Re: [PATCH 4/4] x86/efi: Allocate a trampoline if needed in efi_free_boot_services()

From	Andy Lutomirski <luto@amacapital.net>
Newsgroups	linux.kernel
Subject	Re: [PATCH 4/4] x86/efi: Allocate a trampoline if needed in efi_free_boot_services()
Date	2016-08-02 20:30 +0200
Message-ID	<s1MBY-8c3-47@gated-at.bofh.it> (permalink)
References	<rZjup-84c-3@gated-at.bofh.it> <rZjup-84c-15@gated-at.bofh.it> <s1dEd-1XU-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Sun, Jul 31, 2016 at 10:07 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> On 07/26/16 15:55, Andy Lutomirski wrote:
>> +             /*
>> +              * Nasty quirk: if all sub-1MB memory is used for boot
>> +              * services, we can get here without having allocated the
>> +              * real mode trampoline.  It's too late to hand boot services
>> +              * memory back to the memblock allocator, so instead
>> +              * try to reclaim a single page if needed.
>> +              *
>
> This comment makes no sense.  Nowhere is there a dependency on a single
> page, and this refers to allocation, not reclaim...

I wrote that while I had the misapprehension that it was a page and I
forgot to fix it.  How about:

Nasty quirk: if all sub-1MB memory is used for boot
services, we can get here without having allocated the
real mode trampoline.  It's too late to hand boot services
memory back to the memblock allocator, so instead
try to manually allocate the trampoline if needed.

Thread

[PATCH 4.8? 0/4] Allow the trampoline to use EFI boot services RAM Andy Lutomirski <luto@kernel.org> - 2016-07-27 01:00 +0200
  [PATCH 4/4] x86/efi: Allocate a trampoline if needed in efi_free_boot_services() Andy Lutomirski <luto@kernel.org> - 2016-07-27 01:00 +0200
    Re: [PATCH 4/4] x86/efi: Allocate a trampoline if needed in  efi_free_boot_services() "H. Peter Anvin" <hpa@zytor.com> - 2016-08-01 07:10 +0200
      Re: [PATCH 4/4] x86/efi: Allocate a trampoline if needed in efi_free_boot_services() Andy Lutomirski <luto@amacapital.net> - 2016-08-02 20:30 +0200
  [PATCH 3/4] x86/boot: Rework reserve_real_mode() to allow multiple tries Andy Lutomirski <luto@kernel.org> - 2016-07-27 01:00 +0200
  Re: [PATCH 4.8? 0/4] Allow the trampoline to use EFI boot services  RAM Matt Fleming <matt@codeblueprint.co.uk> - 2016-07-31 23:40 +0200
    Re: [PATCH 4.8? 0/4] Allow the trampoline to use EFI boot services  RAM Matt Fleming <matt@codeblueprint.co.uk> - 2016-08-04 11:30 +0200

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