From mboxrd@z Thu Jan 1 00:00:00 1970 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 9A12CD35661 for ; Wed, 28 Jan 2026 00:48:55 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4079010E5E5; Wed, 28 Jan 2026 00:48:52 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="Sl1bG/6H"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id AA1FE10E5DD; Wed, 28 Jan 2026 00:48:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1769561329; x=1801097329; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=OnOQh1Qj33/UNnWPRm4ArdCwn+OnRbMVCy4pH3tEYXA=; b=Sl1bG/6HBDTQCq7ZtvezBe3D8ehngPp81IeQoZ3iJlhBS8bTAuencvtb 46igQwLEIe+jPyKSdJ6PzDQb085K4CorWpmOWUSXlEtS9dR71IY/zOccp rUdrHznqSWclkdqUlzUti0MDK+4+a27WT9+KhhVsW7Qie7CwkqAMto9C7 kvyQE22cJHbTCyLBkfjrmzjJ7+XwWOsERTDpyv8BSY9C9ac83MvvgzDrV nE8YZizLGQRd9464ZRfClhQ59jL1/u/tlHmbOfqtC4dMoCCD+gbL1XQ1L 2dBMsiMX7D1/CsgJaLwrQKAAKpMy6/DNJ8UwAi/6LDAAbqDDl8FTqACbi A==; X-CSE-ConnectionGUID: uEJxkX6AT525NTrmhGLyCQ== X-CSE-MsgGUID: M0Q9+/GqTE2iBKoJkSsKvA== X-IronPort-AV: E=McAfee;i="6800,10657,11684"; a="93427518" X-IronPort-AV: E=Sophos;i="6.21,257,1763452800"; d="scan'208";a="93427518" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jan 2026 16:48:48 -0800 X-CSE-ConnectionGUID: lKB6kxkKTtGoQ5dg5tV6sw== X-CSE-MsgGUID: 0LSlxnlMSpSI6rxqnVN2WQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,257,1763452800"; d="scan'208";a="238822657" Received: from lstrano-desk.jf.intel.com ([10.54.39.91]) by orviesa002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jan 2026 16:48:48 -0800 From: Matthew Brost To: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: leonro@nvidia.com, francois.dugast@intel.com, thomas.hellstrom@linux.intel.com, himal.prasad.ghimiray@intel.com, jgg@ziepe.ca Subject: [RFC PATCH v3 05/11] drm/pagemap: Reduce number of IOVA link calls Date: Tue, 27 Jan 2026 16:48:35 -0800 Message-Id: <20260128004841.2436896-6-matthew.brost@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260128004841.2436896-1-matthew.brost@intel.com> References: <20260128004841.2436896-1-matthew.brost@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" Each IOVA link call results in a page walk, which is relatively expensive. Reduce the number of IOVA link calls by collapsing contiguous physical pages into a single IOVA link operation. Signed-off-by: Matthew Brost --- drivers/gpu/drm/drm_pagemap.c | 49 ++++++++++++++++++++++++++--------- 1 file changed, 37 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c index b928c89f4bd1..a167064ce41a 100644 --- a/drivers/gpu/drm/drm_pagemap.c +++ b/drivers/gpu/drm/drm_pagemap.c @@ -305,7 +305,8 @@ drm_pagemap_migrate_map_system_pages(struct device *dev, struct dma_iova_state *state) { struct page *dummy_page = NULL; - unsigned long i, psize; + unsigned long i, j, psize; + phys_addr_t phys = -1; bool try_alloc = false; for (i = 0; i < npages;) { @@ -339,26 +340,50 @@ drm_pagemap_migrate_map_system_pages(struct device *dev, if (dma_use_iova(state)) { bool found_dummy = page && !dummy_page; + bool phys_match; int err; - if (found_dummy) { - unsigned long j; + if (found_dummy && i) { + err = dma_iova_link(dev, state, + page_to_phys(page), + 0, i * PAGE_SIZE, + dir, 0); + if (err) + return err; + } + + if (phys == -1) { + phys = page_to_phys(page); + j = i; + phys_match = true; + } else { + phys_match = phys + (i - j) * PAGE_SIZE == + page_to_phys(page); + } - for (j = 0; j < i; ++j) { + if (psize != PAGE_SIZE || !phys_match || + (i + 1) == npages) { + err = dma_iova_link(dev, state, phys, + j * PAGE_SIZE, + psize * ((i - j) + + phys_match), + dir, 0); + if (err) + return err; + + if (!phys_match && (i + 1) == npages) { err = dma_iova_link(dev, state, page_to_phys(page), - j * PAGE_SIZE, - PAGE_SIZE, dir, 0); + i * PAGE_SIZE, + psize, + dir, 0); if (err) return err; } - } - err = dma_iova_link(dev, state, page_to_phys(page), - i * PAGE_SIZE, psize, - dir, 0); - if (err) - return err; + phys = page_to_phys(page); + j = i; + } if (page != dummy_page) dma_addr = state->addr + i * PAGE_SIZE; -- 2.34.1