mips, thp: remove infrastructure for handling splitting PMDs

With new refcounting we don't need to mark PMDs splitting.  Let's drop
code to handle this.

pmdp_splitting_flush() is not needed too: on splitting PMD we will do
pmdp_clear_flush() + set_pte_at().  pmdp_clear_flush() will do IPI as
needed for fast_gup.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/mips/include/asm/pgtable-bits.h b/arch/mips/include/asm/pgtable-bits.h
index ff7ad91c85db325b27dacb8987c9e1b930088855..97b313882678084857129b811cea812a723c6a3a 100644 (file)
--- a/arch/mips/include/asm/pgtable-bits.h
+++ b/arch/mips/include/asm/pgtable-bits.h
@@ -131,14 +131,12 @@
 /* Huge TLB page */
 #define _PAGE_HUGE_SHIFT       (_PAGE_MODIFIED_SHIFT + 1)
 #define _PAGE_HUGE             (1 << _PAGE_HUGE_SHIFT)
-#define _PAGE_SPLITTING_SHIFT  (_PAGE_HUGE_SHIFT + 1)
-#define _PAGE_SPLITTING                (1 << _PAGE_SPLITTING_SHIFT)
 #endif /* CONFIG_64BIT && CONFIG_MIPS_HUGE_TLB_SUPPORT */
 
 #if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
 /* XI - page cannot be executed */
-#ifdef _PAGE_SPLITTING_SHIFT
-#define _PAGE_NO_EXEC_SHIFT    (_PAGE_SPLITTING_SHIFT + 1)
+#ifdef _PAGE_HUGE_SHIFT
+#define _PAGE_NO_EXEC_SHIFT    (_PAGE_HUGE_SHIFT + 1)
 #else
 #define _PAGE_NO_EXEC_SHIFT    (_PAGE_MODIFIED_SHIFT + 1)
 #endif
@@ -153,8 +151,8 @@
 
 #if defined(_PAGE_NO_READ_SHIFT)
 #define _PAGE_GLOBAL_SHIFT     (_PAGE_NO_READ_SHIFT + 1)
-#elif defined(_PAGE_SPLITTING_SHIFT)
-#define _PAGE_GLOBAL_SHIFT     (_PAGE_SPLITTING_SHIFT + 1)
+#elif defined(_PAGE_HUGE_SHIFT)
+#define _PAGE_GLOBAL_SHIFT     (_PAGE_HUGE_SHIFT + 1)
 #else
 #define _PAGE_GLOBAL_SHIFT     (_PAGE_MODIFIED_SHIFT + 1)
 #endif

diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index 8957f15e21ec4c911e8ebe017ea8cb4ea1276ad4..6995b4a02e2359bf6e2e1b8493bcae55443753f1 100644 (file)
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -482,27 +482,9 @@ static inline pmd_t pmd_mkhuge(pmd_t pmd)
        return pmd;
 }
 
-static inline int pmd_trans_splitting(pmd_t pmd)
-{
-       return !!(pmd_val(pmd) & _PAGE_SPLITTING);
-}
-
-static inline pmd_t pmd_mksplitting(pmd_t pmd)
-{
-       pmd_val(pmd) |= _PAGE_SPLITTING;
-
-       return pmd;
-}
-
 extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
                       pmd_t *pmdp, pmd_t pmd);
 
-#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
-/* Extern to avoid header file madness */
-extern void pmdp_splitting_flush(struct vm_area_struct *vma,
-                                       unsigned long address,
-                                       pmd_t *pmdp);
-
 #define __HAVE_ARCH_PMD_WRITE
 static inline int pmd_write(pmd_t pmd)
 {

diff --git a/arch/mips/mm/gup.c b/arch/mips/mm/gup.c
index 36a35115dc2ea6a86d90d8b85627dad9d3f4615c..1afd87c999b0c22f1ab08508a233126b5d6d9f2b 100644 (file)
--- a/arch/mips/mm/gup.c
+++ b/arch/mips/mm/gup.c
@@ -107,18 +107,7 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
                pmd_t pmd = *pmdp;
 
                next = pmd_addr_end(addr, end);
-               /*
-                * The pmd_trans_splitting() check below explains why
-                * pmdp_splitting_flush has to flush the tlb, to stop
-                * this gup-fast code from running while we set the
-                * splitting bit in the pmd. Returning zero will take
-                * the slow path that will call wait_split_huge_page()
-                * if the pmd is still in splitting state. gup-fast
-                * can't because it has irq disabled and
-                * wait_split_huge_page() would never return as the
-                * tlb flush IPI wouldn't run.
-                */
-               if (pmd_none(pmd) || pmd_trans_splitting(pmd))
+               if (pmd_none(pmd))
                        return 0;
                if (unlikely(pmd_huge(pmd))) {
                        if (!gup_huge_pmd(pmd, addr, next, write, pages,nr))

diff --git a/arch/mips/mm/pgtable-64.c b/arch/mips/mm/pgtable-64.c
index e8adc0069d66f17fcc6e27915fa1d5eb8e8258a6..ce4473e7c0d261b04d7bf44fcfc8ddc6414435d9 100644 (file)
--- a/arch/mips/mm/pgtable-64.c
+++ b/arch/mips/mm/pgtable-64.c
@@ -62,20 +62,6 @@ void pmd_init(unsigned long addr, unsigned long pagetable)
 }
 #endif
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-
-void pmdp_splitting_flush(struct vm_area_struct *vma,
-                        unsigned long address,
-                        pmd_t *pmdp)
-{
-       if (!pmd_trans_splitting(*pmdp)) {
-               pmd_t pmd = pmd_mksplitting(*pmdp);
-               set_pmd_at(vma->vm_mm, address, pmdp, pmd);
-       }
-}
-
-#endif
-
 pmd_t mk_pmd(struct page *page, pgprot_t prot)
 {
        pmd_t pmd;

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 32e0be27673fefbeca6839929e61a581c8980902..482192cc8f2b88ae89f4cf1495c0dd6055a5bda6 100644 (file)
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -240,7 +240,6 @@ static void output_pgtable_bits_defines(void)
        pr_define("_PAGE_MODIFIED_SHIFT %d\n", _PAGE_MODIFIED_SHIFT);
 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
        pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);
-       pr_define("_PAGE_SPLITTING_SHIFT %d\n", _PAGE_SPLITTING_SHIFT);
 #endif
 #ifdef CONFIG_CPU_MIPSR2
        if (cpu_has_rixi) {