base/dma-contiguous.c > +++ b/drivers/base/dma-contiguous.c > @@ -46,7 +46,7 @@ struct cma *dma_contiguous_default_area; > * Users, who want to set the size of global CMA area for their system > * should use cma= kernel parameter. > */ > -static const phys_addr_t size_bytes = CMA_SIZE_MBYTES * SZ_1M; > +static const phys_addr_t size_bytes = (phys_addr_t)CMA_SIZE_MBYTES * SZ_1M; > static phys_addr_t size_cmdline = -1; > static phys_addr_t base_cmdline; > static phys_addr_t limit_cmdline; >