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-rw-r--r--arch/arm64/Kconfig1
-rw-r--r--arch/arm64/mm/flush.c14
2 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 20ea89d9ac2f..2d7399ab0491 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -96,6 +96,7 @@ config ARM64
select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
select ARCH_WANT_FRAME_POINTERS
select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
+ select ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP
select ARCH_WANT_LD_ORPHAN_WARN
select ARCH_WANTS_NO_INSTR
select ARCH_HAS_UBSAN_SANITIZE_ALL
diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
index a06c6ac770d4..840d998879ad 100644
--- a/arch/arm64/mm/flush.c
+++ b/arch/arm64/mm/flush.c
@@ -75,6 +75,20 @@ EXPORT_SYMBOL_GPL(__sync_icache_dcache);
*/
void flush_dcache_page(struct page *page)
{
+ /*
+ * Only the head page's flags of HugeTLB can be cleared since the tail
+ * vmemmap pages associated with each HugeTLB page are mapped with
+ * read-only when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is enabled (more
+ * details can refer to vmemmap_remap_pte()). Although
+ * __sync_icache_dcache() only set PG_dcache_clean flag on the head
+ * page struct, there is more than one page struct with PG_dcache_clean
+ * associated with the HugeTLB page since the head vmemmap page frame
+ * is reused (more details can refer to the comments above
+ * page_fixed_fake_head()).
+ */
+ if (hugetlb_free_vmemmap_enabled() && PageHuge(page))
+ page = compound_head(page);
+
if (test_bit(PG_dcache_clean, &page->flags))
clear_bit(PG_dcache_clean, &page->flags);
}