Re: [PATCH v2 05/18] x86, acpi: Split acpi_boot_table_init() into two parts.

Toshi Kani
2013-08-01T23:33:20Z

On Thu, 2013-08-01 at 15:06 +0800, Tang Chen wrote:
> In ACPI, SRAT(System Resource Affinity Table) contains NUMA info.
> The memory affinities in SRAT record every memory range in the
> system, and also, flags specifying if the memory range is
> hotpluggable.
> (Please refer to ACPI spec 5.0 5.2.16)
>
> memblock starts to work at very early time, and SRAT has not been
> parsed. So we don't know which memory is hotpluggable. In order
> to use memblock to reserve hotpluggable memory, we need to obtain
> SRAT memory affinity info earlier.
>
> In the current acpi_boot_table_init(), it does the following:
> 1. Parse RSDT, so that we can find all the tables.
> 2. Initialize acpi_gbl_root_table_list, an array of acpi table
> descriptorsused to store each table's address, length, signature,
> and so on.
> 3. Check if there is any table in initrd intending to override
> tables from firmware. If so, override the firmware tables.
> 4. Initialize all the data in acpi_gbl_root_table_list.
>
> In order to parse SRAT at early time, we need to do similar job as
> step 1 and 2 above earlier to obtain SRAT. It will be very convenient
> if we have acpi_gbl_root_table_list initialized. We can use address
> and signature to find SRAT.
>
> Since step 1 and 2 allocates no memory, it is OK to do these two
> steps earlier.
>
> But step 3 will check acpi initrd table override, not just SRAT,
> but also all the other tables. So it is better to keep it untouched.
>
> This patch splits acpi_boot_table_init() into two steps:
> 1. Parse RSDT, which cannot be overrided, and initialize
> acpi_gbl_root_table_list. (step 1 + 2 above)
> 2. Install all ACPI tables into acpi_gbl_root_table_list.
> (step 3 + 4 above)
>
> In later patches, we will do step 1 + 2 earlier.
>
> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
> ---
> drivers/acpi/acpica/tbutils.c | 25 ++++++++++++++++++++++---
> drivers/acpi/tables.c | 2 ++
> include/acpi/acpixf.h | 2 ++
> 3 files changed, 26 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/acpica/tbutils.c b/drivers/acpi/acpica/tbutils.c

This patch needs to be reviewed by ACPICA folks. I'd suggest to change
the patch title to "x86, ACPICA:". I added Bob to the list.

Thanks,
-Toshi

> index ce3d5db..9d68ffc 100644
> --- a/drivers/acpi/acpica/tbutils.c
> +++ b/drivers/acpi/acpica/tbutils.c
> @@ -766,9 +766,30 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
> */
> acpi_os_unmap_memory(table, length);
>
> + return_ACPI_STATUS(AE_OK);
> +}
> +
> +/*******************************************************************************
> + *
> + * FUNCTION: acpi_tb_install_root_table
> + *
> + * DESCRIPTION: This function installs all the ACPI tables in RSDT into
> + * acpi_gbl_root_table_list.
> + *
> + ******************************************************************************/
> +
> +void __init
> +acpi_tb_install_root_table()
> +{
> + int i;
> +
> /*
> * Complete the initialization of the root table array by examining
> - * the header of each table
> + * the header of each table.
> + *
> + * First two entries in the table array are reserved for the DSDT
> + * and FACS, which are not actually present in the RSDT/XSDT - they
> + * come from the FADT.
> */
> for (i = 2; i < acpi_gbl_root_table_list.current_table_count; i++) {
> acpi_tb_install_table(acpi_gbl_root_table_list.tables[i].
> @@ -782,6 +803,4 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
> acpi_tb_parse_fadt(i);
> }
> }
> -
> - return_ACPI_STATUS(AE_OK);
> }
> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
> index d67a1fe..8860e79 100644
> --- a/drivers/acpi/tables.c
> +++ b/drivers/acpi/tables.c
> @@ -353,6 +353,8 @@ int __init acpi_table_init(void)
> if (ACPI_FAILURE(status))
> return 1;
>
> + acpi_tb_install_root_table();
> +
> check_multiple_madt();
> return 0;
> }
> diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
> index 454881e..f5549b5 100644
> --- a/include/acpi/acpixf.h
> +++ b/include/acpi/acpixf.h
> @@ -116,6 +116,8 @@ acpi_status
> acpi_initialize_tables(struct acpi_table_desc *initial_storage,
> u32 initial_table_count, u8 allow_resize);
>
> +void acpi_tb_install_root_table(void);
> +
> acpi_status __init acpi_initialize_subsystem(void);
>
> acpi_status acpi_enable_subsystem(u32 flags);