Re: [PATCH v5 06/22] x86, ACPI: Split acpi_initrd_override tofind/copy two functions

From: Toshi Kani
Date: Mon Jun 17 2013 - 20:24:35 EST

On Fri, 2013-06-14 at 17:56 -0700, Yinghai Lu wrote:
> To parse srat early, we need to move acpi table probing early.
> acpi_initrd_table_override is before acpi table probing. So we need to
> move it early too.
> Current code acpi_initrd_table_override is after init_mem_mapping and
> relocate_initrd(), so it can scan initrd and copy acpi tables with kernel
> virtual address of initrd.
> Copying need to be after memblock is ready, because it need to allocate
> buffer for new acpi tables.
> So we have to split that function to find and copy two functions.
> Find should be as early as possible. Copy should be after memblock is ready.
> Finding could be done in head_32.S and head64.c, just like microcode
> early scanning. In head_32.S, it is 32bit flat mode, we don't
> need to set page table to access it. In head64.c, #PF set page table
> could help us access initrd with kernel low mapping address.
> Copying could be done just after memblock is ready and before probing
> acpi tables, and we need to early_ioremap to access source and target
> range, as init_mem_mapping is not called yet.
> While a dummy version of acpi_initrd_override() was defined when
> !CONFIG_ACPI_INITRD_TABLE_OVERRIDE, the prototype and dummy version
> were conditionalized inside CONFIG_ACPI. This forced setup_arch() to
> have its own #ifdefs around acpi_initrd_override() as otherwise build
> would fail when !CONFIG_ACPI. Move the prototypes and dummy
> implementations of the newly split functions below CONFIG_ACPI block
> in acpi.h so that we can do away with #ifdefs in its user.
> -v2: Split one patch out according to tj.
> also don't pass table_nr around.
> -v3: Add Tj's changelog about moving down to #idef in acpi.h to
> avoid #idef in setup.c
> Signed-off-by: Yinghai <yinghai@xxxxxxxxxx>
> Cc: Pekka Enberg <penberg@xxxxxxxxxx>
> Cc: Jacob Shin <jacob.shin@xxxxxxx>
> Cc: Rafael J. Wysocki <rjw@xxxxxxx>
> Cc: linux-acpi@xxxxxxxxxxxxxxx
> Acked-by: Tejun Heo <tj@xxxxxxxxxx>
> Tested-by: Thomas Renninger <trenn@xxxxxxx>
> Reviewed-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
> Tested-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>

Looks good to me.

Acked-by: Toshi Kani <toshi.kani@xxxxxx>


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