From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e32.co.us.ibm.com (e32.co.us.ibm.com [32.97.110.150]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e32.co.us.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id B46DB2C00D0 for ; Fri, 28 Dec 2012 16:21:54 +1100 (EST) Received: from /spool/local by e32.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 27 Dec 2012 22:21:51 -0700 Received: from d03relay05.boulder.ibm.com (d03relay05.boulder.ibm.com [9.17.195.107]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id 7C7D61FF0027 for ; Thu, 27 Dec 2012 22:21:39 -0700 (MST) Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay05.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id qBS5LmmT084438 for ; Thu, 27 Dec 2012 22:21:48 -0700 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id qBS5LlNY015839 for ; Thu, 27 Dec 2012 22:21:47 -0700 Date: Fri, 28 Dec 2012 13:21:35 +0800 From: Gavin Shan To: Thadeu Lima de Souza Cascardo Subject: Re: [PATCH] ppc/iommu: prevent false TCE leak message Message-ID: <20121228052135.GB9975@shangw.(null)> References: <1356625686-8943-1-git-send-email-cascardo@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1356625686-8943-1-git-send-email-cascardo@linux.vnet.ibm.com> Cc: paulus@samba.org, linuxppc-dev@lists.ozlabs.org, anton@samba.org Reply-To: Gavin Shan List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Dec 27, 2012 at 02:28:06PM -0200, Thadeu Lima de Souza Cascardo wrote: >When a device DMA window includes the address 0, it's reserved in the >TCE bitmap to avoid returning that address to drivers. > >When the device is removed, the bitmap is checked for any mappings not >removed by the driver, indicating a possible DMA mapping leak. Since the >reserved address is not cleared, a message is printed, warning of such a >leak. > >Check for the reservation, and clear it before checking for any other >standing mappings. > >Signed-off-by: Thadeu Lima de Souza Cascardo >--- > arch/powerpc/kernel/iommu.c | 5 +++++ > 1 files changed, 5 insertions(+), 0 deletions(-) > >diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c >index 8226c6c..226e9e5 100644 >--- a/arch/powerpc/kernel/iommu.c >+++ b/arch/powerpc/kernel/iommu.c >@@ -717,6 +717,11 @@ void iommu_free_table(struct iommu_table *tbl, const char *node_name) > return; > } > >+ /* In case we have reserved the first bit, we should not emit >+ * the warning below. */ At least, the comment would look like: /* * xxxxxxx */ >+ if (tbl->it_offset == 0) >+ clear_bit(0, tbl->it_map); >+ > /* verify that table contains no entries */ > /* it_size is in entries, and we're examining 64 at a time */ The comment would be merged as well? :-) > for (i = 0; i < (tbl->it_size/64); i++) { Thanks, Gavin