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>
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0c0e184..05136ad 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 @@ static vm_fault_t do_huge_pmd_wp_page_fallback(struct vm_fault *vmf,
 
 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 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
 				    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 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
 	 * 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 @@ void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
 	 * 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 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 	 *     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,