Received-SPF: pass (google.com: domain of linux-kernel+bounces-90979-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Precedence: bulk
MIME-Version: 1.0
References: <CAL_JsqKNGjKq3vcUPFiPa9JNq-8=oP=uBSD=tyKaPMH3cvAkww@mail.gmail.com>
 <20240304150227.166053-1-skseofh@gmail.com>
In-Reply-To: <20240304150227.166053-1-skseofh@gmail.com>
From: Rob Herring <robh+dt@kernel.org>
Date: Mon, 4 Mar 2024 11:05:22 -0600
Message-ID: <CAL_JsqKaZ4KcvfNZmn2gj+yXa8eLgzMpdhJJ=+OmMJPvzm-1Qg@mail.gmail.com>
Subject: Re: [PATCH] of: fdt: modify small size memory check
To: skseofh@gmail.com
Cc: devicetree@vger.kernel.org, frowand.list@gmail.com, 
	linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Mon, Mar 4, 2024 at 9:03=E2=80=AFAM <skseofh@gmail.com> wrote:
>
>
> >>
> >> From: Daero Lee <skseofh@gmail.com>
> >>
> >> After page aligning, the size may become zero. So I added exception
> >> handling code for size 0.
> >
> >That may be true, but when would anyone only have memory regions of
> >less than 2 pages. In any case memblock_add will just do nothing. What
> >is the actual problem you are having?
> >
> >Rob
>
> Ignore the previous mail.
> I modified the patch to clear this size check routine. Please check

You still haven't answered my questions above.

Though the patch below is a bit more readable than what we currently have..=
.

>
> -------------------------------------------------------------------------
> From 2135d37c37f8c369033f79102b17ddf5bb3ff838 Mon Sep 17 00:00:00 2001
> From: Daero Lee <skseofh@gmail.com>
> Date: Mon, 4 Mar 2024 23:21:14 +0900
> Subject: [PATCH] of: fdt: modify small size memory check
>
> Small size memory which is less than 1 PAGE_SIZE after page align
> should not be added to memblock.
>
> In this patch, the size check was modified to make it clear.
>
> Signed-off-by: Daero Lee <skseofh@gmail.com>
> ---
>  drivers/of/fdt.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index bf502ba8da95..9cf844e664b0 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -1220,18 +1220,16 @@ int __init early_init_dt_scan_chosen(char *cmdlin=
e)
>  void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
>  {
>         const u64 phys_offset =3D MIN_MEMBLOCK_ADDR;
> +       u64 abase =3D PAGE_ALIGN(base), aend =3D PAGE_ALIGN_DOWN(base + s=
ize);
>
> -       if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
> +       if((aend - abase) < PAGE_SIZE) {
>                 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
>                         base, base + size);
>                 return;
>         }
>
> -       if (!PAGE_ALIGNED(base)) {
> -               size -=3D PAGE_SIZE - (base & ~PAGE_MASK);
> -               base =3D PAGE_ALIGN(base);
> -       }
> -       size &=3D PAGE_MASK;
> +       base =3D abase;
> +       size =3D (aend - abase) & PAGE_MASK;
>
>         if (base > MAX_MEMBLOCK_ADDR) {
>                 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
> --
> 2.25.1
>
>