From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E75AA1917FB; Mon, 3 Nov 2025 17:45:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762191915; cv=none; b=Hlfl6XFO3zaEosqeCP3v3feYmtWn+AbwnIb6JbdbYkR/XplNhvra/98s9mPG0EkpWwX5u98UGkHswttxE2JXhMKxC1+Zxkwto1OotYqM8MW1bhnQX03+Bt4VaXz9Pr3De2gGxSimYopNBNDOfJuI6M5aHSBPmIX7NO1KYph3CJo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762191915; c=relaxed/simple; bh=W+qr5DwMeVjhNwTz4GD8p3W4iUptYbkU5ExtMChr/xo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=sW4JM6OIiGyEFdMc4/76VkX1GuId/UF7fB7QVytxdfUuETQDVps9ZUZziA0LSxo1QxCq3uv6b7mYlk7k3/BzrMdNKeNJVmnBHgydc8PFhIy7jCXuSOJNy8tpmGcNnw2GdIV6l4GKkCp4MHErDKrt4nTLgcapRdZkSsRnkcSKAjc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=D/EJDKWk; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="D/EJDKWk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E09D4C4CEF8; Mon, 3 Nov 2025 17:45:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762191914; bh=W+qr5DwMeVjhNwTz4GD8p3W4iUptYbkU5ExtMChr/xo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=D/EJDKWk966ytiAE0+j5TuPyzBCXXDpboYv3OUu2QbF7sd8Ee5gkdzs9sS1n8zWSk vK1mdIM1LCd2RxmfwB/X0UwPPwBQR/UIFyddjyGJcGcgJWTAM11cf24B1QlNtADpT1 y9WR+I8EtyRz/fiomZ9jwWKv6uI2nuWgOije/uYCeUIqRTTu3tBHClKPW88zgmG+/t OSxgWAwzyEqm9DEP9/x0D1byujZlePfo3lL0LyOTjWj0rs9OxtSsbBrcOFDDB8Y3l8 YTMpthcTueMGrU11TO4d59WlF7c5j7oDsg5267Koxw/yaQs6fbhVO0pp44ZgVwR7pf pkWR85TYbXAzg== Message-ID: Date: Mon, 3 Nov 2025 11:45:11 -0600 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 5/5] Documentation/amdgpu: Add UMA carveout details To: "Yo-Jung Leo Lin (AMD)" , Alex Deucher , =?UTF-8?Q?Christian_K=C3=B6nig?= , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Jonathan Corbet Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, anson.tsao@amd.com References: <20251103-vram-carveout-tuning-for-upstream-v1-0-17e2a72639c5@amd.com> <20251103-vram-carveout-tuning-for-upstream-v1-5-17e2a72639c5@amd.com> Content-Language: en-US From: "Mario Limonciello (AMD) (kernel.org)" In-Reply-To: <20251103-vram-carveout-tuning-for-upstream-v1-5-17e2a72639c5@amd.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11/3/2025 1:51 AM, Yo-Jung Leo Lin (AMD) wrote: > Add documentation for the uma_carveout_options and uma_carveout > attributes in sysfs > > Signed-off-by: Yo-Jung Leo Lin (AMD) > --- > Documentation/gpu/amdgpu/driver-misc.rst | 26 ++++++++++++++++++++++++++ > drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c | 17 +++++++++++++++++ > 2 files changed, 43 insertions(+) > > diff --git a/Documentation/gpu/amdgpu/driver-misc.rst b/Documentation/gpu/amdgpu/driver-misc.rst > index 25b0c857816e..5a71fa9c6782 100644 > --- a/Documentation/gpu/amdgpu/driver-misc.rst > +++ b/Documentation/gpu/amdgpu/driver-misc.rst > @@ -128,3 +128,29 @@ smartshift_bias > > .. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c > :doc: smartshift_bias > + > +UMA Carveout > +============ > + > +Some versions of Atom ROM expose available options for the VRAM carveout sizes, > +and allow changes to the carveout size via the ATCS function code 0xA on supported > +BIOS implementation. > + > +For those platforms, users can use the following file to set the carveout size, > +in a way similar to what Windows users can do in the "Tuning" tab in AMD > +Adrenalin. > + > +Note that for BIOS implementations that don't support this, these files will not > +get created at all. > + > +uma_carveout_options > +-------------------- > + > +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c > + :doc: uma_carveout_options > + > +uma_carveout > +-------------------- > + > +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c > + :doc: uma_carveout How do you feel about adding some sample output from a test system for both files? This might make it easier for userspace to implement parsing it. > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c > index 1ebfd925b761..e9f71888ce57 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c > @@ -1855,6 +1855,17 @@ const struct attribute_group amdgpu_vbios_version_attr_group = { > .is_visible = amdgpu_vbios_version_attrs_is_visible, > }; > > +/** > + * DOC: uma_carveout > + * > + * This file is both readable and writable. When read, it shows the > + * index of the current setting. Writing a valid index to this file > + * allows users to change the UMA carveout size to the selected option > + * on the next boot. > + * > + * The available options and their corresponding indices can be read > + * from the uma_carveout_options file. > + */ > static ssize_t uma_carveout_show(struct device *dev, > struct device_attribute *attr, > char *buf) > @@ -1904,6 +1915,12 @@ static ssize_t uma_carveout_store(struct device *dev, > } > static DEVICE_ATTR_RW(uma_carveout); > > +/** > + * DOC: uma_carveout_options > + * > + * This is a read-only file that lists all available UMA allocation > + * options and their corresponding indices. > + */ > static ssize_t uma_carveout_options_show(struct device *dev, > struct device_attribute *attr, > char *buf) >