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 A0A05213240; Wed, 5 Feb 2025 09:14:04 +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=1738746844; cv=none; b=Rp20+fTalAJzsT9E6n6q8C/VqdyY00AYhcEdClqEwt8n0TvkMQ53M5KsUV5e+6Bw47dQ5QWYv2s8b1ggGerc3OON320Lt/l4quELfZpUgTlagSSzVi5ZjhW+NsV9P0nTED/ZJZ/SmBZr7YwqZBDKWCbHlzCJtgKTkZCgIiQLQ/g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738746844; c=relaxed/simple; bh=4C2JCBvwyEf/X2nHPrRMmWtMS/VF3OfV5sTLegNX37Y=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=kKR8vWtTv+0ylpB3d5fisghF1WCZI/stfBA+eVHzY8qseFxLU4qXqTUcF1wXOZmHufTMuzhWH6et9JdK3aOKfsDlSPKKgCEDfMv8YomVtlpx8apR1odS8zXj8+4E+cu7H6sW3Ps3xRDpDS4VyuVgCugyAKSkv4SnVcH3how4roM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qgTAJYj7; 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="qgTAJYj7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D14B7C4CED1; Wed, 5 Feb 2025 09:13:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738746844; bh=4C2JCBvwyEf/X2nHPrRMmWtMS/VF3OfV5sTLegNX37Y=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=qgTAJYj7he3xj5vx6537c+N0Gqm8DOtAgpmH3h1hKA+KhJr6iB1oBfJrM/4FpnYK9 zY5e/VJxhZPBQMwAQQgUeZ/cNHG0tTwtgErxvItRjxJOiVejHN0FirRST+0kSMMJRr ut6HN5jaAgWOFwxv64Vv/+xG8oEXJQxPIe/ymoaNkxM8LPiXkwuAK/zahlRbALG2V6 WnhtEt6n3F7hqezB6lJRWKI2GEgcZNPpq9Xqoq7IIxVoaMLwm7QWSoFkspkjvCHz2U W+GDekkfQDVL82VGA+02ti+atf6xdm2gc65+nD7vW0MnGFPN8DVul8qOMJWlmT5kNm ndaQtCogl6k4A== Message-ID: Date: Wed, 5 Feb 2025 10:13:52 +0100 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: [RFC PATCH 3/5] dt-bindings: gpu: Add protected heap name to Mali Valhall CSF binding To: Florent Tomasin , Vinod Koul , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Boris Brezillon , Steven Price , Liviu Dudau , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T . J . Mercier" , =?UTF-8?Q?Christian_K=C3=B6nig?= , Matthias Brugger , AngeloGioacchino Del Regno , Yong Wu Cc: dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, nd@arm.com, Akash Goel References: <36b57dcf20860398ba83985e1c5b6f6958d08ba7.1738228114.git.florent.tomasin@arm.com> <7234f25c-a2aa-4834-931b-aeeb7a49dfa7@kernel.org> <4b9deab1-e330-4c93-8260-75276c2bc9ff@arm.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGVBBMBCgA/AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJgPO8PBQkUX63hAAoJEBuTQ307 QWKbBn8P+QFxwl7pDsAKR1InemMAmuykCHl+XgC0LDqrsWhAH5TYeTVXGSyDsuZjHvj+FRP+ gZaEIYSw2Yf0e91U9HXo3RYhEwSmxUQ4Fjhc9qAwGKVPQf6YuQ5yy6pzI8brcKmHHOGrB3tP /MODPt81M1zpograAC2WTDzkICfHKj8LpXp45PylD99J9q0Y+gb04CG5/wXs+1hJy/dz0tYy iua4nCuSRbxnSHKBS5vvjosWWjWQXsRKd+zzXp6kfRHHpzJkhRwF6ArXi4XnQ+REnoTfM5Fk VmVmSQ3yFKKePEzoIriT1b2sXO0g5QXOAvFqB65LZjXG9jGJoVG6ZJrUV1MVK8vamKoVbUEe 0NlLl/tX96HLowHHoKhxEsbFzGzKiFLh7hyboTpy2whdonkDxpnv/H8wE9M3VW/fPgnL2nPe xaBLqyHxy9hA9JrZvxg3IQ61x7rtBWBUQPmEaK0azW+l3ysiNpBhISkZrsW3ZUdknWu87nh6 eTB7mR7xBcVxnomxWwJI4B0wuMwCPdgbV6YDUKCuSgRMUEiVry10xd9KLypR9Vfyn1AhROrq AubRPVeJBf9zR5UW1trJNfwVt3XmbHX50HCcHdEdCKiT9O+FiEcahIaWh9lihvO0ci0TtVGZ MCEtaCE80Q3Ma9RdHYB3uVF930jwquplFLNF+IBCn5JRzsFNBFVDXDQBEADNkrQYSREUL4D3 Gws46JEoZ9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLue MNsWLJBvBaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6ei OMheesVS5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wA GldWsRxbf3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA 6z6lBZn0WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9 YegxWKvXXHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt 91pFzBSOIpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gU BLHFTg2hYnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/ JoFzZ4B0p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu 4vXVFBYIGmpyNPYzRm0QPwARAQABwsF8BBgBCgAmAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtB YpsFAmA872oFCRRflLYACgkQG5NDfTtBYpvScw/9GrqBrVLuJoJ52qBBKUBDo4E+5fU1bjt0 Gv0nh/hNJuecuRY6aemU6HOPNc2t8QHMSvwbSF+Vp9ZkOvrM36yUOufctoqON+wXrliEY0J4 ksR89ZILRRAold9Mh0YDqEJc1HmuxYLJ7lnbLYH1oui8bLbMBM8S2Uo9RKqV2GROLi44enVt vdrDvo+CxKj2K+d4cleCNiz5qbTxPUW/cgkwG0lJc4I4sso7l4XMDKn95c7JtNsuzqKvhEVS oic5by3fbUnuI0cemeizF4QdtX2uQxrP7RwHFBd+YUia7zCcz0//rv6FZmAxWZGy5arNl6Vm lQqNo7/Poh8WWfRS+xegBxc6hBXahpyUKphAKYkah+m+I0QToCfnGKnPqyYIMDEHCS/RfqA5 t8F+O56+oyLBAeWX7XcmyM6TGeVfb+OZVMJnZzK0s2VYAuI0Rl87FBFYgULdgqKV7R7WHzwD uZwJCLykjad45hsWcOGk3OcaAGQS6NDlfhM6O9aYNwGL6tGt/6BkRikNOs7VDEa4/HlbaSJo 7FgndGw1kWmkeL6oQh7wBvYll2buKod4qYntmNKEicoHGU+x91Gcan8mCoqhJkbqrL7+nXG2 5Q/GS5M9RFWS+nYyJh+c3OcfKqVcZQNANItt7+ULzdNJuhvTRRdC3g9hmCEuNSr+CLMdnRBY fv0= In-Reply-To: <4b9deab1-e330-4c93-8260-75276c2bc9ff@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 03/02/2025 16:31, Florent Tomasin wrote: > Hi Krzysztof > > On 30/01/2025 13:25, Krzysztof Kozlowski wrote: >> On 30/01/2025 14:08, Florent Tomasin wrote: >>> Allow mali-valhall-csf driver to retrieve a protected >>> heap at probe time by passing the name of the heap >>> as attribute to the device tree GPU node. >> >> Please wrap commit message according to Linux coding style / submission >> process (neither too early nor over the limit): >> https://elixir.bootlin.com/linux/v6.4-rc1/source/Documentation/process/submitting-patches.rst#L597 > Apologies, I think I made quite few other mistakes in the style of the > patches I sent. I will work on improving this aspect, appreciated > >> Why this cannot be passed by phandle, just like all reserved regions? >> >> From where do you take these protected heaps? Firmware? This would >> explain why no relation is here (no probe ordering, no device links, >> nothing connecting separate devices). > > The protected heap is generaly obtained from a firmware (TEE) and could > sometimes be a carved-out memory with restricted access. Which is a reserved memory, isn't it? > > The Panthor CSF kernel driver does not own or manage the protected heap > and is instead a consumer of it (assuming the heap is made available by > the system integrator). > > I initially used a phandle, but then I realised it would introduce a new > API to share the heap across kernel driver. In addition I found this > patch series: > - > https://lore.kernel.org/lkml/20230911023038.30649-1-yong.wu@mediatek.com/#t > > which introduces a DMA Heap API to the rest of the kernel to find a > heap by name: > - dma_heap_find() > > I then decided to follow that approach to help isolate the heap > management from the GPU driver code. In the Panthor driver, if the > heap is not found at probe time, the driver will defer the probe until > the exporter made it available. I don't talk here really about the driver but even above mediatek patchset uses reserved memory bindings. You explained some things about driver yet you did not answer the question. This looks like reserved memory. If it does not, bring arguments why this binding cannot be a reserved memory, why hardware is not a carve out memory. Best regards, Krzysztof