[patch 126/131] mm/thp: rename pmd_mknotpresent() as pmd_mkinvalid()

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From: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Subject: mm/thp: rename pmd_mknotpresent() as pmd_mkinvalid()

pmd_present() is expected to test positive after pmdp_mknotpresent() as
the PMD entry still points to a valid huge page in memory. 
pmdp_mknotpresent() implies that given PMD entry is just invalidated from
MMU perspective while still holding on to pmd_page() referred valid huge
page thus also clearing pmd_present() test.  This creates the following
situation which is counter intuitive.

[pmd_present(pmd_mknotpresent(pmd)) = true]

This renames pmd_mknotpresent() as pmd_mkinvalid() reflecting the helper's
functionality more accurately while changing the above mentioned situation
as follows.  This does not create any functional change.

[pmd_present(pmd_mkinvalid(pmd)) = true]

This is not applicable for platforms that define own pmdp_invalidate() via
__HAVE_ARCH_PMDP_INVALIDATE.  Suggestion for renaming came during a
previous discussion here.

https://patchwork.kernel.org/patch/11019637/

[anshuman.khandual@xxxxxxx: change pmd_mknotvalid() to pmd_mkinvalid() per Will]
  Link: http://lkml.kernel.org/r/1587520326-10099-3-git-send-email-anshuman.khandual@xxxxxxx
Link: http://lkml.kernel.org/r/1584680057-13753-3-git-send-email-anshuman.khandual@xxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Suggested-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Acked-by: Will Deacon <will@xxxxxxxxxx>
Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 arch/arc/include/asm/hugepage.h       |    2 +-
 arch/arm/include/asm/pgtable-3level.h |    2 +-
 arch/arm64/include/asm/pgtable.h      |    2 +-
 arch/mips/include/asm/pgtable.h       |    2 +-
 arch/x86/include/asm/pgtable.h        |    2 +-
 arch/x86/mm/kmmio.c                   |    2 +-
 mm/pgtable-generic.c                  |    2 +-
 7 files changed, 7 insertions(+), 7 deletions(-)

--- a/arch/arc/include/asm/hugepage.h~mm-thp-rename-pmd_mknotpresent-as-pmd_mknotvalid
+++ a/arch/arc/include/asm/hugepage.h
@@ -26,7 +26,7 @@ static inline pmd_t pte_pmd(pte_t pte)
 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
 #define pmd_mkhuge(pmd)		pte_pmd(pte_mkhuge(pmd_pte(pmd)))
-#define pmd_mknotpresent(pmd)	pte_pmd(pte_mknotpresent(pmd_pte(pmd)))
+#define pmd_mkinvalid(pmd)	pte_pmd(pte_mknotpresent(pmd_pte(pmd)))
 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
 
 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
--- a/arch/arm64/include/asm/pgtable.h~mm-thp-rename-pmd_mknotpresent-as-pmd_mknotvalid
+++ a/arch/arm64/include/asm/pgtable.h
@@ -366,7 +366,7 @@ static inline int pmd_protnone(pmd_t pmd
 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
-#define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_SECT_VALID))
+#define pmd_mkinvalid(pmd)	(__pmd(pmd_val(pmd) & ~PMD_SECT_VALID))
 
 #define pmd_thp_or_huge(pmd)	(pmd_huge(pmd) || pmd_trans_huge(pmd))
 
--- a/arch/arm/include/asm/pgtable-3level.h~mm-thp-rename-pmd_mknotpresent-as-pmd_mknotvalid
+++ a/arch/arm/include/asm/pgtable-3level.h
@@ -221,7 +221,7 @@ PMD_BIT_FUNC(mkyoung,   |= PMD_SECT_AF);
 #define pmdp_establish generic_pmdp_establish
 
 /* represent a notpresent pmd by faulting entry, this is used by pmdp_invalidate */
-static inline pmd_t pmd_mknotpresent(pmd_t pmd)
+static inline pmd_t pmd_mkinvalid(pmd_t pmd)
 {
 	return __pmd(pmd_val(pmd) & ~L_PMD_SECT_VALID);
 }
--- a/arch/mips/include/asm/pgtable.h~mm-thp-rename-pmd_mknotpresent-as-pmd_mknotvalid
+++ a/arch/mips/include/asm/pgtable.h
@@ -631,7 +631,7 @@ static inline pmd_t pmd_modify(pmd_t pmd
 	return pmd;
 }
 
-static inline pmd_t pmd_mknotpresent(pmd_t pmd)
+static inline pmd_t pmd_mkinvalid(pmd_t pmd)
 {
 	pmd_val(pmd) &= ~(_PAGE_PRESENT | _PAGE_VALID | _PAGE_DIRTY);
 
--- a/arch/x86/include/asm/pgtable.h~mm-thp-rename-pmd_mknotpresent-as-pmd_mknotvalid
+++ a/arch/x86/include/asm/pgtable.h
@@ -624,7 +624,7 @@ static inline pud_t pfn_pud(unsigned lon
 	return __pud(pfn | check_pgprot(pgprot));
 }
 
-static inline pmd_t pmd_mknotpresent(pmd_t pmd)
+static inline pmd_t pmd_mkinvalid(pmd_t pmd)
 {
 	return pfn_pmd(pmd_pfn(pmd),
 		      __pgprot(pmd_flags(pmd) & ~(_PAGE_PRESENT|_PAGE_PROTNONE)));
--- a/arch/x86/mm/kmmio.c~mm-thp-rename-pmd_mknotpresent-as-pmd_mknotvalid
+++ a/arch/x86/mm/kmmio.c
@@ -130,7 +130,7 @@ static void clear_pmd_presence(pmd_t *pm
 	pmdval_t v = pmd_val(*pmd);
 	if (clear) {
 		*old = v;
-		new_pmd = pmd_mknotpresent(*pmd);
+		new_pmd = pmd_mkinvalid(*pmd);
 	} else {
 		/* Presume this has been called with clear==true previously */
 		new_pmd = __pmd(*old);
--- a/mm/pgtable-generic.c~mm-thp-rename-pmd_mknotpresent-as-pmd_mknotvalid
+++ a/mm/pgtable-generic.c
@@ -194,7 +194,7 @@ pgtable_t pgtable_trans_huge_withdraw(st
 pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
 		     pmd_t *pmdp)
 {
-	pmd_t old = pmdp_establish(vma, address, pmdp, pmd_mknotpresent(*pmdp));
+	pmd_t old = pmdp_establish(vma, address, pmdp, pmd_mkinvalid(*pmdp));
 	flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 	return old;
 }
_



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