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 1563E2C3240; Tue, 3 Jun 2025 07:48:18 +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=1748936901; cv=none; b=eFXkuu/nCyqUovr9XN4JuXOpQa3V3KjLHyj5BkdjTF7SOIM4Tt4scMDB2yfsI/xLokT9nlWDlZqRhOEj2uzoYWnvNdHdIP8j+ssdxkAFU8IWb3I6XWEJzf8T+YCRLyNfioQBeNucYxualDg9yJaCj/TDlqMyaK9BcVdnfXoZD1Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748936901; c=relaxed/simple; bh=7/E2PZuS4xuO6ru4tVmW9wWcgEN+UdjTQfwPp/jVbLw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jFxQiUUykHEzKBBWuREROy87Hz3EAdXGxRkFdwy0jaBPNHKb7ITagJRjHuu3+TsaWkw/4eEzOUupWbYvooJFqm4TROZqNeQ7PuLjZs/Almwm8t+YG7V8fsHbWjckKqa4KYSHCH7NW/2n9CUcn4TPuec+YjoVnyzuXXz5cZFftMU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bPJcWEeg; 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="bPJcWEeg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9A4DC4CEED; Tue, 3 Jun 2025 07:48:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748936898; bh=7/E2PZuS4xuO6ru4tVmW9wWcgEN+UdjTQfwPp/jVbLw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bPJcWEegGmPrknxY/HQNjWITDH1jVIsj4qm7CIV5o0hvAbjeGtz7MW8+a3SNZdCdh bc4OTGVFjVCTT+oF/GR0JZaZb1IuazvjGxfnM4IiEdeHtBJlz3r63lvs8HbRLKfvVo aK/AtHpjGbJoA2A6tANmgeArsq7kixhM6Ed8ymmBY6aCvhA4dScXcFCk5TlsJq36J6 lbyaZdo9Ardhe6ixAg/j6vFNdrNDrrN6mIPak3Jx2uBsn63RJUapN7K6rUayoMnAvr ttEEp6wtGPOyk9yQFW0wATtiPcDApPZ9NhKfiKVShk2e/Zr0Mh4RwZEOD18UU9Q6GH ZOTyDZfjE8w/A== Date: Tue, 3 Jun 2025 09:48:09 +0200 From: Lorenzo Pieralisi To: Peter Maydell , Rob Herring , Krzysztof Kozlowski Cc: Marc Zyngier , Thomas Gleixner , Conor Dooley , Catalin Marinas , Will Deacon , andre.przywara@arm.com, Arnd Bergmann , Sascha Bischoff , Timothy Hayes , "Liam R. Howlett" , Mark Rutland , Jiri Slaby , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, suzuki.poulose@arm.com Subject: Re: [PATCH v4 01/26] dt-bindings: interrupt-controller: Add Arm GICv5 Message-ID: References: <20250513-gicv5-host-v4-0-b36e9b15a6c3@kernel.org> <20250513-gicv5-host-v4-1-b36e9b15a6c3@kernel.org> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, May 29, 2025 at 02:17:26PM +0100, Peter Maydell wrote: > On Thu, 29 May 2025 at 13:44, Lorenzo Pieralisi wrote: > > > > [+Andre, Peter] > > > > On Tue, May 13, 2025 at 07:47:54PM +0200, Lorenzo Pieralisi wrote: > > > + reg: > > > + minItems: 1 > > > + items: > > > + - description: IRS control frame > > > > I came across it while testing EL3 firmware, raising the topic for > > discussion. > > > > The IRS (and the ITS) has a config frame (need to patch the typo > > s/control/config, already done) per interrupt domain supported, that is, > > it can have up to 4 config frames: > > > > - EL3 > > - Secure > > - Realm > > - Non-Secure > > > > The one described in this binding is the non-secure one. > > > > IIUC, everything described in the DT represents the non-secure address > > space. > > The dt bindings do allow for describing Secure-world devices: > Documentation/devicetree/bindings/arm/secure.txt has the > details. We use this in QEMU so we can provide a DTB to > guest EL3 firmware that tells it where the hardware is > (and which EL3 can then pass on to an NS kernel). It would > be helpful for the GICv5 binding to be defined in a way that > we can do this for a GICv5 system too. It would be good to understand what DT {should/should not} describe and whether this DT usage to configure firmware is under the DT maintainers radar or it is an attempt at reusing it to avoid implementing a configuration scheme. Rob, Krzysztof, Any thoughts on the matter please ? [...] > The tempting thing to do is to have regs[] list the frames > in some given order, but the spec makes them not simple > supersets, allowing all of: > * NS > * S > * NS, S, EL3 > * NS, Realm, EL3 > * NS, Realm, S, EL3 Maybe reg-names can help ? Even though first we need to understand what resources should be described in DT. Current bindings are reviewed and I am not keen on dragging this discussion on forever - the information the kernel requires is there, I'd like to bring this to a close. Thanks, Lorenzo > > secure.txt says: > # The general principle of the naming scheme for Secure world bindings > # is that any property that needs a different value in the Secure world > # can be supported by prefixing the property name with "secure-". So for > # instance "secure-foo" would override "foo". > > So maybe we could have > reg : the NS frame(s) > secure-reg : the S frame(s) > realm-reg : the Realm frame(s) > root-reg : the EL3 frame(s) > > ?? > > thanks > -- PMM