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

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

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://lore.barebox.org/20230110193251.2821638-1-m.niestroj@grinn-global.com
> 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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