arm64, 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/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 69d2e2f86bce3f65a76637e9ab3cd9251d6f3d16..64dc55a2f7bcd2e35161fc160638b26a8cf56e79 100644 (file)
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -353,19 +353,11 @@ static inline pgprot_t mk_sect_prot(pgprot_t prot)
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 #define pmd_trans_huge(pmd)    (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
-#define pmd_trans_splitting(pmd)       pte_special(pmd_pte(pmd))
-#ifdef CONFIG_HAVE_RCU_TABLE_FREE
-#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
-struct vm_area_struct;
-void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
-                         pmd_t *pmdp);
-#endif /* CONFIG_HAVE_RCU_TABLE_FREE */
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 #define pmd_dirty(pmd)         pte_dirty(pmd_pte(pmd))
 #define pmd_young(pmd)         pte_young(pmd_pte(pmd))
 #define pmd_wrprotect(pmd)     pte_pmd(pte_wrprotect(pmd_pte(pmd)))
-#define pmd_mksplitting(pmd)   pte_pmd(pte_mkspecial(pmd_pte(pmd)))
 #define pmd_mkold(pmd)         pte_pmd(pte_mkold(pmd_pte(pmd)))
 #define pmd_mkwrite(pmd)       pte_pmd(pte_mkwrite(pmd_pte(pmd)))
 #define pmd_mkdirty(pmd)       pte_pmd(pte_mkdirty(pmd_pte(pmd)))

diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
index 46649d6e6c5a5608caa84015d3ce4f09d3d47eee..60585bde1264a172e4e598ce73a550272d0a40f2 100644 (file)
--- a/arch/arm64/mm/flush.c
+++ b/arch/arm64/mm/flush.c
@@ -102,19 +102,3 @@ EXPORT_SYMBOL(flush_dcache_page);
  * Additional functions defined in assembly.
  */
 EXPORT_SYMBOL(flush_icache_range);
-
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-#ifdef CONFIG_HAVE_RCU_TABLE_FREE
-void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
-                         pmd_t *pmdp)
-{
-       pmd_t pmd = pmd_mksplitting(*pmdp);
-
-       VM_BUG_ON(address & ~PMD_MASK);
-       set_pmd_at(vma->vm_mm, address, pmdp, pmd);
-
-       /* dummy IPI to serialise against fast_gup */
-       kick_all_cpus_sync();
-}
-#endif /* CONFIG_HAVE_RCU_TABLE_FREE */
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */