From patchwork Thu Sep 8 10:39:11 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: akash.goel@intel.com X-Patchwork-Id: 9320905 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 5175260231 for ; Thu, 8 Sep 2016 10:26:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 34E802973E for ; Thu, 8 Sep 2016 10:26:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 29AC02979B; Thu, 8 Sep 2016 10:26:01 +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=-4.2 required=2.0 tests=BAYES_00, 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 CE8072973E for ; Thu, 8 Sep 2016 10:26:00 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 304836EE10; Thu, 8 Sep 2016 10:26:00 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6E4C16EE10 for ; Thu, 8 Sep 2016 10:25:55 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga104.fm.intel.com with ESMTP; 08 Sep 2016 03:25:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos; i="5.30,300,1470726000"; d="scan'208"; a="1053038075" Received: from akashgoe-desktop.iind.intel.com ([10.223.82.36]) by fmsmga002.fm.intel.com with ESMTP; 08 Sep 2016 03:25:53 -0700 From: akash.goel@intel.com To: intel-gfx@lists.freedesktop.org Date: Thu, 8 Sep 2016 16:09:11 +0530 Message-Id: <1473331158-21082-12-git-send-email-akash.goel@intel.com> X-Mailer: git-send-email 1.9.2 In-Reply-To: <1473331158-21082-1-git-send-email-akash.goel@intel.com> References: <1473331158-21082-1-git-send-email-akash.goel@intel.com> Cc: Akash Goel Subject: [Intel-gfx] [PATCH 11/18] drm/i915: Optimization to reduce the sampling time of GuC log buffer X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 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 From: Akash Goel GuC firmware sends an interrupt to flush the log buffer when it becomes half full, so Driver doesn't really need to sample the complete buffer and can just copy only the newly written data by GuC into the local buffer, i.e. as per the read & write pointer values. Moreover the flush interrupt would generally come for one type of log buffer, when it becomes half full, so at that time the other 2 types of log buffer would comparatively have much lesser unread data in them. In case of overflow reported by GuC, Driver do need to copy the entire buffer as the whole buffer would contain the unread data. v2: Rebase. v3: Fix the blooper of doing the copy twice. (Tvrtko) v4: Add curlies for 'else' case also, matching the 'if'. (Tvrtko) Signed-off-by: Akash Goel Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_guc_submission.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index dbf7c84..ae52d10 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -1036,11 +1036,12 @@ static unsigned int guc_get_log_buffer_size(enum guc_log_buffer_type type) static void guc_read_update_log_buffer(struct intel_guc *guc) { + unsigned int buffer_size, read_offset, write_offset, bytes_to_copy, full_cnt; struct guc_log_buffer_state *log_buf_state, *log_buf_snapshot_state; struct guc_log_buffer_state log_buf_state_local; - unsigned int buffer_size, write_offset, full_cnt; enum guc_log_buffer_type type; void *src_data, *dst_data; + bool new_overflow; if (WARN_ON(!guc->log.buf_addr)) return; @@ -1063,12 +1064,13 @@ static void guc_read_update_log_buffer(struct intel_guc *guc) memcpy(&log_buf_state_local, log_buf_state, sizeof(struct guc_log_buffer_state)); buffer_size = guc_get_log_buffer_size(type); + read_offset = log_buf_state_local.read_ptr; write_offset = log_buf_state_local.sampled_write_ptr; full_cnt = log_buf_state_local.buffer_full_cnt; /* Bookkeeping stuff */ guc->log.flush_count[type] += log_buf_state_local.flush_to_file; - guc_check_log_buf_overflow(guc, type, full_cnt); + new_overflow = guc_check_log_buf_overflow(guc, type, full_cnt); /* Update the state of shared log buffer */ log_buf_state->read_ptr = write_offset; @@ -1091,7 +1093,27 @@ static void guc_read_update_log_buffer(struct intel_guc *guc) log_buf_snapshot_state++; /* Now copy the actual logs. */ - memcpy(dst_data, src_data, buffer_size); + if (unlikely(new_overflow)) { + /* copy the whole buffer in case of overflow */ + read_offset = 0; + write_offset = buffer_size; + } else if (unlikely((read_offset > buffer_size) || + (write_offset > buffer_size))) { + DRM_ERROR("invalid log buffer state\n"); + /* copy whole buffer as offsets are unreliable */ + read_offset = 0; + write_offset = buffer_size; + } + + /* Just copy the newly written data */ + if (read_offset > write_offset) { + memcpy(dst_data, src_data, write_offset); + bytes_to_copy = buffer_size - read_offset; + } else { + bytes_to_copy = write_offset - read_offset; + } + memcpy(dst_data + read_offset, + src_data + read_offset, bytes_to_copy); src_data += buffer_size; dst_data += buffer_size;