From patchwork Wed Jan 25 13:44:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Weinan Z" X-Patchwork-Id: 9537085 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 20F2E601D3 for ; Wed, 25 Jan 2017 13:49:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 14D7D282E2 for ; Wed, 25 Jan 2017 13:49:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 098DF282EC; Wed, 25 Jan 2017 13:49:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 15C75282E2 for ; Wed, 25 Jan 2017 13:49:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B41B76E9F7; Wed, 25 Jan 2017 13:49:52 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id F07BE6E9F6; Wed, 25 Jan 2017 13:49:50 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga105.jf.intel.com with ESMTP; 25 Jan 2017 05:49:50 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos; i="5.33,284,1477983600"; d="scan'208"; a="1117637775" Received: from weinanli-build.sh.intel.com ([10.239.12.23]) by fmsmga002.fm.intel.com with ESMTP; 25 Jan 2017 05:49:49 -0800 From: Weinan Li To: intel-gfx@lists.freedesktop.org Date: Wed, 25 Jan 2017 21:44:51 +0800 Message-Id: <1485351892-20012-1-git-send-email-weinan.z.li@intel.com> X-Mailer: git-send-email 1.9.1 Cc: intel-gvt-dev@lists.freedesktop.org Subject: [Intel-gfx] [PATCH v2 2/3] drm/i915: noop forcewake get/put when vgpu activated X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Host maintian the hardware's forcewake state, guest don't need and also can't control it. Although vgpu_read/write bypass forcewake_get/put in MMIO read/write, but still have separate path called by "intel_uncore_forcewake_get/put" and "intel_uncore_forcewake_get/put__locked". Unnecessary MMIO access in guest waste much CPU cost. Since we full virtualize the MMIO, just noop the forcewake get/put. Signed-off-by: Weinan Li Reviewed-by: Chris Wilson --- drivers/gpu/drm/i915/intel_uncore.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index abe0888..9fad4de 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -133,6 +133,13 @@ } static void +vgpu_fw_domains_nop(struct drm_i915_private *dev_priv, + enum forcewake_domains fw_domains) +{ + /* Guest driver doesn't need to takes care forcewake. */ +} + +static void fw_domains_posting_read(struct drm_i915_private *dev_priv) { struct intel_uncore_forcewake_domain *d; @@ -1374,6 +1381,12 @@ static void intel_uncore_fw_domains_init(struct drm_i915_private *dev_priv) fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER, FORCEWAKE, FORCEWAKE_ACK); } + if (intel_vgpu_active(dev_priv)) { + dev_priv->uncore.funcs.force_wake_get = + vgpu_fw_domains_nop; + dev_priv->uncore.funcs.force_wake_put = + vgpu_fw_domains_nop; + } /* All future platforms are expected to require complex power gating */ WARN_ON(dev_priv->uncore.fw_domains == 0);