Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [v5.4 stable] arm: stm32: Regression observed on "no-map"
 reserved memory region
To:     Quentin Perret <qperret@google.com>,
        Florian Fainelli <f.fainelli@gmail.com>
CC:     Ard Biesheuvel <ardb@kernel.org>, Rob Herring <robh+dt@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Sasha Levin <sashal@kernel.org>,
        stable <stable@vger.kernel.org>, Arnd Bergmann <arnd@arndb.de>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Nicolas Boichat <drinkcat@chromium.org>,
        Stephen Boyd <swboyd@chromium.org>,
        KarimAllah Ahmed <karahmed@amazon.de>,
        Android Kernel Team <kernel-team@android.com>,
        Architecture Mailman List <boot-architecture@lists.linaro.org>,
        Frank Rowand <frowand.list@gmail.com>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
References: <4a4734d6-49df-677b-71d3-b926c44d89a9@foss.st.com>
 <CAL_JsqKGG8E9Y53+az+5qAOOGiZRAA-aD-1tKB-hcOp+m3CJYw@mail.gmail.com>
 <001f8550-b625-17d2-85a6-98a483557c70@foss.st.com>
 <CAL_Jsq+LUPZFhXd+j-xM67rZB=pvEvZM+1sfckip0Lqq02PkZQ@mail.gmail.com>
 <CAMj1kXE2Mgr9CsAMnKXff+96xhDaE5OLeNhypHvpN815vZGZhQ@mail.gmail.com>
 <d7f9607a-9fcb-7ba2-6e39-03030da2deb0@gmail.com>
 <YH/ixPnHMxNo08mJ@google.com>
 <cc8f96a4-6c85-b869-d3cf-5dc543982054@gmail.com>
 <YIFzMkW+tXonTf0K@google.com>
From:   Alexandre TORGUE <alexandre.torgue@foss.st.com>
Message-ID: <ad90b2bb-0fab-9f06-28dd-038e8005490b@foss.st.com>
Date:   Fri, 7 May 2021 17:15:20 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
In-Reply-To: <YIFzMkW+tXonTf0K@google.com>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hi Quentin

On 4/22/21 2:59 PM, Quentin Perret wrote:
> On Wednesday 21 Apr 2021 at 07:33:52 (-0700), Florian Fainelli wrote:
>> It is not, otherwise I would have noticed earlier, can you try the same
>> thing that happens on my platform with a reserved region (without
>> no-map) adjacent to a reserved region with 'no-map'?
> 
> I just tried, but still no luck. FTR, I tried to reproduce your setup
> with the following DT:
> 
>          memory@40000000 {
>                  reg = <0x00 0x40000000 0x01 0x00>;
>                  device_type = "memory";
>          };
> 
>          reserved-memory {
>                  #address-cells = <2>;
>                  #size-cells = <2>;
>                  ranges;
> 
>                  foo@fdfff000{
>                          reg = <0x00 0xfdfff000 0x0 0x1000>;
>                  };
>                  bar@fe000000{
>                          reg = <0x00 0xfe000000 0x0 0x2000000>;
>                          no-map;
>                  };
>          };
> 
> And with 5.4.102 and 5.10.31 I get the following in /proc/iomem
> 
> <...>
> 40000000-fdffffff : System RAM
>    40080000-412cffff : Kernel code
>    412d0000-417affff : reserved
>    417b0000-419f8fff : Kernel data
>    48000000-48008fff : reserved
>    f7c00000-fdbfffff : reserved
>    fdfff000-fdffffff : reserved
> fe000000-ffffffff : reserved
> 100000000-13fffffff : System RAM
> <...>
> 
> which looks about right. I'll keep trying a few other things.

Did you get time to continue some tests on this issue ?

On my side this DT is not working:

memory@c0000000 {
         reg = <0xc0000000 0x20000000>;
};

reserved-memory {
         #address-cells = <1>;
         #size-cells = <1>;
         ranges;

         gpu_reserved: gpu@d4000000 {
                 reg = <0xd4000000 0x4000000>;
                 no-map;
         };
};

Let me know if I can help.

regards
Alex

> Thanks,
> Quentin
>