Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751366Ab3HSUEN (ORCPT ); Mon, 19 Aug 2013 16:04:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60122 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751117Ab3HSUEM (ORCPT ); Mon, 19 Aug 2013 16:04:12 -0400 Subject: [PATCH] pci: Add pci_walk_slot() interface To: bhelgaas@google.com From: Alex Williamson Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 19 Aug 2013 14:04:10 -0600 Message-ID: <20130819195917.9062.43580.stgit@bling.home> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3340 Lines: 102 We have a pci_walk_bus() interface, but it's exceptionally cumbersome for the callback function to figure out if the device is relevant if the caller is trying to walk all the devices in or below a slot. Add a variant to walk only slot devices. Signed-off-by: Alex Williamson --- This allows me to use pci_walk_bus() and pci_walk_slot() instead of rolling my own for iterating devices for bus/slot reset. Please consider for 3.12 to go with the rest of the bus/slot infrastructure. drivers/pci/bus.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 2 ++ 2 files changed, 58 insertions(+) diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index b1ff02a..316579a 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -283,6 +283,62 @@ void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), } EXPORT_SYMBOL_GPL(pci_walk_bus); +/** pci_walk_slot - walk devices in/under slot, calling callback. + * @slot slot whose devices should be walked + * @cb callback to be called for each device found + * @userdata arbitrary pointer to be passed to callback. + * + * Walk the given slot, including any bridged devices + * on buses under this slot. Call the provided callback + * on each device found. + * + * We check the return of @cb each time. If it returns anything + * other than 0, we break out. + * + */ +void pci_walk_slot(struct pci_slot *slot, int (*cb)(struct pci_dev *, void *), + void *userdata) +{ + struct pci_dev *dev; + struct pci_bus *bus; + struct list_head *next; + int retval; + + bus = slot->bus; + down_read(&pci_bus_sem); + next = slot->bus->devices.next; + for (;;) { + if (next == &bus->devices) { + /* end of this bus, go up or finish */ + if (bus == slot->bus) + break; + next = bus->self->bus_list.next; + bus = bus->self->bus; + continue; + } + dev = list_entry(next, struct pci_dev, bus_list); + + /* skip anything on the top level bus not in our slot */ + if (dev->bus == slot->bus && dev->slot != slot) { + next = dev->bus_list.next; + continue; + } + + if (dev->subordinate) { + /* this is a pci-pci bridge, do its devices next */ + next = dev->subordinate->devices.next; + bus = dev->subordinate; + } else + next = dev->bus_list.next; + + retval = cb(dev, userdata); + if (retval) + break; + } + up_read(&pci_bus_sem); +} +EXPORT_SYMBOL_GPL(pci_walk_slot); + struct pci_bus *pci_bus_get(struct pci_bus *bus) { if (bus) diff --git a/include/linux/pci.h b/include/linux/pci.h index daf40cd..cbb291b 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1087,6 +1087,8 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), void *userdata); +void pci_walk_slot(struct pci_slot *slot, int (*cb)(struct pci_dev *, void *), + void *userdata); int pci_cfg_space_size_ext(struct pci_dev *dev); int pci_cfg_space_size(struct pci_dev *dev); unsigned char pci_bus_max_busnr(struct pci_bus *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/