From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755880AbXFYTlq (ORCPT ); Mon, 25 Jun 2007 15:41:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753822AbXFYTl1 (ORCPT ); Mon, 25 Jun 2007 15:41:27 -0400 Received: from mtagate6.uk.ibm.com ([195.212.29.139]:42250 "EHLO mtagate6.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753554AbXFYTlZ (ORCPT ); Mon, 25 Jun 2007 15:41:25 -0400 Date: Mon, 25 Jun 2007 15:41:12 -0400 From: Muli Ben-Yehuda To: Yinghai Lu Cc: Andi Kleen , Andrew Morton , Alan Cox , "Eric W. Biederman" , Vivek Goyal , Linux Kernel Mailing List Subject: Re: [PATCH] x86-64: disable the GART in shutdown v2 Message-ID: <20070625194112.GC5334@rhun.ibm.com> References: <200706221219.16243.yinghai.lu@sun.com> <467C6906.6020105@sun.com> <200706221934.59966.yinghai.lu@sun.com> <200706251234.04548.yinghai.lu@sun.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200706251234.04548.yinghai.lu@sun.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 25, 2007 at 12:34:03PM -0700, Yinghai Lu wrote: > [PATCH] x86-64: disable the GART in shutdown > > For K8 system: 4G RAM with memory hole remapping enabled, or more than 4G RAM > installed. when using kexec to load second kernel. In the second kernel, > when mem is allocated for GART, it will do the memset for clear, it will cause > restart, because some device still used that for dma. > solution will be: > in second kernel: disable that at first before we try to allocate mem for it. > or in the first kernel: do disable that before shutdown. > Andi/Eric/Alan prefer to second one for clean shutdown in first kernel. > Andi also point out need to consider to AGP enable but mem less 4G case too. > > Signed-off-by: Yinghai Lu > > arch/x86_64/kernel/pci-dma.c | 5 +++++ > arch/x86_64/kernel/pci-gart.c | 21 +++++++++++++++++++++ > arch/x86_64/kernel/reboot.c | 4 ++++ > include/asm-x86_64/proto.h | 7 +++++++ > 4 files changed, 37 insertions(+) > diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c > index ae091cd..6c4fe16 100644 > --- a/arch/x86_64/kernel/pci-gart.c > +++ b/arch/x86_64/kernel/pci-gart.c > @@ -571,6 +571,27 @@ static const struct dma_mapping_ops gart_dma_ops = { > .unmap_sg = gart_unmap_sg, > }; > > +void gart_iommu_shutdown(void) > +{ > + struct pci_dev *dev; > + int i; > + extra blank line > + > + if (noagp && (dma_ops != &gart_dma_ops)) > + return; noagp? did you mean 'no_agp'? > + > + for (i = 0; i < num_k8_northbridges; i++) { > + u32 ctl; > + > + dev = k8_northbridges[i]; > + pci_read_config_dword(dev, 0x90, &ctl); > + > + ctl &= ~1; > + > + pci_write_config_dword(dev, 0x90, ctl); > + } > +} > + > void __init gart_iommu_init(void) > { > struct agp_kern_info info; > diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c > index 9f80aad..b406b54 100644 > --- a/arch/x86_64/kernel/pci-dma.c > +++ b/arch/x86_64/kernel/pci-dma.c > @@ -322,6 +322,11 @@ static int __init pci_iommu_init(void) > return 0; > } > > +void pci_iommu_shutdown(void) > +{ > + gart_iommu_shutdown(); I really dislike this. Here's how this function is going to look in a few months: void pci_iommu_shutdown(void) { gart_iommu_shutdown(); calgary_iommu_shutdown(); vtd_iommu_shutdown(); amd_iommu_shutdown(); /* etc, ad nauseam */ } Where all of these are no-ops, except one. Now what's wrong with this picture? > diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h > index 85255db..b70aa0c 100644 > --- a/include/asm-x86_64/proto.h > +++ b/include/asm-x86_64/proto.h > @@ -85,11 +85,13 @@ extern int exception_trace; > extern unsigned cpu_khz; > extern unsigned tsc_khz; > > +extern void pci_iommu_shutdown(void); > extern void no_iommu_init(void); > extern int force_iommu, no_iommu; > extern int iommu_detected; > #ifdef CONFIG_IOMMU > extern void gart_iommu_init(void); > +extern void gart_iommu_shutdown(void); > extern void __init gart_parse_options(char *); > extern void iommu_hole_init(void); > extern int fallback_aper_order; > @@ -101,6 +103,11 @@ extern int fix_aperture; > #else > #define iommu_aperture 0 > #define iommu_aperture_allowed 0 > + > +static inline void gart_iommu_shutdown(void) > +{ > +} > + I suggest include/asm-x86_64/iommu.h for this. proto.h doesn't have anything to do with it. Cheers, Muli