linux-kernel - Re: [PATCH v2 4/4] arm64: dts: broadcom: Add support for BCM2712

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZkXFi6_2DkXRNgSL@apocalypse>
Date: Thu, 16 May 2024 10:36:27 +0200
From: Andrea della Porta <andrea.porta@...e.com>
To: Florian Fainelli <florian.fainelli@...adcom.com>
Cc: Andrea della Porta <andrea.porta@...e.com>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
	Conor Dooley <conor+dt@...nel.org>, Ray Jui <rjui@...adcom.com>,
	Scott Branden <sbranden@...adcom.com>,
	Broadcom internal kernel review list <bcm-kernel-feedback-list@...adcom.com>,
	Ulf Hansson <ulf.hansson@...aro.org>,
	Adrian Hunter <adrian.hunter@...el.com>,
	Kamal Dasu <kamal.dasu@...adcom.com>,
	Al Cooper <alcooperx@...il.com>, Eric Anholt <eric@...olt.net>,
	Stefan Wahren <wahrenst@....net>, devicetree@...r.kernel.org,
	linux-rpi-kernel@...ts.infradead.org,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	linux-mmc@...r.kernel.org
Subject: Re: [PATCH v2 4/4] arm64: dts: broadcom: Add support for BCM2712

On 09:14 Fri 10 May     , Florian Fainelli wrote:
> On 5/10/24 07:35, Andrea della Porta wrote:
> 
> This should be #size-cells = <2> to be future proof and support over 4GB of
> DRAM, because the DDR controller and the memory map on that chip have been
> designed with that requirement.
> 
> > +
> > +	interrupt-parent = <&gicv2>;
> > +
> > +	axi: axi {
> > +		compatible = "simple-bus";
> > +		#address-cells = <2>;
> > +		#size-cells = <1>;
> > +		ranges;
> 
> The AXI peripheral window should be defined in the ranges property. The
> aperture is from 0x10_0000_0000 to 0x10_3FFF_FFFF.
> 
> From that point on you can define all peripherals under the axi node to be
> relative to that axi aperture, just like what you did for the legacy Pi
> peripherals in the subsequent bus node.

This doesn't seem to match with what I have here:
- some axi peripherals goes beyond 0x10_3FFF_FFFF (e.g. the interrupt
  controller is @0x107fff9000)
- downstream dts have that ranges going from 0x10 0x00000000 0x11 0x00000000,
  so to span all the peripheral (included e.g. the above int controller)
- another comment in downstream dts says: // 10_00000000-1x_xxxxxxxx = up to
  64GB system RAM

I'm a little confused here, of course we could also define multiple ranges
but I don't really know what the boundaries are. Anyway, I would opt for the
extended range (0x10 0x00000000 - 0x11 0x00000000) unless there is concern
about it. Any thoughts?

Many thanks,
Andrea