mm/mmu_notifier: use structure for invalidate_range_start/end calls v2

To avoid having to change many call sites everytime we want to add a
parameter use a structure to group all parameters for the mmu_notifier
invalidate_range_start/end cakks.  No functional changes with this patch.

[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/20181205053628.3210-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
From: Jérôme Glisse <jglisse@redhat.com>
Subject: mm/mmu_notifier: use structure for invalidate_range_start/end calls v3

fix build warning in migrate.c when CONFIG_MMU_NOTIFIER=n

Link: http://lkml.kernel.org/r/20181213171330.8489-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

12 files changed, 185 insertions, 209 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0c0e18409fde..05136ad0f325 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1134,8 +1134,7 @@ static vm_fault_t do_huge_pmd_wp_page_fallback(struct vm_fault *vmf,
 	int i;
 	vm_fault_t ret = 0;
 	struct page **pages;
-	unsigned long mmun_start;	/* For mmu_notifiers */
-	unsigned long mmun_end;		/* For mmu_notifiers */
+	struct mmu_notifier_range range;
 
 	pages = kmalloc_array(HPAGE_PMD_NR, sizeof(struct page *),
 			      GFP_KERNEL);
@@ -1173,9 +1172,9 @@ static vm_fault_t do_huge_pmd_wp_page_fallback(struct vm_fault *vmf,
 		cond_resched();
 	}
 
-	mmun_start = haddr;
-	mmun_end   = haddr + HPAGE_PMD_SIZE;
-	mmu_notifier_invalidate_range_start(vma->vm_mm, mmun_start, mmun_end);
+	mmu_notifier_range_init(&range, vma->vm_mm, haddr,
+				haddr + HPAGE_PMD_SIZE);
+	mmu_notifier_invalidate_range_start(&range);
 
 	vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd);
 	if (unlikely(!pmd_same(*vmf->pmd, orig_pmd)))
@@ -1220,8 +1219,7 @@ static vm_fault_t do_huge_pmd_wp_page_fallback(struct vm_fault *vmf,
 	 * No need to double call mmu_notifier->invalidate_range() callback as
 	 * the above pmdp_huge_clear_flush_notify() did already call it.
 	 */
-	mmu_notifier_invalidate_range_only_end(vma->vm_mm, mmun_start,
-						mmun_end);
+	mmu_notifier_invalidate_range_only_end(&range);
 
 	ret |= VM_FAULT_WRITE;
 	put_page(page);
@@ -1231,7 +1229,7 @@ out:
 
 out_free_pages:
 	spin_unlock(vmf->ptl);
-	mmu_notifier_invalidate_range_end(vma->vm_mm, mmun_start, mmun_end);
+	mmu_notifier_invalidate_range_end(&range);
 	for (i = 0; i < HPAGE_PMD_NR; i++) {
 		memcg = (void *)page_private(pages[i]);
 		set_page_private(pages[i], 0);
@@ -1248,8 +1246,7 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
 	struct page *page = NULL, *new_page;
 	struct mem_cgroup *memcg;
 	unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
-	unsigned long mmun_start;	/* For mmu_notifiers */
-	unsigned long mmun_end;		/* For mmu_notifiers */
+	struct mmu_notifier_range range;
 	gfp_t huge_gfp;			/* for allocation and charge */
 	vm_fault_t ret = 0;
 
@@ -1338,9 +1335,9 @@ alloc:
 				    vma, HPAGE_PMD_NR);
 	__SetPageUptodate(new_page);
 
-	mmun_start = haddr;
-	mmun_end   = haddr + HPAGE_PMD_SIZE;
-	mmu_notifier_invalidate_range_start(vma->vm_mm, mmun_start, mmun_end);
+	mmu_notifier_range_init(&range, vma->vm_mm, haddr,
+				haddr + HPAGE_PMD_SIZE);
+	mmu_notifier_invalidate_range_start(&range);
 
 	spin_lock(vmf->ptl);
 	if (page)
@@ -1375,8 +1372,7 @@ out_mn:
 	 * No need to double call mmu_notifier->invalidate_range() callback as
 	 * the above pmdp_huge_clear_flush_notify() did already call it.
 	 */
-	mmu_notifier_invalidate_range_only_end(vma->vm_mm, mmun_start,
-					       mmun_end);
+	mmu_notifier_invalidate_range_only_end(&range);
 out:
 	return ret;
 out_unlock:
@@ -2015,14 +2011,15 @@ void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
 		unsigned long address)
 {
 	spinlock_t *ptl;
-	struct mm_struct *mm = vma->vm_mm;
-	unsigned long haddr = address & HPAGE_PUD_MASK;
+	struct mmu_notifier_range range;
 
-	mmu_notifier_invalidate_range_start(mm, haddr, haddr + HPAGE_PUD_SIZE);
-	ptl = pud_lock(mm, pud);
+	mmu_notifier_range_init(&range, vma->vm_mm, address & HPAGE_PUD_MASK,
+				(address & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE);
+	mmu_notifier_invalidate_range_start(&range);
+	ptl = pud_lock(vma->vm_mm, pud);
 	if (unlikely(!pud_trans_huge(*pud) && !pud_devmap(*pud)))
 		goto out;
-	__split_huge_pud_locked(vma, pud, haddr);
+	__split_huge_pud_locked(vma, pud, range.start);
 
 out:
 	spin_unlock(ptl);
@@ -2030,8 +2027,7 @@ out:
 	 * No need to double call mmu_notifier->invalidate_range() callback as
 	 * the above pudp_huge_clear_flush_notify() did already call it.
 	 */
-	mmu_notifier_invalidate_range_only_end(mm, haddr, haddr +
-					       HPAGE_PUD_SIZE);
+	mmu_notifier_invalidate_range_only_end(&range);
 }
 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 
@@ -2233,11 +2229,12 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 		unsigned long address, bool freeze, struct page *page)
 {
 	spinlock_t *ptl;
-	struct mm_struct *mm = vma->vm_mm;
-	unsigned long haddr = address & HPAGE_PMD_MASK;
+	struct mmu_notifier_range range;
 
-	mmu_notifier_invalidate_range_start(mm, haddr, haddr + HPAGE_PMD_SIZE);
-	ptl = pmd_lock(mm, pmd);
+	mmu_notifier_range_init(&range, vma->vm_mm, address & HPAGE_PMD_MASK,
+				(address & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE);
+	mmu_notifier_invalidate_range_start(&range);
+	ptl = pmd_lock(vma->vm_mm, pmd);
 
 	/*
 	 * If caller asks to setup a migration entries, we need a page to check
@@ -2253,7 +2250,7 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 			clear_page_mlock(page);
 	} else if (!(pmd_devmap(*pmd) || is_pmd_migration_entry(*pmd)))
 		goto out;
-	__split_huge_pmd_locked(vma, pmd, haddr, freeze);
+	__split_huge_pmd_locked(vma, pmd, range.start, freeze);
 out:
 	spin_unlock(ptl);
 	/*
@@ -2269,8 +2266,7 @@ out:
 	 *     any further changes to individual pte will notify. So no need
 	 *     to call mmu_notifier->invalidate_range()
 	 */
-	mmu_notifier_invalidate_range_only_end(mm, haddr, haddr +
-					       HPAGE_PMD_SIZE);
+	mmu_notifier_invalidate_range_only_end(&range);
 }
 
 void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index a80832487981..12000ba5c868 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3240,16 +3240,16 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 	int cow;
 	struct hstate *h = hstate_vma(vma);
 	unsigned long sz = huge_page_size(h);
-	unsigned long mmun_start;	/* For mmu_notifiers */
-	unsigned long mmun_end;		/* For mmu_notifiers */
+	struct mmu_notifier_range range;
 	int ret = 0;
 
 	cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
 
-	mmun_start = vma->vm_start;
-	mmun_end = vma->vm_end;
-	if (cow)
-		mmu_notifier_invalidate_range_start(src, mmun_start, mmun_end);
+	if (cow) {
+		mmu_notifier_range_init(&range, src, vma->vm_start,
+					vma->vm_end);
+		mmu_notifier_invalidate_range_start(&range);
+	}
 
 	for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
 		spinlock_t *src_ptl, *dst_ptl;
@@ -3325,7 +3325,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 	}
 
 	if (cow)
-		mmu_notifier_invalidate_range_end(src, mmun_start, mmun_end);
+		mmu_notifier_invalidate_range_end(&range);
 
 	return ret;
 }
@@ -3342,8 +3342,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
 	struct page *page;
 	struct hstate *h = hstate_vma(vma);
 	unsigned long sz = huge_page_size(h);
-	unsigned long mmun_start = start;	/* For mmu_notifiers */
-	unsigned long mmun_end   = end;		/* For mmu_notifiers */
+	struct mmu_notifier_range range;
 
 	WARN_ON(!is_vm_hugetlb_page(vma));
 	BUG_ON(start & ~huge_page_mask(h));
@@ -3359,8 +3358,9 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
 	/*
 	 * If sharing possible, alert mmu notifiers of worst case.
 	 */
-	adjust_range_if_pmd_sharing_possible(vma, &mmun_start, &mmun_end);
-	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+	mmu_notifier_range_init(&range, mm, start, end);
+	adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end);
+	mmu_notifier_invalidate_range_start(&range);
 	address = start;
 	for (; address < end; address += sz) {
 		ptep = huge_pte_offset(mm, address, sz);
@@ -3428,7 +3428,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		if (ref_page)
 			break;
 	}
-	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+	mmu_notifier_invalidate_range_end(&range);
 	tlb_end_vma(tlb, vma);
 }
 
@@ -3546,9 +3546,8 @@ static vm_fault_t hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
 	struct page *old_page, *new_page;
 	int outside_reserve = 0;
 	vm_fault_t ret = 0;
-	unsigned long mmun_start;	/* For mmu_notifiers */
-	unsigned long mmun_end;		/* For mmu_notifiers */
 	unsigned long haddr = address & huge_page_mask(h);
+	struct mmu_notifier_range range;
 
 	pte = huge_ptep_get(ptep);
 	old_page = pte_page(pte);
@@ -3627,9 +3626,8 @@ retry_avoidcopy:
 	__SetPageUptodate(new_page);
 	set_page_huge_active(new_page);
 
-	mmun_start = haddr;
-	mmun_end = mmun_start + huge_page_size(h);
-	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+	mmu_notifier_range_init(&range, mm, haddr, haddr + huge_page_size(h));
+	mmu_notifier_invalidate_range_start(&range);
 
 	/*
 	 * Retake the page table lock to check for racing updates
@@ -3642,7 +3640,7 @@ retry_avoidcopy:
 
 		/* Break COW */
 		huge_ptep_clear_flush(vma, haddr, ptep);
-		mmu_notifier_invalidate_range(mm, mmun_start, mmun_end);
+		mmu_notifier_invalidate_range(mm, range.start, range.end);
 		set_huge_pte_at(mm, haddr, ptep,
 				make_huge_pte(vma, new_page, 1));
 		page_remove_rmap(old_page, true);
@@ -3651,7 +3649,7 @@ retry_avoidcopy:
 		new_page = old_page;
 	}
 	spin_unlock(ptl);
-	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+	mmu_notifier_invalidate_range_end(&range);
 out_release_all:
 	restore_reserve_on_error(h, vma, haddr, new_page);
 	put_page(new_page);
@@ -4340,21 +4338,21 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
 	pte_t pte;
 	struct hstate *h = hstate_vma(vma);
 	unsigned long pages = 0;
-	unsigned long f_start = start;
-	unsigned long f_end = end;
 	bool shared_pmd = false;
+	struct mmu_notifier_range range;
 
 	/*
 	 * In the case of shared PMDs, the area to flush could be beyond
-	 * start/end.  Set f_start/f_end to cover the maximum possible
+	 * start/end.  Set range.start/range.end to cover the maximum possible
 	 * range if PMD sharing is possible.
 	 */
-	adjust_range_if_pmd_sharing_possible(vma, &f_start, &f_end);
+	mmu_notifier_range_init(&range, mm, start, end);
+	adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end);
 
 	BUG_ON(address >= end);
-	flush_cache_range(vma, f_start, f_end);
+	flush_cache_range(vma, range.start, range.end);
 
-	mmu_notifier_invalidate_range_start(mm, f_start, f_end);
+	mmu_notifier_invalidate_range_start(&range);
 	i_mmap_lock_write(vma->vm_file->f_mapping);
 	for (; address < end; address += huge_page_size(h)) {
 		spinlock_t *ptl;
@@ -4405,7 +4403,7 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
 	 * did unshare a page of pmds, flush the range corresponding to the pud.
 	 */
 	if (shared_pmd)
-		flush_hugetlb_tlb_range(vma, f_start, f_end);
+		flush_hugetlb_tlb_range(vma, range.start, range.end);
 	else
 		flush_hugetlb_tlb_range(vma, start, end);
 	/*
@@ -4415,7 +4413,7 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
 	 * See Documentation/vm/mmu_notifier.rst
 	 */
 	i_mmap_unlock_write(vma->vm_file->f_mapping);
-	mmu_notifier_invalidate_range_end(mm, f_start, f_end);
+	mmu_notifier_invalidate_range_end(&range);
 
 	return pages << h->order;
 }
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 43ce2f4d2551..4f017339ddb2 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -944,8 +944,7 @@ static void collapse_huge_page(struct mm_struct *mm,
 	int isolated = 0, result = 0;
 	struct mem_cgroup *memcg;
 	struct vm_area_struct *vma;
-	unsigned long mmun_start;	/* For mmu_notifiers */
-	unsigned long mmun_end;		/* For mmu_notifiers */
+	struct mmu_notifier_range range;
 	gfp_t gfp;
 
 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
@@ -1017,9 +1016,8 @@ static void collapse_huge_page(struct mm_struct *mm,
 	pte = pte_offset_map(pmd, address);
 	pte_ptl = pte_lockptr(mm, pmd);
 
-	mmun_start = address;
-	mmun_end   = address + HPAGE_PMD_SIZE;
-	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+	mmu_notifier_range_init(&range, mm, address, address + HPAGE_PMD_SIZE);
+	mmu_notifier_invalidate_range_start(&range);
 	pmd_ptl = pmd_lock(mm, pmd); /* probably unnecessary */
 	/*
 	 * After this gup_fast can't run anymore. This also removes
@@ -1029,7 +1027,7 @@ static void collapse_huge_page(struct mm_struct *mm,
 	 */
 	_pmd = pmdp_collapse_flush(vma, address, pmd);
 	spin_unlock(pmd_ptl);
-	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+	mmu_notifier_invalidate_range_end(&range);
 
 	spin_lock(pte_ptl);
 	isolated = __collapse_huge_page_isolate(vma, address, pte);
diff --git a/mm/ksm.c b/mm/ksm.c
index 1a088306ef81..38c0360482fa 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1042,8 +1042,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
 	};
 	int swapped;
 	int err = -EFAULT;
-	unsigned long mmun_start;	/* For mmu_notifiers */
-	unsigned long mmun_end;		/* For mmu_notifiers */
+	struct mmu_notifier_range range;
 
 	pvmw.address = page_address_in_vma(page, vma);
 	if (pvmw.address == -EFAULT)
@@ -1051,9 +1050,9 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
 
 	BUG_ON(PageTransCompound(page));
 
-	mmun_start = pvmw.address;
-	mmun_end   = pvmw.address + PAGE_SIZE;
-	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+	mmu_notifier_range_init(&range, mm, pvmw.address,
+				pvmw.address + PAGE_SIZE);
+	mmu_notifier_invalidate_range_start(&range);
 
 	if (!page_vma_mapped_walk(&pvmw))
 		goto out_mn;
@@ -1105,7 +1104,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
 out_unlock:
 	page_vma_mapped_walk_done(&pvmw);
 out_mn:
-	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+	mmu_notifier_invalidate_range_end(&range);
 out:
 	return err;
 }
@@ -1129,8 +1128,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
 	spinlock_t *ptl;
 	unsigned long addr;
 	int err = -EFAULT;
-	unsigned long mmun_start;	/* For mmu_notifiers */
-	unsigned long mmun_end;		/* For mmu_notifiers */
+	struct mmu_notifier_range range;
 
 	addr = page_address_in_vma(page, vma);
 	if (addr == -EFAULT)
@@ -1140,9 +1138,8 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
 	if (!pmd)
 		goto out;
 
-	mmun_start = addr;
-	mmun_end   = addr + PAGE_SIZE;
-	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+	mmu_notifier_range_init(&range, mm, addr, addr + PAGE_SIZE);
+	mmu_notifier_invalidate_range_start(&range);
 
 	ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
 	if (!pte_same(*ptep, orig_pte)) {
@@ -1188,7 +1185,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
 	pte_unmap_unlock(ptep, ptl);
 	err = 0;
 out_mn:
-	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+	mmu_notifier_invalidate_range_end(&range);
 out:
 	return err;
 }
diff --git a/mm/madvise.c b/mm/madvise.c
index 6cb1ca93e290..21a7881a2db4 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -458,29 +458,30 @@ static void madvise_free_page_range(struct mmu_gather *tlb,
 static int madvise_free_single_vma(struct vm_area_struct *vma,
 			unsigned long start_addr, unsigned long end_addr)
 {
-	unsigned long start, end;
 	struct mm_struct *mm = vma->vm_mm;
+	struct mmu_notifier_range range;
 	struct mmu_gather tlb;
 
 	/* MADV_FREE works for only anon vma at the moment */
 	if (!vma_is_anonymous(vma))
 		return -EINVAL;
 
-	start = max(vma->vm_start, start_addr);
-	if (start >= vma->vm_end)
+	range.start = max(vma->vm_start, start_addr);
+	if (range.start >= vma->vm_end)
 		return -EINVAL;
-	end = min(vma->vm_end, end_addr);
-	if (end <= vma->vm_start)
+	range.end = min(vma->vm_end, end_addr);
+	if (range.end <= vma->vm_start)
 		return -EINVAL;
+	mmu_notifier_range_init(&range, mm, range.start, range.end);
 
 	lru_add_drain();
-	tlb_gather_mmu(&tlb, mm, start, end);
+	tlb_gather_mmu(&tlb, mm, range.start, range.end);
 	update_hiwater_rss(mm);
 
-	mmu_notifier_invalidate_range_start(mm, start, end);
-	madvise_free_page_range(&tlb, vma, start, end);
-	mmu_notifier_invalidate_range_end(mm, start, end);
-	tlb_finish_mmu(&tlb, start, end);
+	mmu_notifier_invalidate_range_start(&range);
+	madvise_free_page_range(&tlb, vma, range.start, range.end);
+	mmu_notifier_invalidate_range_end(&range);
+	tlb_finish_mmu(&tlb, range.start, range.end);
 
 	return 0;
 }
diff --git a/mm/memory.c b/mm/memory.c
index 4ad2d293ddc2..b7a8bfe5f5ec 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -973,8 +973,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	unsigned long next;
 	unsigned long addr = vma->vm_start;
 	unsigned long end = vma->vm_end;
-	unsigned long mmun_start;	/* For mmu_notifiers */
-	unsigned long mmun_end;		/* For mmu_notifiers */
+	struct mmu_notifier_range range;
 	bool is_cow;
 	int ret;
 
@@ -1008,11 +1007,11 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	 * is_cow_mapping() returns true.
 	 */
 	is_cow = is_cow_mapping(vma->vm_flags);
-	mmun_start = addr;
-	mmun_end   = end;
-	if (is_cow)
-		mmu_notifier_invalidate_range_start(src_mm, mmun_start,
-						    mmun_end);
+
+	if (is_cow) {
+		mmu_notifier_range_init(&range, src_mm, addr, end);
+		mmu_notifier_invalidate_range_start(&range);
+	}
 
 	ret = 0;
 	dst_pgd = pgd_offset(dst_mm, addr);
@@ -1029,7 +1028,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	} while (dst_pgd++, src_pgd++, addr = next, addr != end);
 
 	if (is_cow)
-		mmu_notifier_invalidate_range_end(src_mm, mmun_start, mmun_end);
+		mmu_notifier_invalidate_range_end(&range);
 	return ret;
 }
 
@@ -1332,12 +1331,13 @@ void unmap_vmas(struct mmu_gather *tlb,
 		struct vm_area_struct *vma, unsigned long start_addr,
 		unsigned long end_addr)
 {
-	struct mm_struct *mm = vma->vm_mm;
+	struct mmu_notifier_range range;
 
-	mmu_notifier_invalidate_range_start(mm, start_addr, end_addr);
+	mmu_notifier_range_init(&range, vma->vm_mm, start_addr, end_addr);
+	mmu_notifier_invalidate_range_start(&range);
 	for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next)
 		unmap_single_vma(tlb, vma, start_addr, end_addr, NULL);
-	mmu_notifier_invalidate_range_end(mm, start_addr, end_addr);
+	mmu_notifier_invalidate_range_end(&range);
 }
 
 /**
@@ -1351,18 +1351,18 @@ void unmap_vmas(struct mmu_gather *tlb,
 void zap_page_range(struct vm_area_struct *vma, unsigned long start,
 		unsigned long size)
 {
-	struct mm_struct *mm = vma->vm_mm;
+	struct mmu_notifier_range range;
 	struct mmu_gather tlb;
-	unsigned long end = start + size;
 
 	lru_add_drain();
-	tlb_gather_mmu(&tlb, mm, start, end);
-	update_hiwater_rss(mm);
-	mmu_notifier_invalidate_range_start(mm, start, end);
-	for ( ; vma && vma->vm_start < end; vma = vma->vm_next)
-		unmap_single_vma(&tlb, vma, start, end, NULL);
-	mmu_notifier_invalidate_range_end(mm, start, end);
-	tlb_finish_mmu(&tlb, start, end);
+	mmu_notifier_range_init(&range, vma->vm_mm, start, start + size);
+	tlb_gather_mmu(&tlb, vma->vm_mm, start, range.end);
+	update_hiwater_rss(vma->vm_mm);
+	mmu_notifier_invalidate_range_start(&range);
+	for ( ; vma && vma->vm_start < range.end; vma = vma->vm_next)
+		unmap_single_vma(&tlb, vma, start, range.end, NULL);
+	mmu_notifier_invalidate_range_end(&range);
+	tlb_finish_mmu(&tlb, start, range.end);
 }
 
 /**
@@ -1377,17 +1377,17 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long start,
 static void zap_page_range_single(struct vm_area_struct *vma, unsigned long address,
 		unsigned long size, struct zap_details *details)
 {
-	struct mm_struct *mm = vma->vm_mm;
+	struct mmu_notifier_range range;
 	struct mmu_gather tlb;
-	unsigned long end = address + size;
 
 	lru_add_drain();
-	tlb_gather_mmu(&tlb, mm, address, end);
-	update_hiwater_rss(mm);
-	mmu_notifier_invalidate_range_start(mm, address, end);
-	unmap_single_vma(&tlb, vma, address, end, details);
-	mmu_notifier_invalidate_range_end(mm, address, end);
-	tlb_finish_mmu(&tlb, address, end);
+	mmu_notifier_range_init(&range, vma->vm_mm, address, address + size);
+	tlb_gather_mmu(&tlb, vma->vm_mm, address, range.end);
+	update_hiwater_rss(vma->vm_mm);
+	mmu_notifier_invalidate_range_start(&range);
+	unmap_single_vma(&tlb, vma, address, range.end, details);
+	mmu_notifier_invalidate_range_end(&range);
+	tlb_finish_mmu(&tlb, address, range.end);
 }
 
 /**
@@ -2247,9 +2247,8 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
 	struct page *new_page = NULL;
 	pte_t entry;
 	int page_copied = 0;
-	const unsigned long mmun_start = vmf->address & PAGE_MASK;
-	const unsigned long mmun_end = mmun_start + PAGE_SIZE;
 	struct mem_cgroup *memcg;
+	struct mmu_notifier_range range;
 
 	if (unlikely(anon_vma_prepare(vma)))
 		goto oom;
@@ -2272,7 +2271,9 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
 
 	__SetPageUptodate(new_page);
 
-	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+	mmu_notifier_range_init(&range, mm, vmf->address & PAGE_MASK,
+				(vmf->address & PAGE_MASK) + PAGE_SIZE);
+	mmu_notifier_invalidate_range_start(&range);
 
 	/*
 	 * Re-check the pte - we dropped the lock
@@ -2349,7 +2350,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
 	 * No need to double call mmu_notifier->invalidate_range() callback as
 	 * the above ptep_clear_flush_notify() did already call it.
 	 */
-	mmu_notifier_invalidate_range_only_end(mm, mmun_start, mmun_end);
+	mmu_notifier_invalidate_range_only_end(&range);
 	if (old_page) {
 		/*
 		 * Don't let another task, with possibly unlocked vma,
@@ -4030,7 +4031,7 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 #endif /* __PAGETABLE_PMD_FOLDED */
 
 static int __follow_pte_pmd(struct mm_struct *mm, unsigned long address,
-			    unsigned long *start, unsigned long *end,
+			    struct mmu_notifier_range *range,
 			    pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp)
 {
 	pgd_t *pgd;
@@ -4058,10 +4059,10 @@ static int __follow_pte_pmd(struct mm_struct *mm, unsigned long address,
 		if (!pmdpp)
 			goto out;
 
-		if (start && end) {
-			*start = address & PMD_MASK;
-			*end = *start + PMD_SIZE;
-			mmu_notifier_invalidate_range_start(mm, *start, *end);
+		if (range) {
+			mmu_notifier_range_init(range, mm, address & PMD_MASK,
+					     (address & PMD_MASK) + PMD_SIZE);
+			mmu_notifier_invalidate_range_start(range);
 		}
 		*ptlp = pmd_lock(mm, pmd);
 		if (pmd_huge(*pmd)) {
@@ -4069,17 +4070,17 @@ static int __follow_pte_pmd(struct mm_struct *mm, unsigned long address,
 			return 0;
 		}
 		spin_unlock(*ptlp);
-		if (start && end)
-			mmu_notifier_invalidate_range_end(mm, *start, *end);
+		if (range)
+			mmu_notifier_invalidate_range_end(range);
 	}
 
 	if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
 		goto out;
 
-	if (start && end) {
-		*start = address & PAGE_MASK;
-		*end = *start + PAGE_SIZE;
-		mmu_notifier_invalidate_range_start(mm, *start, *end);
+	if (range) {
+		range->start = address & PAGE_MASK;
+		range->end = range->start + PAGE_SIZE;
+		mmu_notifier_invalidate_range_start(range);
 	}
 	ptep = pte_offset_map_lock(mm, pmd, address, ptlp);
 	if (!pte_present(*ptep))
@@ -4088,8 +4089,8 @@ static int __follow_pte_pmd(struct mm_struct *mm, unsigned long address,
 	return 0;
 unlock:
 	pte_unmap_unlock(ptep, *ptlp);
-	if (start && end)
-		mmu_notifier_invalidate_range_end(mm, *start, *end);
+	if (range)
+		mmu_notifier_invalidate_range_end(range);
 out:
 	return -EINVAL;
 }
@@ -4101,20 +4102,20 @@ static inline int follow_pte(struct mm_struct *mm, unsigned long address,
 
 	/* (void) is needed to make gcc happy */
 	(void) __cond_lock(*ptlp,
-			   !(res = __follow_pte_pmd(mm, address, NULL, NULL,
+			   !(res = __follow_pte_pmd(mm, address, NULL,
 						    ptepp, NULL, ptlp)));
 	return res;
 }
 
 int follow_pte_pmd(struct mm_struct *mm, unsigned long address,
-			     unsigned long *start, unsigned long *end,
-			     pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp)
+		   struct mmu_notifier_range *range,
+		   pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp)
 {
 	int res;
 
 	/* (void) is needed to make gcc happy */
 	(void) __cond_lock(*ptlp,
-			   !(res = __follow_pte_pmd(mm, address, start, end,
+			   !(res = __follow_pte_pmd(mm, address, range,
 						    ptepp, pmdpp, ptlp)));
 	return res;
 }
diff --git a/mm/migrate.c b/mm/migrate.c
index acda06f99754..462163f5f278 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2299,6 +2299,7 @@ next:
  */
 static void migrate_vma_collect(struct migrate_vma *migrate)
 {
+	struct mmu_notifier_range range;
 	struct mm_walk mm_walk;
 
 	mm_walk.pmd_entry = migrate_vma_collect_pmd;
@@ -2310,13 +2311,11 @@ static void migrate_vma_collect(struct migrate_vma *migrate)
 	mm_walk.mm = migrate->vma->vm_mm;
 	mm_walk.private = migrate;
 
-	mmu_notifier_invalidate_range_start(mm_walk.mm,
-					    migrate->start,
-					    migrate->end);
+	mmu_notifier_range_init(&range, mm_walk.mm, migrate->start,
+				migrate->end);
+	mmu_notifier_invalidate_range_start(&range);
 	walk_page_range(migrate->start, migrate->end, &mm_walk);
-	mmu_notifier_invalidate_range_end(mm_walk.mm,
-					  migrate->start,
-					  migrate->end);
+	mmu_notifier_invalidate_range_end(&range);
 
 	migrate->end = migrate->start + (migrate->npages << PAGE_SHIFT);
 }
@@ -2697,9 +2696,8 @@ static void migrate_vma_pages(struct migrate_vma *migrate)
 {
 	const unsigned long npages = migrate->npages;
 	const unsigned long start = migrate->start;
-	struct vm_area_struct *vma = migrate->vma;
-	struct mm_struct *mm = vma->vm_mm;
-	unsigned long addr, i, mmu_start;
+	struct mmu_notifier_range range;
+	unsigned long addr, i;
 	bool notified = false;
 
 	for (i = 0, addr = start; i < npages; addr += PAGE_SIZE, i++) {
@@ -2718,11 +2716,12 @@ static void migrate_vma_pages(struct migrate_vma *migrate)
 				continue;
 			}
 			if (!notified) {
-				mmu_start = addr;
 				notified = true;
-				mmu_notifier_invalidate_range_start(mm,
-								mmu_start,
-								migrate->end);
+
+				mmu_notifier_range_init(&range,
+							migrate->vma->vm_mm,
+							addr, migrate->end);
+				mmu_notifier_invalidate_range_start(&range);
 			}
 			migrate_vma_insert_page(migrate, addr, newpage,
 						&migrate->src[i],
@@ -2763,8 +2762,7 @@ static void migrate_vma_pages(struct migrate_vma *migrate)
 	 * did already call it.
 	 */
 	if (notified)
-		mmu_notifier_invalidate_range_only_end(mm, mmu_start,
-						       migrate->end);
+		mmu_notifier_invalidate_range_only_end(&range);
 }
 
 /*
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 74a7dc3d11c8..9c884abc7850 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -167,28 +167,20 @@ void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
 	srcu_read_unlock(&srcu, id);
 }
 
-int __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
-				  unsigned long start, unsigned long end,
-				  bool blockable)
+int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
 {
-	struct mmu_notifier_range _range, *range = &_range;
 	struct mmu_notifier *mn;
 	int ret = 0;
 	int id;
 
-	range->blockable = blockable;
-	range->start = start;
-	range->end = end;
-	range->mm = mm;
-
 	id = srcu_read_lock(&srcu);
-	hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+	hlist_for_each_entry_rcu(mn, &range->mm->mmu_notifier_mm->list, hlist) {
 		if (mn->ops->invalidate_range_start) {
 			int _ret = mn->ops->invalidate_range_start(mn, range);
 			if (_ret) {
 				pr_info("%pS callback failed with %d in %sblockable context.\n",
-						mn->ops->invalidate_range_start, _ret,
-						!blockable ? "non-" : "");
+					mn->ops->invalidate_range_start, _ret,
+					!range->blockable ? "non-" : "");
 				ret = _ret;
 			}
 		}
@@ -199,27 +191,14 @@ int __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
 }
 EXPORT_SYMBOL_GPL(__mmu_notifier_invalidate_range_start);
 
-void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
-					 unsigned long start,
-					 unsigned long end,
+void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range,
 					 bool only_end)
 {
-	struct mmu_notifier_range _range, *range = &_range;
 	struct mmu_notifier *mn;
 	int id;
 
-	/*
-	 * The end call back will never be call if the start refused to go
-	 * through because of blockable was false so here assume that we
-	 * can block.
-	 */
-	range->blockable = true;
-	range->start = start;
-	range->end = end;
-	range->mm = mm;
-
 	id = srcu_read_lock(&srcu);
-	hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+	hlist_for_each_entry_rcu(mn, &range->mm->mmu_notifier_mm->list, hlist) {
 		/*
 		 * Call invalidate_range here too to avoid the need for the
 		 * subsystem of having to register an invalidate_range_end
@@ -234,7 +213,9 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
 		 * already happen under page table lock.
 		 */
 		if (!only_end && mn->ops->invalidate_range)
-			mn->ops->invalidate_range(mn, mm, start, end);
+			mn->ops->invalidate_range(mn, range->mm,
+						  range->start,
+						  range->end);
 		if (mn->ops->invalidate_range_end)
 			mn->ops->invalidate_range_end(mn, range);
 	}
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 6d331620b9e5..36cb358db170 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -167,11 +167,12 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
 		pgprot_t newprot, int dirty_accountable, int prot_numa)
 {
 	pmd_t *pmd;
-	struct mm_struct *mm = vma->vm_mm;
 	unsigned long next;
 	unsigned long pages = 0;
 	unsigned long nr_huge_updates = 0;
-	unsigned long mni_start = 0;
+	struct mmu_notifier_range range;
+
+	range.start = 0;
 
 	pmd = pmd_offset(pud, addr);
 	do {
@@ -183,9 +184,9 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
 			goto next;
 
 		/* invoke the mmu notifier if the pmd is populated */
-		if (!mni_start) {
-			mni_start = addr;
-			mmu_notifier_invalidate_range_start(mm, mni_start, end);
+		if (!range.start) {
+			mmu_notifier_range_init(&range, vma->vm_mm, addr, end);
+			mmu_notifier_invalidate_range_start(&range);
 		}
 
 		if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) {
@@ -214,8 +215,8 @@ next:
 		cond_resched();
 	} while (pmd++, addr = next, addr != end);
 
-	if (mni_start)
-		mmu_notifier_invalidate_range_end(mm, mni_start, end);
+	if (range.start)
+		mmu_notifier_invalidate_range_end(&range);
 
 	if (nr_huge_updates)
 		count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates);
diff --git a/mm/mremap.c b/mm/mremap.c
index 7f9f9180e401..def01d86e36f 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -197,16 +197,14 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
 		bool need_rmap_locks)
 {
 	unsigned long extent, next, old_end;
+	struct mmu_notifier_range range;
 	pmd_t *old_pmd, *new_pmd;
-	unsigned long mmun_start;	/* For mmu_notifiers */
-	unsigned long mmun_end;		/* For mmu_notifiers */
 
 	old_end = old_addr + len;
 	flush_cache_range(vma, old_addr, old_end);
 
-	mmun_start = old_addr;
-	mmun_end   = old_end;
-	mmu_notifier_invalidate_range_start(vma->vm_mm, mmun_start, mmun_end);
+	mmu_notifier_range_init(&range, vma->vm_mm, old_addr, old_end);
+	mmu_notifier_invalidate_range_start(&range);
 
 	for (; old_addr < old_end; old_addr += extent, new_addr += extent) {
 		cond_resched();
@@ -247,7 +245,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
 			  new_pmd, new_addr, need_rmap_locks);
 	}
 
-	mmu_notifier_invalidate_range_end(vma->vm_mm, mmun_start, mmun_end);
+	mmu_notifier_invalidate_range_end(&range);
 
 	return len + old_addr - old_end;	/* how much done */
 }
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 5442cb12e4ed..f0e8cd9edb1a 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -528,19 +528,20 @@ bool __oom_reap_task_mm(struct mm_struct *mm)
 		 * count elevated without a good reason.
 		 */
 		if (vma_is_anonymous(vma) || !(vma->vm_flags & VM_SHARED)) {
-			const unsigned long start = vma->vm_start;
-			const unsigned long end = vma->vm_end;
+			struct mmu_notifier_range range;
 			struct mmu_gather tlb;
 
-			tlb_gather_mmu(&tlb, mm, start, end);
-			if (mmu_notifier_invalidate_range_start_nonblock(mm, start, end)) {
-				tlb_finish_mmu(&tlb, start, end);
+			mmu_notifier_range_init(&range, mm, vma->vm_start,
+						vma->vm_end);
+			tlb_gather_mmu(&tlb, mm, range.start, range.end);
+			if (mmu_notifier_invalidate_range_start_nonblock(&range)) {
+				tlb_finish_mmu(&tlb, range.start, range.end);
 				ret = false;
 				continue;
 			}
-			unmap_page_range(&tlb, vma, start, end, NULL);
-			mmu_notifier_invalidate_range_end(mm, start, end);
-			tlb_finish_mmu(&tlb, start, end);
+			unmap_page_range(&tlb, vma, range.start, range.end, NULL);
+			mmu_notifier_invalidate_range_end(&range);
+			tlb_finish_mmu(&tlb, range.start, range.end);
 		}
 	}
 
diff --git a/mm/rmap.c b/mm/rmap.c
index 85b7f9423352..c75f72f6fe0e 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -889,15 +889,17 @@ static bool page_mkclean_one(struct page *page, struct vm_area_struct *vma,
 		.address = address,
 		.flags = PVMW_SYNC,
 	};
-	unsigned long start = address, end;
+	struct mmu_notifier_range range;
 	int *cleaned = arg;
 
 	/*
 	 * We have to assume the worse case ie pmd for invalidation. Note that
 	 * the page can not be free from this function.
 	 */
-	end = min(vma->vm_end, start + (PAGE_SIZE << compound_order(page)));
-	mmu_notifier_invalidate_range_start(vma->vm_mm, start, end);
+	mmu_notifier_range_init(&range, vma->vm_mm, address,
+				min(vma->vm_end, address +
+				    (PAGE_SIZE << compound_order(page))));
+	mmu_notifier_invalidate_range_start(&range);
 
 	while (page_vma_mapped_walk(&pvmw)) {
 		unsigned long cstart;
@@ -949,7 +951,7 @@ static bool page_mkclean_one(struct page *page, struct vm_area_struct *vma,
 			(*cleaned)++;
 	}
 
-	mmu_notifier_invalidate_range_end(vma->vm_mm, start, end);
+	mmu_notifier_invalidate_range_end(&range);
 
 	return true;
 }
@@ -1345,7 +1347,7 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 	pte_t pteval;
 	struct page *subpage;
 	bool ret = true;
-	unsigned long start = address, end;
+	struct mmu_notifier_range range;
 	enum ttu_flags flags = (enum ttu_flags)arg;
 
 	/* munlock has nothing to gain from examining un-locked vmas */
@@ -1369,15 +1371,18 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 	 * Note that the page can not be free in this function as call of
 	 * try_to_unmap() must hold a reference on the page.
 	 */
-	end = min(vma->vm_end, start + (PAGE_SIZE << compound_order(page)));
+	mmu_notifier_range_init(&range, vma->vm_mm, vma->vm_start,
+				min(vma->vm_end, vma->vm_start +
+				    (PAGE_SIZE << compound_order(page))));
 	if (PageHuge(page)) {
 		/*
 		 * If sharing is possible, start and end will be adjusted
 		 * accordingly.
 		 */
-		adjust_range_if_pmd_sharing_possible(vma, &start, &end);
+		adjust_range_if_pmd_sharing_possible(vma, &range.start,
+						     &range.end);
 	}
-	mmu_notifier_invalidate_range_start(vma->vm_mm, start, end);
+	mmu_notifier_invalidate_range_start(&range);
 
 	while (page_vma_mapped_walk(&pvmw)) {
 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
@@ -1428,9 +1433,10 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 				 * we must flush them all.  start/end were
 				 * already adjusted above to cover this range.
 				 */
-				flush_cache_range(vma, start, end);
-				flush_tlb_range(vma, start, end);
-				mmu_notifier_invalidate_range(mm, start, end);
+				flush_cache_range(vma, range.start, range.end);
+				flush_tlb_range(vma, range.start, range.end);
+				mmu_notifier_invalidate_range(mm, range.start,
+							      range.end);
 
 				/*
 				 * The ref count of the PMD page was dropped
@@ -1650,7 +1656,7 @@ discard:
 		put_page(page);
 	}
 
-	mmu_notifier_invalidate_range_end(vma->vm_mm, start, end);
+	mmu_notifier_invalidate_range_end(&range);
 
 	return ret;
 }