mm: remove checks for pte_index

Since pte_index is always defined, we don't need to check whether it's
defined or not.  Delete the slow version that doesn't depend on it and
remove the #define since nobody needs to test for it.

Link: https://lkml.kernel.org/r/20230819031837.3160096-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Christian Dietrich <stettberger@dokucode.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Matthew Wilcox (Oracle)

include/linux/pgtable.h

@@ -63,7 +63,6 @@ static inline unsigned long pte_index(unsigned long address)
 {
 	return (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
 }
-#define pte_index pte_index
 
 #ifndef pmd_index
 static inline unsigned long pmd_index(unsigned long address)

mm/memory.c

@@ -1869,7 +1869,6 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr,
 	return retval;
 }
 
-#ifdef pte_index
 static int insert_page_in_batch_locked(struct vm_area_struct *vma, pte_t *pte,
 			unsigned long addr, struct page *page, pgprot_t prot)
 {
@@ -1884,7 +1883,7 @@ static int insert_page_in_batch_locked(struct vm_area_struct *vma, pte_t *pte,
 }
 
 /* insert_pages() amortizes the cost of spinlock operations
- * when inserting pages in a loop. Arch *must* define pte_index.
+ * 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)
@@ -1943,7 +1942,6 @@ static int insert_pages(struct vm_area_struct *vma, unsigned long addr,
 	*num = remaining_pages_total;
 	return ret;
 }
-#endif  /* ifdef pte_index */
 
 /**
  * vm_insert_pages - insert multiple pages into user vma, batching the pmd lock.
@@ -1963,7 +1961,6 @@ static int insert_pages(struct vm_area_struct *vma, unsigned long addr,
 int vm_insert_pages(struct vm_area_struct *vma, unsigned long addr,
 			struct page **pages, unsigned long *num)
 {
-#ifdef pte_index
 	const unsigned long end_addr = addr + (*num * PAGE_SIZE) - 1;
 
 	if (addr < vma->vm_start || end_addr >= vma->vm_end)
@@ -1975,18 +1972,6 @@ int vm_insert_pages(struct vm_area_struct *vma, unsigned long addr,
 	}
 	/* Defer page refcount checking till we're about to map that page. */
 	return insert_pages(vma, addr, pages, num, vma->vm_page_prot);
-#else
-	unsigned long idx = 0, pgcount = *num;
-	int err = -EINVAL;
-
-	for (; idx < pgcount; ++idx) {
-		err = vm_insert_page(vma, addr + (PAGE_SIZE * idx), pages[idx]);
-		if (err)
-			break;
-	}
-	*num = pgcount - idx;
-	return err;
-#endif  /* ifdef pte_index */
 }
 EXPORT_SYMBOL(vm_insert_pages);