Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756304AbYFSW6W (ORCPT ); Thu, 19 Jun 2008 18:58:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753517AbYFSW6K (ORCPT ); Thu, 19 Jun 2008 18:58:10 -0400 Received: from smtp-outbound-1.vmware.com ([65.113.40.141]:37884 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752811AbYFSW6I (ORCPT ); Thu, 19 Jun 2008 18:58:08 -0400 Subject: [PATCH 2/2] acpi based pci gap caluculation From: Alok Kataria Reply-To: akataria@vmware.com To: "Brown, Len" , Andrew Morton Cc: linux-acpi@vger.kernel.org, LKML Content-Type: text/plain Organization: VMware INC. Date: Thu, 19 Jun 2008 15:58:06 -0700 Message-Id: <1213916286.27983.37.camel@promb-2n-dhcp368.eng.vmware.com> Mime-Version: 1.0 X-Mailer: Evolution 2.8.0 (2.8.0-40.el5) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3334 Lines: 119 Evaluates the _CRS object under PCI0 looking for producer resources. Then searches the e820 memory space for a gap within these producer resources. Allows us to find a gap for the unclaimed pci resources or MMIO resources for hotplug devices within the BIOS allowed pci regions. Signed-off-by: Alok N Kataria Index: linux-2.6/arch/x86/pci/acpi.c =================================================================== --- linux-2.6.orig/arch/x86/pci/acpi.c 2008-06-13 13:58:53.000000000 -0700 +++ linux-2.6/arch/x86/pci/acpi.c 2008-06-13 14:10:05.000000000 -0700 @@ -4,6 +4,7 @@ #include #include #include +#include #include "pci.h" struct pci_root_info { @@ -14,6 +15,11 @@ int busnum; }; +struct gap_info { + unsigned long gapstart; + unsigned long gapsize; +}; + static acpi_status resource_to_addr(struct acpi_resource *resource, struct acpi_resource_address64 *addr) @@ -110,6 +116,70 @@ } } +static acpi_status search_gap(struct acpi_resource *resource, void *data) +{ + struct acpi_resource_address64 addr; + acpi_status status; + struct gap_info *gap = data; + + status = resource_to_addr(resource, &addr); + if (ACPI_SUCCESS(status) && + addr.resource_type == ACPI_MEMORY_RANGE && + addr.address_length > gap->gapsize) { + e820_search_gap(&gap->gapstart, &gap->gapsize, + (addr.minimum + addr.translation_offset)); + } + + return AE_OK; +} + +/* + * Search for a hole in the 32 bit address space for PCI to assign MMIO + * resources for hotplug or unconfigured resources. + * We query the CRS object of the PCI root device to look for possible producer + * resources in the tree and consider these while calulating the start address + * for this hole. + */ +static void pci_setup_gap(acpi_handle *handle) +{ + struct gap_info gap; + acpi_status status; + + gap.gapstart = 0; + gap.gapsize = 0x400000; + + status = acpi_walk_resources(handle, METHOD_NAME__CRS, + search_gap, &gap); + + if (ACPI_SUCCESS(status)) { + unsigned long round; + + if (!gap.gapstart) { + printk(KERN_ERR "ACPI_PCI: Warning: Cannot find a gap " + "in the 32bit address range\n" + "ACPI_PCI: May collide with the " + "hotpluggable memory address range\n"); + } + /* + * Round the gapstart, uses the same logic as in + * e820_gap_setup + */ + round = 0x100000; + while ((gap.gapsize >> 4) > round) + round += round; + /* Fun with two's complement */ + pci_mem_start = (gap.gapstart + round) & -round; + + printk(KERN_INFO "ACPI_PCI: PCI resources should " + "start at %lx (gap: %lx:%lx)\n", + pci_mem_start, gap.gapstart, gap.gapsize); + } else { + printk(KERN_ERR "ACPI_PCI: Error while searching for gap in " + "the 32bit address range for PCI\n"); + } +} + + static void get_current_resources(struct acpi_device *device, int busnum, int domain, struct pci_bus *bus) @@ -215,6 +285,8 @@ if (bus && (pci_probe & PCI_USE__CRS)) get_current_resources(device, busnum, domain, bus); + + pci_setup_gap(device->handle); return bus; } -- 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/