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 B02BBCCF9EA for ; Sat, 25 Oct 2025 12:04:44 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6557810E266; Sat, 25 Oct 2025 12:04:44 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="mW7DQJhD"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.18]) by gabe.freedesktop.org (Postfix) with ESMTPS id F1A9910E266; Sat, 25 Oct 2025 12:04:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1761393882; x=1792929882; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=2TjLEPKYMXodeV5eqatLZyGvUKihrSdW7WVutuXMHpA=; b=mW7DQJhD55z4ND+sODdZO0LvBRoZMvFR/rz/8uEXV2Bq7mYTLHRg1jk5 EY5e016bDxEqFzNkK/9lbp96vONZMBIe2rBD7rG4tdaVx3MVQ5WZJ6C2l T66aLUSuk/PbW0Z+r6aevGOE+mS/UJqIwwtr9fzk6VsG/jlW+U7t2qu+z xBs3nnraOHp+rtDT3f2kfBSc4IaoxLzD37KpDBqwdkby02mOhTaCgaw0h Ofuc975tEPSWMHd9MyymD0HeLHmjjcg0ynNJW+AetJbJ2S8ef8KeoMdKY V2oJ4Jqk2QSAF81xnroZPTHCN2a/hbc3wIHa6FjAodq9v87yZqjiUMgfx A==; X-CSE-ConnectionGUID: ldFTNjsZTkasUk5HcUdK2Q== X-CSE-MsgGUID: KZJZB+tKTsSYdZF7A45MTg== X-IronPort-AV: E=McAfee;i="6800,10657,11586"; a="63590372" X-IronPort-AV: E=Sophos;i="6.19,254,1754982000"; d="scan'208";a="63590372" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Oct 2025 05:04:42 -0700 X-CSE-ConnectionGUID: SvHcXAQSSq+7FWBn3ZBzWQ== X-CSE-MsgGUID: yWkfm9viThSpCttW4NVaog== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,254,1754982000"; d="scan'208";a="189023677" Received: from smoticic-mobl1.ger.corp.intel.com (HELO fedora) ([10.245.245.168]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Oct 2025 05:04:39 -0700 From: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= To: intel-xe@lists.freedesktop.org Cc: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= , dri-devel@lists.freedesktop.org, himal.prasad.ghimiray@intel.com, apopple@nvidia.com, airlied@gmail.com, Simona Vetter , felix.kuehling@amd.com, Matthew Brost , =?UTF-8?q?Christian=20K=C3=B6nig?= , dakr@kernel.org, "Mrozek, Michal" , Joonas Lahtinen Subject: [PATCH 02/15] drm/pagemap: Add a refcounted drm_pagemap backpointer to struct drm_pagemap_zdd Date: Sat, 25 Oct 2025 14:03:59 +0200 Message-ID: <20251025120412.12262-3-thomas.hellstrom@linux.intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251025120412.12262-1-thomas.hellstrom@linux.intel.com> References: <20251025120412.12262-1-thomas.hellstrom@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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" To be able to keep track of drm_pagemap usage, add a refcounted backpointer to struct drm_pagemap_zdd. This will keep the drm_pagemap reference count from dropping to zero as long as there are drm_pagemap pages present in a CPU address space. Signed-off-by: Thomas Hellström --- drivers/gpu/drm/drm_pagemap.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c index 4b8692f0b2a2..173b3ecb07d5 100644 --- a/drivers/gpu/drm/drm_pagemap.c +++ b/drivers/gpu/drm/drm_pagemap.c @@ -62,6 +62,7 @@ * * @refcount: Reference count for the zdd * @devmem_allocation: device memory allocation + * @dpagemap: Refcounted pointer to the underlying struct drm_pagemap. * @device_private_page_owner: Device private pages owner * * This structure serves as a generic wrapper installed in @@ -74,11 +75,13 @@ struct drm_pagemap_zdd { struct kref refcount; struct drm_pagemap_devmem *devmem_allocation; + struct drm_pagemap *dpagemap; void *device_private_page_owner; }; /** * drm_pagemap_zdd_alloc() - Allocate a zdd structure. + * @dpagemap: Pointer to the underlying struct drm_pagemap. * @device_private_page_owner: Device private pages owner * * This function allocates and initializes a new zdd structure. It sets up the @@ -87,7 +90,7 @@ struct drm_pagemap_zdd { * Return: Pointer to the allocated zdd on success, ERR_PTR() on failure. */ static struct drm_pagemap_zdd * -drm_pagemap_zdd_alloc(void *device_private_page_owner) +drm_pagemap_zdd_alloc(struct drm_pagemap *dpagemap, void *device_private_page_owner) { struct drm_pagemap_zdd *zdd; @@ -98,6 +101,7 @@ drm_pagemap_zdd_alloc(void *device_private_page_owner) kref_init(&zdd->refcount); zdd->devmem_allocation = NULL; zdd->device_private_page_owner = device_private_page_owner; + zdd->dpagemap = drm_pagemap_get(dpagemap); return zdd; } @@ -127,6 +131,7 @@ static void drm_pagemap_zdd_destroy(struct kref *ref) struct drm_pagemap_zdd *zdd = container_of(ref, struct drm_pagemap_zdd, refcount); struct drm_pagemap_devmem *devmem = zdd->devmem_allocation; + struct drm_pagemap *dpagemap = zdd->dpagemap; if (devmem) { complete_all(&devmem->detached); @@ -134,6 +139,7 @@ static void drm_pagemap_zdd_destroy(struct kref *ref) devmem->ops->devmem_release(devmem); } kfree(zdd); + drm_pagemap_put(dpagemap); } /** @@ -366,7 +372,7 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation, pagemap_addr = buf + (2 * sizeof(*migrate.src) * npages); pages = buf + (2 * sizeof(*migrate.src) + sizeof(*pagemap_addr)) * npages; - zdd = drm_pagemap_zdd_alloc(pgmap_owner); + zdd = drm_pagemap_zdd_alloc(devmem_allocation->dpagemap, pgmap_owner); if (!zdd) { err = -ENOMEM; goto err_free; -- 2.51.0