Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757667AbaGOHli (ORCPT ); Tue, 15 Jul 2014 03:41:38 -0400 Received: from dehamd003.servertools24.de ([31.47.254.18]:33321 "EHLO dehamd003.servertools24.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755536AbaGOHlh (ORCPT ); Tue, 15 Jul 2014 03:41:37 -0400 X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network Message-ID: <53C4DB2D.80406@ladisch.de> Date: Tue, 15 Jul 2014 09:41:33 +0200 From: Clemens Ladisch User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Guenter Roeck CC: Aravind Gopalakrishnan , Borislav Petkov , jdelvare@suse.de, rdunlap@infradead.org, bhelgaas@google.com, lm-sensors@lm-sensors.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH] hwmon, k10temp: Add support for AMD F15h M60h processor References: <1405369388-12729-1-git-send-email-Aravind.Gopalakrishnan@amd.com> <20140714195128.GA25124@pd.tnic> <53C43BDF.2070403@ladisch.de> <20140714203336.GA30926@roeck-us.net> In-Reply-To: <20140714203336.GA30926@roeck-us.net> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Guenter Roeck wrote: > On Mon, Jul 14, 2014 at 10:21:51PM +0200, Clemens Ladisch wrote: >> Borislav Petkov wrote: >>> On Mon, Jul 14, 2014 at 03:23:08PM -0500, Aravind Gopalakrishnan wrote: >>>> + if (boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model == 0x60) { >>>> + pci_bus_write_config_dword(pdev->bus, PCI_DEVFN(0, 0), >>>> + NB_SMU_IND_ADDR, IND_ADDR_OFFSET); >>>> + pci_bus_read_config_dword(pdev->bus, PCI_DEVFN(0, 0), >>>> + NB_SMU_IND_DATA, ®val); >> >> How do you prevent races with any other code that accesses some indirect >> register? >> > I just wanted to ask exactly the same question. I think this will need > locking. If there actually is any other code; these indirect SMU registers appear to be mostly undocumented and to be intended to be used by the BIOS. (Which makes me wonder why the temperature sensor was moved there.) Anyway, if a lock is needed, it looks as if it could go into a helper function such as "amd_nb_smu_ind_read()" in arch/x86/kernel/amd_nb.c. Regards, Clemens -- 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/