arm64: hugetlb: Fix flush_hugetlb_tlb_range() invalidation level

commit c910f2b ("arm64/mm: Update tlb invalidation routines for
FEAT_LPA2") changed the "invalidation level unknown" hint from 0 to
TLBI_TTL_UNKNOWN (INT_MAX). But the fallback "unknown level" path in
flush_hugetlb_tlb_range() was not updated. So as it stands, when trying
to invalidate CONT_PMD_SIZE or CONT_PTE_SIZE hugetlb mappings, we will
spuriously try to invalidate at level 0 on LPA2-enabled systems.

Fix this so that the fallback passes TLBI_TTL_UNKNOWN, and while we are
at it, explicitly use the correct stride and level for CONT_PMD_SIZE and
CONT_PTE_SIZE, which should provide a minor optimization.

Cc: stable@vger.kernel.org
Fixes: c910f2b ("arm64/mm: Update tlb invalidation routines for FEAT_LPA2")
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://lore.kernel.org/r/20250226120656.2400136-4-ryan.roberts@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/hugetlb.h

@@ -76,12 +76,22 @@ static inline void flush_hugetlb_tlb_range(struct vm_area_struct *vma,
 {
 	unsigned long stride = huge_page_size(hstate_vma(vma));
 
-	if (stride == PMD_SIZE)
-		__flush_tlb_range(vma, start, end, stride, false, 2);
-	else if (stride == PUD_SIZE)
-		__flush_tlb_range(vma, start, end, stride, false, 1);
-	else
-		__flush_tlb_range(vma, start, end, PAGE_SIZE, false, 0);
+	switch (stride) {
+#ifndef __PAGETABLE_PMD_FOLDED
+	case PUD_SIZE:
+		__flush_tlb_range(vma, start, end, PUD_SIZE, false, 1);
+		break;
+#endif
+	case CONT_PMD_SIZE:
+	case PMD_SIZE:
+		__flush_tlb_range(vma, start, end, PMD_SIZE, false, 2);
+		break;
+	case CONT_PTE_SIZE:
+		__flush_tlb_range(vma, start, end, PAGE_SIZE, false, 3);
+		break;
+	default:
+		__flush_tlb_range(vma, start, end, PAGE_SIZE, false, TLBI_TTL_UNKNOWN);
+	}
 }
 
 #endif /* __ASM_HUGETLB_H */