[U-Boot] [PATCH 4/5] x86: Move the GDT into global_data

[Bin Meng]

On Mon, Aug 3, 2015 at 8:10 AM, Simon Glass <sjg at chromium.org> wrote:
> Rather than keeping track of the Global Descriptor Table in its own memory
> we may as well put it in global_data with everything else. As a first step,
> stop using the separately allocated GDT.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
>  arch/x86/cpu/cpu.c                 | 9 +++++----
>  arch/x86/include/asm/global_data.h | 4 +++-
>  2 files changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
> index 129777c..4f57145 100644
> --- a/arch/x86/cpu/cpu.c
> +++ b/arch/x86/cpu/cpu.c
> @@ -136,9 +136,10 @@ static void load_gdt(const u64 *boot_gdt, u16 num_entries)
>         asm volatile("lgdtl %0\n" : : "m" (gdt));
>  }
>
> -void setup_gdt(gd_t *id, u64 *gdt_addr)
> +void setup_gdt(gd_t *new_gd, u64 *gdt_addr)
>  {
> -       id->arch.gdt = gdt_addr;
> +       gdt_addr = new_gd->arch.gdt;
> +
>         /* CS: code, read/execute, 4 GB, base 0 */
>         gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff);
>
> @@ -146,9 +147,9 @@ void setup_gdt(gd_t *id, u64 *gdt_addr)
>         gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff);
>
>         /* FS: data, read/write, 4 GB, base (Global Data Pointer) */
> -       id->arch.gd_addr = id;
> +       new_gd->arch.gd_addr = new_gd;
>         gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093,
> -                    (ulong)&id->arch.gd_addr, 0xfffff);
> +                    (ulong)&new_gd->arch.gd_addr, 0xfffff);
>
>         /* 16-bit CS: code, read/execute, 64 kB, base 0 */
>         gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x009b, 0, 0x0ffff);
> diff --git a/arch/x86/include/asm/global_data.h b/arch/x86/include/asm/global_data.h
> index f7e3889..35148ab 100644
> --- a/arch/x86/include/asm/global_data.h
> +++ b/arch/x86/include/asm/global_data.h
> @@ -10,6 +10,8 @@
>
>  #ifndef __ASSEMBLY__
>
> +#include <asm/processor.h>
> +
>  enum pei_boot_mode_t {
>         PEI_BOOT_NONE = 0,
>         PEI_BOOT_SOFT_RESET,
> @@ -44,6 +46,7 @@ struct mtrr_request {
>
>  /* Architecture-specific global data */
>  struct arch_global_data {
> +       u64 gdt[X86_GDT_NUM_ENTRIES] __aligned(16);
>         struct global_data *gd_addr;    /* Location of Global Data */
>         uint8_t x86;                    /* CPU family */
>         uint8_t x86_vendor;             /* CPU vendor */
> @@ -68,7 +71,6 @@ struct arch_global_data {
>         /* MRC training data to save for the next boot */
>         char *mrc_output;
>         unsigned int mrc_output_len;
> -       void *gdt;                      /* Global descriptor table */
>         ulong table;                    /* Table pointer from previous loader */
>  };
>
> --

Reviewed-by: Bin Meng <bmeng.cn at gmail.com>