Re: [PATCH v2] ARM: rpi: parse memory from vc fdt

[SCHNEIDER Johannes <johannes.schneider@leica-geosystems.com>]

> Did you mean to resend a patch already applied to next..?

oh oops, that was a send-patch mishap... please ignore :-S


regards
Johannes

________________________________________
From: Ahmad Fatoum <a.fatoum@pengutronix.de>
Sent: Wednesday, January 11, 2023 11:07
To: SCHNEIDER Johannes; barebox@lists.infradead.org
Cc: Marcin Niestroj; Sascha Hauer
Subject: Re: [PATCH v2] ARM: rpi: parse memory from vc fdt

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On 11.01.23 10:56, Johannes Schneider wrote:
> From: Marcin Niestroj <m.niestroj@emb.dev>

Did you mean to resend a patch already applied to next..?

>
> Currently for RaspberryPi platform there is only one memory bank
> created, based on information fetched over mailbox. This is fine for
> booting Barebox, but unfortunately all the other memory banks are not
> propagated to Linux during boot, thus cannot be utilized. In fact, even
> when using /vc.dtb as device-tree for Linux, all memory nodes in FDT are
> deleted and new ones are created by Barebox by memory fixup mechanism,
> using exising RAM information. As a result RaspberryPi 4 boots Linux
> with 1GB RAM available, instead of 2GB (2 banks, each 1GB).
>
> At the end of VideoCore FDT parsing, do the same as of_probe_memory() in
> mem_initcall does, but for VideoCore provided devicetree/memory
> information. During Linux boot this information is used for memory fixup
> mechanism and in case of RaspberryPi 4 this results in 2 memory banks
> being propagated:
>
>   # ls /proc/device-tree/memory*
>   /proc/device-tree/memory@0:
>   device_type  name         reg
>
>   /proc/device-tree/memory@40000000:
>   device_type  name         reg
>
> Signed-off-by: Marcin Niestroj <m.niestroj@emb.dev>
> Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> Link: https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.barebox.org%2F20230110193251.2821638-1-m.niestroj%40grinn-global.com&data=05%7C01%7C%7Ce22566ee1edc40d19e3108daf3bba3e1%7C1b16ab3eb8f64fe39f3e2db7fe549f6a%7C0%7C0%7C638090284505422798%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=qzGOCullLi46yt9L8%2FpHfZ%2BpdTf0rkR7%2BenfsQlimSY%3D&reserved=0
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> ---
>  arch/arm/boards/raspberry-pi/rpi-common.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/boards/raspberry-pi/rpi-common.c b/arch/arm/boards/raspberry-pi/rpi-common.c
> index 77935e5c88..c6c7fd52bd 100644
> --- a/arch/arm/boards/raspberry-pi/rpi-common.c
> +++ b/arch/arm/boards/raspberry-pi/rpi-common.c
> @@ -258,7 +258,7 @@ static u32 rpi_boot_mode, rpi_boot_part;
>  static void rpi_vc_fdt_parse(void *fdt)
>  {
>       int ret;
> -     struct device_node *root, *chosen, *bootloader;
> +     struct device_node *root, *chosen, *bootloader, *memory;
>       char *str;
>
>       root = of_unflatten_dtb(fdt, INT_MAX);
> @@ -324,6 +324,16 @@ static void rpi_vc_fdt_parse(void *fdt)
>       if (IS_ENABLED(CONFIG_RESET_SOURCE))
>               reset_source_set(rpi_decode_pm_rsts(chosen, bootloader));
>
> +     /* Parse all available nodes with "memory" device_type */
> +     memory = root;
> +     while (1) {
> +             memory = of_find_node_by_type(memory, "memory");
> +             if (!memory)
> +                     break;
> +
> +             of_add_memory(memory, false);
> +     }
> +
>  out:
>       if (root)
>               of_delete_node(root);

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