On Mon, Aug 26, 2019 at 10:40:25AM -0700, Matthew Garrett wrote: > On Mon, Aug 26, 2019 at 1:18 AM Seunghun Han <kkamagui@xxxxxxxxx> wrote: > > To support AMD's fTPM, I removed the busy bit from the ACPI NVS area like > > the reserved area so that AMD's fTPM regions could be assigned in it. > > drivers/acpi/nvs.c saves and restores the contents of NVS regions, and > if other drivers use these regions without any awareness of this then > things may break. I'm reluctant to say that just unilaterally marking > these regions as available is a good thing, but it's clearly what's > expected by AMD's implementation. One approach would be to have a > callback into the nvs code to indicate that a certain region should be > handed off to a driver, which would ensure that we can handle this on > a case by case basis? What if E820 would just have a small piece of code just for fTPM's e.g. it would check the ACPI tree for fTPM's and ignore TPM regions. /Jarkko
