Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937272AbXLQXC2 (ORCPT ); Mon, 17 Dec 2007 18:02:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762357AbXLQXBa (ORCPT ); Mon, 17 Dec 2007 18:01:30 -0500 Received: from ozlabs.org ([203.10.76.45]:55681 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761387AbXLQXB2 (ORCPT ); Mon, 17 Dec 2007 18:01:28 -0500 To: linux-pci@atrey.karlin.mff.cuni.cz CC: Alan Cox , Greg Kroah-Hartman , , Ivan Kokshaysky , , Bartlomiej Zolnierkiewicz , , , From: Benjamin Herrenschmidt Date: Tue, 18 Dec 2007 10:01:15 +1100 Subject: [RFC/PATCH 4/4] [POWERPC] pci: Disable IO/Mem on a device when resources can't be allocated In-Reply-To: <1197932473.576079.142524077033.qpush@grosgo> Message-Id: <20071217230127.46B3BDDE38@ozlabs.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2231 Lines: 61 This patch changes the PowerPC PCI code to disable IO and/or Memory decoding on a PCI device when a resource of that type failed to be allocated. This is done to avoid having unallocated dangling BARs enabled that might try to decode on top of other devices. If a proper resource is assigned later on, then pci_enable_device{,_io,_mem} will take care of re-enabling decoding. Signed-off-by: Benjamin Herrenschmidt --- NOTE: This patch doesn't apply on current upstream, but rather on top of a serie that merges 32 and 64 bits PowerPC PCI resource handling, and which will be in 2.6.25. I post it here mostly to show what I think should be done. A similar patch will have to be done for other architectures. arch/powerpc/kernel/pci-common.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) --- linux-work.orig/arch/powerpc/kernel/pci-common.c 2007-12-18 09:37:52.000000000 +1100 +++ linux-work/arch/powerpc/kernel/pci-common.c 2007-12-18 09:39:27.000000000 +1100 @@ -1016,7 +1016,7 @@ static void __init pcibios_allocate_bus_ } } -static inline void __devinit alloc_resource(struct pci_dev *dev, int idx) +static inline int __devinit alloc_resource(struct pci_dev *dev, int idx) { struct resource *pr, *r = &dev->resource[idx]; @@ -1040,7 +1040,10 @@ static inline void __devinit alloc_resou r->flags |= IORESOURCE_UNSET; r->end -= r->start; r->start = 0; + + return -EBUSY; } + return 0; } static void __init pcibios_allocate_resources(int pass) @@ -1062,8 +1065,12 @@ static void __init pcibios_allocate_reso disabled = !(command & PCI_COMMAND_IO); else disabled = !(command & PCI_COMMAND_MEMORY); - if (pass == disabled) - alloc_resource(dev, idx); + if (pass == disabled && alloc_resource(dev, idx)) { + command &= ~(r->flags & (IORESOURCE_IO | + IORESOURCE_MEM)); + pci_write_config_word(dev, + PCI_COMMAND, command); + } } if (pass) continue; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/