From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e8.ny.us.ibm.com (e8.ny.us.ibm.com [32.97.182.138]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e8.ny.us.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 358192C007C for ; Sat, 19 Jan 2013 06:17:55 +1100 (EST) Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 18 Jan 2013 14:17:52 -0500 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id A1FF26E8041 for ; Fri, 18 Jan 2013 14:17:48 -0500 (EST) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r0IJHnBx086916 for ; Fri, 18 Jan 2013 14:17:49 -0500 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r0IJHm6w006733 for ; Fri, 18 Jan 2013 14:17:49 -0500 Date: Fri, 18 Jan 2013 11:17:36 -0800 From: Nishanth Aravamudan To: benh@kernel.crashing.org Subject: [PATCH] pseries/iommu: ensure TCEs are cleared with non-huge DDW Message-ID: <20130118191736.GC25500@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: nfont@linux.vnet.ibm.com, paulus@samba.org, linuxppc-dev@lists.ozlabs.org, miltonm@bga.com, anton@samba.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , There are now two kinds of DMA windows that might be presented by PowerVM DDW support -- huge windows (that can map all of system memory regardless of the LPAR configuration) and non-huge windows (which can't). They are implemented slightly differently in PowerVM, and thus have different characteristics. The most obvious is that slot isolate doesn't clear the TCEs/window for us with non-huge windows. Thus, when a DLPAR operation occurs on a slot using a non-huge window, TCEs are still present (the notifier chain doesn't currently remove them explicitly) and the DLPAR fails. Fix this by calling remove_ddw() first, which will unmap the DDW TCEs. Note: a corresponding change to drmgr is needed to actually successfully DLPAR, such that the device-tree update (which causes the notifier chain to fire) occurs before slot isolate. Signed-off-by: Nishanth Aravamudan diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index a55b685..b4bb9e1 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -1296,6 +1296,7 @@ static int iommu_reconfig_notifier(struct notifier_block *nb, unsigned long acti switch (action) { case OF_RECONFIG_DETACH_NODE: + remove_ddw(np); if (pci && pci->iommu_table) iommu_free_table(pci->iommu_table, np->full_name); @@ -1308,16 +1309,6 @@ static int iommu_reconfig_notifier(struct notifier_block *nb, unsigned long acti } } spin_unlock(&direct_window_list_lock); - - /* - * Because the notifier runs after isolation of the - * slot, we are guaranteed any DMA window has already - * been revoked and the TCEs have been marked invalid, - * so we don't need a call to remove_ddw(np). However, - * if an additional notifier action is added before the - * isolate call, we should update this code for - * completeness with such a call. - */ break; default: err = NOTIFY_DONE;