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 D70AFFB3CE5 for ; Mon, 30 Mar 2026 09:49:37 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2721410E57E; Mon, 30 Mar 2026 09:49:37 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=collabora.com header.i=@collabora.com header.b="Sx7l6psS"; dkim-atps=neutral Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) by gabe.freedesktop.org (Postfix) with ESMTPS id DB4ED10E5AC for ; Mon, 30 Mar 2026 09:49:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1774864145; bh=vJ9VxiSezaHmUT4R1gM2vBrOcIXoOjygXM32L+tr6kY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Sx7l6psSi64c0+QbHSdp8hr2GMbkQJ6Zzu13V+KlVD0HeRxGbs4FV7CUqQwZckOSq JSQaJ4SYFLPtOJtJ7cVJ3e8O39HTytmnhhU3LPOjSHU/E0FOwI77gECku/JwO4eSPE Iv6kCSP0K2joKs6B5GlMZmiysT1KNPU7Pr4IAH8wYViFL6H+TW+yY0VYYArjwTH5qe aYeu7efcOFm700zg2OgLFivHUjue77Kv3IQ/A96jhg1fXGP5VLxKZlyNaV+mW4eG3R 6cgf7TS4H9Ah8BUuosagiFbDYOgzuSeLchIjFke78M7c6iWt+v27mbp98q9UaCzeBi k/5SXE+mOL9Sg== Received: from fedora (unknown [IPv6:2a01:e0a:2c:6930:a2a7:f53:ebb0:945e]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id BC58D17E41C5; Mon, 30 Mar 2026 11:49:04 +0200 (CEST) From: Boris Brezillon To: Boris Brezillon , Steven Price , Liviu Dudau , =?UTF-8?q?Adri=C3=A1n=20Larumbe?= Cc: dri-devel@lists.freedesktop.org, David Airlie , Simona Vetter , Akash Goel , Rob Clark , Sean Paul , Konrad Dybcio , Akhil P Oommen , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Dmitry Osipenko , Chris Diamand , Danilo Krummrich , Matthew Brost , =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= , Alice Ryhl , Chia-I Wu , kernel@collabora.com Subject: [PATCH v6 8/9] drm/panthor: Track the number of mmap on a BO Date: Mon, 30 Mar 2026 11:48:47 +0200 Message-ID: <20260330094848.2169422-9-boris.brezillon@collabora.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260330094848.2169422-1-boris.brezillon@collabora.com> References: <20260330094848.2169422-1-boris.brezillon@collabora.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" This will be used to order things by reclaimability. v2: - Fix refcounting v3: - Fix refcounting (again) v4: - Collect R-b v5: - Collect R-b v6: - Warn on is_imported() (not supposed to happen since mmap is redirected to the dmabuf layer) instead of adding a conditional in panthor_gem_vm_open() Signed-off-by: Boris Brezillon Reviewed-by: Steven Price --- drivers/gpu/drm/panthor/panthor_gem.c | 42 +++++++++++++++++++++++++-- drivers/gpu/drm/panthor/panthor_gem.h | 3 ++ 2 files changed, 43 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/panthor/panthor_gem.c b/drivers/gpu/drm/panthor/panthor_gem.c index d9c3a71da29b..eb139759beda 100644 --- a/drivers/gpu/drm/panthor/panthor_gem.c +++ b/drivers/gpu/drm/panthor/panthor_gem.c @@ -488,6 +488,7 @@ static void panthor_gem_print_info(struct drm_printer *p, unsigned int indent, drm_printf_indent(p, indent, "vmap_use_count=%u\n", refcount_read(&bo->cmap.vaddr_use_count)); drm_printf_indent(p, indent, "vaddr=%p\n", bo->cmap.vaddr); + drm_printf_indent(p, indent, "mmap_count=%u\n", refcount_read(&bo->cmap.mmap_count)); } static int panthor_gem_pin_locked(struct drm_gem_object *obj) @@ -604,6 +605,13 @@ static int panthor_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *v if (is_cow_mapping(vma->vm_flags)) return -EINVAL; + if (!refcount_inc_not_zero(&bo->cmap.mmap_count)) { + dma_resv_lock(obj->resv, NULL); + if (!refcount_inc_not_zero(&bo->cmap.mmap_count)) + refcount_set(&bo->cmap.mmap_count, 1); + dma_resv_unlock(obj->resv); + } + vm_flags_set(vma, VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP); vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); if (should_map_wc(bo)) @@ -740,13 +748,43 @@ static vm_fault_t panthor_gem_fault(struct vm_fault *vmf) return panthor_gem_any_fault(vmf, 0); } +static void panthor_gem_vm_open(struct vm_area_struct *vma) +{ + struct panthor_gem_object *bo = to_panthor_bo(vma->vm_private_data); + + drm_WARN_ON(bo->base.dev, drm_gem_is_imported(&bo->base)); + drm_WARN_ON(bo->base.dev, !refcount_inc_not_zero(&bo->cmap.mmap_count)); + + drm_gem_vm_open(vma); +} + +static void panthor_gem_vm_close(struct vm_area_struct *vma) +{ + struct panthor_gem_object *bo = to_panthor_bo(vma->vm_private_data); + + if (drm_gem_is_imported(&bo->base)) + goto out; + + if (refcount_dec_not_one(&bo->cmap.mmap_count)) + goto out; + + dma_resv_lock(bo->base.resv, NULL); + if (refcount_dec_and_test(&bo->cmap.mmap_count)) { + /* Nothing to do, pages are reclaimed lazily. */ + } + dma_resv_unlock(bo->base.resv); + +out: + drm_gem_object_put(&bo->base); +} + static const struct vm_operations_struct panthor_gem_vm_ops = { .fault = panthor_gem_fault, #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP .huge_fault = panthor_gem_any_fault, #endif - .open = drm_gem_vm_open, - .close = drm_gem_vm_close, + .open = panthor_gem_vm_open, + .close = panthor_gem_vm_close, }; static const struct drm_gem_object_funcs panthor_gem_funcs = { diff --git a/drivers/gpu/drm/panthor/panthor_gem.h b/drivers/gpu/drm/panthor/panthor_gem.h index b66478c9590c..c0a18dca732c 100644 --- a/drivers/gpu/drm/panthor/panthor_gem.h +++ b/drivers/gpu/drm/panthor/panthor_gem.h @@ -80,6 +80,9 @@ struct panthor_gem_cpu_map { /** @vaddr_use_count: Number of active vmap() requests on this GEM */ refcount_t vaddr_use_count; + + /** @mmap_count: Number of active mmap() requests on this GEM */ + refcount_t mmap_count; }; /** -- 2.53.0