From patchwork Tue Oct 21 10:49:24 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dheeraj Jamwal X-Patchwork-Id: 5116771 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id D04EB9F349 for ; Tue, 21 Oct 2014 11:28:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 12EF820107 for ; Tue, 21 Oct 2014 11:28:55 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3F623200D9 for ; Tue, 21 Oct 2014 11:28:54 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id BCFCBB68; Tue, 21 Oct 2014 11:04:27 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 3EAA6E59 for ; Tue, 21 Oct 2014 11:04:24 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id E0EDA1FAB2 for ; Tue, 21 Oct 2014 11:04:23 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 21 Oct 2014 04:04:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,761,1406617200"; d="scan'208";a="617795356" Received: from ubuntu-desktop.png.intel.com ([10.221.122.25]) by fmsmga002.fm.intel.com with ESMTP; 21 Oct 2014 04:04:22 -0700 From: Dheeraj Jamwal To: ltsi-dev@lists.linuxfoundation.org Date: Tue, 21 Oct 2014 18:49:24 +0800 Message-Id: <1413889294-31328-365-git-send-email-dheerajx.s.jamwal@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> References: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org Subject: [LTSI-dev] [PATCH 0364/1094] drm/i915/bdw: The TLB invalidation mechanism has been removed from INSTPM X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Damien Lespiau While wandering in the spec, I noticed that BDW removes those 2 bits from INSTPM. I couldn't find any direct way to invalidate the TLB (ie without the ring working already). Maybe someone will be more lucky. At least, we now know we may be a problem. Signed-off-by: Damien Lespiau Reviewed-by: Ben Widawsky Signed-off-by: Daniel Vetter (cherry picked from commit dc616b89dbc4bb6a99884d214bd1ed1e0eef59a0) Signed-off-by: Dheeraj Jamwal --- drivers/gpu/drm/i915/intel_ringbuffer.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index c50388a..4eb3e06 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -981,8 +981,14 @@ void intel_ring_setup_status_page(struct intel_ring_buffer *ring) I915_WRITE(mmio, (u32)ring->status_page.gfx_addr); POSTING_READ(mmio); - /* Flush the TLB for this page */ - if (INTEL_INFO(dev)->gen >= 6) { + /* + * Flush the TLB for this page + * + * FIXME: These two bits have disappeared on gen8, so a question + * arises: do we still need this and if so how should we go about + * invalidating the TLB? + */ + if (INTEL_INFO(dev)->gen >= 6 && INTEL_INFO(dev)->gen < 8) { u32 reg = RING_INSTPM(ring->mmio_base); /* ring should be idle before issuing a sync flush*/