Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

10 files changed, 3144 insertions, 0 deletions

diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile
new file mode 100644
index 0000000..2a74581
--- /dev/null
+++ b/arch/s390/mm/Makefile
@@ -0,0 +1,8 @@
+#
+# Makefile for the linux s390-specific parts of the memory manager.
+#
+
+obj-y	 := init.o fault.o extmem.o mmap.o vmem.o pgtable.o
+obj-$(CONFIG_CMM) += cmm.o
+obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
+obj-$(CONFIG_PAGE_STATES) += page-states.o
diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
new file mode 100644
index 0000000..413c240
--- /dev/null
+++ b/arch/s390/mm/cmm.c
@@ -0,0 +1,479 @@
+/*
+ *  arch/s390/mm/cmm.c
+ *
+ *  S390 version
+ *    Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ *  Collaborative memory management interface.
+ */
+
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sysctl.h>
+#include <linux/ctype.h>
+#include <linux/swap.h>
+#include <linux/kthread.h>
+#include <linux/oom.h>
+
+#include <asm/pgalloc.h>
+#include <asm/uaccess.h>
+#include <asm/diag.h>
+
+static char *sender = "VMRMSVM";
+module_param(sender, charp, 0400);
+MODULE_PARM_DESC(sender,
+		 "Guest name that may send SMSG messages (default VMRMSVM)");
+
+#include "../../../drivers/s390/net/smsgiucv.h"
+
+#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
+
+struct cmm_page_array {
+	struct cmm_page_array *next;
+	unsigned long index;
+	unsigned long pages[CMM_NR_PAGES];
+};
+
+static long cmm_pages;
+static long cmm_timed_pages;
+static volatile long cmm_pages_target;
+static volatile long cmm_timed_pages_target;
+static long cmm_timeout_pages;
+static long cmm_timeout_seconds;
+
+static struct cmm_page_array *cmm_page_list;
+static struct cmm_page_array *cmm_timed_page_list;
+static DEFINE_SPINLOCK(cmm_lock);
+
+static struct task_struct *cmm_thread_ptr;
+static wait_queue_head_t cmm_thread_wait;
+static struct timer_list cmm_timer;
+
+static void cmm_timer_fn(unsigned long);
+static void cmm_set_timer(void);
+
+static long
+cmm_alloc_pages(long nr, long *counter, struct cmm_page_array **list)
+{
+	struct cmm_page_array *pa, *npa;
+	unsigned long addr;
+
+	while (nr) {
+		addr = __get_free_page(GFP_NOIO);
+		if (!addr)
+			break;
+		spin_lock(&cmm_lock);
+		pa = *list;
+		if (!pa || pa->index >= CMM_NR_PAGES) {
+			/* Need a new page for the page list. */
+			spin_unlock(&cmm_lock);
+			npa = (struct cmm_page_array *)
+				__get_free_page(GFP_NOIO);
+			if (!npa) {
+				free_page(addr);
+				break;
+			}
+			spin_lock(&cmm_lock);
+			pa = *list;
+			if (!pa || pa->index >= CMM_NR_PAGES) {
+				npa->next = pa;
+				npa->index = 0;
+				pa = npa;
+				*list = pa;
+			} else
+				free_page((unsigned long) npa);
+		}
+		diag10(addr);
+		pa->pages[pa->index++] = addr;
+		(*counter)++;
+		spin_unlock(&cmm_lock);
+		nr--;
+	}
+	return nr;
+}
+
+static long
+cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
+{
+	struct cmm_page_array *pa;
+	unsigned long addr;
+
+	spin_lock(&cmm_lock);
+	pa = *list;
+	while (nr) {
+		if (!pa || pa->index <= 0)
+			break;
+		addr = pa->pages[--pa->index];
+		if (pa->index == 0) {
+			pa = pa->next;
+			free_page((unsigned long) *list);
+			*list = pa;
+		}
+		free_page(addr);
+		(*counter)--;
+		nr--;
+	}
+	spin_unlock(&cmm_lock);
+	return nr;
+}
+
+static int cmm_oom_notify(struct notifier_block *self,
+			  unsigned long dummy, void *parm)
+{
+	unsigned long *freed = parm;
+	long nr = 256;
+
+	nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
+	if (nr > 0)
+		nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list);
+	cmm_pages_target = cmm_pages;
+	cmm_timed_pages_target = cmm_timed_pages;
+	*freed += 256 - nr;
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cmm_oom_nb = {
+	.notifier_call = cmm_oom_notify
+};
+
+static int
+cmm_thread(void *dummy)
+{
+	int rc;
+
+	while (1) {
+		rc = wait_event_interruptible(cmm_thread_wait,
+			(cmm_pages != cmm_pages_target ||
+			 cmm_timed_pages != cmm_timed_pages_target ||
+			 kthread_should_stop()));
+		if (kthread_should_stop() || rc == -ERESTARTSYS) {
+			cmm_pages_target = cmm_pages;
+			cmm_timed_pages_target = cmm_timed_pages;
+			break;
+		}
+		if (cmm_pages_target > cmm_pages) {
+			if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
+				cmm_pages_target = cmm_pages;
+		} else if (cmm_pages_target < cmm_pages) {
+			cmm_free_pages(1, &cmm_pages, &cmm_page_list);
+		}
+		if (cmm_timed_pages_target > cmm_timed_pages) {
+			if (cmm_alloc_pages(1, &cmm_timed_pages,
+					   &cmm_timed_page_list))
+				cmm_timed_pages_target = cmm_timed_pages;
+		} else if (cmm_timed_pages_target < cmm_timed_pages) {
+			cmm_free_pages(1, &cmm_timed_pages,
+			       	       &cmm_timed_page_list);
+		}
+		if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
+			cmm_set_timer();
+	}
+	return 0;
+}
+
+static void
+cmm_kick_thread(void)
+{
+	wake_up(&cmm_thread_wait);
+}
+
+static void
+cmm_set_timer(void)
+{
+	if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
+		if (timer_pending(&cmm_timer))
+			del_timer(&cmm_timer);
+		return;
+	}
+	if (timer_pending(&cmm_timer)) {
+		if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
+			return;
+	}
+	cmm_timer.function = cmm_timer_fn;
+	cmm_timer.data = 0;
+	cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
+	add_timer(&cmm_timer);
+}
+
+static void
+cmm_timer_fn(unsigned long ignored)
+{
+	long nr;
+
+	nr = cmm_timed_pages_target - cmm_timeout_pages;
+	if (nr < 0)
+		cmm_timed_pages_target = 0;
+	else
+		cmm_timed_pages_target = nr;
+	cmm_kick_thread();
+	cmm_set_timer();
+}
+
+void
+cmm_set_pages(long nr)
+{
+	cmm_pages_target = nr;
+	cmm_kick_thread();
+}
+
+long
+cmm_get_pages(void)
+{
+	return cmm_pages;
+}
+
+void
+cmm_add_timed_pages(long nr)
+{
+	cmm_timed_pages_target += nr;
+	cmm_kick_thread();
+}
+
+long
+cmm_get_timed_pages(void)
+{
+	return cmm_timed_pages;
+}
+
+void
+cmm_set_timeout(long nr, long seconds)
+{
+	cmm_timeout_pages = nr;
+	cmm_timeout_seconds = seconds;
+	cmm_set_timer();
+}
+
+static int
+cmm_skip_blanks(char *cp, char **endp)
+{
+	char *str;
+
+	for (str = cp; *str == ' ' || *str == '\t'; str++);
+	*endp = str;
+	return str != cp;
+}
+
+#ifdef CONFIG_CMM_PROC
+
+static struct ctl_table cmm_table[];
+
+static int
+cmm_pages_handler(ctl_table *ctl, int write, struct file *filp,
+		  void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	char buf[16], *p;
+	long nr;
+	int len;
+
+	if (!*lenp || (*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
+
+	if (write) {
+		len = *lenp;
+		if (copy_from_user(buf, buffer,
+				   len > sizeof(buf) ? sizeof(buf) : len))
+			return -EFAULT;
+		buf[sizeof(buf) - 1] = '\0';
+		cmm_skip_blanks(buf, &p);
+		nr = simple_strtoul(p, &p, 0);
+		if (ctl == &cmm_table[0])
+			cmm_set_pages(nr);
+		else
+			cmm_add_timed_pages(nr);
+	} else {
+		if (ctl == &cmm_table[0])
+			nr = cmm_get_pages();
+		else
+			nr = cmm_get_timed_pages();
+		len = sprintf(buf, "%ld\n", nr);
+		if (len > *lenp)
+			len = *lenp;
+		if (copy_to_user(buffer, buf, len))
+			return -EFAULT;
+	}
+	*lenp = len;
+	*ppos += len;
+	return 0;
+}
+
+static int
+cmm_timeout_handler(ctl_table *ctl, int write, struct file *filp,
+		    void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	char buf[64], *p;
+	long nr, seconds;
+	int len;
+
+	if (!*lenp || (*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
+
+	if (write) {
+		len = *lenp;
+		if (copy_from_user(buf, buffer,
+				   len > sizeof(buf) ? sizeof(buf) : len))
+			return -EFAULT;
+		buf[sizeof(buf) - 1] = '\0';
+		cmm_skip_blanks(buf, &p);
+		nr = simple_strtoul(p, &p, 0);
+		cmm_skip_blanks(p, &p);
+		seconds = simple_strtoul(p, &p, 0);
+		cmm_set_timeout(nr, seconds);
+	} else {
+		len = sprintf(buf, "%ld %ld\n",
+			      cmm_timeout_pages, cmm_timeout_seconds);
+		if (len > *lenp)
+			len = *lenp;
+		if (copy_to_user(buffer, buf, len))
+			return -EFAULT;
+	}
+	*lenp = len;
+	*ppos += len;
+	return 0;
+}
+
+static struct ctl_table cmm_table[] = {
+	{
+		.procname	= "cmm_pages",
+		.mode		= 0644,
+		.proc_handler	= &cmm_pages_handler,
+	},
+	{
+		.procname	= "cmm_timed_pages",
+		.mode		= 0644,
+		.proc_handler	= &cmm_pages_handler,
+	},
+	{
+		.procname	= "cmm_timeout",
+		.mode		= 0644,
+		.proc_handler	= &cmm_timeout_handler,
+	},
+	{ .ctl_name = 0 }
+};
+
+static struct ctl_table cmm_dir_table[] = {
+	{
+		.ctl_name	= CTL_VM,
+		.procname	= "vm",
+		.maxlen		= 0,
+		.mode		= 0555,
+		.child		= cmm_table,
+	},
+	{ .ctl_name = 0 }
+};
+#endif
+
+#ifdef CONFIG_CMM_IUCV
+#define SMSG_PREFIX "CMM"
+static void
+cmm_smsg_target(char *from, char *msg)
+{
+	long nr, seconds;
+
+	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
+		return;
+	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
+		return;
+	if (strncmp(msg, "SHRINK", 6) == 0) {
+		if (!cmm_skip_blanks(msg + 6, &msg))
+			return;
+		nr = simple_strtoul(msg, &msg, 0);
+		cmm_skip_blanks(msg, &msg);
+		if (*msg == '\0')
+			cmm_set_pages(nr);
+	} else if (strncmp(msg, "RELEASE", 7) == 0) {
+		if (!cmm_skip_blanks(msg + 7, &msg))
+			return;
+		nr = simple_strtoul(msg, &msg, 0);
+		cmm_skip_blanks(msg, &msg);
+		if (*msg == '\0')
+			cmm_add_timed_pages(nr);
+	} else if (strncmp(msg, "REUSE", 5) == 0) {
+		if (!cmm_skip_blanks(msg + 5, &msg))
+			return;
+		nr = simple_strtoul(msg, &msg, 0);
+		if (!cmm_skip_blanks(msg, &msg))
+			return;
+		seconds = simple_strtoul(msg, &msg, 0);
+		cmm_skip_blanks(msg, &msg);
+		if (*msg == '\0')
+			cmm_set_timeout(nr, seconds);
+	}
+}
+#endif
+
+static struct ctl_table_header *cmm_sysctl_header;
+
+static int
+cmm_init (void)
+{
+	int rc = -ENOMEM;
+
+#ifdef CONFIG_CMM_PROC
+	cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
+	if (!cmm_sysctl_header)
+		goto out;
+#endif
+#ifdef CONFIG_CMM_IUCV
+	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
+	if (rc < 0)
+		goto out_smsg;
+#endif
+	rc = register_oom_notifier(&cmm_oom_nb);
+	if (rc < 0)
+		goto out_oom_notify;
+	init_waitqueue_head(&cmm_thread_wait);
+	init_timer(&cmm_timer);
+	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
+	rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
+	if (!rc)
+		goto out;
+	/*
+	 * kthread_create failed. undo all the stuff from above again.
+	 */
+	unregister_oom_notifier(&cmm_oom_nb);
+
+out_oom_notify:
+#ifdef CONFIG_CMM_IUCV
+	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
+out_smsg:
+#endif
+#ifdef CONFIG_CMM_PROC
+	unregister_sysctl_table(cmm_sysctl_header);
+#endif
+out:
+	return rc;
+}
+
+static void
+cmm_exit(void)
+{
+	kthread_stop(cmm_thread_ptr);
+	unregister_oom_notifier(&cmm_oom_nb);
+	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
+	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
+#ifdef CONFIG_CMM_PROC
+	unregister_sysctl_table(cmm_sysctl_header);
+#endif
+#ifdef CONFIG_CMM_IUCV
+	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
+#endif
+}
+
+module_init(cmm_init);
+module_exit(cmm_exit);
+
+EXPORT_SYMBOL(cmm_set_pages);
+EXPORT_SYMBOL(cmm_get_pages);
+EXPORT_SYMBOL(cmm_add_timed_pages);
+EXPORT_SYMBOL(cmm_get_timed_pages);
+EXPORT_SYMBOL(cmm_set_timeout);
+
+MODULE_LICENSE("GPL");
diff --git a/arch/s390/mm/extmem.c b/arch/s390/mm/extmem.c
new file mode 100644
index 0000000..580fc64
--- /dev/null
+++ b/arch/s390/mm/extmem.c
@@ -0,0 +1,799 @@
+/*
+ * File...........: arch/s390/mm/extmem.c
+ * Author(s)......: Carsten Otte <cotte@de.ibm.com>
+ * 		    Rob M van der Heij <rvdheij@nl.ibm.com>
+ * 		    Steven Shultz <shultzss@us.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * (C) IBM Corporation 2002-2004
+ */
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/bootmem.h>
+#include <linux/ctype.h>
+#include <linux/ioport.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/ebcdic.h>
+#include <asm/errno.h>
+#include <asm/extmem.h>
+#include <asm/cpcmd.h>
+#include <asm/setup.h>
+
+#define DCSS_DEBUG	/* Debug messages on/off */
+
+#define DCSS_NAME "extmem"
+#ifdef DCSS_DEBUG
+#define PRINT_DEBUG(x...)	printk(KERN_DEBUG DCSS_NAME " debug:" x)
+#else
+#define PRINT_DEBUG(x...)   do {} while (0)
+#endif
+#define PRINT_INFO(x...)	printk(KERN_INFO DCSS_NAME " info:" x)
+#define PRINT_WARN(x...)	printk(KERN_WARNING DCSS_NAME " warning:" x)
+#define PRINT_ERR(x...)		printk(KERN_ERR DCSS_NAME " error:" x)
+
+
+#define DCSS_LOADSHR    0x00
+#define DCSS_LOADNSR    0x04
+#define DCSS_PURGESEG   0x08
+#define DCSS_FINDSEG    0x0c
+#define DCSS_LOADNOLY   0x10
+#define DCSS_SEGEXT     0x18
+#define DCSS_LOADSHRX	0x20
+#define DCSS_LOADNSRX	0x24
+#define DCSS_FINDSEGX	0x2c
+#define DCSS_SEGEXTX	0x38
+#define DCSS_FINDSEGA   0x0c
+
+struct qrange {
+	unsigned long  start; /* last byte type */
+	unsigned long  end;   /* last byte reserved */
+};
+
+struct qout64 {
+	unsigned long segstart;
+	unsigned long segend;
+	int segcnt;
+	int segrcnt;
+	struct qrange range[6];
+};
+
+#ifdef CONFIG_64BIT
+struct qrange_old {
+	unsigned int start; /* last byte type */
+	unsigned int end;   /* last byte reserved */
+};
+
+/* output area format for the Diag x'64' old subcode x'18' */
+struct qout64_old {
+	int segstart;
+	int segend;
+	int segcnt;
+	int segrcnt;
+	struct qrange_old range[6];
+};
+#endif
+
+struct qin64 {
+	char qopcode;
+	char rsrv1[3];
+	char qrcode;
+	char rsrv2[3];
+	char qname[8];
+	unsigned int qoutptr;
+	short int qoutlen;
+};
+
+struct dcss_segment {
+	struct list_head list;
+	char dcss_name[8];
+	char res_name[15];
+	unsigned long start_addr;
+	unsigned long end;
+	atomic_t ref_count;
+	int do_nonshared;
+	unsigned int vm_segtype;
+	struct qrange range[6];
+	int segcnt;
+	struct resource *res;
+};
+
+static DEFINE_MUTEX(dcss_lock);
+static LIST_HEAD(dcss_list);
+static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
+					"EW/EN-MIXED" };
+static int loadshr_scode, loadnsr_scode, findseg_scode;
+static int segext_scode, purgeseg_scode;
+static int scode_set;
+
+/* set correct Diag x'64' subcodes. */
+static int
+dcss_set_subcodes(void)
+{
+#ifdef CONFIG_64BIT
+	char *name = kmalloc(8 * sizeof(char), GFP_DMA);
+	unsigned long rx, ry;
+	int rc;
+
+	if (name == NULL)
+		return -ENOMEM;
+
+	rx = (unsigned long) name;
+	ry = DCSS_FINDSEGX;
+
+	strcpy(name, "dummy");
+	asm volatile(
+		"	diag	%0,%1,0x64\n"
+		"0:	ipm	%2\n"
+		"	srl	%2,28\n"
+		"	j	2f\n"
+		"1:	la	%2,3\n"
+		"2:\n"
+		EX_TABLE(0b, 1b)
+		: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
+
+	kfree(name);
+	/* Diag x'64' new subcodes are supported, set to new subcodes */
+	if (rc != 3) {
+		loadshr_scode = DCSS_LOADSHRX;
+		loadnsr_scode = DCSS_LOADNSRX;
+		purgeseg_scode = DCSS_PURGESEG;
+		findseg_scode = DCSS_FINDSEGX;
+		segext_scode = DCSS_SEGEXTX;
+		return 0;
+	}
+#endif
+	/* Diag x'64' new subcodes are not supported, set to old subcodes */
+	loadshr_scode = DCSS_LOADNOLY;
+	loadnsr_scode = DCSS_LOADNSR;
+	purgeseg_scode = DCSS_PURGESEG;
+	findseg_scode = DCSS_FINDSEG;
+	segext_scode = DCSS_SEGEXT;
+	return 0;
+}
+
+/*
+ * Create the 8 bytes, ebcdic VM segment name from
+ * an ascii name.
+ */
+static void
+dcss_mkname(char *name, char *dcss_name)
+{
+	int i;
+
+	for (i = 0; i < 8; i++) {
+		if (name[i] == '\0')
+			break;
+		dcss_name[i] = toupper(name[i]);
+	};
+	for (; i < 8; i++)
+		dcss_name[i] = ' ';
+	ASCEBC(dcss_name, 8);
+}
+
+
+/*
+ * search all segments in dcss_list, and return the one
+ * namend *name. If not found, return NULL.
+ */
+static struct dcss_segment *
+segment_by_name (char *name)
+{
+	char dcss_name[9];
+	struct list_head *l;
+	struct dcss_segment *tmp, *retval = NULL;
+
+	BUG_ON(!mutex_is_locked(&dcss_lock));
+	dcss_mkname (name, dcss_name);
+	list_for_each (l, &dcss_list) {
+		tmp = list_entry (l, struct dcss_segment, list);
+		if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
+			retval = tmp;
+			break;
+		}
+	}
+	return retval;
+}
+
+
+/*
+ * Perform a function on a dcss segment.
+ */
+static inline int
+dcss_diag(int *func, void *parameter,
+           unsigned long *ret1, unsigned long *ret2)
+{
+	unsigned long rx, ry;
+	int rc;
+
+	if (scode_set == 0) {
+		rc = dcss_set_subcodes();
+		if (rc < 0)
+			return rc;
+		scode_set = 1;
+	}
+	rx = (unsigned long) parameter;
+	ry = (unsigned long) *func;
+
+#ifdef CONFIG_64BIT
+	/* 64-bit Diag x'64' new subcode, keep in 64-bit addressing mode */
+	if (*func > DCSS_SEGEXT)
+		asm volatile(
+			"	diag	%0,%1,0x64\n"
+			"	ipm	%2\n"
+			"	srl	%2,28\n"
+			: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
+	/* 31-bit Diag x'64' old subcode, switch to 31-bit addressing mode */
+	else
+		asm volatile(
+			"	sam31\n"
+			"	diag	%0,%1,0x64\n"
+			"	sam64\n"
+			"	ipm	%2\n"
+			"	srl	%2,28\n"
+			: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
+#else
+	asm volatile(
+		"	diag	%0,%1,0x64\n"
+		"	ipm	%2\n"
+		"	srl	%2,28\n"
+		: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
+#endif
+	*ret1 = rx;
+	*ret2 = ry;
+	return rc;
+}
+
+static inline int
+dcss_diag_translate_rc (int vm_rc) {
+	if (vm_rc == 44)
+		return -ENOENT;
+	return -EIO;
+}
+
+
+/* do a diag to get info about a segment.
+ * fills start_address, end and vm_segtype fields
+ */
+static int
+query_segment_type (struct dcss_segment *seg)
+{
+	struct qin64  *qin = kmalloc (sizeof(struct qin64), GFP_DMA);
+	struct qout64 *qout = kmalloc (sizeof(struct qout64), GFP_DMA);
+
+	int diag_cc, rc, i;
+	unsigned long dummy, vmrc;
+
+	if ((qin == NULL) || (qout == NULL)) {
+		rc = -ENOMEM;
+		goto out_free;
+	}
+
+	/* initialize diag input parameters */
+	qin->qopcode = DCSS_FINDSEGA;
+	qin->qoutptr = (unsigned long) qout;
+	qin->qoutlen = sizeof(struct qout64);
+	memcpy (qin->qname, seg->dcss_name, 8);
+
+	diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);
+
+	if (diag_cc < 0) {
+		rc = diag_cc;
+		goto out_free;
+	}
+	if (diag_cc > 1) {
+		PRINT_WARN ("segment_type: diag returned error %ld\n", vmrc);
+		rc = dcss_diag_translate_rc (vmrc);
+		goto out_free;
+	}
+
+#ifdef CONFIG_64BIT
+	/* Only old format of output area of Diagnose x'64' is supported,
+	   copy data for the new format. */
+	if (segext_scode == DCSS_SEGEXT) {
+		struct qout64_old *qout_old;
+		qout_old = kzalloc(sizeof(struct qout64_old), GFP_DMA);
+		if (qout_old == NULL) {
+			rc = -ENOMEM;
+			goto out_free;
+		}
+		memcpy(qout_old, qout, sizeof(struct qout64_old));
+		qout->segstart = (unsigned long) qout_old->segstart;
+		qout->segend = (unsigned long) qout_old->segend;
+		qout->segcnt = qout_old->segcnt;
+		qout->segrcnt = qout_old->segrcnt;
+
+		if (qout->segcnt > 6)
+			qout->segrcnt = 6;
+		for (i = 0; i < qout->segrcnt; i++) {
+			qout->range[i].start =
+				(unsigned long) qout_old->range[i].start;
+			qout->range[i].end =
+				(unsigned long) qout_old->range[i].end;
+		}
+		kfree(qout_old);
+	}
+#endif
+	if (qout->segcnt > 6) {
+		rc = -ENOTSUPP;
+		goto out_free;
+	}
+
+	if (qout->segcnt == 1) {
+		seg->vm_segtype = qout->range[0].start & 0xff;
+	} else {
+		/* multi-part segment. only one type supported here:
+		    - all parts are contiguous
+		    - all parts are either EW or EN type
+		    - maximum 6 parts allowed */
+		unsigned long start = qout->segstart >> PAGE_SHIFT;
+		for (i=0; i<qout->segcnt; i++) {
+			if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
+			    ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
+				rc = -ENOTSUPP;
+				goto out_free;
+			}
+			if (start != qout->range[i].start >> PAGE_SHIFT) {
+				rc = -ENOTSUPP;
+				goto out_free;
+			}
+			start = (qout->range[i].end >> PAGE_SHIFT) + 1;
+		}
+		seg->vm_segtype = SEG_TYPE_EWEN;
+	}
+
+	/* analyze diag output and update seg */
+	seg->start_addr = qout->segstart;
+	seg->end = qout->segend;
+
+	memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
+	seg->segcnt = qout->segcnt;
+
+	rc = 0;
+
+ out_free:
+	kfree(qin);
+	kfree(qout);
+	return rc;
+}
+
+/*
+ * get info about a segment
+ * possible return values:
+ * -ENOSYS  : we are not running on VM
+ * -EIO     : could not perform query diagnose
+ * -ENOENT  : no such segment
+ * -ENOTSUPP: multi-part segment cannot be used with linux
+ * -ENOSPC  : segment cannot be used (overlaps with storage)
+ * -ENOMEM  : out of memory
+ * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
+ */
+int
+segment_type (char* name)
+{
+	int rc;
+	struct dcss_segment seg;
+
+	if (!MACHINE_IS_VM)
+		return -ENOSYS;
+
+	dcss_mkname(name, seg.dcss_name);
+	rc = query_segment_type (&seg);
+	if (rc < 0)
+		return rc;
+	return seg.vm_segtype;
+}
+
+/*
+ * check if segment collides with other segments that are currently loaded
+ * returns 1 if this is the case, 0 if no collision was found
+ */
+static int
+segment_overlaps_others (struct dcss_segment *seg)
+{
+	struct list_head *l;
+	struct dcss_segment *tmp;
+
+	BUG_ON(!mutex_is_locked(&dcss_lock));
+	list_for_each(l, &dcss_list) {
+		tmp = list_entry(l, struct dcss_segment, list);
+		if ((tmp->start_addr >> 20) > (seg->end >> 20))
+			continue;
+		if ((tmp->end >> 20) < (seg->start_addr >> 20))
+			continue;
+		if (seg == tmp)
+			continue;
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * real segment loading function, called from segment_load
+ */
+static int
+__segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
+{
+	struct dcss_segment *seg = kmalloc(sizeof(struct dcss_segment),
+			GFP_DMA);
+	int rc, diag_cc;
+	unsigned long start_addr, end_addr, dummy;
+
+	if (seg == NULL) {
+		rc = -ENOMEM;
+		goto out;
+	}
+	dcss_mkname (name, seg->dcss_name);
+	rc = query_segment_type (seg);
+	if (rc < 0)
+		goto out_free;
+
+	if (loadshr_scode == DCSS_LOADSHRX) {
+		if (segment_overlaps_others(seg)) {
+			rc = -EBUSY;
+			goto out_free;
+		}
+	}
+
+	rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
+
+	if (rc)
+		goto out_free;
+
+	seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
+	if (seg->res == NULL) {
+		rc = -ENOMEM;
+		goto out_shared;
+	}
+	seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
+	seg->res->start = seg->start_addr;
+	seg->res->end = seg->end;
+	memcpy(&seg->res_name, seg->dcss_name, 8);
+	EBCASC(seg->res_name, 8);
+	seg->res_name[8] = '\0';
+	strncat(seg->res_name, " (DCSS)", 7);
+	seg->res->name = seg->res_name;
+	rc = seg->vm_segtype;
+	if (rc == SEG_TYPE_SC ||
+	    ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared))
+		seg->res->flags |= IORESOURCE_READONLY;
+	if (request_resource(&iomem_resource, seg->res)) {
+		rc = -EBUSY;
+		kfree(seg->res);
+		goto out_shared;
+	}
+
+	if (do_nonshared)
+		diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
+				&start_addr, &end_addr);
+	else
+		diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
+				&start_addr, &end_addr);
+	if (diag_cc < 0) {
+		dcss_diag(&purgeseg_scode, seg->dcss_name,
+				&dummy, &dummy);
+		rc = diag_cc;
+		goto out_resource;
+	}
+	if (diag_cc > 1) {
+		PRINT_WARN ("segment_load: could not load segment %s - "
+				"diag returned error (%ld)\n",
+				name, end_addr);
+		rc = dcss_diag_translate_rc(end_addr);
+		dcss_diag(&purgeseg_scode, seg->dcss_name,
+				&dummy, &dummy);
+		goto out_resource;
+	}
+	seg->start_addr = start_addr;
+	seg->end = end_addr;
+	seg->do_nonshared = do_nonshared;
+	atomic_set(&seg->ref_count, 1);
+	list_add(&seg->list, &dcss_list);
+	*addr = seg->start_addr;
+	*end  = seg->end;
+	if (do_nonshared)
+		PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
+				"type %s in non-shared mode\n", name,
+				(void*)seg->start_addr, (void*)seg->end,
+				segtype_string[seg->vm_segtype]);
+	else {
+		PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
+				"type %s in shared mode\n", name,
+				(void*)seg->start_addr, (void*)seg->end,
+				segtype_string[seg->vm_segtype]);
+	}
+	goto out;
+ out_resource:
+	release_resource(seg->res);
+	kfree(seg->res);
+ out_shared:
+	vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
+ out_free:
+	kfree(seg);
+ out:
+	return rc;
+}
+
+/*
+ * this function loads a DCSS segment
+ * name         : name of the DCSS
+ * do_nonshared : 0 indicates that the dcss should be shared with other linux images
+ *                1 indicates that the dcss should be exclusive for this linux image
+ * addr         : will be filled with start address of the segment
+ * end          : will be filled with end address of the segment
+ * return values:
+ * -ENOSYS  : we are not running on VM
+ * -EIO     : could not perform query or load diagnose
+ * -ENOENT  : no such segment
+ * -ENOTSUPP: multi-part segment cannot be used with linux
+ * -ENOSPC  : segment cannot be used (overlaps with storage)
+ * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
+ * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
+ * -EPERM   : segment is currently loaded with incompatible permissions
+ * -ENOMEM  : out of memory
+ * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
+ */
+int
+segment_load (char *name, int do_nonshared, unsigned long *addr,
+		unsigned long *end)
+{
+	struct dcss_segment *seg;
+	int rc;
+
+	if (!MACHINE_IS_VM)
+		return -ENOSYS;
+
+	mutex_lock(&dcss_lock);
+	seg = segment_by_name (name);
+	if (seg == NULL)
+		rc = __segment_load (name, do_nonshared, addr, end);
+	else {
+		if (do_nonshared == seg->do_nonshared) {
+			atomic_inc(&seg->ref_count);
+			*addr = seg->start_addr;
+			*end  = seg->end;
+			rc    = seg->vm_segtype;
+		} else {
+			*addr = *end = 0;
+			rc    = -EPERM;
+		}
+	}
+	mutex_unlock(&dcss_lock);
+	return rc;
+}
+
+/*
+ * this function modifies the shared state of a DCSS segment. note that
+ * name         : name of the DCSS
+ * do_nonshared : 0 indicates that the dcss should be shared with other linux images
+ *                1 indicates that the dcss should be exclusive for this linux image
+ * return values:
+ * -EIO     : could not perform load diagnose (segment gone!)
+ * -ENOENT  : no such segment (segment gone!)
+ * -EAGAIN  : segment is in use by other exploiters, try later
+ * -EINVAL  : no segment with the given name is currently loaded - name invalid
+ * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
+ * 0	    : operation succeeded
+ */
+int
+segment_modify_shared (char *name, int do_nonshared)
+{
+	struct dcss_segment *seg;
+	unsigned long start_addr, end_addr, dummy;
+	int rc, diag_cc;
+
+	mutex_lock(&dcss_lock);
+	seg = segment_by_name (name);
+	if (seg == NULL) {
+		rc = -EINVAL;
+		goto out_unlock;
+	}
+	if (do_nonshared == seg->do_nonshared) {
+		PRINT_INFO ("segment_modify_shared: not reloading segment %s"
+				" - already in requested mode\n",name);
+		rc = 0;
+		goto out_unlock;
+	}
+	if (atomic_read (&seg->ref_count) != 1) {
+		PRINT_WARN ("segment_modify_shared: not reloading segment %s - "
+				"segment is in use by other driver(s)\n",name);
+		rc = -EAGAIN;
+		goto out_unlock;
+	}
+	release_resource(seg->res);
+	if (do_nonshared)
+		seg->res->flags &= ~IORESOURCE_READONLY;
+	else
+		if (seg->vm_segtype == SEG_TYPE_SR ||
+		    seg->vm_segtype == SEG_TYPE_ER)
+			seg->res->flags |= IORESOURCE_READONLY;
+
+	if (request_resource(&iomem_resource, seg->res)) {
+		PRINT_WARN("segment_modify_shared: could not reload segment %s"
+			   " - overlapping resources\n", name);
+		rc = -EBUSY;
+		kfree(seg->res);
+		goto out_del_mem;
+	}
+
+	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
+	if (do_nonshared)
+		diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
+				&start_addr, &end_addr);
+	else
+		diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
+				&start_addr, &end_addr);
+	if (diag_cc < 0) {
+		rc = diag_cc;
+		goto out_del_res;
+	}
+	if (diag_cc > 1) {
+		PRINT_WARN ("segment_modify_shared: could not reload segment %s"
+				" - diag returned error (%ld)\n",
+				name, end_addr);
+		rc = dcss_diag_translate_rc(end_addr);
+		goto out_del_res;
+	}
+	seg->start_addr = start_addr;
+	seg->end = end_addr;
+	seg->do_nonshared = do_nonshared;
+	rc = 0;
+	goto out_unlock;
+ out_del_res:
+	release_resource(seg->res);
+	kfree(seg->res);
+ out_del_mem:
+	vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
+	list_del(&seg->list);
+	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
+	kfree(seg);
+ out_unlock:
+	mutex_unlock(&dcss_lock);
+	return rc;
+}
+
+/*
+ * Decrease the use count of a DCSS segment and remove
+ * it from the address space if nobody is using it
+ * any longer.
+ */
+void
+segment_unload(char *name)
+{
+	unsigned long dummy;
+	struct dcss_segment *seg;
+
+	if (!MACHINE_IS_VM)
+		return;
+
+	mutex_lock(&dcss_lock);
+	seg = segment_by_name (name);
+	if (seg == NULL) {
+		PRINT_ERR ("could not find segment %s in segment_unload, "
+				"please report to linux390@de.ibm.com\n",name);
+		goto out_unlock;
+	}
+	if (atomic_dec_return(&seg->ref_count) != 0)
+		goto out_unlock;
+	release_resource(seg->res);
+	kfree(seg->res);
+	vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
+	list_del(&seg->list);
+	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
+	kfree(seg);
+out_unlock:
+	mutex_unlock(&dcss_lock);
+}
+
+/*
+ * save segment content permanently
+ */
+void
+segment_save(char *name)
+{
+	struct dcss_segment *seg;
+	int startpfn = 0;
+	int endpfn = 0;
+	char cmd1[160];
+	char cmd2[80];
+	int i, response;
+
+	if (!MACHINE_IS_VM)
+		return;
+
+	mutex_lock(&dcss_lock);
+	seg = segment_by_name (name);
+
+	if (seg == NULL) {
+		PRINT_ERR("could not find segment %s in segment_save, please "
+			  "report to linux390@de.ibm.com\n", name);
+		goto out;
+	}
+
+	startpfn = seg->start_addr >> PAGE_SHIFT;
+	endpfn = (seg->end) >> PAGE_SHIFT;
+	sprintf(cmd1, "DEFSEG %s", name);
+	for (i=0; i<seg->segcnt; i++) {
+		sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
+			seg->range[i].start >> PAGE_SHIFT,
+			seg->range[i].end >> PAGE_SHIFT,
+			segtype_string[seg->range[i].start & 0xff]);
+	}
+	sprintf(cmd2, "SAVESEG %s", name);
+	response = 0;
+	cpcmd(cmd1, NULL, 0, &response);
+	if (response) {
+		PRINT_ERR("segment_save: DEFSEG failed with response code %i\n",
+			  response);
+		goto out;
+	}
+	cpcmd(cmd2, NULL, 0, &response);
+	if (response) {
+		PRINT_ERR("segment_save: SAVESEG failed with response code %i\n",
+			  response);
+		goto out;
+	}
+out:
+	mutex_unlock(&dcss_lock);
+}
+
+/*
+ * print appropriate error message for segment_load()/segment_type()
+ * return code
+ */
+void segment_warning(int rc, char *seg_name)
+{
+	switch (rc) {
+	case -ENOENT:
+		PRINT_WARN("cannot load/query segment %s, "
+			   "does not exist\n", seg_name);
+		break;
+	case -ENOSYS:
+		PRINT_WARN("cannot load/query segment %s, "
+			   "not running on VM\n", seg_name);
+		break;
+	case -EIO:
+		PRINT_WARN("cannot load/query segment %s, "
+			   "hardware error\n", seg_name);
+		break;
+	case -ENOTSUPP:
+		PRINT_WARN("cannot load/query segment %s, "
+			   "is a multi-part segment\n", seg_name);
+		break;
+	case -ENOSPC:
+		PRINT_WARN("cannot load/query segment %s, "
+			   "overlaps with storage\n", seg_name);
+		break;
+	case -EBUSY:
+		PRINT_WARN("cannot load/query segment %s, "
+			   "overlaps with already loaded dcss\n", seg_name);
+		break;
+	case -EPERM:
+		PRINT_WARN("cannot load/query segment %s, "
+			   "already loaded in incompatible mode\n", seg_name);
+		break;
+	case -ENOMEM:
+		PRINT_WARN("cannot load/query segment %s, "
+			   "out of memory\n", seg_name);
+		break;
+	case -ERANGE:
+		PRINT_WARN("cannot load/query segment %s, "
+			   "exceeds kernel mapping range\n", seg_name);
+		break;
+	default:
+		PRINT_WARN("cannot load/query segment %s, "
+			   "return value %i\n", seg_name, rc);
+		break;
+	}
+}
+
+EXPORT_SYMBOL(segment_load);
+EXPORT_SYMBOL(segment_unload);
+EXPORT_SYMBOL(segment_save);
+EXPORT_SYMBOL(segment_type);
+EXPORT_SYMBOL(segment_modify_shared);
+EXPORT_SYMBOL(segment_warning);
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
new file mode 100644
index 0000000..4d53720
--- /dev/null
+++ b/arch/s390/mm/fault.c
@@ -0,0 +1,614 @@
+/*
+ *  arch/s390/mm/fault.c
+ *
+ *  S390 version
+ *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Hartmut Penner (hp@de.ibm.com)
+ *               Ulrich Weigand (uweigand@de.ibm.com)
+ *
+ *  Derived from "arch/i386/mm/fault.c"
+ *    Copyright (C) 1995  Linus Torvalds
+ */
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kdebug.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/hardirq.h>
+#include <linux/kprobes.h>
+#include <linux/uaccess.h>
+#include <linux/hugetlb.h>
+#include <asm/system.h>
+#include <asm/pgtable.h>
+#include <asm/s390_ext.h>
+#include <asm/mmu_context.h>
+#include "../kernel/entry.h"
+
+#ifndef CONFIG_64BIT
+#define __FAIL_ADDR_MASK 0x7ffff000
+#define __FIXUP_MASK 0x7fffffff
+#define __SUBCODE_MASK 0x0200
+#define __PF_RES_FIELD 0ULL
+#else /* CONFIG_64BIT */
+#define __FAIL_ADDR_MASK -4096L
+#define __FIXUP_MASK ~0L
+#define __SUBCODE_MASK 0x0600
+#define __PF_RES_FIELD 0x8000000000000000ULL
+#endif /* CONFIG_64BIT */
+
+#ifdef CONFIG_SYSCTL
+extern int sysctl_userprocess_debug;
+#endif
+
+#ifdef CONFIG_KPROBES
+static inline int notify_page_fault(struct pt_regs *regs, long err)
+{
+	int ret = 0;
+
+	/* kprobe_running() needs smp_processor_id() */
+	if (!user_mode(regs)) {
+		preempt_disable();
+		if (kprobe_running() && kprobe_fault_handler(regs, 14))
+			ret = 1;
+		preempt_enable();
+	}
+
+	return ret;
+}
+#else
+static inline int notify_page_fault(struct pt_regs *regs, long err)
+{
+	return 0;
+}
+#endif
+
+
+/*
+ * Unlock any spinlocks which will prevent us from getting the
+ * message out.
+ */
+void bust_spinlocks(int yes)
+{
+	if (yes) {
+		oops_in_progress = 1;
+	} else {
+		int loglevel_save = console_loglevel;
+		console_unblank();
+		oops_in_progress = 0;
+		/*
+		 * OK, the message is on the console.  Now we call printk()
+		 * without oops_in_progress set so that printk will give klogd
+		 * a poke.  Hold onto your hats...
+		 */
+		console_loglevel = 15;
+		printk(" ");
+		console_loglevel = loglevel_save;
+	}
+}
+
+/*
+ * Returns the address space associated with the fault.
+ * Returns 0 for kernel space, 1 for user space and
+ * 2 for code execution in user space with noexec=on.
+ */
+static inline int check_space(struct task_struct *tsk)
+{
+	/*
+	 * The lowest two bits of S390_lowcore.trans_exc_code
+	 * indicate which paging table was used.
+	 */
+	int desc = S390_lowcore.trans_exc_code & 3;
+
+	if (desc == 3)	/* Home Segment Table Descriptor */
+		return switch_amode == 0;
+	if (desc == 2)	/* Secondary Segment Table Descriptor */
+		return tsk->thread.mm_segment.ar4;
+#ifdef CONFIG_S390_SWITCH_AMODE
+	if (unlikely(desc == 1)) { /* STD determined via access register */
+		/* %a0 always indicates primary space. */
+		if (S390_lowcore.exc_access_id != 0) {
+			save_access_regs(tsk->thread.acrs);
+			/*
+			 * An alet of 0 indicates primary space.
+			 * An alet of 1 indicates secondary space.
+			 * Any other alet values generate an
+			 * alen-translation exception.
+			 */
+			if (tsk->thread.acrs[S390_lowcore.exc_access_id])
+				return tsk->thread.mm_segment.ar4;
+		}
+	}
+#endif
+	/* Primary Segment Table Descriptor */
+	return switch_amode << s390_noexec;
+}
+
+/*
+ * Send SIGSEGV to task.  This is an external routine
+ * to keep the stack usage of do_page_fault small.
+ */
+static void do_sigsegv(struct pt_regs *regs, unsigned long error_code,
+		       int si_code, unsigned long address)
+{
+	struct siginfo si;
+
+#if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
+#if defined(CONFIG_SYSCTL)
+	if (sysctl_userprocess_debug)
+#endif
+	{
+		printk("User process fault: interruption code 0x%lX\n",
+		       error_code);
+		printk("failing address: %lX\n", address);
+		show_regs(regs);
+	}
+#endif
+	si.si_signo = SIGSEGV;
+	si.si_code = si_code;
+	si.si_addr = (void __user *) address;
+	force_sig_info(SIGSEGV, &si, current);
+}
+
+static void do_no_context(struct pt_regs *regs, unsigned long error_code,
+			  unsigned long address)
+{
+	const struct exception_table_entry *fixup;
+
+	/* Are we prepared to handle this kernel fault?  */
+	fixup = search_exception_tables(regs->psw.addr & __FIXUP_MASK);
+	if (fixup) {
+		regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
+		return;
+	}
+
+	/*
+	 * Oops. The kernel tried to access some bad page. We'll have to
+	 * terminate things with extreme prejudice.
+	 */
+	if (check_space(current) == 0)
+		printk(KERN_ALERT "Unable to handle kernel pointer dereference"
+		       " at virtual kernel address %p\n", (void *)address);
+	else
+		printk(KERN_ALERT "Unable to handle kernel paging request"
+		       " at virtual user address %p\n", (void *)address);
+
+	die("Oops", regs, error_code);
+	do_exit(SIGKILL);
+}
+
+static void do_low_address(struct pt_regs *regs, unsigned long error_code)
+{
+	/* Low-address protection hit in kernel mode means
+	   NULL pointer write access in kernel mode.  */
+	if (regs->psw.mask & PSW_MASK_PSTATE) {
+		/* Low-address protection hit in user mode 'cannot happen'. */
+		die ("Low-address protection", regs, error_code);
+		do_exit(SIGKILL);
+	}
+
+	do_no_context(regs, error_code, 0);
+}
+
+/*
+ * We ran out of memory, or some other thing happened to us that made
+ * us unable to handle the page fault gracefully.
+ */
+static int do_out_of_memory(struct pt_regs *regs, unsigned long error_code,
+			    unsigned long address)
+{
+	struct task_struct *tsk = current;
+	struct mm_struct *mm = tsk->mm;
+
+	up_read(&mm->mmap_sem);
+	if (is_global_init(tsk)) {
+		yield();
+		down_read(&mm->mmap_sem);
+		return 1;
+	}
+	printk("VM: killing process %s\n", tsk->comm);
+	if (regs->psw.mask & PSW_MASK_PSTATE)
+		do_group_exit(SIGKILL);
+	do_no_context(regs, error_code, address);
+	return 0;
+}
+
+static void do_sigbus(struct pt_regs *regs, unsigned long error_code,
+		      unsigned long address)
+{
+	struct task_struct *tsk = current;
+	struct mm_struct *mm = tsk->mm;
+
+	up_read(&mm->mmap_sem);
+	/*
+	 * Send a sigbus, regardless of whether we were in kernel
+	 * or user mode.
+	 */
+	tsk->thread.prot_addr = address;
+	tsk->thread.trap_no = error_code;
+	force_sig(SIGBUS, tsk);
+
+	/* Kernel mode? Handle exceptions or die */
+	if (!(regs->psw.mask & PSW_MASK_PSTATE))
+		do_no_context(regs, error_code, address);
+}
+
+#ifdef CONFIG_S390_EXEC_PROTECT
+static int signal_return(struct mm_struct *mm, struct pt_regs *regs,
+			 unsigned long address, unsigned long error_code)
+{
+	u16 instruction;
+	int rc;
+#ifdef CONFIG_COMPAT
+	int compat;
+#endif
+
+	pagefault_disable();
+	rc = __get_user(instruction, (u16 __user *) regs->psw.addr);
+	pagefault_enable();
+	if (rc)
+		return -EFAULT;
+
+	up_read(&mm->mmap_sem);
+	clear_tsk_thread_flag(current, TIF_SINGLE_STEP);
+#ifdef CONFIG_COMPAT
+	compat = test_tsk_thread_flag(current, TIF_31BIT);
+	if (compat && instruction == 0x0a77)
+		sys32_sigreturn();
+	else if (compat && instruction == 0x0aad)
+		sys32_rt_sigreturn();
+	else
+#endif
+	if (instruction == 0x0a77)
+		sys_sigreturn();
+	else if (instruction == 0x0aad)
+		sys_rt_sigreturn();
+	else {
+		current->thread.prot_addr = address;
+		current->thread.trap_no = error_code;
+		do_sigsegv(regs, error_code, SEGV_MAPERR, address);
+	}
+	return 0;
+}
+#endif /* CONFIG_S390_EXEC_PROTECT */
+
+/*
+ * This routine handles page faults.  It determines the address,
+ * and the problem, and then passes it off to one of the appropriate
+ * routines.
+ *
+ * error_code:
+ *   04       Protection           ->  Write-Protection  (suprression)
+ *   10       Segment translation  ->  Not present       (nullification)
+ *   11       Page translation     ->  Not present       (nullification)
+ *   3b       Region third trans.  ->  Not present       (nullification)
+ */
+static inline void
+do_exception(struct pt_regs *regs, unsigned long error_code, int write)
+{
+	struct task_struct *tsk;
+	struct mm_struct *mm;
+	struct vm_area_struct *vma;
+	unsigned long address;
+	int space;
+	int si_code;
+	int fault;
+
+	if (notify_page_fault(regs, error_code))
+		return;
+
+	tsk = current;
+	mm = tsk->mm;
+
+	/* get the failing address and the affected space */
+	address = S390_lowcore.trans_exc_code & __FAIL_ADDR_MASK;
+	space = check_space(tsk);
+
+	/*
+	 * Verify that the fault happened in user space, that
+	 * we are not in an interrupt and that there is a 
+	 * user context.
+	 */
+	if (unlikely(space == 0 || in_atomic() || !mm))
+		goto no_context;
+
+	/*
+	 * When we get here, the fault happened in the current
+	 * task's user address space, so we can switch on the
+	 * interrupts again and then search the VMAs
+	 */
+	local_irq_enable();
+
+	down_read(&mm->mmap_sem);
+
+	si_code = SEGV_MAPERR;
+	vma = find_vma(mm, address);
+	if (!vma)
+		goto bad_area;
+
+#ifdef CONFIG_S390_EXEC_PROTECT
+	if (unlikely((space == 2) && !(vma->vm_flags & VM_EXEC)))
+		if (!signal_return(mm, regs, address, error_code))
+			/*
+			 * signal_return() has done an up_read(&mm->mmap_sem)
+			 * if it returns 0.
+			 */
+			return;
+#endif
+
+	if (vma->vm_start <= address)
+		goto good_area;
+	if (!(vma->vm_flags & VM_GROWSDOWN))
+		goto bad_area;
+	if (expand_stack(vma, address))
+		goto bad_area;
+/*
+ * Ok, we have a good vm_area for this memory access, so
+ * we can handle it..
+ */
+good_area:
+	si_code = SEGV_ACCERR;
+	if (!write) {
+		/* page not present, check vm flags */
+		if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
+			goto bad_area;
+	} else {
+		if (!(vma->vm_flags & VM_WRITE))
+			goto bad_area;
+	}
+
+survive:
+	if (is_vm_hugetlb_page(vma))
+		address &= HPAGE_MASK;
+	/*
+	 * If for any reason at all we couldn't handle the fault,
+	 * make sure we exit gracefully rather than endlessly redo
+	 * the fault.
+	 */
+	fault = handle_mm_fault(mm, vma, address, write);
+	if (unlikely(fault & VM_FAULT_ERROR)) {
+		if (fault & VM_FAULT_OOM) {
+			if (do_out_of_memory(regs, error_code, address))
+				goto survive;
+			return;
+		} else if (fault & VM_FAULT_SIGBUS) {
+			do_sigbus(regs, error_code, address);
+			return;
+		}
+		BUG();
+	}
+	if (fault & VM_FAULT_MAJOR)
+		tsk->maj_flt++;
+	else
+		tsk->min_flt++;
+
+        up_read(&mm->mmap_sem);
+	/*
+	 * The instruction that caused the program check will
+	 * be repeated. Don't signal single step via SIGTRAP.
+	 */
+	clear_tsk_thread_flag(tsk, TIF_SINGLE_STEP);
+        return;
+
+/*
+ * Something tried to access memory that isn't in our memory map..
+ * Fix it, but check if it's kernel or user first..
+ */
+bad_area:
+	up_read(&mm->mmap_sem);
+
+	/* User mode accesses just cause a SIGSEGV */
+	if (regs->psw.mask & PSW_MASK_PSTATE) {
+		tsk->thread.prot_addr = address;
+		tsk->thread.trap_no = error_code;
+		do_sigsegv(regs, error_code, si_code, address);
+		return;
+	}
+
+no_context:
+	do_no_context(regs, error_code, address);
+}
+
+void __kprobes do_protection_exception(struct pt_regs *regs,
+				       long error_code)
+{
+	/* Protection exception is supressing, decrement psw address. */
+	regs->psw.addr -= (error_code >> 16);
+	/*
+	 * Check for low-address protection.  This needs to be treated
+	 * as a special case because the translation exception code
+	 * field is not guaranteed to contain valid data in this case.
+	 */
+	if (unlikely(!(S390_lowcore.trans_exc_code & 4))) {
+		do_low_address(regs, error_code);
+		return;
+	}
+	do_exception(regs, 4, 1);
+}
+
+void __kprobes do_dat_exception(struct pt_regs *regs, long error_code)
+{
+	do_exception(regs, error_code & 0xff, 0);
+}
+
+#ifdef CONFIG_64BIT
+void __kprobes do_asce_exception(struct pt_regs *regs, unsigned long error_code)
+{
+	struct mm_struct *mm;
+	struct vm_area_struct *vma;
+	unsigned long address;
+	int space;
+
+	mm = current->mm;
+	address = S390_lowcore.trans_exc_code & __FAIL_ADDR_MASK;
+	space = check_space(current);
+
+	if (unlikely(space == 0 || in_atomic() || !mm))
+		goto no_context;
+
+	local_irq_enable();
+
+	down_read(&mm->mmap_sem);
+	vma = find_vma(mm, address);
+	up_read(&mm->mmap_sem);
+
+	if (vma) {
+		update_mm(mm, current);
+		return;
+	}
+
+	/* User mode accesses just cause a SIGSEGV */
+	if (regs->psw.mask & PSW_MASK_PSTATE) {
+		current->thread.prot_addr = address;
+		current->thread.trap_no = error_code;
+		do_sigsegv(regs, error_code, SEGV_MAPERR, address);
+		return;
+	}
+
+no_context:
+	do_no_context(regs, error_code, address);
+}
+#endif
+
+#ifdef CONFIG_PFAULT 
+/*
+ * 'pfault' pseudo page faults routines.
+ */
+static ext_int_info_t ext_int_pfault;
+static int pfault_disable = 0;
+
+static int __init nopfault(char *str)
+{
+	pfault_disable = 1;
+	return 1;
+}
+
+__setup("nopfault", nopfault);
+
+typedef struct {
+	__u16 refdiagc;
+	__u16 reffcode;
+	__u16 refdwlen;
+	__u16 refversn;
+	__u64 refgaddr;
+	__u64 refselmk;
+	__u64 refcmpmk;
+	__u64 reserved;
+} __attribute__ ((packed, aligned(8))) pfault_refbk_t;
+
+int pfault_init(void)
+{
+	pfault_refbk_t refbk =
+		{ 0x258, 0, 5, 2, __LC_CURRENT, 1ULL << 48, 1ULL << 48,
+		  __PF_RES_FIELD };
+        int rc;
+
+	if (!MACHINE_IS_VM || pfault_disable)
+		return -1;
+	asm volatile(
+		"	diag	%1,%0,0x258\n"
+		"0:	j	2f\n"
+		"1:	la	%0,8\n"
+		"2:\n"
+		EX_TABLE(0b,1b)
+		: "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc");
+        __ctl_set_bit(0, 9);
+        return rc;
+}
+
+void pfault_fini(void)
+{
+	pfault_refbk_t refbk =
+	{ 0x258, 1, 5, 2, 0ULL, 0ULL, 0ULL, 0ULL };
+
+	if (!MACHINE_IS_VM || pfault_disable)
+		return;
+	__ctl_clear_bit(0,9);
+	asm volatile(
+		"	diag	%0,0,0x258\n"
+		"0:\n"
+		EX_TABLE(0b,0b)
+		: : "a" (&refbk), "m" (refbk) : "cc");
+}
+
+static void pfault_interrupt(__u16 error_code)
+{
+	struct task_struct *tsk;
+	__u16 subcode;
+
+	/*
+	 * Get the external interruption subcode & pfault
+	 * initial/completion signal bit. VM stores this 
+	 * in the 'cpu address' field associated with the
+         * external interrupt. 
+	 */
+	subcode = S390_lowcore.cpu_addr;
+	if ((subcode & 0xff00) != __SUBCODE_MASK)
+		return;
+
+	/*
+	 * Get the token (= address of the task structure of the affected task).
+	 */
+	tsk = *(struct task_struct **) __LC_PFAULT_INTPARM;
+
+	if (subcode & 0x0080) {
+		/* signal bit is set -> a page has been swapped in by VM */
+		if (xchg(&tsk->thread.pfault_wait, -1) != 0) {
+			/* Initial interrupt was faster than the completion
+			 * interrupt. pfault_wait is valid. Set pfault_wait
+			 * back to zero and wake up the process. This can
+			 * safely be done because the task is still sleeping
+			 * and can't produce new pfaults. */
+			tsk->thread.pfault_wait = 0;
+			wake_up_process(tsk);
+			put_task_struct(tsk);
+		}
+	} else {
+		/* signal bit not set -> a real page is missing. */
+		get_task_struct(tsk);
+		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+		if (xchg(&tsk->thread.pfault_wait, 1) != 0) {
+			/* Completion interrupt was faster than the initial
+			 * interrupt (swapped in a -1 for pfault_wait). Set
+			 * pfault_wait back to zero and exit. This can be
+			 * done safely because tsk is running in kernel 
+			 * mode and can't produce new pfaults. */
+			tsk->thread.pfault_wait = 0;
+			set_task_state(tsk, TASK_RUNNING);
+			put_task_struct(tsk);
+		} else
+			set_tsk_need_resched(tsk);
+	}
+}
+
+void __init pfault_irq_init(void)
+{
+	if (!MACHINE_IS_VM)
+		return;
+
+	/*
+	 * Try to get pfault pseudo page faults going.
+	 */
+	if (register_early_external_interrupt(0x2603, pfault_interrupt,
+					      &ext_int_pfault) != 0)
+		panic("Couldn't request external interrupt 0x2603");
+
+	if (pfault_init() == 0)
+		return;
+
+	/* Tough luck, no pfault. */
+	pfault_disable = 1;
+	unregister_early_external_interrupt(0x2603, pfault_interrupt,
+					    &ext_int_pfault);
+}
+#endif
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
new file mode 100644
index 0000000..f28c43d
--- /dev/null
+++ b/arch/s390/mm/hugetlbpage.c
@@ -0,0 +1,140 @@
+/*
+ *  IBM System z Huge TLB Page Support for Kernel.
+ *
+ *    Copyright 2007 IBM Corp.
+ *    Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+
+
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+				   pte_t *pteptr, pte_t pteval)
+{
+	pmd_t *pmdp = (pmd_t *) pteptr;
+	pte_t shadow_pteval = pteval;
+	unsigned long mask;
+
+	if (!MACHINE_HAS_HPAGE) {
+		pteptr = (pte_t *) pte_page(pteval)[1].index;
+		mask = pte_val(pteval) &
+				(_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO);
+		pte_val(pteval) = (_SEGMENT_ENTRY + __pa(pteptr)) | mask;
+		if (mm->context.noexec) {
+			pteptr += PTRS_PER_PTE;
+			pte_val(shadow_pteval) =
+					(_SEGMENT_ENTRY + __pa(pteptr)) | mask;
+		}
+	}
+
+	pmd_val(*pmdp) = pte_val(pteval);
+	if (mm->context.noexec) {
+		pmdp = get_shadow_table(pmdp);
+		pmd_val(*pmdp) = pte_val(shadow_pteval);
+	}
+}
+
+int arch_prepare_hugepage(struct page *page)
+{
+	unsigned long addr = page_to_phys(page);
+	pte_t pte;
+	pte_t *ptep;
+	int i;
+
+	if (MACHINE_HAS_HPAGE)
+		return 0;
+
+	ptep = (pte_t *) pte_alloc_one(&init_mm, address);
+	if (!ptep)
+		return -ENOMEM;
+
+	pte = mk_pte(page, PAGE_RW);
+	for (i = 0; i < PTRS_PER_PTE; i++) {
+		set_pte_at(&init_mm, addr + i * PAGE_SIZE, ptep + i, pte);
+		pte_val(pte) += PAGE_SIZE;
+	}
+	page[1].index = (unsigned long) ptep;
+	return 0;
+}
+
+void arch_release_hugepage(struct page *page)
+{
+	pte_t *ptep;
+
+	if (MACHINE_HAS_HPAGE)
+		return;
+
+	ptep = (pte_t *) page[1].index;
+	if (!ptep)
+		return;
+	pte_free(&init_mm, ptep);
+	page[1].index = 0;
+}
+
+pte_t *huge_pte_alloc(struct mm_struct *mm,
+			unsigned long addr, unsigned long sz)
+{
+	pgd_t *pgdp;
+	pud_t *pudp;
+	pmd_t *pmdp = NULL;
+
+	pgdp = pgd_offset(mm, addr);
+	pudp = pud_alloc(mm, pgdp, addr);
+	if (pudp)
+		pmdp = pmd_alloc(mm, pudp, addr);
+	return (pte_t *) pmdp;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+	pgd_t *pgdp;
+	pud_t *pudp;
+	pmd_t *pmdp = NULL;
+
+	pgdp = pgd_offset(mm, addr);
+	if (pgd_present(*pgdp)) {
+		pudp = pud_offset(pgdp, addr);
+		if (pud_present(*pudp))
+			pmdp = pmd_offset(pudp, addr);
+	}
+	return (pte_t *) pmdp;
+}
+
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+	return 0;
+}
+
+struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
+			      int write)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+int pmd_huge(pmd_t pmd)
+{
+	if (!MACHINE_HAS_HPAGE)
+		return 0;
+
+	return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE);
+}
+
+int pud_huge(pud_t pud)
+{
+	return 0;
+}
+
+struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
+			     pmd_t *pmdp, int write)
+{
+	struct page *page;
+
+	if (!MACHINE_HAS_HPAGE)
+		return NULL;
+
+	page = pmd_page(*pmdp);
+	if (page)
+		page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
+	return page;
+}
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
new file mode 100644
index 0000000..158b0d6
--- /dev/null
+++ b/arch/s390/mm/init.c
@@ -0,0 +1,191 @@
+/*
+ *  arch/s390/mm/init.c
+ *
+ *  S390 version
+ *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Hartmut Penner (hp@de.ibm.com)
+ *
+ *  Derived from "arch/i386/mm/init.c"
+ *    Copyright (C) 1995  Linus Torvalds
+ */
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/bootmem.h>
+#include <linux/pfn.h>
+#include <linux/poison.h>
+#include <linux/initrd.h>
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/dma.h>
+#include <asm/lowcore.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/sections.h>
+
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
+char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+
+/*
+ * paging_init() sets up the page tables
+ */
+void __init paging_init(void)
+{
+	static const int ssm_mask = 0x04000000L;
+	unsigned long max_zone_pfns[MAX_NR_ZONES];
+	unsigned long pgd_type;
+
+	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;
+#else
+	S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
+	pgd_type = _SEGMENT_ENTRY_EMPTY;
+#endif
+	clear_table((unsigned long *) init_mm.pgd, pgd_type,
+		    sizeof(unsigned long)*2048);
+	vmem_map_init();
+
+        /* enable virtual mapping in kernel mode */
+	__ctl_load(S390_lowcore.kernel_asce, 1, 1);
+	__ctl_load(S390_lowcore.kernel_asce, 7, 7);
+	__ctl_load(S390_lowcore.kernel_asce, 13, 13);
+	__raw_local_irq_ssm(ssm_mask);
+
+	sparse_memory_present_with_active_regions(MAX_NUMNODES);
+	sparse_init();
+	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
+#ifdef CONFIG_ZONE_DMA
+	max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
+#endif
+	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
+	free_area_init_nodes(max_zone_pfns);
+}
+
+void __init mem_init(void)
+{
+	unsigned long codesize, reservedpages, datasize, initsize;
+
+        max_mapnr = num_physpages = max_low_pfn;
+        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
+
+        /* clear the zero-page */
+        memset(empty_zero_page, 0, PAGE_SIZE);
+
+	/* Setup guest page hinting */
+	cmma_init();
+
+	/* this will put all low memory onto the freelists */
+	totalram_pages += free_all_bootmem();
+
+	reservedpages = 0;
+
+	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
+	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
+	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
+        printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
+                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
+                max_mapnr << (PAGE_SHIFT-10),
+                codesize >> 10,
+                reservedpages << (PAGE_SHIFT-10),
+                datasize >>10,
+                initsize >> 10);
+	printk("Write protected kernel read-only data: %#lx - %#lx\n",
+	       (unsigned long)&_stext,
+	       PFN_ALIGN((unsigned long)&_eshared) - 1);
+}
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+void kernel_map_pages(struct page *page, int numpages, int enable)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	unsigned long address;
+	int i;
+
+	for (i = 0; i < numpages; i++) {
+		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_invalidate(&init_mm, address, pte);
+			continue;
+		}
+		*pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
+		/* Flush cpu write queue. */
+		mb();
+	}
+}
+#endif
+
+void free_initmem(void)
+{
+        unsigned long addr;
+
+        addr = (unsigned long)(&__init_begin);
+        for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
+		ClearPageReserved(virt_to_page(addr));
+		init_page_count(virt_to_page(addr));
+		memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
+		free_page(addr);
+		totalram_pages++;
+        }
+        printk ("Freeing unused kernel memory: %ldk freed\n",
+		((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+        if (start < end)
+                printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
+        for (; start < end; start += PAGE_SIZE) {
+                ClearPageReserved(virt_to_page(start));
+                init_page_count(virt_to_page(start));
+                free_page(start);
+                totalram_pages++;
+        }
+}
+#endif
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int arch_add_memory(int nid, u64 start, u64 size)
+{
+	struct pglist_data *pgdat;
+	struct zone *zone;
+	int rc;
+
+	pgdat = NODE_DATA(nid);
+	zone = pgdat->node_zones + ZONE_MOVABLE;
+	rc = vmem_add_mapping(start, size);
+	if (rc)
+		return rc;
+	rc = __add_pages(zone, PFN_DOWN(start), PFN_DOWN(size));
+	if (rc)
+		vmem_remove_mapping(start, size);
+	return rc;
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
new file mode 100644
index 0000000..5932a82
--- /dev/null
+++ b/arch/s390/mm/mmap.c
@@ -0,0 +1,151 @@
+/*
+ *  linux/arch/s390/mm/mmap.c
+ *
+ *  flexible mmap layout support
+ *
+ * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *
+ * Started by Ingo Molnar <mingo@elte.hu>
+ */
+
+#include <linux/personality.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <asm/pgalloc.h>
+
+/*
+ * Top of mmap area (just below the process stack).
+ *
+ * Leave an at least ~128 MB hole.
+ */
+#define MIN_GAP (128*1024*1024)
+#define MAX_GAP (TASK_SIZE/6*5)
+
+static inline unsigned long mmap_base(void)
+{
+	unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
+
+	if (gap < MIN_GAP)
+		gap = MIN_GAP;
+	else if (gap > MAX_GAP)
+		gap = MAX_GAP;
+
+	return TASK_SIZE - (gap & PAGE_MASK);
+}
+
+static inline int mmap_is_legacy(void)
+{
+#ifdef CONFIG_64BIT
+	/*
+	 * Force standard allocation for 64 bit programs.
+	 */
+	if (!test_thread_flag(TIF_31BIT))
+		return 1;
+#endif
+	return sysctl_legacy_va_layout ||
+	    (current->personality & ADDR_COMPAT_LAYOUT) ||
+	    current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY;
+}
+
+#ifndef CONFIG_64BIT
+
+/*
+ * This function, called very early during the creation of a new
+ * process VM image, sets up which VM layout function to use:
+ */
+void arch_pick_mmap_layout(struct mm_struct *mm)
+{
+	/*
+	 * Fall back to the standard layout if the personality
+	 * bit is set, or if the expected stack growth is unlimited:
+	 */
+	if (mmap_is_legacy()) {
+		mm->mmap_base = TASK_UNMAPPED_BASE;
+		mm->get_unmapped_area = arch_get_unmapped_area;
+		mm->unmap_area = arch_unmap_area;
+	} else {
+		mm->mmap_base = mmap_base();
+		mm->get_unmapped_area = arch_get_unmapped_area_topdown;
+		mm->unmap_area = arch_unmap_area_topdown;
+	}
+}
+EXPORT_SYMBOL_GPL(arch_pick_mmap_layout);
+
+#else
+
+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;
+	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);
+		if (rc)
+			return (unsigned long) rc;
+	}
+	return addr;
+}
+
+static unsigned long
+s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
+			  const unsigned long len, const unsigned long pgoff,
+			  const unsigned long flags)
+{
+	struct mm_struct *mm = current->mm;
+	unsigned long addr = addr0;
+	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);
+		if (rc)
+			return (unsigned long) rc;
+	}
+	return addr;
+}
+/*
+ * This function, called very early during the creation of a new
+ * process VM image, sets up which VM layout function to use:
+ */
+void arch_pick_mmap_layout(struct mm_struct *mm)
+{
+	/*
+	 * Fall back to the standard layout if the personality
+	 * bit is set, or if the expected stack growth is unlimited:
+	 */
+	if (mmap_is_legacy()) {
+		mm->mmap_base = TASK_UNMAPPED_BASE;
+		mm->get_unmapped_area = s390_get_unmapped_area;
+		mm->unmap_area = arch_unmap_area;
+	} else {
+		mm->mmap_base = mmap_base();
+		mm->get_unmapped_area = s390_get_unmapped_area_topdown;
+		mm->unmap_area = arch_unmap_area_topdown;
+	}
+}
+EXPORT_SYMBOL_GPL(arch_pick_mmap_layout);
+
+#endif
diff --git a/arch/s390/mm/page-states.c b/arch/s390/mm/page-states.c
new file mode 100644
index 0000000..fc0ad73
--- /dev/null
+++ b/arch/s390/mm/page-states.c
@@ -0,0 +1,79 @@
+/*
+ * arch/s390/mm/page-states.c
+ *
+ * Copyright IBM Corp. 2008
+ *
+ * Guest page hinting for unused pages.
+ *
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+
+#define ESSA_SET_STABLE		1
+#define ESSA_SET_UNUSED		2
+
+static int cmma_flag;
+
+static int __init cmma(char *str)
+{
+	char *parm;
+	parm = strstrip(str);
+	if (strcmp(parm, "yes") == 0 || strcmp(parm, "on") == 0) {
+		cmma_flag = 1;
+		return 1;
+	}
+	cmma_flag = 0;
+	if (strcmp(parm, "no") == 0 || strcmp(parm, "off") == 0)
+		return 1;
+	return 0;
+}
+
+__setup("cmma=", cmma);
+
+void __init cmma_init(void)
+{
+	register unsigned long tmp asm("0") = 0;
+	register int rc asm("1") = -EOPNOTSUPP;
+
+	if (!cmma_flag)
+		return;
+	asm volatile(
+		"       .insn rrf,0xb9ab0000,%1,%1,0,0\n"
+		"0:     la      %0,0\n"
+		"1:\n"
+		EX_TABLE(0b,1b)
+		: "+&d" (rc), "+&d" (tmp));
+	if (rc)
+		cmma_flag = 0;
+}
+
+void arch_free_page(struct page *page, int order)
+{
+	int i, rc;
+
+	if (!cmma_flag)
+		return;
+	for (i = 0; i < (1 << order); i++)
+		asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0"
+			     : "=&d" (rc)
+			     : "a" ((page_to_pfn(page) + i) << PAGE_SHIFT),
+			       "i" (ESSA_SET_UNUSED));
+}
+
+void arch_alloc_page(struct page *page, int order)
+{
+	int i, rc;
+
+	if (!cmma_flag)
+		return;
+	for (i = 0; i < (1 << order); i++)
+		asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0"
+			     : "=&d" (rc)
+			     : "a" ((page_to_pfn(page) + i) << PAGE_SHIFT),
+			       "i" (ESSA_SET_STABLE));
+}
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
new file mode 100644
index 0000000..ef3635b
--- /dev/null
+++ b/arch/s390/mm/pgtable.c
@@ -0,0 +1,299 @@
+/*
+ *  arch/s390/mm/pgtable.c
+ *
+ *    Copyright IBM Corp. 2007
+ *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/quicklist.h>
+
+#include <asm/system.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+
+#ifndef CONFIG_64BIT
+#define ALLOC_ORDER	1
+#define TABLES_PER_PAGE	4
+#define FRAG_MASK	15UL
+#define SECOND_HALVES	10UL
+
+void clear_table_pgstes(unsigned long *table)
+{
+	clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE/4);
+	memset(table + 256, 0, PAGE_SIZE/4);
+	clear_table(table + 512, _PAGE_TYPE_EMPTY, PAGE_SIZE/4);
+	memset(table + 768, 0, PAGE_SIZE/4);
+}
+
+#else
+#define ALLOC_ORDER	2
+#define TABLES_PER_PAGE	2
+#define FRAG_MASK	3UL
+#define SECOND_HALVES	2UL
+
+void clear_table_pgstes(unsigned long *table)
+{
+	clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE/2);
+	memset(table + 256, 0, PAGE_SIZE/2);
+}
+
+#endif
+
+unsigned long *crst_table_alloc(struct mm_struct *mm, int noexec)
+{
+	struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
+
+	if (!page)
+		return NULL;
+	page->index = 0;
+	if (noexec) {
+		struct page *shadow = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
+		if (!shadow) {
+			__free_pages(page, ALLOC_ORDER);
+			return NULL;
+		}
+		page->index = page_to_phys(shadow);
+	}
+	spin_lock(&mm->page_table_lock);
+	list_add(&page->lru, &mm->context.crst_list);
+	spin_unlock(&mm->page_table_lock);
+	return (unsigned long *) page_to_phys(page);
+}
+
+void crst_table_free(struct mm_struct *mm, unsigned long *table)
+{
+	unsigned long *shadow = get_shadow_table(table);
+	struct page *page = virt_to_page(table);
+
+	spin_lock(&mm->page_table_lock);
+	list_del(&page->lru);
+	spin_unlock(&mm->page_table_lock);
+	if (shadow)
+		free_pages((unsigned long) shadow, ALLOC_ORDER);
+	free_pages((unsigned long) table, ALLOC_ORDER);
+}
+
+#ifdef CONFIG_64BIT
+int crst_table_upgrade(struct mm_struct *mm, unsigned long limit)
+{
+	unsigned long *table, *pgd;
+	unsigned long entry;
+
+	BUG_ON(limit > (1UL << 53));
+repeat:
+	table = crst_table_alloc(mm, mm->context.noexec);
+	if (!table)
+		return -ENOMEM;
+	spin_lock(&mm->page_table_lock);
+	if (mm->context.asce_limit < limit) {
+		pgd = (unsigned long *) mm->pgd;
+		if (mm->context.asce_limit <= (1UL << 31)) {
+			entry = _REGION3_ENTRY_EMPTY;
+			mm->context.asce_limit = 1UL << 42;
+			mm->context.asce_bits = _ASCE_TABLE_LENGTH |
+						_ASCE_USER_BITS |
+						_ASCE_TYPE_REGION3;
+		} else {
+			entry = _REGION2_ENTRY_EMPTY;
+			mm->context.asce_limit = 1UL << 53;
+			mm->context.asce_bits = _ASCE_TABLE_LENGTH |
+						_ASCE_USER_BITS |
+						_ASCE_TYPE_REGION2;
+		}
+		crst_table_init(table, entry);
+		pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd);
+		mm->pgd = (pgd_t *) table;
+		table = NULL;
+	}
+	spin_unlock(&mm->page_table_lock);
+	if (table)
+		crst_table_free(mm, table);
+	if (mm->context.asce_limit < limit)
+		goto repeat;
+	update_mm(mm, current);
+	return 0;
+}
+
+void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
+{
+	pgd_t *pgd;
+
+	if (mm->context.asce_limit <= limit)
+		return;
+	__tlb_flush_mm(mm);
+	while (mm->context.asce_limit > limit) {
+		pgd = mm->pgd;
+		switch (pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) {
+		case _REGION_ENTRY_TYPE_R2:
+			mm->context.asce_limit = 1UL << 42;
+			mm->context.asce_bits = _ASCE_TABLE_LENGTH |
+						_ASCE_USER_BITS |
+						_ASCE_TYPE_REGION3;
+			break;
+		case _REGION_ENTRY_TYPE_R3:
+			mm->context.asce_limit = 1UL << 31;
+			mm->context.asce_bits = _ASCE_TABLE_LENGTH |
+						_ASCE_USER_BITS |
+						_ASCE_TYPE_SEGMENT;
+			break;
+		default:
+			BUG();
+		}
+		mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
+		crst_table_free(mm, (unsigned long *) pgd);
+	}
+	update_mm(mm, current);
+}
+#endif
+
+/*
+ * page table entry allocation/free routines.
+ */
+unsigned long *page_table_alloc(struct mm_struct *mm)
+{
+	struct page *page;
+	unsigned long *table;
+	unsigned long bits;
+
+	bits = (mm->context.noexec || mm->context.has_pgste) ? 3UL : 1UL;
+	spin_lock(&mm->page_table_lock);
+	page = NULL;
+	if (!list_empty(&mm->context.pgtable_list)) {
+		page = list_first_entry(&mm->context.pgtable_list,
+					struct page, lru);
+		if ((page->flags & FRAG_MASK) == ((1UL << TABLES_PER_PAGE) - 1))
+			page = NULL;
+	}
+	if (!page) {
+		spin_unlock(&mm->page_table_lock);
+		page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
+		if (!page)
+			return NULL;
+		pgtable_page_ctor(page);
+		page->flags &= ~FRAG_MASK;
+		table = (unsigned long *) page_to_phys(page);
+		if (mm->context.has_pgste)
+			clear_table_pgstes(table);
+		else
+			clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
+		spin_lock(&mm->page_table_lock);
+		list_add(&page->lru, &mm->context.pgtable_list);
+	}
+	table = (unsigned long *) page_to_phys(page);
+	while (page->flags & bits) {
+		table += 256;
+		bits <<= 1;
+	}
+	page->flags |= bits;
+	if ((page->flags & FRAG_MASK) == ((1UL << TABLES_PER_PAGE) - 1))
+		list_move_tail(&page->lru, &mm->context.pgtable_list);
+	spin_unlock(&mm->page_table_lock);
+	return table;
+}
+
+void page_table_free(struct mm_struct *mm, unsigned long *table)
+{
+	struct page *page;
+	unsigned long bits;
+
+	bits = (mm->context.noexec || mm->context.has_pgste) ? 3UL : 1UL;
+	bits <<= (__pa(table) & (PAGE_SIZE - 1)) / 256 / sizeof(unsigned long);
+	page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
+	spin_lock(&mm->page_table_lock);
+	page->flags ^= bits;
+	if (page->flags & FRAG_MASK) {
+		/* Page now has some free pgtable fragments. */
+		list_move(&page->lru, &mm->context.pgtable_list);
+		page = NULL;
+	} else
+		/* All fragments of the 4K page have been freed. */
+		list_del(&page->lru);
+	spin_unlock(&mm->page_table_lock);
+	if (page) {
+		pgtable_page_dtor(page);
+		__free_page(page);
+	}
+}
+
+void disable_noexec(struct mm_struct *mm, struct task_struct *tsk)
+{
+	struct page *page;
+
+	spin_lock(&mm->page_table_lock);
+	/* Free shadow region and segment tables. */
+	list_for_each_entry(page, &mm->context.crst_list, lru)
+		if (page->index) {
+			free_pages((unsigned long) page->index, ALLOC_ORDER);
+			page->index = 0;
+		}
+	/* "Free" second halves of page tables. */
+	list_for_each_entry(page, &mm->context.pgtable_list, lru)
+		page->flags &= ~SECOND_HALVES;
+	spin_unlock(&mm->page_table_lock);
+	mm->context.noexec = 0;
+	update_mm(mm, tsk);
+}
+
+/*
+ * switch on pgstes for its userspace process (for kvm)
+ */
+int s390_enable_sie(void)
+{
+	struct task_struct *tsk = current;
+	struct mm_struct *mm, *old_mm;
+
+	/* Do we have pgstes? if yes, we are done */
+	if (tsk->mm->context.has_pgste)
+		return 0;
+
+	/* lets check if we are allowed to replace the mm */
+	task_lock(tsk);
+	if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
+	    tsk->mm != tsk->active_mm || tsk->mm->ioctx_list) {
+		task_unlock(tsk);
+		return -EINVAL;
+	}
+	task_unlock(tsk);
+
+	/* we copy the mm and let dup_mm create the page tables with_pgstes */
+	tsk->mm->context.alloc_pgste = 1;
+	mm = dup_mm(tsk);
+	tsk->mm->context.alloc_pgste = 0;
+	if (!mm)
+		return -ENOMEM;
+
+	/* Now lets check again if something happened */
+	task_lock(tsk);
+	if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
+	    tsk->mm != tsk->active_mm || tsk->mm->ioctx_list) {
+		mmput(mm);
+		task_unlock(tsk);
+		return -EINVAL;
+	}
+
+	/* ok, we are alone. No ptrace, no threads, etc. */
+	old_mm = tsk->mm;
+	tsk->mm = tsk->active_mm = mm;
+	preempt_disable();
+	update_mm(mm, tsk);
+	cpu_set(smp_processor_id(), mm->cpu_vm_mask);
+	preempt_enable();
+	task_unlock(tsk);
+	mmput(old_mm);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(s390_enable_sie);
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
new file mode 100644
index 0000000..e4868bf
--- /dev/null
+++ b/arch/s390/mm/vmem.c
@@ -0,0 +1,384 @@
+/*
+ *  arch/s390/mm/vmem.c
+ *
+ *    Copyright IBM Corp. 2006
+ *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#include <linux/bootmem.h>
+#include <linux/pfn.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/hugetlb.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <asm/setup.h>
+#include <asm/tlbflush.h>
+#include <asm/sections.h>
+
+static DEFINE_MUTEX(vmem_mutex);
+
+struct memory_segment {
+	struct list_head list;
+	unsigned long start;
+	unsigned long size;
+};
+
+static LIST_HEAD(mem_segs);
+
+static void __ref *vmem_alloc_pages(unsigned int order)
+{
+	if (slab_is_available())
+		return (void *)__get_free_pages(GFP_KERNEL, order);
+	return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
+}
+
+static inline pud_t *vmem_pud_alloc(void)
+{
+	pud_t *pud = NULL;
+
+#ifdef CONFIG_64BIT
+	pud = vmem_alloc_pages(2);
+	if (!pud)
+		return NULL;
+	clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
+#endif
+	return pud;
+}
+
+static inline pmd_t *vmem_pmd_alloc(void)
+{
+	pmd_t *pmd = NULL;
+
+#ifdef CONFIG_64BIT
+	pmd = vmem_alloc_pages(2);
+	if (!pmd)
+		return NULL;
+	clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
+#endif
+	return pmd;
+}
+
+static pte_t __ref *vmem_pte_alloc(void)
+{
+	pte_t *pte;
+
+	if (slab_is_available())
+		pte = (pte_t *) page_table_alloc(&init_mm);
+	else
+		pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t));
+	if (!pte)
+		return NULL;
+	clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY,
+		    PTRS_PER_PTE * sizeof(pte_t));
+	return pte;
+}
+
+/*
+ * Add a physical memory range to the 1:1 mapping.
+ */
+static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
+{
+	unsigned long address;
+	pgd_t *pg_dir;
+	pud_t *pu_dir;
+	pmd_t *pm_dir;
+	pte_t *pt_dir;
+	pte_t  pte;
+	int ret = -ENOMEM;
+
+	for (address = start; address < start + size; address += PAGE_SIZE) {
+		pg_dir = pgd_offset_k(address);
+		if (pgd_none(*pg_dir)) {
+			pu_dir = vmem_pud_alloc();
+			if (!pu_dir)
+				goto out;
+			pgd_populate_kernel(&init_mm, pg_dir, pu_dir);
+		}
+
+		pu_dir = pud_offset(pg_dir, address);
+		if (pud_none(*pu_dir)) {
+			pm_dir = vmem_pmd_alloc();
+			if (!pm_dir)
+				goto out;
+			pud_populate_kernel(&init_mm, pu_dir, pm_dir);
+		}
+
+		pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
+		pm_dir = pmd_offset(pu_dir, address);
+
+#ifdef __s390x__
+		if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) &&
+		    (address + HPAGE_SIZE <= start + size) &&
+		    (address >= HPAGE_SIZE)) {
+			pte_val(pte) |= _SEGMENT_ENTRY_LARGE;
+			pmd_val(*pm_dir) = pte_val(pte);
+			address += HPAGE_SIZE - PAGE_SIZE;
+			continue;
+		}
+#endif
+		if (pmd_none(*pm_dir)) {
+			pt_dir = vmem_pte_alloc();
+			if (!pt_dir)
+				goto out;
+			pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
+		}
+
+		pt_dir = pte_offset_kernel(pm_dir, address);
+		*pt_dir = pte;
+	}
+	ret = 0;
+out:
+	flush_tlb_kernel_range(start, start + size);
+	return ret;
+}
+
+/*
+ * Remove a physical memory range from the 1:1 mapping.
+ * Currently only invalidates page table entries.
+ */
+static void vmem_remove_range(unsigned long start, unsigned long size)
+{
+	unsigned long address;
+	pgd_t *pg_dir;
+	pud_t *pu_dir;
+	pmd_t *pm_dir;
+	pte_t *pt_dir;
+	pte_t  pte;
+
+	pte_val(pte) = _PAGE_TYPE_EMPTY;
+	for (address = start; address < start + size; address += PAGE_SIZE) {
+		pg_dir = pgd_offset_k(address);
+		pu_dir = pud_offset(pg_dir, address);
+		if (pud_none(*pu_dir))
+			continue;
+		pm_dir = pmd_offset(pu_dir, address);
+		if (pmd_none(*pm_dir))
+			continue;
+
+		if (pmd_huge(*pm_dir)) {
+			pmd_clear_kernel(pm_dir);
+			address += HPAGE_SIZE - PAGE_SIZE;
+			continue;
+		}
+
+		pt_dir = pte_offset_kernel(pm_dir, address);
+		*pt_dir = pte;
+	}
+	flush_tlb_kernel_range(start, start + size);
+}
+
+/*
+ * Add a backed mem_map array to the virtual mem_map array.
+ */
+int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
+{
+	unsigned long address, start_addr, end_addr;
+	pgd_t *pg_dir;
+	pud_t *pu_dir;
+	pmd_t *pm_dir;
+	pte_t *pt_dir;
+	pte_t  pte;
+	int ret = -ENOMEM;
+
+	start_addr = (unsigned long) start;
+	end_addr = (unsigned long) (start + nr);
+
+	for (address = start_addr; address < end_addr; address += PAGE_SIZE) {
+		pg_dir = pgd_offset_k(address);
+		if (pgd_none(*pg_dir)) {
+			pu_dir = vmem_pud_alloc();
+			if (!pu_dir)
+				goto out;
+			pgd_populate_kernel(&init_mm, pg_dir, pu_dir);
+		}
+
+		pu_dir = pud_offset(pg_dir, address);
+		if (pud_none(*pu_dir)) {
+			pm_dir = vmem_pmd_alloc();
+			if (!pm_dir)
+				goto out;
+			pud_populate_kernel(&init_mm, pu_dir, pm_dir);
+		}
+
+		pm_dir = pmd_offset(pu_dir, address);
+		if (pmd_none(*pm_dir)) {
+			pt_dir = vmem_pte_alloc();
+			if (!pt_dir)
+				goto out;
+			pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
+		}
+
+		pt_dir = pte_offset_kernel(pm_dir, address);
+		if (pte_none(*pt_dir)) {
+			unsigned long new_page;
+
+			new_page =__pa(vmem_alloc_pages(0));
+			if (!new_page)
+				goto out;
+			pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
+			*pt_dir = pte;
+		}
+	}
+	memset(start, 0, nr * sizeof(struct page));
+	ret = 0;
+out:
+	flush_tlb_kernel_range(start_addr, end_addr);
+	return ret;
+}
+
+/*
+ * Add memory segment to the segment list if it doesn't overlap with
+ * an already present segment.
+ */
+static int insert_memory_segment(struct memory_segment *seg)
+{
+	struct memory_segment *tmp;
+
+	if (seg->start + seg->size > VMEM_MAX_PHYS ||
+	    seg->start + seg->size < seg->start)
+		return -ERANGE;
+
+	list_for_each_entry(tmp, &mem_segs, list) {
+		if (seg->start >= tmp->start + tmp->size)
+			continue;
+		if (seg->start + seg->size <= tmp->start)
+			continue;
+		return -ENOSPC;
+	}
+	list_add(&seg->list, &mem_segs);
+	return 0;
+}
+
+/*
+ * Remove memory segment from the segment list.
+ */
+static void remove_memory_segment(struct memory_segment *seg)
+{
+	list_del(&seg->list);
+}
+
+static void __remove_shared_memory(struct memory_segment *seg)
+{
+	remove_memory_segment(seg);
+	vmem_remove_range(seg->start, seg->size);
+}
+
+int vmem_remove_mapping(unsigned long start, unsigned long size)
+{
+	struct memory_segment *seg;
+	int ret;
+
+	mutex_lock(&vmem_mutex);
+
+	ret = -ENOENT;
+	list_for_each_entry(seg, &mem_segs, list) {
+		if (seg->start == start && seg->size == size)
+			break;
+	}
+
+	if (seg->start != start || seg->size != size)
+		goto out;
+
+	ret = 0;
+	__remove_shared_memory(seg);
+	kfree(seg);
+out:
+	mutex_unlock(&vmem_mutex);
+	return ret;
+}
+
+int vmem_add_mapping(unsigned long start, unsigned long size)
+{
+	struct memory_segment *seg;
+	int ret;
+
+	mutex_lock(&vmem_mutex);
+	ret = -ENOMEM;
+	seg = kzalloc(sizeof(*seg), GFP_KERNEL);
+	if (!seg)
+		goto out;
+	seg->start = start;
+	seg->size = size;
+
+	ret = insert_memory_segment(seg);
+	if (ret)
+		goto out_free;
+
+	ret = vmem_add_mem(start, size, 0);
+	if (ret)
+		goto out_remove;
+	goto out;
+
+out_remove:
+	__remove_shared_memory(seg);
+out_free:
+	kfree(seg);
+out:
+	mutex_unlock(&vmem_mutex);
+	return ret;
+}
+
+/*
+ * map whole physical memory to virtual memory (identity mapping)
+ * we reserve enough space in the vmalloc area for vmemmap to hotplug
+ * additional memory segments.
+ */
+void __init vmem_map_init(void)
+{
+	unsigned long ro_start, ro_end;
+	unsigned long start, end;
+	int i;
+
+	INIT_LIST_HEAD(&init_mm.context.crst_list);
+	INIT_LIST_HEAD(&init_mm.context.pgtable_list);
+	init_mm.context.noexec = 0;
+	ro_start = ((unsigned long)&_stext) & PAGE_MASK;
+	ro_end = PFN_ALIGN((unsigned long)&_eshared);
+	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
+		start = memory_chunk[i].addr;
+		end = memory_chunk[i].addr + memory_chunk[i].size;
+		if (start >= ro_end || end <= ro_start)
+			vmem_add_mem(start, end - start, 0);
+		else if (start >= ro_start && end <= ro_end)
+			vmem_add_mem(start, end - start, 1);
+		else if (start >= ro_start) {
+			vmem_add_mem(start, ro_end - start, 1);
+			vmem_add_mem(ro_end, end - ro_end, 0);
+		} else if (end < ro_end) {
+			vmem_add_mem(start, ro_start - start, 0);
+			vmem_add_mem(ro_start, end - ro_start, 1);
+		} else {
+			vmem_add_mem(start, ro_start - start, 0);
+			vmem_add_mem(ro_start, ro_end - ro_start, 1);
+			vmem_add_mem(ro_end, end - ro_end, 0);
+		}
+	}
+}
+
+/*
+ * Convert memory chunk array to a memory segment list so there is a single
+ * list that contains both r/w memory and shared memory segments.
+ */
+static int __init vmem_convert_memory_chunk(void)
+{
+	struct memory_segment *seg;
+	int i;
+
+	mutex_lock(&vmem_mutex);
+	for (i = 0; i < MEMORY_CHUNKS; i++) {
+		if (!memory_chunk[i].size)
+			continue;
+		seg = kzalloc(sizeof(*seg), GFP_KERNEL);
+		if (!seg)
+			panic("Out of memory...\n");
+		seg->start = memory_chunk[i].addr;
+		seg->size = memory_chunk[i].size;
+		insert_memory_segment(seg);
+	}
+	mutex_unlock(&vmem_mutex);
+	return 0;
+}
+
+core_initcall(vmem_convert_memory_chunk);