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 48B2CC04FFE for ; Thu, 2 May 2024 16:53:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9B02F1125D1; Thu, 2 May 2024 16:53:25 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=collabora.com header.i=@collabora.com header.b="wbcohTXZ"; dkim-atps=neutral Received: from madrid.collaboradmins.com (madrid.collaboradmins.com [46.235.227.194]) by gabe.freedesktop.org (Postfix) with ESMTPS id AA5151125D8 for ; Thu, 2 May 2024 16:53:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1714668802; bh=d/kJMvVWPfPxg1HW/HpKsz5TsUwNP5RT02ecwFIGzno=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=wbcohTXZ8uglcZ4KTTjZw+4Myr+FXtLDnPp6StQIZyzWhFwz+mGwLTXs2SG9g8rci ARvbccfsbYoCp14JmXE1mTYSNJ7NHUDYOcrHJAJgk2cFVzrd2HvoODC/FoStqnTzqH RRzgreUC14JwvOZeJvCAxBVdFS7gPJDtSA3AQAOhPHYF2PO8kwpTjMuB/81gb5bxio pfLbxKuJicORuTusnhesGpGbnIzkYRgbQ//dl3e8RrNCy0PTwf84i1eVQ8R7pAL48j 5ZrQ6JwD6ON7Mgb4jxywmM/d+mTL6dg2BglGtEbCfe2aje5GIaOpbaVC9sPy1lSd6L S38vSR3QtbElw== Received: from localhost (cola.collaboradmins.com [195.201.22.229]) (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 madrid.collaboradmins.com (Postfix) with ESMTPSA id 25FC43782121; Thu, 2 May 2024 16:53:22 +0000 (UTC) Date: Thu, 2 May 2024 18:53:20 +0200 From: Boris Brezillon To: Steven Price Cc: Liviu Dudau , =?UTF-8?B?QWRyacOhbg==?= Larumbe , dri-devel@lists.freedesktop.org, kernel@collabora.com Subject: Re: [PATCH v3 3/5] drm/panthor: Relax the constraints on the tiler chunk size Message-ID: <20240502185320.454fbf69@collabora.com> In-Reply-To: References: <20240502154025.1425278-1-boris.brezillon@collabora.com> <20240502154025.1425278-4-boris.brezillon@collabora.com> Organization: Collabora X-Mailer: Claws Mail 4.2.0 (GTK 3.24.41; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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" On Thu, 2 May 2024 16:47:56 +0100 Steven Price wrote: > On 02/05/2024 16:40, Boris Brezillon wrote: > > The field used to store the chunk size if 12 bits wide, and the encoding > > is chunk_size = chunk_header.chunk_size << 12, which gives us a > > theoretical [4k:8M] range. This range is further limited by > > implementation constraints, and all known implementations seem to > > impose a [128k:8M] range, so do the same here. > > > > We also relax the power-of-two constraint, which doesn't seem to > > exist on v10. This will allow userspace to fine-tune initial/max > > tiler memory on memory-constrained devices. > > > > v3: > > - Add R-bs > > - Fix valid range in the kerneldoc > > Sadly the fixed range didn't make it to this posting... ;) My bad, I was checking the uAPI header and thought I had already fixed it the other day. Should be good in v4. > > Steve > > > > > v2: > > - Turn the power-of-two constraint into a page-aligned constraint to allow > > fine-tune of the initial/max heap memory size > > - Fix the panthor_heap_create() kerneldoc > > > > Fixes: 9cca48fa4f89 ("drm/panthor: Add the heap logical block") > > Signed-off-by: Boris Brezillon > > Reviewed-by: Liviu Dudau > > Reviewed-by: Steven Price > > --- > > drivers/gpu/drm/panthor/panthor_heap.c | 8 ++++---- > > include/uapi/drm/panthor_drm.h | 6 +++++- > > 2 files changed, 9 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/panthor/panthor_heap.c b/drivers/gpu/drm/panthor/panthor_heap.c > > index 3be86ec383d6..683bb94761bc 100644 > > --- a/drivers/gpu/drm/panthor/panthor_heap.c > > +++ b/drivers/gpu/drm/panthor/panthor_heap.c > > @@ -253,8 +253,8 @@ int panthor_heap_destroy(struct panthor_heap_pool *pool, u32 handle) > > * @pool: Pool to instantiate the heap context from. > > * @initial_chunk_count: Number of chunk allocated at initialization time. > > * Must be at least 1. > > - * @chunk_size: The size of each chunk. Must be a power of two between 256k > > - * and 2M. > > + * @chunk_size: The size of each chunk. Must be page-aligned and lie in the > > + * [128k:2M] range. > > * @max_chunks: Maximum number of chunks that can be allocated. > > * @target_in_flight: Maximum number of in-flight render passes. > > * @heap_ctx_gpu_va: Pointer holding the GPU address of the allocated heap > > @@ -284,8 +284,8 @@ int panthor_heap_create(struct panthor_heap_pool *pool, > > if (initial_chunk_count > max_chunks) > > return -EINVAL; > > > > - if (hweight32(chunk_size) != 1 || > > - chunk_size < SZ_256K || chunk_size > SZ_2M) > > + if (!IS_ALIGNED(chunk_size, PAGE_SIZE) || > > + chunk_size < SZ_128K || chunk_size > SZ_8M) > > return -EINVAL; > > > > down_read(&pool->lock); > > diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h > > index 5db80a0682d5..b8220d2e698f 100644 > > --- a/include/uapi/drm/panthor_drm.h > > +++ b/include/uapi/drm/panthor_drm.h > > @@ -898,7 +898,11 @@ struct drm_panthor_tiler_heap_create { > > /** @initial_chunk_count: Initial number of chunks to allocate. Must be at least one. */ > > __u32 initial_chunk_count; > > > > - /** @chunk_size: Chunk size. Must be a power of two at least 256KB large. */ > > + /** > > + * @chunk_size: Chunk size. > > + * > > + * Must be page-aligned and lie in the [128k:8M] range. > > + */ > > __u32 chunk_size; > > > > /** >