linux-kernel - Re: [PATCH 04/21] MIPS memblock: Alter user-defined memory parameter parser

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Message-ID: <756b9060-7a21-ad23-9e74-50670f42753e@imgtec.com>
Date:   Mon, 23 Jan 2017 08:55:16 +0100
From:   Marcin Nowakowski <marcin.nowakowski@...tec.com>
To:     Serge Semin <fancer.lancer@...il.com>, <ralf@...ux-mips.org>,
        <paul.burton@...tec.com>, <rabinv@...s.com>,
        <matt.redfearn@...tec.com>, <james.hogan@...tec.com>,
        <alexander.sverdlin@...ia.com>, <robh+dt@...nel.org>,
        <frowand.list@...il.com>
CC:     <Sergey.Semin@...latforms.ru>, <linux-mips@...ux-mips.org>,
        <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 04/21] MIPS memblock: Alter user-defined memory parameter
 parser

Hi Serge,

On 19.12.2016 03:07, Serge Semin wrote:
> Both new memblock and boot_mem_map subsystems need to be fully
> cleared before a new memory region is added. So the early parser is
> correspondingly modified.
>
> Signed-off-by: Serge Semin <fancer.lancer@...il.com>
> ---
>  arch/mips/kernel/setup.c | 67 +++++++++++++++++-------------
>  1 file changed, 37 insertions(+), 30 deletions(-)
>
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index 9da6f8a..789aafe 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -229,6 +229,43 @@ static void __init print_memory_map(void)
>  }
>
>  /*
> + * Parse "mem=size@...rt" parameter rewriting a defined memory map
> + * We look for mem=size@...rt, where start and size are "value[KkMm]"
> + */
> +static int __init early_parse_mem(char *p)
> +{
> +	static int usermem;

usermem variable seems unnecessary now and could easily be removed?

> +	phys_addr_t start, size;
> +
> +	start = PHYS_OFFSET;
> +	size = memparse(p, &p);
> +	if (*p == '@')
> +		start = memparse(p + 1, &p);
> +
> +	/*
> +	 * If a user specifies memory size, we blow away any automatically
> +	 * generated regions.
> +	 */
> +	if (usermem == 0) {
> +		phys_addr_t ram_start = memblock_start_of_DRAM();
> +		phys_addr_t ram_end = memblock_end_of_DRAM() - ram_start;
> +
> +		pr_notice("Discard memory layout %pa - %pa",
> +			  &ram_start, &ram_end);

missing \n in printk

> +		memblock_remove(ram_start, ram_end - ram_start);
> +		boot_mem_map.nr_map = 0;
> +		usermem = 1;
> +	}
> +	pr_notice("Add userdefined memory region %08zx @ %pa",
> +		  (size_t)size, &start);

ditto

> +	add_memory_region(start, size, BOOT_MEM_RAM);
> +	return 0;
> +}
> +early_param("mem", early_parse_mem);
> +
> +/*
>   * Manage initrd
>   */
>  #ifdef CONFIG_BLK_DEV_INITRD
> @@ -613,31 +650,6 @@ static void __init bootmem_init(void)
>   * initialization hook for anything else was introduced.
>   */
>
> -static int usermem __initdata;
> -
> -static int __init early_parse_mem(char *p)
> -{
> -	phys_addr_t start, size;
> -
> -	/*
> -	 * If a user specifies memory size, we
> -	 * blow away any automatically generated
> -	 * size.
> -	 */
> -	if (usermem == 0) {
> -		boot_mem_map.nr_map = 0;
> -		usermem = 1;
> -	}
> -	start = 0;
> -	size = memparse(p, &p);
> -	if (*p == '@')
> -		start = memparse(p + 1, &p);
> -
> -	add_memory_region(start, size, BOOT_MEM_RAM);
> -	return 0;
> -}
> -early_param("mem", early_parse_mem);
> -
>  #ifdef CONFIG_PROC_VMCORE
>  unsigned long setup_elfcorehdr, setup_elfcorehdr_size;
>  static int __init early_parse_elfcorehdr(char *p)
> @@ -797,11 +809,6 @@ static void __init arch_mem_init(char **cmdline_p)
>
>  	parse_early_param();
>
> -	if (usermem) {
> -		pr_info("User-defined physical RAM map:\n");
> -		print_memory_map();
> -	}
> -
>  	bootmem_init();
>  #ifdef CONFIG_PROC_VMCORE
>  	if (setup_elfcorehdr && setup_elfcorehdr_size) {
>


Regards,
Marcin