Re: [PATCH v2 06/18] x86, acpi: Initialize ACPI root table list earlier.

Toshi Kani
2013-08-01T23:55:22Z

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