From patchwork Mon May 2 14:26:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ramalingam C X-Patchwork-Id: 12834256 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id CC07DC433F5 for ; Mon, 2 May 2022 14:25:33 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 04AA610EB25; Mon, 2 May 2022 14:25:24 +0000 (UTC) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id BDD6110EAE5; Mon, 2 May 2022 14:25:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1651501522; x=1683037522; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=EEaU8Hnu6gEBqEeIu4c5spdZwajT4yqEHVZvMrlOhVg=; b=manM31nLmv20KgFdkg1r1VpCEjO/C2ny39ckch+7GGs1dS0vJVzigJbs 2MvqSU9qP+qrjzs96vPMsDLxL1c7HGBGSLx39D0JekYvn1aBUXSdJEwMu s8HAdileH+VjfppdrKF1/pzltysb+DnUe/QO5PibiEky8wSUJ4Mb3tJqS JDKspXDoDDmRNsAoxvo5E/bhyl7VH1IuGoofgB/lQJe+/K8zEst+XeKNH UIQbzAQf2t/bsMmuUVKXdTaNg0ocybtNPgFn8BJW9y316PmzF5roFRQuw IiZnhzGSXt1lQtQZyhZC6bIJuiwD/mCeaMKSXM4WKLCGVuPB9ZtzI6HX9 g==; X-IronPort-AV: E=McAfee;i="6400,9594,10335"; a="292403408" X-IronPort-AV: E=Sophos;i="5.91,192,1647327600"; d="scan'208";a="292403408" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 May 2022 07:25:22 -0700 X-IronPort-AV: E=Sophos;i="5.91,192,1647327600"; d="scan'208";a="516111197" Received: from ramaling-i9x.iind.intel.com ([10.203.144.108]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 May 2022 07:25:20 -0700 From: Ramalingam C To: intel-gfx , dri-devel Date: Mon, 2 May 2022 19:56:18 +0530 Message-Id: <20220502142618.2704-4-ramalingam.c@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220502142618.2704-1-ramalingam.c@intel.com> References: <20220502142618.2704-1-ramalingam.c@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v3 3/3] drm/i915/gt: Document the eviction of the Flat-CCS objects 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: , Cc: Matthew Auld , Thomas Hellstrom Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Capture the eviction details for Flat-CCS capable, lmem objects. v2: Fix the Flat-ccs capbility of lmem obj with smem residency possibility [Thomas] v3: Fixed the suggestions [Matt] Signed-off-by: Ramalingam C cc: Thomas Hellstrom cc: Matthew Auld Reviewed-by: Matthew Auld --- drivers/gpu/drm/i915/gt/intel_migrate.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_migrate.c b/drivers/gpu/drm/i915/gt/intel_migrate.c index fc6975e55fae..509955885b93 100644 --- a/drivers/gpu/drm/i915/gt/intel_migrate.c +++ b/drivers/gpu/drm/i915/gt/intel_migrate.c @@ -485,16 +485,21 @@ static bool wa_1209644611_applies(int ver, u32 size) * And CCS data can be copied in and out of CCS region through * XY_CTRL_SURF_COPY_BLT. CPU can't access the CCS data directly. * - * When we exhaust the lmem, if the object's placements support smem, then we can - * directly decompress the compressed lmem object into smem and start using it - * from smem itself. + * I915 supports Flat-CCS on lmem only objects. When an objects has smem in + * its preference list, on memory pressure, i915 needs to migrate the lmem + * content into smem. If the lmem object is Flat-CCS compressed by userspace, + * then i915 needs to decompress it. But I915 lack the required information + * for such decompression. Hence I915 supports Flat-CCS only on lmem only objects. * - * But when we need to swapout the compressed lmem object into a smem region - * though objects' placement doesn't support smem, then we copy the lmem content - * as it is into smem region along with ccs data (using XY_CTRL_SURF_COPY_BLT). - * When the object is referred, lmem content will be swaped in along with - * restoration of the CCS data (using XY_CTRL_SURF_COPY_BLT) at corresponding - * location. + * When we exhaust the lmem, Flat-CCS capable objects' lmem backing memory can + * be temporarily evicted to smem, along with the auxiliary CCS state, where + * it can be potentially swapped-out at a later point, if required. + * If userspace later touches the evicted pages, then we always move + * the backing memory back to lmem, which includes restoring the saved CCS state, + * and potentially performing any required swap-in. + * + * For the migration of the lmem objects with smem in placement list, such as + * {lmem, smem}, objects are treated as non Flat-CCS capable objects. */ static inline u32 *i915_flush_dw(u32 *cmd, u32 flags)