s390/mm: make use of ipte range facility

Invalidate several pte entries at once if the ipte range facility
is available. Currently this works only for DEBUG_PAGE_ALLOC where
several up to 2 ^ MAX_ORDER may be invalidated at once.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 47 insertions, 7 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 7c4af56f2b73..2de229c1b467 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1053,6 +1053,22 @@ static inline void __ptep_ipte_local(unsigned long address, pte_t *ptep)
                 : "=m" (*ptep) : "m" (*ptep), "a" (pto), "a" (address));
 }
 
+static inline void __ptep_ipte_range(unsigned long address, int nr, pte_t *ptep)
+{
+        unsigned long pto = (unsigned long) ptep;
+
+#ifndef CONFIG_64BIT
+        /* pto in ESA mode must point to the start of the segment table */
+        pto &= 0x7ffffc00;
+#endif
+        /* Invalidate a range of ptes + global TLB flush of the ptes */
+        do {
+                asm volatile(
+                        "       .insn rrf,0xb2210000,%2,%0,%1,0"
+                        : "+a" (address), "+a" (nr) : "a" (pto) : "memory");
+        } while (nr != 255);
+}
+
 static inline void ptep_flush_direct(struct mm_struct *mm,
                                      unsigned long address, pte_t *ptep)
 {
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index 8400f494623f..3fef3b299665 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -6,6 +6,7 @@
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <asm/cacheflush.h>
+#include <asm/facility.h>
 #include <asm/pgtable.h>
 #include <asm/page.h>
 
@@ -103,27 +104,50 @@ int set_memory_x(unsigned long addr, int numpages)
 }
 
 #ifdef CONFIG_DEBUG_PAGEALLOC
+
+static void ipte_range(pte_t *pte, unsigned long address, int nr)
+{
+        int i;
+
+        if (test_facility(13) && IS_ENABLED(CONFIG_64BIT)) {
+                __ptep_ipte_range(address, nr - 1, pte);
+                return;
+        }
+        for (i = 0; i < nr; i++) {
+                __ptep_ipte(address, pte);
+                address += PAGE_SIZE;
+                pte++;
+        }
+}
+
 void kernel_map_pages(struct page *page, int numpages, int enable)
 {
         unsigned long address;
+        int nr, i, j;
         pgd_t *pgd;
         pud_t *pud;
         pmd_t *pmd;
         pte_t *pte;
-        int i;
 
-        for (i = 0; i < numpages; i++) {
+        for (i = 0; i < numpages;) {
                 address = page_to_phys(page + i);
                 pgd = pgd_offset_k(address);
                 pud = pud_offset(pgd, address);
                 pmd = pmd_offset(pud, address);
                 pte = pte_offset_kernel(pmd, address);
-                if (!enable) {
-                        __ptep_ipte(address, pte);
-                        pte_val(*pte) = _PAGE_INVALID;
-                        continue;
+                nr = (unsigned long)pte >> ilog2(sizeof(long));
+                nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1));
+                nr = min(numpages - i, nr);
+                if (enable) {
+                        for (j = 0; j < nr; j++) {
+                                pte_val(*pte) = __pa(address);
+                                address += PAGE_SIZE;
+                                pte++;
+                        }
+                } else {
+                        ipte_range(pte, address, nr);
                 }
-                pte_val(*pte) = __pa(address);
+                i += nr;
         }
 }