From patchwork Mon Jun 11 11:08:45 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10457565 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 3980460467 for ; Mon, 11 Jun 2018 11:09:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2F02227E63 for ; Mon, 11 Jun 2018 11:09:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2397A2837E; Mon, 11 Jun 2018 11:09:08 +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 B4E0B27E63 for ; Mon, 11 Jun 2018 11:09:07 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 34A1F89CCB; Mon, 11 Jun 2018 11:09:07 +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 92A3089C7F for ; Mon, 11 Jun 2018 11:09:01 +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 12009250-1500050 for multiple; Mon, 11 Jun 2018 12:08:49 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Mon, 11 Jun 2018 12:08:49 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Mon, 11 Jun 2018 12:08:45 +0100 Message-Id: <20180611110845.31890-2-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180611110845.31890-1-chris@chris-wilson.co.uk> References: <20180611110845.31890-1-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 2/2] drm/i915: Wrap around the tail offset before setting ring->tail 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 The HW only accepts offsets within ring->size, and fails peculiarly if the RING_HEAD or RING_TAIL is set to ring->size. Therefore whenever we set ring->head/ring->tail we want to make sure it is within value (using intel_ring_wrap()). v2: Double check execlists as well v3: Remove redundancy with assert_ring_tail_valid() v4: Just assert in intel_ring_reset() rather than be over-defensive. Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Cc: Mika Kuoppala Cc: Matthew Auld Cc: Tvrtko Ursulin Reviewed-by: Joonas Lahtinen #v2 --- drivers/gpu/drm/i915/intel_lrc.c | 6 ++++-- drivers/gpu/drm/i915/intel_ringbuffer.c | 6 ++++++ drivers/gpu/drm/i915/intel_ringbuffer.h | 20 ++++++++++++++------ 3 files changed, 24 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 091e28f0e024..3e008adf5a01 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1413,6 +1413,7 @@ __execlists_context_pin(struct intel_engine_cs *engine, ce->lrc_reg_state = vaddr + LRC_STATE_PN * PAGE_SIZE; ce->lrc_reg_state[CTX_RING_BUFFER_START+1] = i915_ggtt_offset(ce->ring->vma); + GEM_BUG_ON(!intel_ring_offset_valid(ce->ring, ce->ring->head)); ce->lrc_reg_state[CTX_RING_HEAD+1] = ce->ring->head; ce->state->obj->pin_global++; @@ -2001,9 +2002,10 @@ static void execlists_reset(struct intel_engine_cs *engine, /* Move the RING_HEAD onto the breadcrumb, past the hanging batch */ regs[CTX_RING_BUFFER_START + 1] = i915_ggtt_offset(request->ring->vma); - regs[CTX_RING_HEAD + 1] = request->postfix; - request->ring->head = request->postfix; + request->ring->head = intel_ring_wrap(request->ring, request->postfix); + regs[CTX_RING_HEAD + 1] = request->ring->head; + intel_ring_update_space(request->ring); /* Reset WaIdleLiteRestore:bdw,skl as well */ diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 3af6daa75f51..0189ef1c78c2 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -496,6 +496,10 @@ static int init_ring_common(struct intel_engine_cs *engine) DRM_DEBUG_DRIVER("%s initialization failed [head=%08x], fudging\n", engine->name, I915_READ_HEAD(engine)); + /* Check that the ring offsets point within the ring! */ + GEM_BUG_ON(!intel_ring_offset_valid(ring, ring->head)); + GEM_BUG_ON(!intel_ring_offset_valid(ring, ring->tail)); + intel_ring_update_space(ring); I915_WRITE_HEAD(engine, ring->head); I915_WRITE_TAIL(engine, ring->tail); @@ -1064,6 +1068,8 @@ int intel_ring_pin(struct intel_ring *ring, void intel_ring_reset(struct intel_ring *ring, u32 tail) { + GEM_BUG_ON(!intel_ring_offset_valid(ring, tail)); + ring->tail = tail; ring->head = tail; ring->emit = tail; diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index b44c67849749..e9494557aaa1 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -805,6 +805,19 @@ static inline u32 intel_ring_wrap(const struct intel_ring *ring, u32 pos) return pos & (ring->size - 1); } +static inline bool +intel_ring_offset_valid(const struct intel_ring *ring, + unsigned int pos) +{ + if (pos & -ring->size) /* must be strictly within the ring */ + return false; + + if (!IS_ALIGNED(pos, 8)) /* must be qword aligned */ + return false; + + return true; +} + static inline u32 intel_ring_offset(const struct i915_request *rq, void *addr) { /* Don't write ring->size (equivalent to 0) as that hangs some GPUs. */ @@ -816,12 +829,7 @@ static inline u32 intel_ring_offset(const struct i915_request *rq, void *addr) static inline void assert_ring_tail_valid(const struct intel_ring *ring, unsigned int tail) { - /* We could combine these into a single tail operation, but keeping - * them as seperate tests will help identify the cause should one - * ever fire. - */ - GEM_BUG_ON(!IS_ALIGNED(tail, 8)); - GEM_BUG_ON(tail >= ring->size); + GEM_BUG_ON(!intel_ring_offset_valid(ring, tail)); /* * "Ring Buffer Use"