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From:   Ard Biesheuvel <ardb@kernel.org>
Date:   Wed, 1 Jul 2020 17:28:52 +0200
Message-ID: <CAMj1kXEm89QCN5AqVBQ4pM21SFAXWfyj4_T9UDStL6K2FGNDqw@mail.gmail.com>
Subject: Re: [patch 13/13] Remove (now unused) EFI_UV1_MEMMAP from efi.h
To:     Steve Wahl <steve.wahl@hpe.com>
Cc:     Jonathan Corbet <corbet@lwn.net>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        X86 ML <x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
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        Andy Shevchenko <andy@infradead.org>,
        Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Paul E. McKenney" <paulmck@kernel.org>,
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        Juergen Gross <jgross@suse.com>,
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On Wed, 1 Jul 2020 at 16:18, <steve.wahl@hpe.com> wrote:
>
> With UV1 support removed, EFI_UV1_MEMMAP is no longer used.
>
> Signed-off-by: Steve Wahl <steve.wahl@hpe.com>

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>

> ---
>  arch/x86/include/asm/efi.h |   20 ++------------------
>  1 file changed, 2 insertions(+), 18 deletions(-)
>
> --- linux.orig/arch/x86/include/asm/efi.h       2020-06-17 14:21:49.798542440 -0500
> +++ linux/arch/x86/include/asm/efi.h    2020-06-17 14:28:55.830071857 -0500
> @@ -22,17 +22,7 @@ extern unsigned long efi_fw_vendor, efi_
>   *
>   * This is the main reason why we're doing stable VA mappings for RT
>   * services.
> - *
> - * SGI UV1 machines are known to be incompatible with this scheme, so we
> - * provide an opt-out for these machines via a DMI quirk that sets the
> - * attribute below.
>   */
> -#define EFI_UV1_MEMMAP         EFI_ARCH_1
> -
> -static inline bool efi_have_uv1_memmap(void)
> -{
> -       return IS_ENABLED(CONFIG_X86_UV) && efi_enabled(EFI_UV1_MEMMAP);
> -}
>
>  #define EFI32_LOADER_SIGNATURE "EL32"
>  #define EFI64_LOADER_SIGNATURE "EL64"
> @@ -122,9 +112,7 @@ struct efi_scratch {
>         efi_sync_low_kernel_mappings();                                 \
>         kernel_fpu_begin();                                             \
>         firmware_restrict_branch_speculation_start();                   \
> -                                                                       \
> -       if (!efi_have_uv1_memmap())                                     \
> -               efi_switch_mm(&efi_mm);                                 \
> +       efi_switch_mm(&efi_mm);                                         \
>  })
>
>  #define arch_efi_call_virt(p, f, args...)                              \
> @@ -132,9 +120,7 @@ struct efi_scratch {
>
>  #define arch_efi_call_virt_teardown()                                  \
>  ({                                                                     \
> -       if (!efi_have_uv1_memmap())                                     \
> -               efi_switch_mm(efi_scratch.prev_mm);                     \
> -                                                                       \
> +       efi_switch_mm(efi_scratch.prev_mm);                             \
>         firmware_restrict_branch_speculation_end();                     \
>         kernel_fpu_end();                                               \
>  })
> @@ -176,8 +162,6 @@ extern void efi_delete_dummy_variable(vo
>  extern void efi_switch_mm(struct mm_struct *mm);
>  extern void efi_recover_from_page_fault(unsigned long phys_addr);
>  extern void efi_free_boot_services(void);
> -extern pgd_t * __init efi_uv1_memmap_phys_prolog(void);
> -extern void __init efi_uv1_memmap_phys_epilog(pgd_t *save_pgd);
>
>  /* kexec external ABI */
>  struct efi_setup_data {
>