[PATCH v2 0/3] Free up a couple of MAIRs

[Will Deacon]

Hi folks,

This is version two of the patches I previously posted here:

  v1: https://lore.kernel.org/r/20210506095034.15246-1-will@kernel.org

Changes since v1 include:

 * Only consider EFI_MEMORY_WT as a last resort
 * Emit warning when using Normal-NC for EFI_MEMORY_WT
 * Added acks
 * Rebased onto -rc3

Catalin pointed out that the Device-GRE memory type is unused, despite
having a MAIR allocation. In removing that, I noticed that we also
allocate Normal-WT despite it only being used for EFI_MEMORY_WT mappings,
which is unheard of in isolation.

With these changes, we free up a couple of MAIR entries for more
interesting things (e.g. outer cacheability attributes if we need them
in future for the SLC).

Cheers,

Will

Cc: Christoph Hellwig <hch at lst.de>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Ard Biesheuvel <ardb at kernel.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
Cc: Mark Rutland <mark.rutland at arm.com>

--->8

Will Deacon (3):
  arm64: mm: Remove unused support for Device-GRE memory type
  arm64: acpi: Map EFI_MEMORY_WT memory as Normal-NC
  arm64: mm: Remove unused support for Normal-WT memory type

 arch/arm64/include/asm/memory.h       |  6 ++----
 arch/arm64/include/asm/pgtable-prot.h |  1 -
 arch/arm64/include/asm/sysreg.h       |  2 --
 arch/arm64/kernel/acpi.c              | 22 +++++++++++++++++-----
 arch/arm64/mm/proc.S                  |  2 --
 arch/arm64/mm/ptdump.c                |  4 ----
 6 files changed, 19 insertions(+), 18 deletions(-)

-- 
2.31.1.818.g46aad6cb9e-goog