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 09775D2ECF9 for ; Tue, 20 Jan 2026 06:09:20 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A70EC10E4CE; Tue, 20 Jan 2026 06:09:20 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="H6sDdJUF"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5DCDE10E4CE for ; Tue, 20 Jan 2026 06:09:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1768889358; x=1800425358; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=KOZfxfg2PfqO5Dpi0xoGhQWj7EjH5oF66v5LHSBV0J4=; b=H6sDdJUFWs+YJtQhG4XNHrnBP8DY/TxaVHLyrf2CNyF8Huq5YizFQJZ0 /NerqpdceyAZcuEQZKRlIJUig4B1oeOHS2GVOwi93s/k/gKQYNNV6z1Nj Hvx218gGTfuE/MaRmFNRqU0Cu16fq36t24n7OuzKmd7/WBs54vd1lB79y s1bQyJ28d4fJxkNCPNEbw8agMFbKyIiEc7g9SAgnvJ5oMCU8rPnH1jZ54 gDUBL7g9k2b+WRoE1Jjg2Knml2RGqt/uu/nF8iJ56EKVWOqG1IY6ih5KZ g3X3my0fsnK2KkG10Dcn41fs7ftALyOwLbVsHhj9zaDYLgcgJQuFZLe39 A==; X-CSE-ConnectionGUID: 1efxQifBQsS5ciDophcWhw== X-CSE-MsgGUID: DcAeqTbKQniev8/aWT8GNQ== X-IronPort-AV: E=McAfee;i="6800,10657,11676"; a="72676982" X-IronPort-AV: E=Sophos;i="6.21,240,1763452800"; d="scan'208";a="72676982" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jan 2026 22:09:18 -0800 X-CSE-ConnectionGUID: LHM+0kleTSmvJRVE1y5mdg== X-CSE-MsgGUID: 0MgYVRJzSIuZZfaZq8Sx5A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,240,1763452800"; d="scan'208";a="205658597" Received: from varungup-desk.iind.intel.com ([10.190.238.71]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jan 2026 22:09:17 -0800 From: Arvind Yadav To: intel-xe@lists.freedesktop.org Cc: matthew.brost@intel.com, himal.prasad.ghimiray@intel.com, thomas.hellstrom@linux.intel.com, pallavi.mishra@intel.com Subject: [PATCH v4 2/8] drm/xe/bo: Add purgeable bo state tracking and field madv to xe_bo Date: Tue, 20 Jan 2026 11:38:48 +0530 Message-ID: <20260120060900.3137984-3-arvind.yadav@intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260120060900.3137984-1-arvind.yadav@intel.com> References: <20260120060900.3137984-1-arvind.yadav@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" Add infrastructure for tracking purgeable state of buffer objects. This includes: Introduce enum xe_madv_purgeable_state with three states: - XE_MADV_PURGEABLE_WILLNEED (0): BO is needed and should not be purged. This is the default state for all BOs. - XE_MADV_PURGEABLE_DONTNEED (1): BO is not currently needed and can be purged by the kernel under memory pressure to reclaim resources. Only non-shared BOs can be marked as DONTNEED. - XE_MADV_PURGEABLE_PURGED (2): BO has been purged by the kernel. Accessing a purged BO results in error. Follows i915 semantics where once purged, the BO remains permanently invalid ("once purged, always purged"). Add atomic_t madv field to struct xe_bo for state tracking of purgeable state across concurrent access paths v2: - Add xe_bo_is_purged() helper, improve state documentation v3: - Add the kernel doc(Matthew Brost) - Add the new helpers xe_bo_madv_is_dontneed(Matthew Brost) v4: - @madv_purgeable atomic_t → u32 change across all relevant patches. (Matt) Cc: Matthew Brost Cc: Thomas Hellström Cc: Himal Prasad Ghimiray Signed-off-by: Arvind Yadav --- drivers/gpu/drm/xe/xe_bo.h | 56 ++++++++++++++++++++++++++++++++ drivers/gpu/drm/xe/xe_bo_types.h | 3 ++ 2 files changed, 59 insertions(+) diff --git a/drivers/gpu/drm/xe/xe_bo.h b/drivers/gpu/drm/xe/xe_bo.h index 8ab4474129c3..00e93b3065c9 100644 --- a/drivers/gpu/drm/xe/xe_bo.h +++ b/drivers/gpu/drm/xe/xe_bo.h @@ -86,6 +86,28 @@ #define XE_PCI_BARRIER_MMAP_OFFSET (0x50 << XE_PTE_SHIFT) +/** + * enum xe_madv_purgeable_state - Buffer object purgeable state enumeration + * + * This enum defines the possible purgeable states for a buffer object, + * allowing userspace to provide memory usage hints to the kernel for + * better memory management under pressure. + * + * @XE_MADV_PURGEABLE_WILLNEED: The buffer object is needed and should not be purged. + * This is the default state. + * @XE_MADV_PURGEABLE_DONTNEED: The buffer object is not currently needed and can be + * purged by the kernel under memory pressure. + * @XE_MADV_PURGEABLE_PURGED: The buffer object has been purged by the kernel. + * + * Accessing a purged buffer will result in an error. Per i915 semantics, + * once purged, a BO remains permanently invalid and must be destroyed and recreated. + */ +enum xe_madv_purgeable_state { + XE_MADV_PURGEABLE_WILLNEED, + XE_MADV_PURGEABLE_DONTNEED, + XE_MADV_PURGEABLE_PURGED, +}; + struct sg_table; struct xe_bo *xe_bo_alloc(void); @@ -214,6 +236,40 @@ static inline bool xe_bo_is_protected(const struct xe_bo *bo) return bo->pxp_key_instance; } +/** + * xe_bo_is_purged() - Check if buffer object has been purged + * @bo: The buffer object to check + * + * Checks if the buffer object's backing store has been discarded by the + * kernel due to memory pressure after being marked as purgeable (DONTNEED). + * Once purged, the BO cannot be restored and any attempt to use it will fail. + * + * Context: Caller must hold the BO's dma-resv lock + * Return: true if the BO has been purged, false otherwise + */ +static inline bool xe_bo_is_purged(struct xe_bo *bo) +{ + xe_bo_assert_held(bo); + return bo->madv_purgeable == XE_MADV_PURGEABLE_PURGED; +} + +/** + * xe_bo_madv_is_dontneed() - Check if BO is marked as DONTNEED + * @bo: The buffer object to check + * + * Checks if userspace has marked this BO as DONTNEED (i.e., its contents + * are not currently needed and can be discarded under memory pressure). + * This is used internally to decide whether a BO is eligible for purging. + * + * Context: Caller must hold the BO's dma-resv lock + * Return: true if the BO is marked DONTNEED, false otherwise + */ +static inline bool xe_bo_madv_is_dontneed(struct xe_bo *bo) +{ + xe_bo_assert_held(bo); + return bo->madv_purgeable == XE_MADV_PURGEABLE_DONTNEED; +} + static inline void xe_bo_unpin_map_no_vm(struct xe_bo *bo) { if (likely(bo)) { diff --git a/drivers/gpu/drm/xe/xe_bo_types.h b/drivers/gpu/drm/xe/xe_bo_types.h index d4fe3c8dca5b..6acfed0c0bb4 100644 --- a/drivers/gpu/drm/xe/xe_bo_types.h +++ b/drivers/gpu/drm/xe/xe_bo_types.h @@ -108,6 +108,9 @@ struct xe_bo { * from default */ u64 min_align; + + /** @madv_purgeable: user space advise on BO purgeability */ + u32 madv_purgeable; }; #endif -- 2.43.0