Revert "mm/memory.c: add vm_insert_pages()"

This reverts commit a561d7c.

include/linux/mm.h

@@ -2603,8 +2603,6 @@ struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
 int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
  unsigned long pfn, unsigned long size, pgprot_t);
 int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
-int vm_insert_pages(struct vm_area_struct *vma, unsigned long addr,
- struct page **pages, unsigned long *num);
 int vm_map_pages(struct vm_area_struct *vma, struct page **pages,
  unsigned long num);
 int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages,

mm/memory.c

@@ -1407,7 +1407,8 @@ void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
 }
 EXPORT_SYMBOL_GPL(zap_vma_ptes);
 
-static pmd_t *walk_to_pmd(struct mm_struct *mm, unsigned long addr)
+pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
+ spinlock_t **ptl)
 {
  pgd_t *pgd;
  p4d_t *p4d;
@@ -1426,16 +1427,6 @@ static pmd_t *walk_to_pmd(struct mm_struct *mm, unsigned long addr)
  return NULL;
 
  VM_BUG_ON(pmd_trans_huge(*pmd));
- return pmd;
-}
-
-pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
- spinlock_t **ptl)
-{
- pmd_t *pmd = walk_to_pmd(mm, addr);
-
- if (!pmd)
- return NULL;
  return pte_alloc_map_lock(mm, pmd, addr, ptl);
 }
 
@@ -1460,15 +1451,6 @@ static int insert_page_into_pte_locked(struct mm_struct *mm, pte_t *pte,
  return 0;
 }
 
-static int insert_page_in_batch_locked(struct mm_struct *mm, pmd_t *pmd,
- unsigned long addr, struct page *page, pgprot_t prot)
-{
- const int err = validate_page_before_insert(page);
-
- return err ? err : insert_page_into_pte_locked(
- mm, pte_offset_map(pmd, addr), addr, page, prot);
-}
-
 /*
  * This is the old fallback for page remapping.
  *
@@ -1497,95 +1479,6 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr,
  return retval;
 }
 
-/* insert_pages() amortizes the cost of spinlock operations
- * when inserting pages in a loop.
- */
-static int insert_pages(struct vm_area_struct *vma, unsigned long addr,
- struct page **pages, unsigned long *num, pgprot_t prot)
-{
- pmd_t *pmd = NULL;
- spinlock_t *pte_lock = NULL;
- struct mm_struct *const mm = vma->vm_mm;
- unsigned long curr_page_idx = 0;
- unsigned long remaining_pages_total = *num;
- unsigned long pages_to_write_in_pmd;
- int ret;
-more:
- ret = -EFAULT;
- pmd = walk_to_pmd(mm, addr);
- if (!pmd)
- goto out;
-
- pages_to_write_in_pmd = min_t(unsigned long,
- remaining_pages_total, PTRS_PER_PTE - pte_index(addr));
-
- /* Allocate the PTE if necessary; takes PMD lock once only. */
- ret = -ENOMEM;
- if (pte_alloc(mm, pmd, addr))
- goto out;
- pte_lock = pte_lockptr(mm, pmd);
-
- while (pages_to_write_in_pmd) {
- int pte_idx = 0;
- const int batch_size = min_t(int, pages_to_write_in_pmd, 8);
-
- spin_lock(pte_lock);
- for (; pte_idx < batch_size; ++pte_idx) {
- int err = insert_page_in_batch_locked(mm, pmd,
- addr, pages[curr_page_idx], prot);
- if (unlikely(err)) {
- spin_unlock(pte_lock);
- ret = err;
- remaining_pages_total -= pte_idx;
- goto out;
- }
- addr += PAGE_SIZE;
- ++curr_page_idx;
- }
- spin_unlock(pte_lock);
- pages_to_write_in_pmd -= batch_size;
- remaining_pages_total -= batch_size;
- }
- if (remaining_pages_total)
- goto more;
- ret = 0;
-out:
- *num = remaining_pages_total;
- return ret;
-}
-
-/**
- * vm_insert_pages - insert multiple pages into user vma, batching the pmd lock.
- * @vma: user vma to map to
- * @addr: target start user address of these pages
- * @pages: source kernel pages
- * @num: in: number of pages to map. out: number of pages that were *not*
- * mapped. (0 means all pages were successfully mapped).
- *
- * Preferred over vm_insert_page() when inserting multiple pages.
- *
- * In case of error, we may have mapped a subset of the provided
- * pages. It is the caller's responsibility to account for this case.
- *
- * The same restrictions apply as in vm_insert_page().
- */
-int vm_insert_pages(struct vm_area_struct *vma, unsigned long addr,
- struct page **pages, unsigned long *num)
-{
- const unsigned long end_addr = addr + (*num * PAGE_SIZE) - 1;
-
- if (addr < vma->vm_start || end_addr >= vma->vm_end)
- return -EFAULT;
- if (!(vma->vm_flags & VM_MIXEDMAP)) {
- BUG_ON(down_read_trylock(&vma->vm_mm->mmap_sem));
- BUG_ON(vma->vm_flags & VM_PFNMAP);
- vma->vm_flags |= VM_MIXEDMAP;
- }
- /* Defer page refcount checking till we're about to map that page. */
- return insert_pages(vma, addr, pages, num, vma->vm_page_prot);
-}
-EXPORT_SYMBOL(vm_insert_pages);
-
 /**
  * vm_insert_page - insert single page into user vma
  * @vma: user vma to map to