From patchwork Thu Jun 24 07:04:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Brost X-Patchwork-Id: 12341067 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 BFE76C49EA6 for ; Thu, 24 Jun 2021 06:48:04 +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 918A1613CC for ; Thu, 24 Jun 2021 06:48:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 918A1613CC 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 682566EA20; Thu, 24 Jun 2021 06:47:33 +0000 (UTC) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2C5C76E848; Thu, 24 Jun 2021 06:47:29 +0000 (UTC) IronPort-SDR: 5jPB1Yh7Lx+0tQe4u0OhMde4cbjCc40n9pR4xky/mF25dMor+pICNZXmw1qfW2xH5zwFTC4lKn wJ5g99+jkq+Q== X-IronPort-AV: E=McAfee;i="6200,9189,10024"; a="207346744" X-IronPort-AV: E=Sophos;i="5.83,295,1616482800"; d="scan'208";a="207346744" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jun 2021 23:47:25 -0700 IronPort-SDR: ab12i3mL+dp82DS4E90pjqfhy9hXNl19PU3RM0hW5PDeubOwTbLCUTt1NcbuIrb3a0R44CIHZq OicQiu3fnB9w== X-IronPort-AV: E=Sophos;i="5.83,295,1616482800"; d="scan'208";a="556390878" Received: from dhiatt-server.jf.intel.com ([10.54.81.3]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jun 2021 23:47:24 -0700 From: Matthew Brost To: , Date: Thu, 24 Jun 2021 00:04:34 -0700 Message-Id: <20210624070516.21893-6-matthew.brost@intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210624070516.21893-1-matthew.brost@intel.com> References: <20210624070516.21893-1-matthew.brost@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 05/47] 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. Also update to ct_write to return -EIO rather than -EPIPE on a corrupted descriptor. Signed-off-by: John Harrison Signed-off-by: Daniele Ceraolo Spurio Signed-off-by: Matthew Brost --- drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 47 +++++++++++++++++++++-- drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h | 4 ++ 2 files changed, 48 insertions(+), 3 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 c9a65d05911f..27ec30b5ef47 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c @@ -319,6 +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; @@ -392,7 +393,7 @@ static int ct_write(struct intel_guc_ct *ct, unsigned int i; if (unlikely(ctb->broken)) - return -EPIPE; + return -EIO; if (unlikely(desc->status)) goto corrupted; @@ -464,7 +465,7 @@ static int ct_write(struct intel_guc_ct *ct, CT_ERROR(ct, "Corrupted descriptor head=%u tail=%u status=%#x\n", desc->head, desc->tail, desc->status); ctb->broken = true; - return -EPIPE; + return -EIO; } /** @@ -507,6 +508,18 @@ 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)) + CT_ERROR(ct, "CT deadlocked\n"); + + 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; @@ -518,6 +531,26 @@ 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 -EIO; + 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, @@ -530,7 +563,7 @@ static int ct_send_nb(struct intel_guc_ct *ct, spin_lock_irqsave(&ctb->lock, spin_flags); - ret = h2g_has_room(ctb, len + 1); + ret = has_room_nb(ct, len + 1); if (unlikely(ret)) goto out; @@ -574,11 +607,19 @@ static int ct_send(struct intel_guc_ct *ct, retry: spin_lock_irqsave(&ct->ctbs.send.lock, flags); if (unlikely(!h2g_has_room(ctb, len + 1))) { + if (ct->stall_time == KTIME_MAX) + ct->stall_time = ktime_get(); spin_unlock_irqrestore(&ct->ctbs.send.lock, flags); + + if (unlikely(ct_deadlocked(ct))) + return -EIO; + cond_resched(); goto retry; } + ct->stall_time = KTIME_MAX; + fence = ct_get_next_fence(ct); request.fence = fence; request.status = 0; 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 eb69263324ba..55ef7c52472f 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);