diff options
| author | Steve Capper <steve.capper@linaro.org> | 2014-02-11 16:33:54 +0000 |
|---|---|---|
| committer | Steve Capper <steve.capper@linaro.org> | 2014-08-11 13:28:34 +0100 |
| commit | d6f9fff293f3cd8b4433bc8df7f5a5fc3238cdde (patch) | |
| tree | 9bf47fb37e27bdba8783c14c63a5ce760eecab9c | |
| parent | d6847b8e0b593293174cfc4088e82e0c7414da56 (diff) | |
| download | linux-d6f9fff293f3cd8b4433bc8df7f5a5fc3238cdde.tar.gz | |
arm64: mm: Enable HAVE_RCU_TABLE_FREE logic
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 <steve.capper@linaro.org>
| -rw-r--r-- | arch/arm64/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/tlb.h | 18 |
2 files changed, 17 insertions, 2 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 839f48c26ef..e03b47cae2b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -50,6 +50,7 @@ config ARM64 select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP + select HAVE_RCU_TABLE_FREE select HAVE_SYSCALL_TRACEPOINTS select IRQ_DOMAIN select MODULES_USE_ELF_RELA diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h index 80e2c08900d..8e4dde52290 100644 --- a/arch/arm64/include/asm/tlb.h +++ b/arch/arm64/include/asm/tlb.h @@ -23,6 +23,20 @@ #include <asm-generic/tlb.h> +#include <linux/pagemap.h> +#include <linux/swap.h> + +#ifdef CONFIG_HAVE_RCU_TABLE_FREE + +#define tlb_remove_entry(tlb, entry) tlb_remove_table(tlb, entry) +static inline void __tlb_remove_table(void *_table) +{ + free_page_and_swap_cache((struct page *)_table); +} +#else +#define tlb_remove_entry(tlb, entry) tlb_remove_page(tlb, entry) +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ + /* * There's three ways the TLB shootdown code is used: * 1. Unmapping a range of vmas. See zap_page_range(), unmap_region(). @@ -88,7 +102,7 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, { pgtable_page_dtor(pte); tlb_add_flush(tlb, addr); - tlb_remove_page(tlb, pte); + tlb_remove_entry(tlb, pte); } #ifndef CONFIG_ARM64_64K_PAGES @@ -96,7 +110,7 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr) { tlb_add_flush(tlb, addr); - tlb_remove_page(tlb, virt_to_page(pmdp)); + tlb_remove_entry(tlb, virt_to_page(pmdp)); } #endif |