[RFC V2 00/10] arm64/mm: Enable FEAT_LPA2 (52 bits PA support on 4K|16K pages)

From: Anshuman Khandual <anshuman.khandual@arm.com>
To: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc: akpm@linux-foundation.org, suzuki.poulose@arm.com,
	mark.rutland@arm.com, will@kernel.org, catalin.marinas@arm.com,
	maz@kernel.org, james.morse@arm.com, steven.price@arm.com,
	Anshuman Khandual <anshuman.khandual@arm.com>
Subject: [RFC V2 00/10] arm64/mm: Enable FEAT_LPA2 (52 bits PA support on 4K|16K pages)
Date: Mon, 26 Jul 2021 12:07:15 +0530	[thread overview]
Message-ID: <1627281445-12445-1-git-send-email-anshuman.khandual@arm.com> (raw)

This series enables 52 bits PA support for 4K and 16K page configs via
existing CONFIG_ARM64_PA_BITS_52, utilizing a new arch feature FEAT_LPA2
which is available from ARM v8.7. IDMAP needs changes to accommodate two
new level of page tables in certain scenarios like (4K|39VA|52PA) but the
same problem also exists for (16K|36VA|48PA) which needs fixing. I have
sent a fix for 16K case [1] and later will enable it for FEAT_LPA2 as well.

This series applies on v5.14-rc3.

Testing:

Build and boot tested (individual patches) on all existing and new
FEAT_LPA2 enabled config combinations.

Pending:

- Enable IDMAP for FEAT_LPA2
- Enable 52 bit VA range on 4K/16K page sizes
- Evaluate KVM and SMMU impacts from FEAT_LPA2

[1] https://lore.kernel.org/lkml/1627019894-14819-1-git-send-email-anshuman.khandual@arm.com/

Changes in RFC V2:

- Changed FEAT_LPA2 presence qualifying criteria wrt ID_AA64MMFR0_TGRAN_LPA2
- Changed FEAT_LPA2 specific encoding which drops the additional tmp variable
- Fixed [phys|pte]_to_[pte|phys]() helpers when FEAT_LPA2 is implemented

Changes in RFC V1:

https://lore.kernel.org/lkml/1626229291-6569-1-git-send-email-anshuman.khandual@arm.com/

Anshuman Khandual (10):
  mm/mmap: Dynamically initialize protection_map[]
  arm64/mm: Consolidate TCR_EL1 fields
  arm64/mm: Add FEAT_LPA2 specific TCR_EL1.DS field
  arm64/mm: Add FEAT_LPA2 specific ID_AA64MMFR0.TGRAN[2]
  arm64/mm: Add CONFIG_ARM64_PA_BITS_52_[LPA|LPA2]
  arm64/mm: Add FEAT_LPA2 specific encoding
  arm64/mm: Detect and enable FEAT_LPA2
  arm64/mm: Add FEAT_LPA2 specific PTE_SHARED and PMD_SECT_S
  arm64/mm: Add FEAT_LPA2 specific fallback (48 bits PA) when not implemented
  arm64/mm: Enable CONFIG_ARM64_PA_BITS_52 on CONFIG_ARM64_[4K|16K]_PAGES

 arch/arm64/Kconfig                      |  9 ++++++-
 arch/arm64/include/asm/assembler.h      | 42 ++++++++++++++++++++++++++-------
 arch/arm64/include/asm/kernel-pgtable.h |  4 ++--
 arch/arm64/include/asm/memory.h         |  1 +
 arch/arm64/include/asm/pgtable-hwdef.h  | 28 ++++++++++++++++++----
 arch/arm64/include/asm/pgtable.h        | 18 +++++++++++---
 arch/arm64/include/asm/sysreg.h         |  9 +++----
 arch/arm64/kernel/head.S                | 30 +++++++++++++++++++++++
 arch/arm64/mm/mmu.c                     |  3 +++
 arch/arm64/mm/pgd.c                     |  2 +-
 arch/arm64/mm/proc.S                    | 11 ++++++++-
 arch/arm64/mm/ptdump.c                  | 26 ++++++++++++++++++--
 mm/mmap.c                               | 26 ++++++++++++++++----
 13 files changed, 177 insertions(+), 32 deletions(-)

-- 
2.7.4