tlb: mmu_gather: Remove start/end arguments from tlb_gather_mmu()

The 'start' and 'end' arguments to tlb_gather_mmu() are no longer
needed now that there is a separate function for 'fullmm' flushing.

Remove the unused arguments and update all callers.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Yu Zhao <yuzhao@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/CAHk-=wjQWa14_4UpfDf=fiineNP+RH74kZeDMo_f1D35xNzq9w@mail.gmail.com

6 files changed, 16 insertions, 36 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 33db4fa62c7b..89635f407232 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3967,23 +3967,9 @@ void __unmap_hugepage_range_final(struct mmu_gather *tlb,
 void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
 			  unsigned long end, struct page *ref_page)
 {
-	struct mm_struct *mm;
 	struct mmu_gather tlb;
-	unsigned long tlb_start = start;
-	unsigned long tlb_end = end;
 
-	/*
-	 * If shared PMDs were possibly used within this vma range, adjust
-	 * start/end for worst case tlb flushing.
-	 * Note that we can not be sure if PMDs are shared until we try to
-	 * unmap pages.  However, we want to make sure TLB flushing covers
-	 * the largest possible range.
-	 */
-	adjust_range_if_pmd_sharing_possible(vma, &tlb_start, &tlb_end);
-
-	mm = vma->vm_mm;
-
-	tlb_gather_mmu(&tlb, mm, tlb_start, tlb_end);
+	tlb_gather_mmu(&tlb, vma->vm_mm);
 	__unmap_hugepage_range(&tlb, vma, start, end, ref_page);
 	tlb_finish_mmu(&tlb);
 }
diff --git a/mm/madvise.c b/mm/madvise.c
index 1b68520ea3f4..0938fd3ad228 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -506,7 +506,7 @@ static long madvise_cold(struct vm_area_struct *vma,
 		return -EINVAL;
 
 	lru_add_drain();
-	tlb_gather_mmu(&tlb, mm, start_addr, end_addr);
+	tlb_gather_mmu(&tlb, mm);
 	madvise_cold_page_range(&tlb, vma, start_addr, end_addr);
 	tlb_finish_mmu(&tlb);
 
@@ -558,7 +558,7 @@ static long madvise_pageout(struct vm_area_struct *vma,
 		return 0;
 
 	lru_add_drain();
-	tlb_gather_mmu(&tlb, mm, start_addr, end_addr);
+	tlb_gather_mmu(&tlb, mm);
 	madvise_pageout_page_range(&tlb, vma, start_addr, end_addr);
 	tlb_finish_mmu(&tlb);
 
@@ -723,7 +723,7 @@ static int madvise_free_single_vma(struct vm_area_struct *vma,
 				range.start, range.end);
 
 	lru_add_drain();
-	tlb_gather_mmu(&tlb, mm, range.start, range.end);
+	tlb_gather_mmu(&tlb, mm);
 	update_hiwater_rss(mm);
 
 	mmu_notifier_invalidate_range_start(&range);
diff --git a/mm/memory.c b/mm/memory.c
index 7bd3f122bd10..9e8576a83147 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1534,7 +1534,7 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long start,
 	lru_add_drain();
 	mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm,
 				start, start + size);
-	tlb_gather_mmu(&tlb, vma->vm_mm, start, range.end);
+	tlb_gather_mmu(&tlb, vma->vm_mm);
 	update_hiwater_rss(vma->vm_mm);
 	mmu_notifier_invalidate_range_start(&range);
 	for ( ; vma && vma->vm_start < range.end; vma = vma->vm_next)
@@ -1561,7 +1561,7 @@ static void zap_page_range_single(struct vm_area_struct *vma, unsigned long addr
 	lru_add_drain();
 	mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm,
 				address, address + size);
-	tlb_gather_mmu(&tlb, vma->vm_mm, address, range.end);
+	tlb_gather_mmu(&tlb, vma->vm_mm);
 	update_hiwater_rss(vma->vm_mm);
 	mmu_notifier_invalidate_range_start(&range);
 	unmap_single_vma(&tlb, vma, address, range.end, details);
diff --git a/mm/mmap.c b/mm/mmap.c
index 4eac7c63edbe..90673febce6a 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2671,7 +2671,7 @@ static void unmap_region(struct mm_struct *mm,
 	struct mmu_gather tlb;
 
 	lru_add_drain();
-	tlb_gather_mmu(&tlb, mm, start, end);
+	tlb_gather_mmu(&tlb, mm);
 	update_hiwater_rss(mm);
 	unmap_vmas(&tlb, vma, start, end);
 	free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS,
diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c
index 5f5e45d9eb50..0dc7149b0c61 100644
--- a/mm/mmu_gather.c
+++ b/mm/mmu_gather.c
@@ -253,21 +253,17 @@ void tlb_flush_mmu(struct mmu_gather *tlb)
  * tlb_gather_mmu - initialize an mmu_gather structure for page-table tear-down
  * @tlb: the mmu_gather structure to initialize
  * @mm: the mm_struct of the target address space
- * @start: start of the region that will be removed from the page-table
- * @end: end of the region that will be removed from the page-table
+ * @fullmm: @mm is without users and we're going to destroy the full address
+ *	    space (exit/execve)
  *
  * Called to initialize an (on-stack) mmu_gather structure for page-table
- * tear-down from @mm. The @start and @end are set to 0 and -1
- * respectively when @mm is without users and we're going to destroy
- * the full address space (exit/execve).
+ * tear-down from @mm.
  */
 static void __tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
-			     unsigned long start, unsigned long end)
+			     bool fullmm)
 {
 	tlb->mm = mm;
-
-	/* Is it from 0 to ~0? */
-	tlb->fullmm     = !(start | (end+1));
+	tlb->fullmm = fullmm;
 
 #ifndef CONFIG_MMU_GATHER_NO_GATHER
 	tlb->need_flush_all = 0;
@@ -287,16 +283,14 @@ static void __tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
 	inc_tlb_flush_pending(tlb->mm);
 }
 
-void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
-		    unsigned long start, unsigned long end)
+void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm)
 {
-	WARN_ON(!(start | (end + 1))); /* Use _fullmm() instead */
-	__tlb_gather_mmu(tlb, mm, start, end);
+	__tlb_gather_mmu(tlb, mm, false);
 }
 
 void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm)
 {
-	__tlb_gather_mmu(tlb, mm, 0, -1);
+	__tlb_gather_mmu(tlb, mm, true);
 }
 
 /**
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 757e557211fb..c9a33ffe38b7 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -546,7 +546,7 @@ bool __oom_reap_task_mm(struct mm_struct *mm)
 			mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0,
 						vma, mm, vma->vm_start,
 						vma->vm_end);
-			tlb_gather_mmu(&tlb, mm, range.start, range.end);
+			tlb_gather_mmu(&tlb, mm);
 			if (mmu_notifier_invalidate_range_start_nonblock(&range)) {
 				tlb_finish_mmu(&tlb);
 				ret = false;