On Wed, Mar 17, 2021 at 11:28 PM George Kennedy <george.kennedy@xxxxxxxxxx> wrote: > > > > On 3/17/2021 4:14 PM, Rafael J. Wysocki wrote: > > On Monday, March 15, 2021 5:19:29 PM CET Rafael J. Wysocki wrote: > >> On Sun, Mar 14, 2021 at 8:00 PM Mike Rapoport <rppt@xxxxxxxxxxxxx> wrote: > >>> On Thu, Mar 11, 2021 at 04:36:31PM +0100, Rafael J. Wysocki wrote: > >>>> On Wed, Mar 10, 2021 at 8:47 PM David Hildenbrand <david@xxxxxxxxxx> wrote: > >>>>>> There is some care that should be taken to make sure we get the order > >>>>>> right, but I don't see a fundamental issue here. > >>>> Me neither. > >>>> > >>>>>> If I understand correctly, Rafael's concern is about changing the parts of > >>>>>> ACPICA that should be OS agnostic, so I think we just need another place to > >>>>>> call memblock_reserve() rather than acpi_tb_install_table_with_override(). > >>>> Something like this. > >>>> > >>>> There is also the problem that memblock_reserve() needs to be called > >>>> for all of the tables early enough, which will require some reordering > >>>> of the early init code. > >>>> > >>>>>> Since the reservation should be done early in x86::setup_arch() (and > >>>>>> probably in arm64::setup_arch()) we might just have a function that parses > >>>>>> table headers and reserves them, similarly to how we parse the tables > >>>>>> during KASLR setup. > >>>> Right. > >>> I've looked at it a bit more and we do something like the patch below that > >>> nearly duplicates acpi_tb_parse_root_table() which is not very nice. > >> It looks to me that the code need not be duplicated (see below). > >> > >>> Besides, reserving ACPI tables early and then calling acpi_table_init() > >>> (and acpi_tb_parse_root_table() again would mean doing the dance with > >>> early_memremap() twice for no good reason. > >> That'd be simply inefficient which is kind of acceptable to me to start with. > >> > >> And I changing the ACPICA code can be avoided at least initially, it > >> by itself would be a good enough reason. > >> > >>> I believe the most effective way to deal with this would be to have a > >>> function that does parsing, reservation and installs the tables supplied by > >>> the firmware which can be called really early and then another function > >>> that overrides tables if needed a some later point. > >> I agree that this should be the direction to go into. > > So maybe something like the patch below? > > Do you want me to try it out in the failing setup? Yes, please!
