[RFC PATCH V4 6/7] arm64: mm: Enable HAVE_RCU_TABLE_FREE logic
From: Steve Capper <hidden>
Date: 2014-03-28 15:01:54
Also in:
linux-arch, linux-mm
Subsystem:
arm64 port (aarch64 architecture), mmu gather and tlb invalidation, the rest · Maintainers:
Catalin Marinas, Will Deacon, "Aneesh Kumar K.V", Andrew Morton, Nick Piggin, Peter Zijlstra, Linus Torvalds
In order to implement fast_get_user_pages we need to ensure that the page table walker is protected from page table pages being freed from under it. This patch enables HAVE_RCU_TABLE_FREE, any page table pages belonging to address spaces with multiple users will be call_rcu_sched freed. Meaning that disabling interrupts will block the free and protect the fast gup page walker. Signed-off-by: Steve Capper <redacted> --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/tlb.h | 8 ++++++++ 2 files changed, 9 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 27bbcfc..6185f95 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig@@ -38,6 +38,7 @@ config ARM64 select HAVE_MEMBLOCK select HAVE_PATA_PLATFORM select HAVE_PERF_EVENTS + select HAVE_RCU_TABLE_FREE select IRQ_DOMAIN select MODULES_USE_ELF_RELA select NO_BOOTMEM
diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
index 72cadf5..58a8b78 100644
--- a/arch/arm64/include/asm/tlb.h
+++ b/arch/arm64/include/asm/tlb.h@@ -22,6 +22,14 @@ #include <asm-generic/tlb.h> +#include <linux/pagemap.h> +#include <linux/swap.h> + +static inline void __tlb_remove_table(void *_table) +{ + free_page_and_swap_cache((struct page *)_table); +} + /* * There's three ways the TLB shootdown code is used: * 1. Unmapping a range of vmas. See zap_page_range(), unmap_region().
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1.8.1.4