5 files changed, 68 insertions, 53 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 4f289ff..011358c 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -128,28 +128,11 @@ static inline int is_zero_pfn(unsigned long pfn)
  * effect, this also makes sure that 64 bit module code cannot be used
  * as system call address.
  */
-
 extern unsigned long VMALLOC_START;
+extern unsigned long VMALLOC_END;
+extern struct page *vmemmap;
 
-#ifndef __s390x__
-#define VMALLOC_SIZE	(96UL << 20)
-#define VMALLOC_END	0x7e000000UL
-#define VMEM_MAP_END	0x80000000UL
-#else /* __s390x__ */
-#define VMALLOC_SIZE	(128UL << 30)
-#define VMALLOC_END	0x3e000000000UL
-#define VMEM_MAP_END	0x40000000000UL
-#endif /* __s390x__ */
-
-/*
- * VMEM_MAX_PHYS is the highest physical address that can be added to the 1:1
- * mapping. This needs to be calculated at compile time since the size of the
- * VMEM_MAP is static but the size of struct page can change.
- */
-#define VMEM_MAX_PAGES	((VMEM_MAP_END - VMALLOC_END) / sizeof(struct page))
-#define VMEM_MAX_PFN	min(VMALLOC_START >> PAGE_SHIFT, VMEM_MAX_PAGES)
-#define VMEM_MAX_PHYS	((VMEM_MAX_PFN << PAGE_SHIFT) & ~((16 << 20) - 1))
-#define vmemmap		((struct page *) VMALLOC_END)
+#define VMEM_MAX_PHYS ((unsigned long) vmemmap)
 
 /*
  * A 31 bit pagetable entry of S390 has following format:
diff --git a/arch/s390/include/asm/sparsemem.h b/arch/s390/include/asm/sparsemem.h
index 545d219..0fb3402 100644
--- a/arch/s390/include/asm/sparsemem.h
+++ b/arch/s390/include/asm/sparsemem.h
@@ -4,8 +4,8 @@
 #ifdef CONFIG_64BIT
 
 #define SECTION_SIZE_BITS	28
-#define MAX_PHYSADDR_BITS	42
-#define MAX_PHYSMEM_BITS	42
+#define MAX_PHYSADDR_BITS	46
+#define MAX_PHYSMEM_BITS	46
 
 #else
 
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 26b601c..66903ee 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -94,6 +94,15 @@ struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];
 int __initdata memory_end_set;
 unsigned long __initdata memory_end;
 
+unsigned long VMALLOC_START;
+EXPORT_SYMBOL(VMALLOC_START);
+
+unsigned long VMALLOC_END;
+EXPORT_SYMBOL(VMALLOC_END);
+
+struct page *vmemmap;
+EXPORT_SYMBOL(vmemmap);
+
 /* An array with a pointer to the lowcore of every CPU. */
 struct _lowcore *lowcore_ptr[NR_CPUS];
 EXPORT_SYMBOL(lowcore_ptr);
@@ -277,6 +286,15 @@ static int __init early_parse_mem(char *p)
 }
 early_param("mem", early_parse_mem);
 
+static int __init parse_vmalloc(char *arg)
+{
+	if (!arg)
+		return -EINVAL;
+	VMALLOC_END = (memparse(arg, &arg) + PAGE_SIZE - 1) & PAGE_MASK;
+	return 0;
+}
+early_param("vmalloc", parse_vmalloc);
+
 unsigned int user_mode = HOME_SPACE_MODE;
 EXPORT_SYMBOL_GPL(user_mode);
 
@@ -478,8 +496,7 @@ EXPORT_SYMBOL_GPL(real_memory_size);
 
 static void __init setup_memory_end(void)
 {
-	unsigned long memory_size;
-	unsigned long max_mem;
+	unsigned long vmax, vmalloc_size, tmp;
 	int i;
 
 
@@ -489,12 +506,9 @@ static void __init setup_memory_end(void)
 		memory_end_set = 1;
 	}
 #endif
-	memory_size = 0;
+	real_memory_size = 0;
 	memory_end &= PAGE_MASK;
 
-	max_mem = memory_end ? min(VMEM_MAX_PHYS, memory_end) : VMEM_MAX_PHYS;
-	memory_end = min(max_mem, memory_end);
-
 	/*
 	 * Make sure all chunks are MAX_ORDER aligned so we don't need the
 	 * extra checks that HOLES_IN_ZONE would require.
@@ -514,23 +528,48 @@ static void __init setup_memory_end(void)
 			chunk->addr = start;
 			chunk->size = end - start;
 		}
+		real_memory_size = max(real_memory_size,
+				       chunk->addr + chunk->size);
 	}
 
+	/* Choose kernel address space layout: 2, 3, or 4 levels. */
+#ifdef CONFIG_64BIT
+	vmalloc_size = VMALLOC_END ?: 128UL << 30;
+	tmp = (memory_end ?: real_memory_size) / PAGE_SIZE;
+	tmp = tmp * (sizeof(struct page) + PAGE_SIZE) + vmalloc_size;
+	if (tmp <= (1UL << 42))
+		vmax = 1UL << 42;	/* 3-level kernel page table */
+	else
+		vmax = 1UL << 53;	/* 4-level kernel page table */
+#else
+	vmalloc_size = VMALLOC_END ?: 96UL << 20;
+	vmax = 1UL << 31;		/* 2-level kernel page table */
+#endif
+	/* vmalloc area is at the end of the kernel address space. */
+	VMALLOC_END = vmax;
+	VMALLOC_START = vmax - vmalloc_size;
+
+	/* Split remaining virtual space between 1:1 mapping & vmemmap array */
+	tmp = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
+	tmp = VMALLOC_START - tmp * sizeof(struct page);
+	tmp &= ~((vmax >> 11) - 1);	/* align to page table level */
+	tmp = min(tmp, 1UL << MAX_PHYSMEM_BITS);
+	vmemmap = (struct page *) tmp;
+
+	/* Take care that memory_end is set and <= vmemmap */
+	memory_end = min(memory_end ?: real_memory_size, tmp);
+
+	/* Fixup memory chunk array to fit into 0..memory_end */
 	for (i = 0; i < MEMORY_CHUNKS; i++) {
 		struct mem_chunk *chunk = &memory_chunk[i];
 
-		real_memory_size = max(real_memory_size,
-				       chunk->addr + chunk->size);
-		if (chunk->addr >= max_mem) {
+		if (chunk->addr >= memory_end) {
 			memset(chunk, 0, sizeof(*chunk));
 			continue;
 		}
-		if (chunk->addr + chunk->size > max_mem)
-			chunk->size = max_mem - chunk->addr;
-		memory_size = max(memory_size, chunk->addr + chunk->size);
+		if (chunk->addr + chunk->size > memory_end)
+			chunk->size = memory_end - chunk->addr;
 	}
-	if (!memory_end)
-		memory_end = memory_size;
 }
 
 void *restart_stack __attribute__((__section__(".data")));
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index d4b9fb4..5d63301 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -93,18 +93,22 @@ static unsigned long setup_zero_pages(void)
 void __init paging_init(void)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES];
-	unsigned long pgd_type;
+	unsigned long pgd_type, asce_bits;
 
 	init_mm.pgd = swapper_pg_dir;
-	S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
 #ifdef CONFIG_64BIT
-	/* A three level page table (4TB) is enough for the kernel space. */
-	S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
-	pgd_type = _REGION3_ENTRY_EMPTY;
+	if (VMALLOC_END > (1UL << 42)) {
+		asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
+		pgd_type = _REGION2_ENTRY_EMPTY;
+	} else {
+		asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
+		pgd_type = _REGION3_ENTRY_EMPTY;
+	}
 #else
-	S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
+	asce_bits = _ASCE_TABLE_LENGTH;
 	pgd_type = _SEGMENT_ENTRY_EMPTY;
 #endif
+	S390_lowcore.kernel_asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
 	clear_table((unsigned long *) init_mm.pgd, pgd_type,
 		    sizeof(unsigned long)*2048);
 	vmem_map_init();
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index dc2269f..9a4d02f 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -33,17 +33,6 @@
 #define FRAG_MASK	0x03
 #endif
 
-unsigned long VMALLOC_START = VMALLOC_END - VMALLOC_SIZE;
-EXPORT_SYMBOL(VMALLOC_START);
-
-static int __init parse_vmalloc(char *arg)
-{
-	if (!arg)
-		return -EINVAL;
-	VMALLOC_START = (VMALLOC_END - memparse(arg, &arg)) & PAGE_MASK;
-	return 0;
-}
-early_param("vmalloc", parse_vmalloc);
 
 unsigned long *crst_table_alloc(struct mm_struct *mm)
 {