soc/amd/common/block/psp_gen2: add get_psp_mmio_base

Add get_psp_mmio_base which reads the PSP MMIO base address from the
hardware registers. Since this function will not only be called in
ramstage, but also in SMM, we can't just look for the specific domain
resource consumer like it is done for the IOAPICs in the northbridge,
but have to get this base address from the registers. In order to limit
the performance impact of this, the base address gets cached in a static
variable if an enabled PSP MMIO base register is found. We expect that
this register is locked when it was configured and enabled; if we run
into the unexpected case that the PSP MMIO register is enabled, but not
locked, set the lock bit of the corresponding base address register to
be sure that it won't change until the next reset and that the hardware
value can't be different than the cached value.

This is a preparation to move back to using MMIO access to the PSP
registers and will also enable cases that require the use of the MMIO
mapping of the PSP registers.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I1d51e30f186508b0fe1ab5eb79c73e6d4b9d1a4a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83446
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Reviewed-by: Martin Roth <martin.roth@amd.corp-partner.google.com>

0 files changed, 0 insertions, 0 deletions