In order to reduce the likelihood that we will need to rely on the logic
that disables and re-enables the MMU for updating a page table entry
safely, expose the XIP version of the helper routine via a HOB and use
it instead of the one that is copied into DRAM. Since the XIP copy is
already clean to the PoC, and will never end up getting unmapped during
a block entry split, we can use it safely without any cache maintenance,
and without running the risk of pulling the rug from under our feet when
updating an entry by going through an invalid mapping.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Leif Lindholm <quic_llindhol@quicinc.com>
In preparation of dropping PcdPrePiCpuMemorySize entirely, base the
maximum size of the identity map on the capabilities of the CPU.
Since that may exceed what is architecturally permitted when using
4 KB pages, take MAX_ADDRESS into account as well.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
As reported by Eugene, the practice of sizing the address space in the
virtual memory system based on the maximum address in the table passed
to ArmConfigureMmu() is problematic, since it fails to take into account
the fact that the GCD memory space may be extended at a later time, both
for memory and for MMIO. So instead, choose the VA size identical to the
GCD memory map size, which is based on PcdPrePiCpuMemorySize on ARM
systems.
Reported-by: Eugene Cohen <eugene@hp.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Eugene Cohen <eugene@hp.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
This introduces a special version of ArmMmuLib for PEIMs that takes care
only to perform cache maintenance on the live entry replacement routine
if the module is not executing in place. Not only is such cache maintenance
unnecessary in that case, it may be actively harmful on some systems that
fail to tolerate cache maintenance operations on NOR flash regions.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Ard Biesheuvel
Michael D Kinney
Ard Biesheuvel