KVM: Remove kvm_is_transparent_hugepage() and PageTransCompoundMap()

Now that arm64 has stopped using kvm_is_transparent_hugepage(),
we can remove it, as well as PageTransCompoundMap() which was
only used by the former.
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210726153552.1535838-5-maz@kernel.org

include/linux/page-flags.h

@@ -632,43 +632,6 @@ static inline int PageTransCompound(struct page *page)
 	return PageCompound(page);
 }
 
-/*
- * PageTransCompoundMap is the same as PageTransCompound, but it also
- * guarantees the primary MMU has the entire compound page mapped
- * through pmd_trans_huge, which in turn guarantees the secondary MMUs
- * can also map the entire compound page. This allows the secondary
- * MMUs to call get_user_pages() only once for each compound page and
- * to immediately map the entire compound page with a single secondary
- * MMU fault. If there will be a pmd split later, the secondary MMUs
- * will get an update through the MMU notifier invalidation through
- * split_huge_pmd().
- *
- * Unlike PageTransCompound, this is safe to be called only while
- * split_huge_pmd() cannot run from under us, like if protected by the
- * MMU notifier, otherwise it may result in page->_mapcount check false
- * positives.
- *
- * We have to treat page cache THP differently since every subpage of it
- * would get _mapcount inc'ed once it is PMD mapped.  But, it may be PTE
- * mapped in the current process so comparing subpage's _mapcount to
- * compound_mapcount to filter out PTE mapped case.
- */
-static inline int PageTransCompoundMap(struct page *page)
-{
-	struct page *head;
-
-	if (!PageTransCompound(page))
-		return 0;
-
-	if (PageAnon(page))
-		return atomic_read(&page->_mapcount) < 0;
-
-	head = compound_head(page);
-	/* File THP is PMD mapped and not PTE mapped */
-	return atomic_read(&page->_mapcount) ==
-	       atomic_read(compound_mapcount_ptr(head));
-}
-
 /*
  * PageTransTail returns true for both transparent huge pages
  * and hugetlbfs pages, so it should only be called when it's known

virt/kvm/kvm_main.c

@@ -189,16 +189,6 @@ bool kvm_is_reserved_pfn(kvm_pfn_t pfn)
 	return true;
 }
 
-bool kvm_is_transparent_hugepage(kvm_pfn_t pfn)
-{
-	struct page *page = pfn_to_page(pfn);
-
-	if (!PageTransCompoundMap(page))
-		return false;
-
-	return is_transparent_hugepage(compound_head(page));
-}
-
 /*
  * Switches to specified vcpu, until a matching vcpu_put()
  */