Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757161AbYHAHHQ (ORCPT ); Fri, 1 Aug 2008 03:07:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753400AbYHAHGp (ORCPT ); Fri, 1 Aug 2008 03:06:45 -0400 Received: from 69-30-77-85.dq1sn.easystreet.com ([69.30.77.85]:49867 "EHLO camus.anholt.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753209AbYHAHGp (ORCPT ); Fri, 1 Aug 2008 03:06:45 -0400 From: Eric Anholt To: linux-kernel@vger.kernel.org Cc: keithp@keithp.com, Matthew Wilcox , Matthew Wilcox Subject: [PATCH] PCI: Add pci_read_base() API Date: Thu, 31 Jul 2008 23:58:37 -0700 Message-Id: <1217573919-7496-1-git-send-email-eric@anholt.net> X-Mailer: git-send-email 1.5.6.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3710 Lines: 106 From: Matthew Wilcox Some devices have a BAR at a non-standard address. The pci_read_base() API allows us to probe these BARs and fill in a resource for it as if they were standard BARs. Signed-off-by: Matthew Wilcox --- drivers/pci/probe.c | 47 ++++++++++++++++++++++++++++++++++++++++------- include/linux/pci.h | 10 ++++++++++ 2 files changed, 50 insertions(+), 7 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 7098dfb..1518c4f 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -181,13 +181,6 @@ static u64 pci_size(u64 base, u64 maxbase, u64 mask) return size; } -enum pci_bar_type { - pci_bar_unknown, /* Standard PCI BAR probe */ - pci_bar_io, /* An io port BAR */ - pci_bar_mem32, /* A 32-bit memory BAR */ - pci_bar_mem64, /* A 64-bit memory BAR */ -}; - static inline enum pci_bar_type decode_bar(struct resource *res, u32 bar) { if ((bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) { @@ -300,6 +293,46 @@ static int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, goto out; } +/** + * pci_read_base - Read a BAR from a specified location + * @dev: The PCI device to read + * @type: The type of BAR to read + * @res: A struct resource to be filled in + * @reg: The address in PCI config space to read the BAR from. + * + * Some devices have BARs in unusual places. This function lets a driver ask + * the PCI subsystem to read it and place it in the resource tree. If it is + * like a ROM BAR with an enable in bit 0, the caller should specify a @type + * of io, mem32 or mem64. If it's like a normal BAR with memory type in the + * low bits, specify unknown, even if the caller knows what kind of BAR it is. + * + * Returns -ENXIO if the BAR was not successfully read. If the BAR is read, + * but no suitable parent resource can be found for the BAR, this function + * returns -ENODEV. If the resource cannot be inserted into the resource tree, + * it will return -EBUSY. Note that the resource is still 'live' for these + * last two cases; the caller should set res->flags to 0 if this is not wanted. + */ +int pci_read_base(struct pci_dev *dev, enum pci_bar_type type, + struct resource *res, unsigned int reg) +{ + struct pci_bus_region region; + struct resource *parent; + + __pci_read_base(dev, type, res, reg); + if (!res->flags) + return -ENXIO; + + region.start = res->start; + region.end = res->end; + pcibios_bus_to_resource(dev, res, ®ion); + + parent = pci_find_parent_resource(dev, res); + if (!parent) + return -ENODEV; + return request_resource(parent, res); +} +EXPORT_SYMBOL_GPL(pci_read_base); + static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) { unsigned int pos, reg; diff --git a/include/linux/pci.h b/include/linux/pci.h index 825be38..fa7e10a 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -312,6 +312,16 @@ struct pci_bus { #define pci_bus_b(n) list_entry(n, struct pci_bus, node) #define to_pci_bus(n) container_of(n, struct pci_bus, dev) +enum pci_bar_type { + pci_bar_unknown, /* Standard PCI BAR probe */ + pci_bar_io, /* An io port BAR */ + pci_bar_mem32, /* A 32-bit memory BAR */ + pci_bar_mem64, /* A 64-bit memory BAR */ +}; + +int pci_read_base(struct pci_dev *dev, enum pci_bar_type type, + struct resource *res, unsigned int reg); + /* * Error values that may be returned by PCI functions. */ -- 1.5.6.3 -- 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/