1 files changed, 23 insertions, 7 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 979fe3dc0788..dd647c919a66 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -119,13 +119,12 @@ static inline int is_zero_pfn(unsigned long pfn)
 
 #ifndef __ASSEMBLY__
 /*
- * The vmalloc area will always be on the topmost area of the kernel
- * mapping. We reserve 96MB (31bit) / 128GB (64bit) for vmalloc,
- * which should be enough for any sane case.
- * By putting vmalloc at the top, we maximise the gap between physical
- * memory and vmalloc to catch misplaced memory accesses. As a side
- * effect, this also makes sure that 64 bit module code cannot be used
- * as system call address.
+ * The vmalloc and module area will always be on the topmost area of the kernel
+ * mapping. We reserve 96MB (31bit) / 128GB (64bit) for vmalloc and modules.
+ * On 64 bit kernels we have a 2GB area at the top of the vmalloc area where
+ * modules will reside. That makes sure that inter module branches always
+ * happen without trampolines and in addition the placement within a 2GB frame
+ * is branch prediction unit friendly.
  */
 extern unsigned long VMALLOC_START;
 extern unsigned long VMALLOC_END;
@@ -133,6 +132,14 @@ extern struct page *vmemmap;
 
 #define VMEM_MAX_PHYS ((unsigned long) vmemmap)
 
+#ifdef CONFIG_64BIT
+extern unsigned long MODULES_VADDR;
+extern unsigned long MODULES_END;
+#define MODULES_VADDR   MODULES_VADDR
+#define MODULES_END     MODULES_END
+#define MODULES_LEN     (1UL << 31)
+#endif
+
 /*
  * A 31 bit pagetable entry of S390 has following format:
  *  |   PFRA          |    |  OS  |
@@ -507,6 +514,15 @@ static inline int pmd_none(pmd_t pmd)
         return (pmd_val(pmd) & _SEGMENT_ENTRY_INV) != 0UL;
 }
 
+static inline int pmd_large(pmd_t pmd)
+{
+#ifdef CONFIG_64BIT
+        return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE);
+#else
+        return 0;
+#endif
+}
+
 static inline int pmd_bad(pmd_t pmd)
 {
         unsigned long mask = ~_SEGMENT_ENTRY_ORIGIN & ~_SEGMENT_ENTRY_INV;