From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [obsolete] x86-pci-do-not-expect-pci-devices-to-return-zeroes-in-pcie-space.patch removed from -mm tree Date: Fri, 14 May 2010 16:02:25 -0700 Message-ID: <201005142302.o4EN2PiU027721@imap1.linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:46268 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750865Ab0ENXCt (ORCPT ); Fri, 14 May 2010 19:02:49 -0400 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: petr@vandrovec.name, hpa@zytor.com, jacob.jun.pan@intel.com, jbarnes@virtuousgeek.org, mingo@redhat.com, tglx@linutronix.de, mm-commits@vger.kernel.org The patch titled x86/pci: do not expect PCI devices to return zeroes in PCIe space has been removed from the -mm tree. Its filename was x86-pci-do-not-expect-pci-devices-to-return-zeroes-in-pcie-space.patch This patch was dropped because it is obsolete The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: x86/pci: do not expect PCI devices to return zeroes in PCIe space From: Petr Vandrovec openSUSE11.3 32bit kernels hang when installed to the VMware's VMs because Moorestown fixed capabilities detection code enters endless loop on Intel's AGP bridges (with device ID=7191). There is no reason why old pre-PCIe/PCI-X devices should return zeroes when configuration space above 0x100 is accessed. If these devices decode just low 8 bits of register number, conventional space repeats 15 times in PCIe config space. And Moorestown parser for fixed bars then can enter endless loop when finding Intel AGP bridge device 0x7191 with secondary latency timer programmed to 0x40 - when such device is encountered, code will enter endless loop of reading registers 0x718 (reading 0x40010100) and 0x400 (reading 0x71918086). This change adds additional condition to the test: if device id/vendor match first PCIe capability, then device is not really PCIe. It should not cause any problems: fixed_bar_cap is invoked only on Intel's devices, so only time there is possibilty to have false match would be if first PCIe capability would have ID 0x8086, and even then that address of next capability pointer and capability version will match device ID seems highly unlikely. This fix unbreaks 32bit 2.6.33+ kernels configured with Moorestown support to boot on AMD rev 10h+ processors under VMware in VMs which lack PCIe support. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=15888 Signed-off-by: Petr Vandrovec Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Jacob Pan Cc: Jesse Barnes Signed-off-by: Andrew Morton --- arch/x86/pci/mrst.c | 7 +++++++ 1 file changed, 7 insertions(+) diff -puN arch/x86/pci/mrst.c~x86-pci-do-not-expect-pci-devices-to-return-zeroes-in-pcie-space arch/x86/pci/mrst.c --- a/arch/x86/pci/mrst.c~x86-pci-do-not-expect-pci-devices-to-return-zeroes-in-pcie-space +++ a/arch/x86/pci/mrst.c @@ -55,12 +55,16 @@ static int fixed_bar_cap(struct pci_bus { int pos; u32 pcie_cap = 0, cap_data; + u32 devid; pos = PCIE_CAP_OFFSET; if (!raw_pci_ext_ops) return 0; + if (raw_pci_ops->read(pci_domain_nr(bus), bus->number, devfn, 0, 4, &devid)) + return 0; + while (pos) { if (raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number, devfn, pos, 4, &pcie_cap)) @@ -69,6 +73,9 @@ static int fixed_bar_cap(struct pci_bus if (pcie_cap == 0xffffffff) return 0; + if (pcie_cap == devid && pos == PCIE_CAP_OFFSET) + return 0; + if (PCI_EXT_CAP_ID(pcie_cap) == PCI_EXT_CAP_ID_VNDR) { raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number, devfn, pos + 4, 4, &cap_data); _ Patches currently in -mm which might be from petr@vandrovec.name are x86-pci-do-not-expect-pci-devices-to-return-zeroes-in-pcie-space.patch