s390/mm,vmem: use 2GB frames for identity mapping

Use 2GB frames for indentity mapping if EDAT2 is
available to reduce TLB pressure.

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

3 files changed, 23 insertions, 6 deletions

diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index cbc6668acb85..04e4892247d2 100644
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c
@@ -150,6 +150,7 @@ static void walk_pmd_level(struct seq_file *m, struct pg_state *st,
 static void walk_pud_level(struct seq_file *m, struct pg_state *st,
                            pgd_t *pgd, unsigned long addr)
 {
+        unsigned int prot;
         pud_t *pud;
         int i;
 
@@ -157,7 +158,11 @@ static void walk_pud_level(struct seq_file *m, struct pg_state *st,
                 st->current_address = addr;
                 pud = pud_offset(pgd, addr);
                 if (!pud_none(*pud))
-                        walk_pmd_level(m, st, pud, addr);
+                        if (pud_large(*pud)) {
+                                prot = pud_val(*pud) & _PAGE_RO;
+                                note_page(m, st, prot, 2);
+                        } else
+                                walk_pmd_level(m, st, pud, addr);
                 else
                         note_page(m, st, _PAGE_INVALID, 2);
                 addr += PUD_SIZE;
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index 00be01c4b4f3..c7ec7c2e46b0 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -19,7 +19,7 @@ static pte_t *walk_page_table(unsigned long addr)
         if (pgd_none(*pgdp))
                 return NULL;
         pudp = pud_offset(pgdp, addr);
-        if (pud_none(*pudp))
+        if (pud_none(*pudp) || pud_large(*pudp))
                 return NULL;
         pmdp = pmd_offset(pudp, addr);
         if (pmd_none(*pmdp) || pmd_large(*pmdp))
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 387c7c60b5b8..bf37a094a46b 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -89,6 +89,7 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
         int ret = -ENOMEM;
 
         while (address < end) {
+                pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
                 pg_dir = pgd_offset_k(address);
                 if (pgd_none(*pg_dir)) {
                         pu_dir = vmem_pud_alloc();
@@ -96,18 +97,24 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
                                 goto out;
                         pgd_populate(&init_mm, pg_dir, pu_dir);
                 }
-
                 pu_dir = pud_offset(pg_dir, address);
+#if defined(CONFIG_64BIT) && !defined(CONFIG_DEBUG_PAGEALLOC)
+                if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address &&
+                    !(address & ~PUD_MASK) && (address + PUD_SIZE <= end)) {
+                        pte_val(pte) |= _REGION3_ENTRY_LARGE;
+                        pte_val(pte) |= _REGION_ENTRY_TYPE_R3;
+                        pud_val(*pu_dir) = pte_val(pte);
+                        address += PUD_SIZE;
+                        continue;
+                }
+#endif
                 if (pud_none(*pu_dir)) {
                         pm_dir = vmem_pmd_alloc();
                         if (!pm_dir)
                                 goto out;
                         pud_populate(&init_mm, pu_dir, pm_dir);
                 }
-
-                pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
                 pm_dir = pmd_offset(pu_dir, address);
-
 #if defined(CONFIG_64BIT) && !defined(CONFIG_DEBUG_PAGEALLOC)
                 if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address &&
                     !(address & ~PMD_MASK) && (address + PMD_SIZE <= end)) {
@@ -160,6 +167,11 @@ static void vmem_remove_range(unsigned long start, unsigned long size)
                         address += PUD_SIZE;
                         continue;
                 }
+                if (pud_large(*pu_dir)) {
+                        pud_clear(pu_dir);
+                        address += PUD_SIZE;
+                        continue;
+                }
                 pm_dir = pmd_offset(pu_dir, address);
                 if (pmd_none(*pm_dir)) {
                         address += PMD_SIZE;