Re: [PATCH v2 4/6] arm64/mm: Implement pXX_leaf_size() support

[Peter Zijlstra]

Now with pmd_cont() defined...

---
Subject: arm64/mm: Implement pXX_leaf_size() support
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Fri Nov 13 11:46:06 CET 2020

ARM64 has non-pagetable aligned large page support with PTE_CONT, when
this bit is set the page is part of a super-page. Match the hugetlb
code and support these super pages for PTE and PMD levels.

This enables PERF_SAMPLE_{DATA,CODE}_PAGE_SIZE to report accurate
pagetable leaf sizes.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
 arch/arm64/include/asm/pgtable.h |    4 ++++
 1 file changed, 4 insertions(+)

--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -407,6 +407,7 @@ static inline int pmd_trans_huge(pmd_t p
 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
 #define pmd_valid(pmd)		pte_valid(pmd_pte(pmd))
+#define pmd_cont(pmd)		pte_cont(pmd_pte(pmd))
 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
@@ -503,6 +504,9 @@ extern pgprot_t phys_mem_access_prot(str
 				 PMD_TYPE_SECT)
 #define pmd_leaf(pmd)		pmd_sect(pmd)
 
+#define pmd_leaf_size(pmd)	(pmd_cont(pmd) ? CONT_PMD_SIZE : PMD_SIZE)
+#define pte_leaf_size(pte)	(pte_cont(pte) ? CONT_PTE_SIZE : PAGE_SIZE)
+
 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
 static inline bool pud_sect(pud_t pud) { return false; }
 static inline bool pud_table(pud_t pud) { return true; }