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@arm.com: change pmd_mknotvalid() to pmd_mkinvalid() per Will]
  Link: http://lkml.kernel.org/r/1587520326-10099-3-git-send-email-anshuman.khandual@arm.com
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Link: http://lkml.kernel.org/r/1584680057-13753-3-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Anshuman Khandual 2020-06-03 16:03:45 -07:00 committed by Linus Torvalds
parent 124cb3a62d
commit 86ec2da037
7 changed files with 7 additions and 7 deletions

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@ -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))

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@ -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);
}

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@ -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))

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@ -631,7 +631,7 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
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);

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@ -624,7 +624,7 @@ static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot)
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)));

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@ -130,7 +130,7 @@ static void clear_pmd_presence(pmd_t *pmd, bool clear, pmdval_t *old)
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);

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@ -194,7 +194,7 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
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;
}