s390: implement the new page table range API

Add set_ptes() and update_mmu_cache_range().

Link: https://lkml.kernel.org/r/20230802151406.3735276-24-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/s390/include/asm/pgtable.h

@@ -47,6 +47,7 @@ static inline void update_page_count(int level, long count)
  * tables contain all the necessary information.
  */
 #define update_mmu_cache(vma, address, ptep)     do { } while (0)
+#define update_mmu_cache_range(vmf, vma, addr, ptep, nr) do { } while (0)
 #define update_mmu_cache_pmd(vma, address, ptep) do { } while (0)
 
 /*
@@ -1316,20 +1317,34 @@ pgprot_t pgprot_writecombine(pgprot_t prot);
 pgprot_t pgprot_writethrough(pgprot_t prot);
 
 /*
- * Certain architectures need to do special things when PTEs
- * within a page table are directly modified.  Thus, the following
- * hook is made available.
+ * Set multiple PTEs to consecutive pages with a single call.  All PTEs
+ * are within the same folio, PMD and VMA.
  */
-static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
-			      pte_t *ptep, pte_t entry)
+static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, pte_t entry, unsigned int nr)
 {
 	if (pte_present(entry))
 		entry = clear_pte_bit(entry, __pgprot(_PAGE_UNUSED));
-	if (mm_has_pgste(mm))
-		ptep_set_pte_at(mm, addr, ptep, entry);
-	else
-		set_pte(ptep, entry);
+	if (mm_has_pgste(mm)) {
+		for (;;) {
+			ptep_set_pte_at(mm, addr, ptep, entry);
+			if (--nr == 0)
+				break;
+			ptep++;
+			entry = __pte(pte_val(entry) + PAGE_SIZE);
+			addr += PAGE_SIZE;
+		}
+	} else {
+		for (;;) {
+			set_pte(ptep, entry);
+			if (--nr == 0)
+				break;
+			ptep++;
+			entry = __pte(pte_val(entry) + PAGE_SIZE);
+		}
+	}
 }
+#define set_ptes set_ptes
 
 /*
  * Conversion functions: convert a page and protection to a page entry,