Message-ID: <1375401251.10300.53.camel@misato.fc.hp.com>
Subject: Re: [PATCH v2 06/18] x86, acpi: Initialize ACPI root table list
 earlier.
From: Toshi Kani <toshi.kani@hp.com>
To: Tang Chen <tangchen@cn.fujitsu.com>
Cc: rjw@sisk.pl, lenb@kernel.org, tglx@linutronix.de, mingo@elte.hu,
        hpa@zytor.com, akpm@linux-foundation.org, tj@kernel.org, trenn@suse.de,
        yinghai@kernel.org, jiang.liu@huawei.com, wency@cn.fujitsu.com,
        laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com,
        izumi.taku@jp.fujitsu.com, mgorman@suse.de, minchan@kernel.org,
        mina86@mina86.com, gong.chen@linux.intel.com,
        vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com,
        riel@redhat.com, jweiner@redhat.com, prarit@redhat.com,
        zhangyanfei@cn.fujitsu.com, yanghy@cn.fujitsu.com, x86@kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, linux-acpi@vger.kernel.org
Date: Thu, 01 Aug 2013 17:54:11 -0600
In-Reply-To: <1375340800-19332-7-git-send-email-tangchen@cn.fujitsu.com>
References: <1375340800-19332-1-git-send-email-tangchen@cn.fujitsu.com>
	 <1375340800-19332-7-git-send-email-tangchen@cn.fujitsu.com>
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On Thu, 2013-08-01 at 15:06 +0800, Tang Chen wrote:
> We have split acpi_table_init() into two steps:
> 1. Pares RSDT or XSDT, and initialize acpi_gbl_root_table_list.
>    This step will record all tables' physical address in memory.
> 2. Check acpi initrd table override and install all tables into
>    acpi_gbl_root_table_list.
> 
> This patch does step 1 earlier, right after memblock is ready.
> 
> When memblock_x86_fill() is called to fulfill memblock.memory[],
> memblock is able to allocate memory.
> 
> This patch introduces a new function acpi_root_table_init() to
> do step 1, and call this function right after memblock_x86_fill()
> is called.
> 
> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
> ---
>  arch/x86/kernel/acpi/boot.c |   38 +++++++++++++++++++++++---------------
>  arch/x86/kernel/setup.c     |    3 +++
>  drivers/acpi/tables.c       |    7 +++++--
>  include/linux/acpi.h        |    2 ++
>  4 files changed, 33 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> index 230c8ea..3da5b3c 100644
> --- a/arch/x86/kernel/acpi/boot.c
> +++ b/arch/x86/kernel/acpi/boot.c
> @@ -1491,6 +1491,28 @@ static struct dmi_system_id __initdata acpi_dmi_table_late[] = {
>  };
>  
>  /*
> + * acpi_root_table_init - Initialize acpi_gbl_root_table_list.
> + *
> + * This function will parse RSDT or XSDT, find all tables' phys addr,
> + * initialize acpi_gbl_root_table_list, and record all tables' phys addr
> + * in acpi_gbl_root_table_list.
> + */
> +void __init acpi_root_table_init(void)

I think acpi_root_table_init() is a bit confusing with
acpi_boot_table_init().  Perhaps, something like
acpi_boot_table_pre_init() or early_acpi_boot_table_init() is better to
indicate that this new function is called before acpi_boot_table_init().

> +{
> +	dmi_check_system(acpi_dmi_table);
> +
> +	/* If acpi_disabled, bail out */
> +	if (acpi_disabled)
> +		return;
> +
> +	/* Initialize the ACPI boot-time table parser */
> +	if (acpi_table_init()) {
> +		disable_acpi();
> +		return;
> +	}
> +}
> +
> +/*
>   * acpi_boot_table_init() and acpi_boot_init()
>   *  called from setup_arch(), always.
>   *	1. checksums all tables
> @@ -1511,21 +1533,7 @@ static struct dmi_system_id __initdata acpi_dmi_table_late[] = {
>  
>  void __init acpi_boot_table_init(void)

The comment of this function needs to be updated.  For instance, it
describes acpi_table_init(), which you just relocated.

 * acpi_table_init() is separate to allow reading SRAT without
 * other side effects.
 *

>  {
> -	dmi_check_system(acpi_dmi_table);
> -
> -	/*
> -	 * If acpi_disabled, bail out
> -	 */
> -	if (acpi_disabled)
> -		return; 

I think this check is still necessary.

Thanks,
-Toshi

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