From patchwork Thu Jul 1 17:15:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Brost X-Patchwork-Id: 12354599 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0177AC11F64 for ; Thu, 1 Jul 2021 16:58:27 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id C43CE61405 for ; Thu, 1 Jul 2021 16:58:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C43CE61405 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 299846EB7F; Thu, 1 Jul 2021 16:58:06 +0000 (UTC) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4879F6EB63; Thu, 1 Jul 2021 16:58:02 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10032"; a="208525585" X-IronPort-AV: E=Sophos;i="5.83,315,1616482800"; d="scan'208";a="208525585" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jul 2021 09:58:01 -0700 X-IronPort-AV: E=Sophos;i="5.83,315,1616482800"; d="scan'208";a="644504681" Received: from dhiatt-server.jf.intel.com ([10.54.81.3]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jul 2021 09:58:01 -0700 From: Matthew Brost To: , Date: Thu, 1 Jul 2021 10:15:48 -0700 Message-Id: <20210701171550.49353-6-matthew.brost@intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210701171550.49353-1-matthew.brost@intel.com> References: <20210701171550.49353-1-matthew.brost@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 5/7] drm/i915/guc: Add stall timer to non blocking CTB send function X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Implement a stall timer which fails H2G CTBs once a period of time with no forward progress is reached to prevent deadlock. v2: (Michal) - Improve error message in ct_deadlock() - Set broken when ct_deadlock() returns true - Return -EPIPE on ct_deadlock() v3: (Michal) - Add ms to stall timer comment (Matthew) - Move broken check to intel_guc_ct_send() Signed-off-by: John Harrison Signed-off-by: Daniele Ceraolo Spurio Signed-off-by: Matthew Brost Reviewed-by: John Harrison --- drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 62 ++++++++++++++++++++--- drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h | 4 ++ 2 files changed, 59 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c index fb825cc1d090..a9cb7b608520 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c @@ -4,6 +4,9 @@ */ #include +#include +#include +#include #include "i915_drv.h" #include "intel_guc_ct.h" @@ -316,6 +319,7 @@ int intel_guc_ct_enable(struct intel_guc_ct *ct) goto err_deregister; ct->enabled = true; + ct->stall_time = KTIME_MAX; return 0; @@ -388,9 +392,6 @@ static int ct_write(struct intel_guc_ct *ct, u32 *cmds = ctb->cmds; unsigned int i; - if (unlikely(ctb->broken)) - return -EPIPE; - if (unlikely(desc->status)) goto corrupted; @@ -506,6 +507,25 @@ static int wait_for_ct_request_update(struct ct_request *req, u32 *status) return err; } +#define GUC_CTB_TIMEOUT_MS 1500 +static inline bool ct_deadlocked(struct intel_guc_ct *ct) +{ + long timeout = GUC_CTB_TIMEOUT_MS; + bool ret = ktime_ms_delta(ktime_get(), ct->stall_time) > timeout; + + if (unlikely(ret)) { + struct guc_ct_buffer_desc *send = ct->ctbs.send.desc; + struct guc_ct_buffer_desc *recv = ct->ctbs.send.desc; + + CT_ERROR(ct, "Communication stalled for %lld ms, desc status=%#x,%#x\n", + ktime_ms_delta(ktime_get(), ct->stall_time), + send->status, recv->status); + ct->ctbs.send.broken = true; + } + + return ret; +} + static inline bool h2g_has_room(struct intel_guc_ct_buffer *ctb, u32 len_dw) { struct guc_ct_buffer_desc *desc = ctb->desc; @@ -517,6 +537,26 @@ static inline bool h2g_has_room(struct intel_guc_ct_buffer *ctb, u32 len_dw) return space >= len_dw; } +static int has_room_nb(struct intel_guc_ct *ct, u32 len_dw) +{ + struct intel_guc_ct_buffer *ctb = &ct->ctbs.send; + + lockdep_assert_held(&ct->ctbs.send.lock); + + if (unlikely(!h2g_has_room(ctb, len_dw))) { + if (ct->stall_time == KTIME_MAX) + ct->stall_time = ktime_get(); + + if (unlikely(ct_deadlocked(ct))) + return -EPIPE; + else + return -EBUSY; + } + + ct->stall_time = KTIME_MAX; + return 0; +} + static int ct_send_nb(struct intel_guc_ct *ct, const u32 *action, u32 len, @@ -529,11 +569,9 @@ static int ct_send_nb(struct intel_guc_ct *ct, spin_lock_irqsave(&ctb->lock, spin_flags); - ret = h2g_has_room(ctb, len + GUC_CTB_HDR_LEN); - if (unlikely(!ret)) { - ret = -EBUSY; + ret = has_room_nb(ct, len + GUC_CTB_HDR_LEN); + if (unlikely(ret)) goto out; - } fence = ct_get_next_fence(ct); ret = ct_write(ct, action, len, fence, flags); @@ -576,8 +614,13 @@ static int ct_send(struct intel_guc_ct *ct, retry: spin_lock_irqsave(&ctb->lock, flags); if (unlikely(!h2g_has_room(ctb, len + GUC_CTB_HDR_LEN))) { + if (ct->stall_time == KTIME_MAX) + ct->stall_time = ktime_get(); spin_unlock_irqrestore(&ctb->lock, flags); + if (unlikely(ct_deadlocked(ct))) + return -EPIPE; + if (msleep_interruptible(sleep_period_ms)) return -EINTR; sleep_period_ms = sleep_period_ms << 1; @@ -585,6 +628,8 @@ static int ct_send(struct intel_guc_ct *ct, goto retry; } + ct->stall_time = KTIME_MAX; + fence = ct_get_next_fence(ct); request.fence = fence; request.status = 0; @@ -647,6 +692,9 @@ int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len, return -ENODEV; } + if (unlikely(ct->ctbs.send.broken)) + return -EPIPE; + if (flags & INTEL_GUC_CT_SEND_NB) return ct_send_nb(ct, action, len, flags); diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h index 5bb8bef024c8..bee03794c1eb 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h @@ -9,6 +9,7 @@ #include #include #include +#include #include "intel_guc_fwif.h" @@ -68,6 +69,9 @@ struct intel_guc_ct { struct list_head incoming; /* incoming requests */ struct work_struct worker; /* handler for incoming requests */ } requests; + + /** @stall_time: time of first time a CTB submission is stalled */ + ktime_t stall_time; }; void intel_guc_ct_init_early(struct intel_guc_ct *ct);