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To:     Youling Tang <tangyouling@loongson.cn>,
        Stefan Asserhall <stefan.asserhall@xilinx.com>,
        Arnd Bergmann <arnd@arndb.de>
Cc:     linux-kernel@vger.kernel.org
References: <1605750037-433-1-git-send-email-tangyouling@loongson.cn>
From:   Michal Simek <monstr@monstr.eu>
Subject: Re: [PATCH] microblaze: Use the common INIT_DATA_SECTION macro in
 vmlinux.lds.S
Message-ID: <d513f0d1-1cfd-9f71-f12e-1b53689ef073@monstr.eu>
Date:   Fri, 20 Nov 2020 14:31:34 +0100
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Hi,

On 19. 11. 20 2:40, Youling Tang wrote:
> Use the common INIT_DATA_SECTION rule for the linker script in an effort
> to regularize the linker script.
> 
> Signed-off-by: Youling Tang <tangyouling@loongson.cn>
> ---
>  arch/microblaze/kernel/vmlinux.lds.S | 24 +-----------------------
>  1 file changed, 1 insertion(+), 23 deletions(-)
> 
> diff --git a/arch/microblaze/kernel/vmlinux.lds.S b/arch/microblaze/kernel/vmlinux.lds.S
> index df07b3d..527ebfc 100644
> --- a/arch/microblaze/kernel/vmlinux.lds.S
> +++ b/arch/microblaze/kernel/vmlinux.lds.S
> @@ -96,10 +96,7 @@ SECTIONS {
>  	__init_begin = .;
>  
>  	INIT_TEXT_SECTION(PAGE_SIZE)
> -
> -	.init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
> -		INIT_DATA
> -	}
> +	INIT_DATA_SECTION(0)
>  
>  	. = ALIGN(4);
>  	.init.ivt : AT(ADDR(.init.ivt) - LOAD_OFFSET) {
> @@ -107,25 +104,6 @@ SECTIONS {
>  		*(.init.ivt)
>  		__ivt_end = .;
>  	}
> -
> -	.init.setup : AT(ADDR(.init.setup) - LOAD_OFFSET) {
> -		INIT_SETUP(0)
> -	}
> -
> -	.initcall.init : AT(ADDR(.initcall.init) - LOAD_OFFSET ) {
> -		INIT_CALLS
> -	}
> -
> -	.con_initcall.init : AT(ADDR(.con_initcall.init) - LOAD_OFFSET) {
> -		CON_INITCALL
> -	}
> -
> -	__init_end_before_initramfs = .;
> -
> -	.init.ramfs : AT(ADDR(.init.ramfs) - LOAD_OFFSET) {
> -		INIT_RAM_FS
> -	}
> -
>  	__init_end = .;
>  
>  	.bss ALIGN (PAGE_SIZE) : AT(ADDR(.bss) - LOAD_OFFSET) {
> 

Thanks for the patch but I can't accept it because recently we found
that there needs to be some resorting in linker to be able to boot.
The issue is that INIT_RAMFS_FS section is text/data/init and bss.
But because microblaze in early code is using two TLBs (16M) each for
early mapping and you have big initramfs bss section is unreachable.
That's why these sections needs to be swapped.
Maybe bss section can be moved up before INIT_DATA_SECTION maybe even
before INIT_TEXT_SECTION and we should be fine.

Thanks,
Michal

-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Xilinx Microblaze
Maintainer of Linux kernel - Xilinx Zynq ARM and ZynqMP ARM64 SoCs
U-Boot custodian - Xilinx Microblaze/Zynq/ZynqMP/Versal SoCs