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/

[[e-mail]: change pmd_mknotvalid() to pmd_mkinvalid() per Will]
Link: http://lkml.kernel.org/r/[e-mail]
Suggested-by: Catalin Marinas <[e-mail]>
Signed-off-by: Anshuman Khandual <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Acked-by: Will Deacon <[e-mail]>
Cc: Vineet Gupta <[e-mail]>
Cc: Russell King <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Thomas Bogendoerfer <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: "H. Peter Anvin" <[e-mail]>
Cc: Steven Rostedt <[e-mail]>
Cc: Dave Hansen <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Benjamin Herrenschmidt <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Linus Torvalds <[e-mail]>

arch/arc/include/asm/hugepage.h

···
 #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))

arch/arm/include/asm/pgtable-3level.h

···
 #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);
 }

arch/arm64/include/asm/pgtable.h

···
 #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))
 

arch/mips/include/asm/pgtable.h

···
 	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);
 

arch/x86/include/asm/pgtable.h

···
 	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)));

arch/x86/mm/kmmio.c

···
 	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);

mm/pgtable-generic.c

···
 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;
 }