Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933266Ab2BAWos (ORCPT ); Wed, 1 Feb 2012 17:44:48 -0500 Received: from rcsinet15.oracle.com ([148.87.113.117]:48676 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757697Ab2BAWop (ORCPT ); Wed, 1 Feb 2012 17:44:45 -0500 From: Yinghai Lu To: Jesse Barnes , Benjamin Herrenschmidt , Tony Luck Cc: Bjorn Helgaas , Dominik Brodowski , Andrew Morton , Linus Torvalds , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Yinghai Lu Subject: [PATCH 12/15] PCI: Allocate bus range instead of use max blindly Date: Wed, 1 Feb 2012 14:43:59 -0800 Message-Id: <1328136242-17725-13-git-send-email-yinghai@kernel.org> X-Mailer: git-send-email 1.7.7 In-Reply-To: <1328136242-17725-1-git-send-email-yinghai@kernel.org> References: <1328136242-17725-1-git-send-email-yinghai@kernel.org> X-Source-IP: ucsinet22.oracle.com [156.151.31.94] X-CT-RefId: str=0001.0A090205.4F29C050.001B,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6148 Lines: 193 every bus have extra busn_res, and linked them toghter to iobusn_resource. when need to find usable bus number range, try probe from iobusn_resource tree. To avoid falling to small hole in the middle, we try from 8 spare bus. if can not find 8 or more in the middle, will try to append 8 on top later. then if can not append, will try to find 7 from the middle, then will try to append 7 on top. then if can not append, will try to find 6 from the middle... for cardbus will only find 4 spare. if extend from top, at last will shrink back to really needed range... -v4: fix checking with pci rescan. Found by Bjorn. Signed-off-by: Yinghai Lu --- drivers/pci/probe.c | 101 ++++++++++++++++++++++++++++++--------------------- 1 files changed, 60 insertions(+), 41 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index b9459c5..97100a9 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -823,10 +823,11 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, { struct pci_bus *child; int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS); - u32 buses, i, j = 0; + u32 buses; u16 bctl; u8 primary, secondary, subordinate; int broken = 0; + struct resource *parent_res = NULL; pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses); primary = buses & 0xFF; @@ -838,10 +839,16 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, /* Check if setup is sensible at all */ if (!pass && - (primary != bus->number || secondary <= bus->number)) { - dev_dbg(&dev->dev, "bus configuration invalid, reconfiguring\n"); + (primary != bus->number || secondary <= bus->number)) broken = 1; - } + + /* more strict checking */ + if (!pass && !broken && !dev->subordinate) + broken = pci_bridge_check_busn_broken(bus, dev, + secondary, subordinate); + + if (broken) + dev_dbg(&dev->dev, "bus configuration invalid, reconfiguring\n"); /* Disable MasterAbortMode during probing to avoid reporting of bus errors (in some architectures) */ @@ -874,6 +881,8 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, child->primary = primary; child->subordinate = subordinate; child->bridge_ctl = bctl; + + pci_bus_insert_busn_res(child, secondary, subordinate); } cmax = pci_scan_child_bus(child); @@ -886,6 +895,11 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, * We need to assign a number to this bus which we always * do in the second pass. */ + resource_size_t shrink_size; + struct resource busn_res; + int ret = -ENOMEM; + int old_max = max; + if (!pass) { if (pcibios_assign_all_busses() || broken) /* Temporarily disable forwarding of the @@ -902,20 +916,44 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, /* Clear errors */ pci_write_config_word(dev, PCI_STATUS, 0xffff); - /* Prevent assigning a bus number that already exists. - * This can happen when a bridge is hot-plugged, so in - * this case we only re-scan this bus. */ - child = pci_find_bus(pci_domain_nr(bus), max+1); - if (!child) { - child = pci_add_new_bus(bus, dev, ++max); - if (!child) - goto out; + if (dev->subordinate) { + /* We get here only for cardbus */ + child = dev->subordinate; + if (!is_cardbus) + dev_warn(&dev->dev, + "rescan scaned bridge as broken one again ?"); + + goto out; } + /* + * For CardBus bridges, we leave 4 bus numbers + * as cards with a PCI-to-PCI bridge can be + * inserted later. + * other just allocate 8 bus to avoid we fall into + * small hole in the middle. + */ + ret = pci_bridge_probe_busn_res(bus, dev, &busn_res, + is_cardbus ? (CARDBUS_RESERVE_BUSNR + 1) : 8, + &parent_res); + + if (ret != 0) + goto out; + + child = pci_add_new_bus(bus, dev, busn_res.start & 0xff); + if (!child) + goto out; + + child->subordinate = busn_res.end & 0xff; + pci_bus_insert_busn_res(child, busn_res.start & 0xff, + busn_res.end & 0xff); + buses = (buses & 0xff000000) | ((unsigned int)(child->primary) << 0) | ((unsigned int)(child->secondary) << 8) | ((unsigned int)(child->subordinate) << 16); + max = child->subordinate; + /* * yenta.c forces a secondary latency timer of 176. * Copy that behaviour here. @@ -946,43 +984,24 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, * the real value of max. */ pci_fixup_parent_subordinate_busnr(child, max); + } else { - /* - * For CardBus bridges, we leave 4 bus numbers - * as cards with a PCI-to-PCI bridge can be - * inserted later. - */ - for (i=0; iparent) { - if ((!pcibios_assign_all_busses()) && - (parent->subordinate > max) && - (parent->subordinate <= max+i)) { - j = 1; - } - parent = parent->parent; - } - if (j) { - /* - * Often, there are two cardbus bridges - * -- try to leave one valid bus number - * for each one. - */ - i /= 2; - break; - } - } - max += i; pci_fixup_parent_subordinate_busnr(child, max); } /* * Set the subordinate bus number to its real value. */ + shrink_size = child->subordinate - max; child->subordinate = max; pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max); + pci_bus_update_busn_res_end(child, max); + + /* shrink some back, if we extend top before */ + if (!is_cardbus && (shrink_size > 0) && parent_res) + pci_bus_shrink_top(bus, shrink_size, parent_res); + + if (old_max > max) + max = old_max; } sprintf(child->name, -- 1.7.7 -- 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/