From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965400AbcHNLb4 (ORCPT ); Sun, 14 Aug 2016 07:31:56 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52387 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965388AbcHNLbt (ORCPT ); Sun, 14 Aug 2016 07:31:49 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Alex Deucher" , "Alex Williamson" , "Andres Rodriguez" Date: Sat, 13 Aug 2016 18:42:51 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 184/305] drm/radeon: fix asic initialization for virtualized environments In-Reply-To: X-SA-Exim-Connect-IP: 92.40.249.202 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.37-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alex Deucher commit 05082b8bbd1a0ffc74235449c4b8930a8c240f85 upstream. When executing in a PCI passthrough based virtuzliation environment, the hypervisor will usually attempt to send a PCIe bus reset signal to the ASIC when the VM reboots. In this scenario, the card is not correctly initialized, but we still consider it to be posted. Therefore, in a passthrough based environemnt we should always post the card to guarantee it is in a good state for driver initialization. Ported from amdgpu commit: amdgpu: fix asic initialization for virtualized environments Cc: Andres Rodriguez Cc: Alex Williamson Signed-off-by: Alex Deucher Signed-off-by: Ben Hutchings --- drivers/gpu/drm/radeon/radeon_device.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) --- a/drivers/gpu/drm/radeon/radeon_device.c +++ b/drivers/gpu/drm/radeon/radeon_device.c @@ -598,6 +598,23 @@ void radeon_gtt_location(struct radeon_d /* * GPU helpers function. */ + +/** + * radeon_device_is_virtual - check if we are running is a virtual environment + * + * Check if the asic has been passed through to a VM (all asics). + * Used at driver startup. + * Returns true if virtual or false if not. + */ +static bool radeon_device_is_virtual(void) +{ +#ifdef CONFIG_X86 + return boot_cpu_has(X86_FEATURE_HYPERVISOR); +#else + return false; +#endif +} + /** * radeon_card_posted - check if the hw has already been initialized * @@ -611,6 +628,10 @@ bool radeon_card_posted(struct radeon_de { uint32_t reg; + /* for pass through, always force asic_init */ + if (radeon_device_is_virtual()) + return false; + /* required for EFI mode on macbook2,1 which uses an r5xx asic */ if (efi_enabled(EFI_BOOT) && (rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE) &&