[U-Boot] [PATCH v1 2/2] x86: zImage: Propagate acpi_rsdp_addr to kernel via boot parameters

[Bin Meng]

On Fri, Jan 12, 2018 at 9:01 PM, Andy Shevchenko
<andriy.shevchenko at linux.intel.com> wrote:
> On Fri, 2018-01-12 at 17:00 +0800, Bin Meng wrote:
>> Hi Andy,
>>
>> On Thu, Jan 11, 2018 at 1:40 AM, Andy Shevchenko
>> <andriy.shevchenko at linux.intel.com> wrote:
>> > New field acpi_rsdp_addr, which has been introduced in boot protocol
>> > v2.14 [1], in boot parameters tells kernel the exact address of RDSP
>> > ACPI table. Knowing it increases robustness of the kernel by
>> > avoiding
>> > in some cases traversal through a part of physical memory.
>> > It will slightly reduce boot time by the same reason.
>> >
>> > [1] See Linux kernel commit
>> >
>> >   2f74cbf947f4 ("x86/boot: Add the ACPI RSDP address to struct
>> > setup_header::acpi_rdsp_addr")
>>
>> I don't see this commit id in my linux tree. Is this in some
>> custodian's tree?
>
> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=2
> f74cbf947f45fa082dda8eac1a1f1299a372f49
>

thanks!

>> > for the details.
>> >
>> > Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
>> > ---
>> >  arch/x86/include/asm/bootparam.h |  1 +
>> >  arch/x86/lib/acpi_table.c        |  7 +++++++
>> >  arch/x86/lib/acpi_table.h        | 10 ++++++++++
>> >  arch/x86/lib/zimage.c            |  6 ++++++
>> >  4 files changed, 24 insertions(+)
>> >  create mode 100644 arch/x86/lib/acpi_table.h
>> >
>> > diff --git a/arch/x86/include/asm/bootparam.h
>> > b/arch/x86/include/asm/bootparam.h
>> > index 48b138c6b0..90768a99ce 100644
>> > --- a/arch/x86/include/asm/bootparam.h
>> > +++ b/arch/x86/include/asm/bootparam.h
>> > @@ -66,6 +66,7 @@ struct setup_header {
>> >         __u64   pref_address;
>> >         __u32   init_size;
>> >         __u32   handover_offset;
>> > +       __u64   acpi_rsdp_addr;
>> >  } __attribute__((packed));
>> >
>> >  struct sys_desc_table {
>> > diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c
>> > index 7b33cd371e..45bfc111ef 100644
>> > --- a/arch/x86/lib/acpi_table.c
>> > +++ b/arch/x86/lib/acpi_table.c
>> > @@ -20,6 +20,7 @@
>> >  #include <asm/mpspec.h>
>> >  #include <asm/tables.h>
>> >  #include <asm/arch/global_nvs.h>
>> > +#include "acpi_table.h"
>> >
>> >  /*
>> >   * IASL compiles the dsdt entries and writes the hex values
>> > @@ -27,6 +28,11 @@
>> >   */
>> >  extern const unsigned char AmlCode[];
>> >
>> > +/*
>> > + * ACPI RSDP address to be used in boot parameters.
>> > + */
>>
>> nits: use single line comment format without the ending .
>
> OK.
>
>>
>> > +unsigned long acpi_rsdp_addr;
>> > +
>> >  static void acpi_write_rsdp(struct acpi_rsdp *rsdp, struct
>> > acpi_rsdt *rsdt,
>> >                             struct acpi_xsdt *xsdt)
>> >  {
>> > @@ -460,6 +466,7 @@ ulong write_acpi_tables(ulong start)
>> >
>> >         debug("current = %x\n", current);
>> >
>> > +       acpi_rsdp_addr = (unsigned long)rsdp;
>> >         debug("ACPI: done\n");
>> >
>> >         /* Don't touch ACPI hardware on HW reduced platforms */
>> > diff --git a/arch/x86/lib/acpi_table.h b/arch/x86/lib/acpi_table.h
>> > new file mode 100644
>> > index 0000000000..cece5d1420
>> > --- /dev/null
>> > +++ b/arch/x86/lib/acpi_table.h
>> > @@ -0,0 +1,10 @@
>> > +/*
>> > + * SPDX-License-Identifier:    GPL-2.0
>> > + */
>> > +
>> > +#ifndef _X86_LIB_ACPI_TABLES_H
>> > +#define _X86_LIB_ACPI_TABLES_H
>> > +
>> > +extern unsigned long acpi_rsdp_addr;
>> > +
>> > +#endif
>> > diff --git a/arch/x86/lib/zimage.c b/arch/x86/lib/zimage.c
>> > index d224db4e07..eae26635b1 100644
>> > --- a/arch/x86/lib/zimage.c
>> > +++ b/arch/x86/lib/zimage.c
>> > @@ -24,6 +24,7 @@
>> >  #include <asm/arch/timestamp.h>
>> >  #endif
>> >  #include <linux/compiler.h>
>> > +#include "acpi_table.h"
>> >
>> >  DECLARE_GLOBAL_DATA_PTR;
>> >
>> > @@ -255,6 +256,11 @@ int setup_zimage(struct boot_params
>> > *setup_base, char *cmd_line, int auto_boot,
>> >                 hdr->hardware_subarch = X86_SUBARCH_INTEL_MID;
>> >  #endif
>> >
>> > +#ifdef CONFIG_GENERATE_ACPI_TABLE
>> > +       if (bootproto >= 0x020e)
>> > +               hdr->acpi_rsdp_addr = acpi_rsdp_addr;
>> > +#endif
>> > +
>> >         setup_video(&setup_base->screen_info);
>> >
>> >         return 0;
>> > --
>>
>> Other than the above nits,
>> Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
>>
>> I can fix the nits when applying if you like.
>
> If you have a chance to do it soon, please, do, otherwise I would send a
> new version later (next week I suppose).

Fixed the nits and mentioned the git commit URL

applied to u-boot-x86, thanks!