Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] make page table upgrade work again
  [S390] make page table walking more robust
  [S390] Dont check for pfn_valid() in uaccess_pt.c
  [S390] ftrace/mcount: fix kernel stack backchain
  [S390] topology: define SD_MC_INIT to fix performance regression
  [S390] __div64_31 broken for CONFIG_MARCH_G5

8 files changed, 48 insertions, 40 deletions

diff --git a/arch/s390/include/asm/mman.h b/arch/s390/include/asm/mman.h
index 7839767d837e..da01432e8f44 100644
--- a/arch/s390/include/asm/mman.h
+++ b/arch/s390/include/asm/mman.h
@@ -22,4 +22,9 @@
 #define MCL_CURRENT     1               /* lock all current mappings */
 #define MCL_FUTURE      2               /* lock all future mappings */
 
+#if defined(__KERNEL__) && !defined(__ASSEMBLY__) && defined(CONFIG_64BIT)
+int s390_mmap_check(unsigned long addr, unsigned long len);
+#define arch_mmap_check(addr,len,flags) s390_mmap_check(addr,len)
+#endif
+
 #endif /* __S390_MMAN_H__ */
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 066b99502e09..db4523fe38ac 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -61,7 +61,7 @@ extern void print_cpu_info(struct cpuinfo_S390 *);
 extern int get_cpu_capability(unsigned int *);
 
 /*
- * User space process size: 2GB for 31 bit, 4TB for 64 bit.
+ * User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit.
  */
 #ifndef __s390x__
 
@@ -70,8 +70,7 @@ extern int get_cpu_capability(unsigned int *);
 
 #else /* __s390x__ */
 
-#define TASK_SIZE_OF(tsk)       (test_tsk_thread_flag(tsk,TIF_31BIT) ? \
-                                        (1UL << 31) : (1UL << 53))
+#define TASK_SIZE_OF(tsk)       ((tsk)->mm->context.asce_limit)
 #define TASK_UNMAPPED_BASE      (test_thread_flag(TIF_31BIT) ? \
                                         (1UL << 30) : (1UL << 41))
 #define TASK_SIZE               TASK_SIZE_OF(current)
diff --git a/arch/s390/include/asm/topology.h b/arch/s390/include/asm/topology.h
index c93eb50e1d09..c979c3b56ab0 100644
--- a/arch/s390/include/asm/topology.h
+++ b/arch/s390/include/asm/topology.h
@@ -30,6 +30,8 @@ static inline void s390_init_cpu_topology(void)
 };
 #endif
 
+#define SD_MC_INIT SD_CPU_INIT
+
 #include <asm-generic/topology.h>
 
 #endif /* _ASM_S390_TOPOLOGY_H */
diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
index 397d131a345f..80641224a095 100644
--- a/arch/s390/kernel/mcount.S
+++ b/arch/s390/kernel/mcount.S
@@ -5,6 +5,8 @@
  *
  */
 
+#include <asm/asm-offsets.h>
+
 #ifndef CONFIG_64BIT
 .globl _mcount
 _mcount:
@@ -14,7 +16,7 @@ _mcount:
         ahi     %r15,-96
         l       %r3,100(%r15)
         la      %r2,0(%r14)
-        st      %r1,0(%r15)
+        st      %r1,__SF_BACKCHAIN(%r15)
         la      %r3,0(%r3)
         bras    %r14,0f
         .long   ftrace_trace_function
@@ -38,7 +40,7 @@ _mcount:
         stg     %r14,112(%r15)
         lgr     %r1,%r15
         aghi    %r15,-160
-        stg     %r1,0(%r15)
+        stg     %r1,__SF_BACKCHAIN(%r15)
         lgr     %r2,%r14
         lg      %r3,168(%r15)
         larl    %r14,ftrace_trace_function
diff --git a/arch/s390/lib/div64.c b/arch/s390/lib/div64.c
index a5f8300bf3ee..d9e62c0b576a 100644
--- a/arch/s390/lib/div64.c
+++ b/arch/s390/lib/div64.c
@@ -61,7 +61,7 @@ static uint32_t __div64_31(uint64_t *n, uint32_t base)
                 "       clr     %0,%3\n"
                 "       jl      0f\n"
                 "       slr     %0,%3\n"
-                "       alr     %1,%2\n"
+                "       ahi     %1,1\n"
                 "0:\n"
                 : "+d" (reg2), "+d" (reg3), "=d" (tmp)
                 : "d" (base), "2" (1UL) : "cc" );
diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
index d66215b0fde9..b0b84c35b0ad 100644
--- a/arch/s390/lib/uaccess_pt.c
+++ b/arch/s390/lib/uaccess_pt.c
@@ -119,8 +119,6 @@ retry:
                         goto fault;
 
                 pfn = pte_pfn(*pte);
-                if (!pfn_valid(pfn))
-                        goto out;
 
                 offset = uaddr & (PAGE_SIZE - 1);
                 size = min(n - done, PAGE_SIZE - offset);
@@ -135,7 +133,6 @@ retry:
                 done += size;
                 uaddr += size;
         } while (done < n);
-out:
         spin_unlock(&mm->page_table_lock);
         return n - done;
 fault:
@@ -163,9 +160,6 @@ retry:
                 goto fault;
 
         pfn = pte_pfn(*pte);
-        if (!pfn_valid(pfn))
-                goto out;
-
         ret = (pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE - 1));
 out:
         return ret;
@@ -244,11 +238,6 @@ retry:
                         goto fault;
 
                 pfn = pte_pfn(*pte);
-                if (!pfn_valid(pfn)) {
-                        done = -1;
-                        goto out;
-                }
-
                 offset = uaddr & (PAGE_SIZE-1);
                 addr = (char *)(pfn << PAGE_SHIFT) + offset;
                 len = min(count - done, PAGE_SIZE - offset);
@@ -256,7 +245,6 @@ retry:
                 done += len_str;
                 uaddr += len_str;
         } while ((len_str == len) && (done < count));
-out:
         spin_unlock(&mm->page_table_lock);
         return done + 1;
 fault:
@@ -325,12 +313,7 @@ retry:
                 }
 
                 pfn_from = pte_pfn(*pte_from);
-                if (!pfn_valid(pfn_from))
-                        goto out;
                 pfn_to = pte_pfn(*pte_to);
-                if (!pfn_valid(pfn_to))
-                        goto out;
-
                 offset_from = uaddr_from & (PAGE_SIZE-1);
                 offset_to = uaddr_from & (PAGE_SIZE-1);
                 offset_max = max(offset_from, offset_to);
@@ -342,7 +325,6 @@ retry:
                 uaddr_from += size;
                 uaddr_to += size;
         } while (done < n);
-out:
         spin_unlock(&mm->page_table_lock);
         return n - done;
 fault:
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index 5932a824547a..e008d236cc15 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -35,7 +35,7 @@
  * Leave an at least ~128 MB hole.
  */
 #define MIN_GAP (128*1024*1024)
-#define MAX_GAP (TASK_SIZE/6*5)
+#define MAX_GAP (STACK_TOP/6*5)
 
 static inline unsigned long mmap_base(void)
 {
@@ -46,7 +46,7 @@ static inline unsigned long mmap_base(void)
         else if (gap > MAX_GAP)
                 gap = MAX_GAP;
 
-        return TASK_SIZE - (gap & PAGE_MASK);
+        return STACK_TOP - (gap & PAGE_MASK);
 }
 
 static inline int mmap_is_legacy(void)
@@ -89,42 +89,58 @@ EXPORT_SYMBOL_GPL(arch_pick_mmap_layout);
 
 #else
 
+int s390_mmap_check(unsigned long addr, unsigned long len)
+{
+        if (!test_thread_flag(TIF_31BIT) &&
+            len >= TASK_SIZE && TASK_SIZE < (1UL << 53))
+                return crst_table_upgrade(current->mm, 1UL << 53);
+        return 0;
+}
+
 static unsigned long
 s390_get_unmapped_area(struct file *filp, unsigned long addr,
                 unsigned long len, unsigned long pgoff, unsigned long flags)
 {
         struct mm_struct *mm = current->mm;
+        unsigned long area;
         int rc;
 
-        addr = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
-        if (addr & ~PAGE_MASK)
-                return addr;
-        if (unlikely(mm->context.asce_limit < addr + len)) {
-                rc = crst_table_upgrade(mm, addr + len);
+        area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
+        if (!(area & ~PAGE_MASK))
+                return area;
+        if (area == -ENOMEM &&
+            !test_thread_flag(TIF_31BIT) && TASK_SIZE < (1UL << 53)) {
+                /* Upgrade the page table to 4 levels and retry. */
+                rc = crst_table_upgrade(mm, 1UL << 53);
                 if (rc)
                         return (unsigned long) rc;
+                area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
         }
-        return addr;
+        return area;
 }
 
 static unsigned long
-s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
+s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr,
                           const unsigned long len, const unsigned long pgoff,
                           const unsigned long flags)
 {
         struct mm_struct *mm = current->mm;
-        unsigned long addr = addr0;
+        unsigned long area;
         int rc;
 
-        addr = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
-        if (addr & ~PAGE_MASK)
-                return addr;
-        if (unlikely(mm->context.asce_limit < addr + len)) {
-                rc = crst_table_upgrade(mm, addr + len);
+        area = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
+        if (!(area & ~PAGE_MASK))
+                return area;
+        if (area == -ENOMEM &&
+            !test_thread_flag(TIF_31BIT) && TASK_SIZE < (1UL << 53)) {
+                /* Upgrade the page table to 4 levels and retry. */
+                rc = crst_table_upgrade(mm, 1UL << 53);
                 if (rc)
                         return (unsigned long) rc;
+                area = arch_get_unmapped_area_topdown(filp, addr, len,
+                                                      pgoff, flags);
         }
-        return addr;
+        return area;
 }
 /*
  * This function, called very early during the creation of a new
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 0767827540b1..6b6ddc4ea02b 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -117,6 +117,7 @@ repeat:
                 crst_table_init(table, entry);
                 pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd);
                 mm->pgd = (pgd_t *) table;
+                mm->task_size = mm->context.asce_limit;
                 table = NULL;
         }
         spin_unlock(&mm->page_table_lock);
@@ -154,6 +155,7 @@ void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
                         BUG();
                 }
                 mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
+                mm->task_size = mm->context.asce_limit;
                 crst_table_free(mm, (unsigned long *) pgd);
         }
         update_mm(mm, current);