Messages in this thread |  | | Subject | Re: [PATCH v2 3/4] efi/arm: map UEFI memory map earlier on boot | | From | James Morse <> | | Date | Thu, 5 Jul 2018 12:02:15 +0100 |
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Hi Akashi,
On 05/07/18 10:43, AKASHI Takahiro wrote: > On Wed, Jul 04, 2018 at 08:49:32PM +0200, Ard Biesheuvel wrote: >> On 4 July 2018 at 19:06, Will Deacon <will.deacon@arm.com> wrote: >>> On Tue, Jun 19, 2018 at 03:44:23PM +0900, AKASHI Takahiro wrote: >>>> Since arm_enter_runtime_services() was modified to always create a virtual >>>> mapping of UEFI memory map in the previous patch, it is now renamed to >>>> efi_enter_virtual_mode() and called earlier before acpi_load_tables() >>>> in acpi_early_init(). >>>> >>>> This will allow us to use UEFI memory map in acpi_os_ioremap() to create >>>> mappings of ACPI tables using memory attributes described in UEFI memory >>>> map.
>>> Hmm, this is ugly as hell. Is there nothing else we can piggy-back off? >>> It's also fairly jarring that, on x86, efi_enter_virtual_mode() is called >>> a few lines later, *after* acpi_early_init() has been called.
>> Currently, there is a gap where we have already torn down the early >> mapping and haven't created the definitive mapping of the UEFI memory >> map. There are other reasons why this is an issue, and I recently >> proposed [0] myself to address one of them
>> Akashi-san, could you please confirm whether the patch below would be >> sufficient for you? Apologies for going back and forth on this, but I >> agree with Will that we should try to avoid warts like the one above >> in generic code. >> >> [0] https://marc.info/?l=linux-efi&m=152930773507524&w=2 > > I think that this patch will also work. > Please drop my patch#2 and #3 if you want to pick up my patchset, Will.
Patch 2 is what changes arm_enable_runtime_services() to map the efi memory map before bailing out due to efi=noruntime.
Without it, 'efi=noruntime' means no-acpi-tables.
Thanks,
James
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