Re: [PATCH 04/14] x86, ACPI: make acpi override finding work with 32bit flat mode

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 7 Mar 2013 22:57:21 -0800 Yinghai Lu <yinghai@kernel.org> wrote:

> >
> >> @@ -552,38 +552,47 @@ u8 __init acpi_table_checksum(u8 *buffer, u32 length)
> >>       return sum;
> >>  }
> >>
> >> -/* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
> >> -static const char * const table_sigs[] = {
> >> -     ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ,
> >> -     ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT,
> >> -     ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF,
> >> -     ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET,
> >> -     ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI,
> >> -     ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA,
> >> -     ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT,
> >> -     ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT,
> >> -     ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, NULL };
> >
> > Why is this table made a stack variable?  What's the benefit of doing
> > that?
> 
> so I do need to switch global variables to phys and access it.

What Tejun means is that it should be marked "static" within
acpi_initrd_override(), so we don't have to build a copy on the stack
at runtime each time acpi_initrd_override() is called.

While we're there, it should be __initdata also.