Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <1542787873-8429-1-git-send-email-miles.chen@mediatek.com>
In-Reply-To: <1542787873-8429-1-git-send-email-miles.chen@mediatek.com>
From:   Rob Herring <robh+dt@kernel.org>
Date:   Wed, 21 Nov 2018 10:39:03 -0600
Message-ID: <CAL_JsqLGvUYQmCGXLgSO+6kFj2i87dpaTbMGbyu5oMt=eeu35A@mail.gmail.com>
Subject: Re: [RFC PATCH] of: make MAX_RESERVED_REGIONS configurable
To:     Miles Chen <miles.chen@mediatek.com>
Cc:     Frank Rowand <frowand.list@gmail.com>, devicetree@vger.kernel.org,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>,
        linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Nov 21, 2018 at 2:11 AM <miles.chen@mediatek.com> wrote:
>
> From: Miles Chen <miles.chen@mediatek.com>
>
> When we use more than 32 entries in /resered-memory,
> there will be an error message: "not enough space all defined regions.".
> We can increase MAX_RESERVED_REGIONS to fix this.
>
> commit 22f8cc6e3373 ("drivers: of: increase MAX_RESERVED_REGIONS to 32")
> increased MAX_RESERVED_REGIONS to 32 but I'm not sure if increasing
> MAX_RESERVED_REGIONS to 64 is suitable for everyone.
>
> In this RFC patch, CONFIG_MAX_OF_RESERVED_REGIONS is added and used as
> MAX_RESERVED_REGIONS. Add a sanity test to make sure that
> MAX_RESERVED_REGIONS is less than INIT_MEMBLOCK_REGIONS.
> Users can configure CONFIG_MAX_OF_RESERVED_REGIONS according to their
> need.

I don't want a kconfig option for this. I think it should be dynamic instead.

The current flow is like this:

for each reserved node:
  - call memblock_reserve
  - Add info to reserved_mem array

I think we should change it to:

for each reserved node:
  - call memblock_reserve
  - count number of nodes

Alloc array using memblock_alloc

for each reserved node:
   - Add info to reserved_mem array

Rob