From b0284cd29a957e62d60c2886fd663be93c56f9c0 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Thu, 3 Nov 2022 18:10:34 -0700 Subject: mm: Do not enable PG_arch_2 for all 64-bit architectures Commit 4beba9486abd ("mm: Add PG_arch_2 page flag") introduced a new page flag for all 64-bit architectures. However, even if an architecture is 64-bit, it may still have limited spare bits in the 'flags' member of 'struct page'. This may happen if an architecture enables SPARSEMEM without SPARSEMEM_VMEMMAP as is the case with the newly added loongarch. This architecture port needs 19 more bits for the sparsemem section information and, while it is currently fine with PG_arch_2, adding any more PG_arch_* flags will trigger build-time warnings. Add a new CONFIG_ARCH_USES_PG_ARCH_X option which can be selected by architectures that need more PG_arch_* flags beyond PG_arch_1. Select it on arm64. Signed-off-by: Catalin Marinas [pcc@google.com: fix build with CONFIG_ARM64_MTE disabled] Signed-off-by: Peter Collingbourne Reported-by: kernel test robot Cc: Andrew Morton Cc: Steven Price Reviewed-by: Steven Price Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221104011041.290951-2-pcc@google.com --- arch/arm64/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm64/Kconfig') diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 505c8a1ccbe0..cd93d0738425 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1965,6 +1965,7 @@ config ARM64_MTE depends on ARM64_PAN select ARCH_HAS_SUBPAGE_FAULTS select ARCH_USES_HIGH_VMA_FLAGS + select ARCH_USES_PG_ARCH_X help Memory Tagging (part of the ARMv8.5 Extensions) provides architectural support for run-time, always-on detection of -- cgit v1.2.3