From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760484AbbA2Jgw (ORCPT ); Thu, 29 Jan 2015 04:36:52 -0500 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:44860 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1760094AbbA2JGI (ORCPT ); Thu, 29 Jan 2015 04:06:08 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Myron Stowe , Bjorn Helgaas , Matthew Wilcox , Jiri Slaby Subject: [PATCH 3.12 014/176] PCI: Restore detection of read-only BARs Date: Wed, 28 Jan 2015 15:27:24 +0100 Message-Id: X-Mailer: git-send-email 2.2.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Myron Stowe 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 36e8164882ca6d3c41cb91e6f09a3ed236841f80 upstream. Commit 6ac665c63dca ("PCI: rewrite PCI BAR reading code") masked off low-order bits from 'l', but not from 'sz'. Both are passed to pci_size(), which compares 'base == maxbase' to check for read-only BARs. The masking of 'l' means that comparison will never be 'true', so the check for read-only BARs no longer works. Resolve this by also masking off the low-order bits of 'sz' before passing it into pci_size() as 'maxbase'. With this change, pci_size() will once again catch the problems that have been encountered to date: - AGP aperture BAR of AMD-7xx host bridges: if the AGP window is disabled, this BAR is read-only and read as 0x00000008 [1] - BARs 0-4 of ALi IDE controllers can be non-zero and read-only [1] - Intel Sandy Bridge - Thermal Management Controller [8086:0103]; BAR 0 returning 0xfed98004 [2] - Intel Xeon E5 v3/Core i7 Power Control Unit [8086:2fc0]; Bar 0 returning 0x00001a [3] Link: [1] https://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/drivers/pci/probe.c?id=1307ef6621991f1c4bc3cec1b5a4ebd6fd3d66b9 ("PCI: probing read-only BARs" (pre-git)) Link: [2] https://bugzilla.kernel.org/show_bug.cgi?id=43331 Link: [3] https://bugzilla.kernel.org/show_bug.cgi?id=85991 Reported-by: William Unruh Reported-by: Martin Lucina Signed-off-by: Myron Stowe Signed-off-by: Bjorn Helgaas CC: Matthew Wilcox Signed-off-by: Jiri Slaby --- drivers/pci/probe.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 7ef0f868b3e0..16b3bd684942 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -214,14 +214,17 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, res->flags |= IORESOURCE_SIZEALIGN; if (res->flags & IORESOURCE_IO) { l &= PCI_BASE_ADDRESS_IO_MASK; + sz &= PCI_BASE_ADDRESS_IO_MASK; mask = PCI_BASE_ADDRESS_IO_MASK & (u32) IO_SPACE_LIMIT; } else { l &= PCI_BASE_ADDRESS_MEM_MASK; + sz &= PCI_BASE_ADDRESS_MEM_MASK; mask = (u32)PCI_BASE_ADDRESS_MEM_MASK; } } else { res->flags |= (l & IORESOURCE_ROM_ENABLE); l &= PCI_ROM_ADDRESS_MASK; + sz &= PCI_ROM_ADDRESS_MASK; mask = (u32)PCI_ROM_ADDRESS_MASK; } -- 2.2.2