powerpc, 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>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Sasha Levin <sasha.levin@oracle.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/powerpc/include/asm/book3s/64/hash-64k.h b/arch/powerpc/include/asm/book3s/64/hash-64k.h
index 9e55e3b..849bbec 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-64k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h
@@ -256,13 +256,6 @@
(_PAGE_PTE | _PAGE_THP_HUGE));
}
-static inline int pmd_trans_splitting(pmd_t pmd)
-{
- if (pmd_trans_huge(pmd))
- return pmd_val(pmd) & _PAGE_SPLITTING;
- return 0;
-}
-
static inline int pmd_large(pmd_t pmd)
{
return !!(pmd_val(pmd) & _PAGE_PTE);
@@ -273,11 +266,6 @@
return __pmd(pmd_val(pmd) & ~_PAGE_PRESENT);
}
-static inline pmd_t pmd_mksplitting(pmd_t pmd)
-{
- return __pmd(pmd_val(pmd) | _PAGE_SPLITTING);
-}
-
#define __HAVE_ARCH_PMD_SAME
static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
{
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index 2ff8b3d..06f17e7 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -41,11 +41,6 @@
#endif
/*
- * THP pages can't be special. So use the _PAGE_SPECIAL
- */
-#define _PAGE_SPLITTING _PAGE_SPECIAL
-
-/*
* We need to differentiate between explicit huge page and THP huge
* page, since THP huge page also need to track real subpage details
*/
@@ -54,9 +49,8 @@
/*
* set of bits not changed in pmd_modify.
*/
-#define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | \
- _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPLITTING | \
- _PAGE_THP_HUGE | _PAGE_PTE | _PAGE_SOFT_DIRTY)
+#define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
+ _PAGE_ACCESSED | _PAGE_THP_HUGE)
#ifdef CONFIG_PPC_64K_PAGES
#include <asm/book3s/64/hash-64k.h>
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index b3a5bad..da11c4a 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -266,10 +266,6 @@
extern pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
unsigned long addr, pmd_t *pmdp);
-#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
-extern void pmdp_splitting_flush(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp);
-
extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp);
#define pmdp_collapse_flush pmdp_collapse_flush
diff --git a/arch/powerpc/mm/hugepage-hash64.c b/arch/powerpc/mm/hugepage-hash64.c
index baf1301..49b152b 100644
--- a/arch/powerpc/mm/hugepage-hash64.c
+++ b/arch/powerpc/mm/hugepage-hash64.c
@@ -39,9 +39,6 @@
/* If PMD busy, retry the access */
if (unlikely(old_pmd & _PAGE_BUSY))
return 0;
- /* If PMD is trans splitting retry the access */
- if (unlikely(old_pmd & _PAGE_SPLITTING))
- return 0;
/* If PMD permissions don't match, take page fault */
if (unlikely(access & ~old_pmd))
return 1;
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 6bd3afa..744e24b 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -958,10 +958,6 @@
/*
* A hugepage collapse is captured by pmd_none, because
* it mark the pmd none and do a hpte invalidate.
- *
- * We don't worry about pmd_trans_splitting here, The
- * caller if it needs to handle the splitting case
- * should check for that.
*/
if (pmd_none(pmd))
return NULL;
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index ea6bc31..3124a20 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -604,55 +604,6 @@
}
/*
- * We mark the pmd splitting and invalidate all the hpte
- * entries for this hugepage.
- */
-void pmdp_splitting_flush(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp)
-{
- unsigned long old, tmp;
-
- VM_BUG_ON(address & ~HPAGE_PMD_MASK);
-
-#ifdef CONFIG_DEBUG_VM
- WARN_ON(!pmd_trans_huge(*pmdp));
- assert_spin_locked(&vma->vm_mm->page_table_lock);
-#endif
-
-#ifdef PTE_ATOMIC_UPDATES
-
- __asm__ __volatile__(
- "1: ldarx %0,0,%3\n\
- andi. %1,%0,%6\n\
- bne- 1b \n\
- oris %1,%0,%4@h \n\
- stdcx. %1,0,%3 \n\
- bne- 1b"
- : "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
- : "r" (pmdp), "i" (_PAGE_SPLITTING), "m" (*pmdp), "i" (_PAGE_BUSY)
- : "cc" );
-#else
- old = pmd_val(*pmdp);
- *pmdp = __pmd(old | _PAGE_SPLITTING);
-#endif
- /*
- * If we didn't had the splitting flag set, go and flush the
- * HPTE entries.
- */
- trace_hugepage_splitting(address, old);
- if (!(old & _PAGE_SPLITTING)) {
- /* We need to flush the hpte */
- if (old & _PAGE_HASHPTE)
- hpte_do_hugepage_flush(vma->vm_mm, address, pmdp, old);
- }
- /*
- * This ensures that generic code that rely on IRQ disabling
- * to prevent a parallel THP split work as expected.
- */
- kick_all_cpus_sync();
-}
-
-/*
* We want to put the pgtable in pmd and use pgtable for tracking
* the base page size hptes
*/