[PATCH RFC v8 23/24] arm64: kpkeys: Enable kpkeys_hardened_pgtables support

[Kevin Brodsky <kevin.brodsky@arm.com>]

The kpkeys_hardened_pgtables feature needs to be initialised as soon
as the buddy allocator becomes available. The canonical place to
handle this is mem_init().

With that done, all the bits are in place and we can advertise
support for kpkeys_hardened_pgtables by selecting
ARCH_HAS_KPKEYS_HARDENED_PGTABLES if ARM64_POE is enabled.

Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
---
 arch/arm64/Kconfig   | 1 +
 arch/arm64/mm/init.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index ab06324a50ae..43d3ab744535 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2146,6 +2146,7 @@ config ARM64_POE
 	select ARCH_USES_HIGH_VMA_FLAGS
 	select ARCH_HAS_PKEYS
 	select ARCH_HAS_KPKEYS
+	select ARCH_HAS_KPKEYS_HARDENED_PGTABLES
 	help
 	  The Permission Overlay Extension is used to implement Memory
 	  Protection Keys. Memory Protection Keys provides a mechanism for
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 97987f850a33..7985045875cf 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -386,6 +386,7 @@ bool page_alloc_available __ro_after_init;
 void __init mem_init(void)
 {
 	page_alloc_available = true;
+	kpkeys_hardened_pgtables_init();
 	swiotlb_update_mem_attributes();
 }
 

-- 
2.51.2