From patchwork Mon Jul 1 06:26:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Manna, Animesh" X-Patchwork-Id: 11025083 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0024B746 for ; Mon, 1 Jul 2019 06:34:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 04A5128329 for ; Mon, 1 Jul 2019 06:34:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id ED1D6284DA; Mon, 1 Jul 2019 06:34:48 +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 8BB3728329 for ; Mon, 1 Jul 2019 06:34:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F12AB89F75; Mon, 1 Jul 2019 06:34:47 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2A01989F75 for ; Mon, 1 Jul 2019 06:34:46 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Jun 2019 23:34:45 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,437,1557212400"; d="scan'208";a="153988767" Received: from amanna.iind.intel.com ([10.223.74.216]) by orsmga007.jf.intel.com with ESMTP; 30 Jun 2019 23:34:43 -0700 From: Animesh Manna To: intel-gfx@lists.freedesktop.org Date: Mon, 1 Jul 2019 11:56:31 +0530 Message-Id: <20190701062632.456-15-animesh.manna@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190701062632.456-1-animesh.manna@intel.com> References: <20190701062632.456-1-animesh.manna@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 14/15] drm/i915/dsb: Documentation for DSB. 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: , Cc: Jani Nikula Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Added docbook info regarding Display State Buffer(DSB) which is added from gen12 onwards to batch submit display HW programming. Cc: Jani Nikula Cc: Rodrigo Vivi Signed-off-by: Animesh Manna --- Documentation/gpu/i915.rst | 9 ++++++ drivers/gpu/drm/i915/intel_dsb.c | 54 ++++++++++++++++++++++++++++++++ 2 files changed, 63 insertions(+) diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst index c38ef0dda605..c5bd804eca55 100644 --- a/Documentation/gpu/i915.rst +++ b/Documentation/gpu/i915.rst @@ -249,6 +249,15 @@ Display PLLs .. kernel-doc:: drivers/gpu/drm/i915/display/intel_dpll_mgr.h :internal: +Display State Buffer +-------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_dsb.c + :doc: DSB + +.. kernel-doc:: drivers/gpu/drm/i915/intel_dsb.c + :internal: + Memory Management and Command Submission ======================================== diff --git a/drivers/gpu/drm/i915/intel_dsb.c b/drivers/gpu/drm/i915/intel_dsb.c index dddaae27d7b5..b74126c99a16 100644 --- a/drivers/gpu/drm/i915/intel_dsb.c +++ b/drivers/gpu/drm/i915/intel_dsb.c @@ -8,6 +8,23 @@ #define DSB_BUF_SIZE (2 * PAGE_SIZE) +/** + * DOC: DSB + * + * A DSB (Display State Buffer) is a queue of MMIO instructions in the memory + * which can be offloaded to DSB HW in Display Controller. DSB HW is a DMA + * engine that can be programmed to download the DSB from memory. + * It allows driver to batch submit display HW programming. This helps to + * reduce loading time and CPU activity, thereby making the context switch + * faster. DSB Support added from Gen12 Intel graphics based platform. + * + * DSB's can access only the pipe, plane, and transcoder Data Island Packet + * registers. + * + * DSB HW can support only register writes (both indexed and direct MMIO + * writes). There are no registers reads possible with DSB HW engine. + */ + /* DSB opcodes. */ #define DSB_OPCODE_SHIFT 24 #define DSB_OPCODE_NOOP 0x0 @@ -72,6 +89,17 @@ static bool intel_dsb_disable_engine(struct intel_dsb *dsb) return true; } +/** + * intel_dsb_get() - Allocate dsb context and return a dsb instance. + * @crtc: intel_crtc structure to get pipe info. + * + * This function will give handle of the DSB instance which + * user want to operate on. + * + * Return : address of Intel_dsb instance requested for. + * In failure case, the dsb instance will not have any command buffer. + */ + struct intel_dsb * intel_dsb_get(struct intel_crtc *crtc) { @@ -164,6 +192,18 @@ static void intel_dsb_indexed_reg_write(struct intel_dsb *dsb, i915_reg_t reg, buf[dsb->free_pos] = 0; } +/** + * intel_dsb_reg_write() -Write to the dsb context for normal + * register. + * @dsb: intel_dsb structure. + * @reg: register address. + * @val: value. + * + * This function is used for writing register-value pair in command + * buffer of DSB. During command buffer overflow, a warning + * is thrown and rest all erroneous condition register programming is done + * through mmio write. + */ void intel_dsb_reg_write(struct intel_dsb *dsb, i915_reg_t reg, u32 val) { struct intel_crtc *crtc = dsb->crtc; @@ -191,6 +231,13 @@ void intel_dsb_reg_write(struct intel_dsb *dsb, i915_reg_t reg, u32 val) i915_mmio_reg_offset(reg); } +/** + * intel_dsb_commit() - Trigger workload execution of DSB. + * @dsb: intel_dsb structure. + * + * This function is used to do actual write to hardware using DSB. + * On errors, fall back to MMIO. Also this function help to reset the context. + */ void intel_dsb_commit(struct intel_dsb *dsb) { struct intel_crtc *crtc = dsb->crtc; @@ -234,6 +281,13 @@ void intel_dsb_commit(struct intel_dsb *dsb) intel_dsb_disable_engine(dsb); } +/** + * intel_dsb_put() - To destroy DSB context. + * @dsb: intel_dsb structure. + * + * This function is used to destroy the dsb-context by doing unpin + * and release the vma object. + */ void intel_dsb_put(struct intel_dsb *dsb) { struct intel_crtc *crtc = dsb->crtc;