From patchwork Mon Nov 28 23:30:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matt Roper X-Patchwork-Id: 13058003 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 35EA3C43217 for ; Mon, 28 Nov 2022 23:30:39 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E6D3410E347; Mon, 28 Nov 2022 23:30:27 +0000 (UTC) Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTPS id B4C3010E344; Mon, 28 Nov 2022 23:30:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669678220; x=1701214220; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=0p/m7KGRokmaJXRofyrPbcr8CIOcr5Zrnq35c2CMFd4=; b=JuY9yuyeKYXfcmytiAEhhTRrX0MjOvt0DnLoZTKD6kpzfjAIuFxXdRF4 i14iJL7AQ9IOL03SXRUeLR4SdVPtl21h5/kO0T3IUGS+ydkAznY4Li87y iVVR0+7X8MFBVQJCZXi1NPo49JmUbBbjZ7wt7orlYFlb4KFtVf7YwTpFF 6V0aqY6RfEuiXZsztWEuCHCSPEB5j1iN4SVdMcWzcAzUrk7zTQbMAHCTp ol8dex3IyjZJxgB+fLqPIsRX2PNCObFHxB8d9ZlVQhO6ckjxyA2AUYJJK i8YuXu44wzRLab173c8HL5dz7XzEBG8Asohyx334AgePEKPMkmv02Mv++ Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10545"; a="302556662" X-IronPort-AV: E=Sophos;i="5.96,201,1665471600"; d="scan'208";a="302556662" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Nov 2022 15:30:20 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10545"; a="706982224" X-IronPort-AV: E=Sophos;i="5.96,201,1665471600"; d="scan'208";a="706982224" Received: from mdroper-desk1.fm.intel.com ([10.1.27.134]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Nov 2022 15:30:19 -0800 From: Matt Roper To: intel-gfx@lists.freedesktop.org Subject: [PATCH v2 0/5] i915: dedicated MCR locking and hardware semaphore Date: Mon, 28 Nov 2022 15:30:09 -0800 Message-Id: <20221128233014.4000136-1-matthew.d.roper@intel.com> X-Mailer: git-send-email 2.38.1 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mika Kuoppala , Balasubramani Vivekanandan , dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" We've been overloading uncore->lock to protect access to the MCR steering register. That's not really what uncore->lock is intended for, and it would be better if we didn't need to hold such a high-traffic spinlock for the whole sequence of (apply steering, access MCR register, restore steering). Switch to a dedicated MCR lock to protect the steering control register over this critical section and stop relying on the high-traffic uncore->lock. On pre-MTL platforms the dedicated MCR lock is just another software lock, but on MTL and beyond we also utilize the hardware-provided STEER_SEMAPHORE that allows us to synchronize with external hardware and firmware agents. v2: - Use irqsave/irqrestore locking; on platforms that use execlist submission instead of GuC, MCR accesses can happen in interrupt context (tasklet) during reset -> error dump. - Extend timeout for hardware semaphore and CI taint if we ever encounter it (this implies a hardware/firmware problem). (Mika) - Add an extra patch optimizing xehp_setup_private_ppat by holding forcewake & mcr lock over the sequence of register writes. (Bala) Cc: Mika Kuoppala Cc: Balasubramani Vivekanandan Matt Roper (5): drm/i915/gt: Correct kerneldoc for intel_gt_mcr_wait_for_reg() drm/i915/gt: Pass gt rather than uncore to lowest-level reads/writes drm/i915/gt: Add dedicated MCR lock drm/i915/mtl: Add hardware-level lock for steering drm/i915/mtl: Hold forcewake and MCR lock over PPAT setup drivers/gpu/drm/i915/gt/intel_gt.c | 7 +- drivers/gpu/drm/i915/gt/intel_gt_mcr.c | 129 ++++++++++++++++++-- drivers/gpu/drm/i915/gt/intel_gt_mcr.h | 2 + drivers/gpu/drm/i915/gt/intel_gt_regs.h | 1 + drivers/gpu/drm/i915/gt/intel_gt_types.h | 8 ++ drivers/gpu/drm/i915/gt/intel_gtt.c | 27 ++-- drivers/gpu/drm/i915/gt/intel_mocs.c | 3 + drivers/gpu/drm/i915/gt/intel_workarounds.c | 12 +- 8 files changed, 162 insertions(+), 27 deletions(-)