From patchwork Thu May 31 18:51:55 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10441845 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 E4278603B5 for ; Thu, 31 May 2018 18:52:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D57C728E77 for ; Thu, 31 May 2018 18:52:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CA97728EB0; Thu, 31 May 2018 18:52:22 +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=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, 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 8310C28E77 for ; Thu, 31 May 2018 18:52:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D232B6E32B; Thu, 31 May 2018 18:52:21 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 67BE96E32C for ; Thu, 31 May 2018 18:52:18 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 11904164-1500050 for multiple; Thu, 31 May 2018 19:52:10 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Thu, 31 May 2018 19:52:09 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Thu, 31 May 2018 19:51:55 +0100 Message-Id: <20180531185204.19520-3-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180531185204.19520-1-chris@chris-wilson.co.uk> References: <20180531185204.19520-1-chris@chris-wilson.co.uk> X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH 02/11] drm/i915/execlists: Reset the CSB head tracking on reset/sanitization X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 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 We can avoid the mmio read of the CSB pointers after reset based on the knowledge that the HW always start writing at entry 0 in the CSB buffer. We need to reset our CSB head tracking after GPU reset (and on sanitization after resume) so that we are expecting to read from entry 0. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/intel_lrc.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 517e92c6a70b..e5cf049c18f8 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -965,22 +965,19 @@ static void process_csb(struct intel_engine_cs *engine) &engine->status_page.page_addr[I915_HWS_CSB_BUF0_INDEX]; unsigned int head, tail; - if (unlikely(execlists->csb_use_mmio)) { - buf = (u32 * __force) - (i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_BUF_LO(engine, 0))); - execlists->csb_head = -1; /* force mmio read of CSB */ - } - /* Clear before reading to catch new interrupts */ clear_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted); smp_mb__after_atomic(); - if (unlikely(execlists->csb_head == -1)) { /* after a reset */ + if (unlikely(execlists->csb_use_mmio)) { if (!fw) { intel_uncore_forcewake_get(i915, execlists->fw_domains); fw = true; } + buf = (u32 * __force) + (i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_BUF_LO(engine, 0))); + head = readl(i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine))); tail = GEN8_CSB_WRITE_PTR(head); head = GEN8_CSB_READ_PTR(head); @@ -1959,7 +1956,7 @@ static void execlists_reset(struct intel_engine_cs *engine, spin_unlock(&engine->timeline.lock); /* Following the reset, we need to reload the CSB read/write pointers */ - engine->execlists.csb_head = -1; + engine->execlists.csb_head = GEN8_CSB_ENTRIES - 1; local_irq_restore(flags); @@ -2460,7 +2457,7 @@ static int logical_ring_init(struct intel_engine_cs *engine) upper_32_bits(ce->lrc_desc); } - engine->execlists.csb_head = -1; + engine->execlists.csb_head = GEN8_CSB_ENTRIES - 1; return 0;