Merge with Linux 2.4.2.

5 files changed, 875 insertions, 0 deletions

diff --git a/arch/s390x/mm/Makefile b/arch/s390x/mm/Makefile
new file mode 100644
index 000000000..73e25bd30
--- /dev/null
+++ b/arch/s390x/mm/Makefile
@@ -0,0 +1,14 @@
+#
+# Makefile for the linux i386-specific parts of the memory manager.
+#
+# Note! Dependencies are done automagically by 'make dep', which also
+# removes any old dependencies. DON'T put your own dependencies here
+# unless it's something special (ie not a .c file).
+#
+# Note 2! The CFLAGS definition is now in the main makefile...
+
+O_TARGET := mm.o
+
+obj-y	 := init.o fault.o ioremap.o extable.o
+
+include $(TOPDIR)/Rules.make
diff --git a/arch/s390x/mm/extable.c b/arch/s390x/mm/extable.c
new file mode 100644
index 000000000..774e86854
--- /dev/null
+++ b/arch/s390x/mm/extable.c
@@ -0,0 +1,61 @@
+/*
+ *  arch/s390/mm/extable.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/extable.c"
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <asm/uaccess.h>
+
+extern const struct exception_table_entry __start___ex_table[];
+extern const struct exception_table_entry __stop___ex_table[];
+
+static inline unsigned long
+search_one_table(const struct exception_table_entry *first,
+		 const struct exception_table_entry *last,
+		 unsigned long value)
+{
+        while (first <= last) {
+		const struct exception_table_entry *mid;
+		long diff;
+
+		mid = (last - first) / 2 + first;
+		diff = mid->insn - value;
+                if (diff == 0)
+                        return mid->fixup;
+                else if (diff < 0)
+                        first = mid+1;
+                else
+                        last = mid-1;
+        }
+        return 0;
+}
+
+unsigned long
+search_exception_table(unsigned long addr)
+{
+	unsigned long ret;
+
+#ifndef CONFIG_MODULES
+	/* There is only the kernel to search.  */
+	ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr);
+	if (ret) return FIX_PSW(ret);
+#else
+	/* The kernel is the last "module" -- no need to treat it special.  */
+	struct module *mp;
+	for (mp = module_list; mp != NULL; mp = mp->next) {
+		if (mp->ex_table_start == NULL)
+			continue;
+		ret = search_one_table(mp->ex_table_start,
+				       mp->ex_table_end - 1, addr);
+		if (ret) return FIX_PSW(ret);
+	}
+#endif
+
+	return 0;
+}
diff --git a/arch/s390x/mm/fault.c b/arch/s390x/mm/fault.c
new file mode 100644
index 000000000..4c324b690
--- /dev/null
+++ b/arch/s390x/mm/fault.c
@@ -0,0 +1,266 @@
+/*
+ *  arch/s390/mm/fault.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/fault.c"
+ *    Copyright (C) 1995  Linus Torvalds
+ */
+
+#include <linux/config.h>
+#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/smp_lock.h>
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/hardirq.h>
+
+#ifdef CONFIG_SYSCTL
+extern int sysctl_userprocess_debug;
+#endif
+
+extern void die(const char *,struct pt_regs *,long);
+
+/*
+ * 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:
+ *             ****0004       Protection           ->  Write-Protection  (suprression)
+ *             ****0010       Segment translation  ->  Not present       (nullification)
+ *             ****0011       Page translation     ->  Not present       (nullification)
+ *             ****003B       Region third exception ->  Not present       (nullification)
+ */
+asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code)
+{
+        struct task_struct *tsk;
+        struct mm_struct *mm;
+        struct vm_area_struct * vma;
+        unsigned long address;
+        unsigned long fixup;
+        int write;
+        unsigned long psw_mask;
+        unsigned long psw_addr;
+	int si_code = SEGV_MAPERR;
+	int kernel_address = 0;
+
+        /*
+         *  get psw mask of Program old psw to find out,
+         *  if user or kernel mode
+         */
+
+        psw_mask = S390_lowcore.program_old_psw.mask;
+        psw_addr = S390_lowcore.program_old_psw.addr;
+
+        /* 
+         * get the failing address 
+         * more specific the segment and page table portion of 
+         * the address 
+         */
+
+        address = S390_lowcore.trans_exc_code&-4096L;
+
+        tsk = current;
+        mm = tsk->mm;
+
+        if (in_interrupt() || !mm)
+                goto no_context;
+
+	/*
+	 * Check which address space the address belongs to
+	 */
+	switch (S390_lowcore.trans_exc_code & 3)
+	{
+	case 0: /* Primary Segment Table Descriptor */
+		kernel_address = 1;
+		goto no_context;
+
+	case 1: /* STD determined via access register */
+		if (S390_lowcore.exc_access_id == 0)
+		{
+			kernel_address = 1;
+			goto no_context;
+		}
+		if (regs && S390_lowcore.exc_access_id < NUM_ACRS)
+		{
+			if (regs->acrs[S390_lowcore.exc_access_id] == 0)
+			{
+				kernel_address = 1;
+				goto no_context;
+			}
+			if (regs->acrs[S390_lowcore.exc_access_id] == 1)
+			{
+				/* user space address */
+				break;
+			}
+		}
+		die("page fault via unknown access register", regs, error_code);
+		break;
+
+	case 2: /* Secondary Segment Table Descriptor */
+	case 3: /* Home Segment Table Descriptor */
+		/* user space address */
+		break;
+	}
+
+
+	/*
+	 * When we get here, the fault happened in the current
+	 * task's user address space, so we search the VMAs
+	 */
+
+        down(&mm->mmap_sem);
+
+        vma = find_vma(mm, address);
+        if (!vma) {
+	        printk("no vma for address %lX\n",address);
+                goto bad_area;
+        }
+        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:
+        write = 0;
+	si_code = SEGV_ACCERR;
+
+        switch (error_code & 0xFF) {
+                case 0x04:                                /* write, present*/
+                        write = 1;
+                        break;
+                case 0x10:                                   /* not present*/
+                case 0x11:                                   /* not present*/
+                case 0x3B:                                   /* not present*/
+                        if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
+                                goto bad_area;
+                        break;
+                default:
+                       printk("code should be 4, 10 or 11 (%lX) \n",error_code&0xFF);  
+                       goto bad_area;
+        }
+
+	/*
+	 * If for any reason at all we couldn't handle the fault,
+	 * make sure we exit gracefully rather than endlessly redo
+	 * the fault.
+	 */
+	switch (handle_mm_fault(mm, vma, address, write)) {
+	case 1:
+		tsk->min_flt++;
+		break;
+	case 2:
+		tsk->maj_flt++;
+		break;
+	case 0:
+		goto do_sigbus;
+	default:
+		goto out_of_memory;
+	}
+
+        up(&mm->mmap_sem);
+        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(&mm->mmap_sem);
+
+        /* User mode accesses just cause a SIGSEGV */
+        if (psw_mask & PSW_PROBLEM_STATE) {
+		struct siginfo si;
+                tsk->thread.prot_addr = address;
+                tsk->thread.trap_no = error_code;
+#ifndef CONFIG_SYSCTL
+#ifdef CONFIG_PROCESS_DEBUG
+                printk("User process fault: interruption code 0x%lX\n",error_code);
+                printk("failing address: %lX\n",address);
+		show_regs(regs);
+#endif
+#else
+		if (sysctl_userprocess_debug) {
+			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*) address;
+		force_sig_info(SIGSEGV, &si, tsk);
+                return;
+	}
+
+no_context:
+        /* Are we prepared to handle this kernel fault?  */
+        if ((fixup = search_exception_table(regs->psw.addr)) != 0) {
+                regs->psw.addr = fixup;
+                return;
+        }
+
+/*
+ * Oops. The kernel tried to access some bad page. We'll have to
+ * terminate things with extreme prejudice.
+ */
+        if (kernel_address)
+                printk(KERN_ALERT "Unable to handle kernel pointer dereference"
+        	       " at virtual kernel address %016lx\n", address);
+        else
+                printk(KERN_ALERT "Unable to handle kernel paging request"
+		       " at virtual user address %016lx\n", address);
+
+/*
+ * need to define, which information is useful here
+ */
+
+        die("Oops", regs, error_code);
+        do_exit(SIGKILL);
+
+
+/*
+ * We ran out of memory, or some other thing happened to us that made
+ * us unable to handle the page fault gracefully.
+*/
+out_of_memory:
+	up(&mm->mmap_sem);
+	printk("VM: killing process %s\n", tsk->comm);
+	if (psw_mask & PSW_PROBLEM_STATE)
+		do_exit(SIGKILL);
+	goto no_context;
+
+do_sigbus:
+	up(&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 (!(psw_mask & PSW_PROBLEM_STATE))
+		goto no_context;
+}
diff --git a/arch/s390x/mm/init.c b/arch/s390x/mm/init.c
new file mode 100644
index 000000000..91d66ccfe
--- /dev/null
+++ b/arch/s390x/mm/init.c
@@ -0,0 +1,405 @@
+/*
+ *  arch/s390/mm/init.c
+ *
+ *  S390 version
+ *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Hartmut Penner (hpenner@de.ibm.com)
+ *
+ *  Derived from "arch/i386/mm/init.c"
+ *    Copyright (C) 1995  Linus Torvalds
+ */
+
+#include <linux/config.h>
+#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>
+#ifdef CONFIG_BLK_DEV_INITRD
+#include <linux/blk.h>
+#endif
+#include <linux/pagemap.h>
+#include <linux/bootmem.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>
+
+static unsigned long totalram_pages;
+
+/*
+ * empty_bad_page is the page that is used for page faults when linux
+ * is out-of-memory. Older versions of linux just did a
+ * do_exit(), but using this instead means there is less risk
+ * for a process dying in kernel mode, possibly leaving an inode
+ * unused etc..
+ *
+ * empty_bad_pte_table is the accompanying page-table: it is initialized
+ * to point to BAD_PAGE entries.
+ *
+ * empty_bad_pmd_table is the accompanying segment table: it is initialized
+ * to point to empty_bad_pte_table page tables.
+ *
+ * ZERO_PAGE is a special page that is used for zero-initialized
+ * data and COW.
+ */
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
+char  empty_bad_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+pmd_t empty_bad_pmd_table[PTRS_PER_PMD] __attribute__((__aligned__(PAGE_SIZE)));
+pte_t empty_bad_pte_table[PTRS_PER_PTE] __attribute__((__aligned__(PAGE_SIZE)));
+
+static int test_access(unsigned long loc)
+{
+	static const int ssm_mask = 0x07000000L;
+	int rc, i;
+
+        rc = 0;
+	for (i=0; i<2; i++) {
+		__asm__ __volatile__(
+                        "    slgr  %0,%0\n"
+			"    ssm   %1\n"
+			"    tprot 0(%2),0\n"
+			"0:  jne   1f\n"
+			"    lghi  %0,1\n"
+			"1:  ssm   %3\n"
+                        ".section __ex_table,\"a\"\n"
+                        "   .align 8\n"
+                        "   .quad  0b,1b\n"
+                        ".previous"
+			: "+&d" (rc) : "i" (0), "a" (loc), "m" (ssm_mask)
+			: "cc");
+		if (rc == 0)
+			break;
+		loc += 0x100000;
+	}
+	return rc;
+}
+
+static pmd_t *get_bad_pmd_table(void)
+{
+       pmd_t v;
+       int i;
+
+       pmd_set(&v, empty_bad_pte_table);
+
+       for (i = 0; i < PTRS_PER_PMD; i++)
+               empty_bad_pmd_table[i] = v;
+
+       return empty_bad_pmd_table;
+}
+
+static pte_t *get_bad_pte_table(void)
+{
+	pte_t v;
+	int i;
+
+	v = pte_mkdirty(mk_pte_phys(__pa(empty_bad_page), PAGE_SHARED));
+
+	for (i = 0; i < PAGE_SIZE/sizeof(pte_t); i++)
+		empty_bad_pte_table[i] = v;
+
+	return empty_bad_pte_table;
+}
+
+pmd_t *
+get_pmd_slow(pgd_t *pgd, unsigned long offset)
+{
+        pmd_t *pmd;
+        int i;
+
+        pmd = (pmd_t *) __get_free_pages(GFP_KERNEL,2);
+        if (pgd_none(*pgd)) {
+                if (pmd) {
+                        for (i = 0; i < PTRS_PER_PMD; i++)
+                                pmd_clear(pmd+i);
+                        pgd_set(pgd, pmd);
+                        return pmd + offset;
+                }
+                pmd = (pmd_t *) get_bad_pmd_table();
+                pgd_set(pgd, pmd);
+                return NULL;
+        }
+        free_pages((unsigned long)pmd,2);
+        if (pgd_bad(*pgd))
+		BUG();
+        return (pmd_t *) pgd_page(*pgd) + offset;
+}
+
+pte_t *get_pte_slow(pmd_t *pmd, unsigned long offset)
+{
+        pte_t *pte;
+        int i;
+
+        pte = (pte_t*) __get_free_page(GFP_KERNEL);
+        if (pmd_none(*pmd)) {
+                if (pte) {
+                        for (i=0;i<PTRS_PER_PTE;i++)
+                                pte_clear(pte+i);
+                        pmd_set(pmd,pte);
+                        return pte + offset;
+                }
+		pte = (pte_t*) get_bad_pte_table();
+                pmd_set(pmd,pte);
+                return NULL;
+        }
+        free_page(__pa(pte));
+        if (pmd_bad(*pmd))
+		BUG();
+        return (pte_t *) pmd_page(*pmd) + offset;
+}
+
+int do_check_pgt_cache(int low, int high)
+{
+        int freed = 0;
+        if(pgtable_cache_size > high) {
+                do {
+                        if(pgd_quicklist)
+                                free_pgd_slow(get_pgd_fast()), freed += 4;
+                        if(pmd_quicklist)
+                                free_pmd_slow(get_pmd_fast()), freed += 4;
+                        if(pte_quicklist)
+                                free_pte_slow(get_pte_fast()), freed++;
+                } while(pgtable_cache_size > low);
+        }
+        return freed;
+}
+
+void show_mem(void)
+{
+        int i, total = 0,reserved = 0;
+        int shared = 0, cached = 0;
+
+        printk("Mem-info:\n");
+        show_free_areas();
+        printk("Free swap:       %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
+        i = max_mapnr;
+        while (i-- > 0) {
+                total++;
+                if (PageReserved(mem_map+i))
+                        reserved++;
+                else if (PageSwapCache(mem_map+i))
+                        cached++;
+                else if (page_count(mem_map+i))
+                        shared += atomic_read(&mem_map[i].count) - 1;
+        }
+        printk("%d pages of RAM\n",total);
+        printk("%d reserved pages\n",reserved);
+        printk("%d pages shared\n",shared);
+        printk("%d pages swap cached\n",cached);
+        printk("%ld pages in page table cache\n",pgtable_cache_size);
+        show_buffers();
+}
+
+/* References to section boundaries */
+
+extern unsigned long _text;
+extern unsigned long _etext;
+extern unsigned long _edata;
+extern unsigned long __bss_start;
+extern unsigned long _end;
+
+extern unsigned long __init_begin;
+extern unsigned long __init_end;
+
+/*
+ * paging_init() sets up the page tables
+ */
+
+unsigned long last_valid_pfn;
+
+void __init paging_init(void)
+{
+        pgd_t * pg_dir;
+	pmd_t * pm_dir;
+        pte_t * pt_dir;
+        pte_t   pte;
+	int     i,j,k;
+        unsigned long address=0;
+        unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
+          _REGION_TABLE;
+	unsigned long end_mem = (unsigned long) __va(max_low_pfn*PAGE_SIZE);
+	static const int ssm_mask = 0x04000000L;
+
+	unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
+	unsigned long dma_pfn, high_pfn;
+
+	dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
+	high_pfn = max_low_pfn;
+
+	if (dma_pfn > high_pfn)
+		zones_size[ZONE_DMA] = high_pfn;
+	else {
+		zones_size[ZONE_DMA] = dma_pfn;
+		zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
+	}
+
+	/* Initialize mem_map[].  */
+	free_area_init(zones_size);
+
+
+	/*
+	 * map whole physical memory to virtual memory (identity mapping) 
+	 */
+
+        pg_dir = swapper_pg_dir;
+	
+        for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
+
+                if (address >= end_mem) {
+                  pgd_clear(pg_dir);
+                  continue;
+                }          
+        
+	        pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
+                pgd_set(pg_dir,pm_dir);
+
+                for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
+                  if (address >= end_mem) {
+                    pmd_clear(pm_dir);
+                    continue; 
+                  }          
+
+                        pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+                        pmd_set(pm_dir,pt_dir);
+	
+                        for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
+                          pte = mk_pte_phys(address, PAGE_KERNEL);
+                          if (address >= end_mem) {
+                            pte_clear(&pte); 
+                            continue;
+                          }
+                          set_pte(pt_dir, pte);
+                          address += PAGE_SIZE;
+                        }
+                }
+        }
+
+        /* enable virtual mapping in kernel mode */
+        __asm__ __volatile__("lctlg 1,1,%0\n\t"
+                             "lctlg 7,7,%0\n\t"
+                             "lctlg 13,13,%0\n\t"
+                             "ssm   %1"
+			     : :"m" (pgdir_k), "m" (ssm_mask));
+
+        local_flush_tlb();
+
+        return;
+}
+
+void __init mem_init(void)
+{
+	unsigned long codesize, reservedpages, datasize, initsize;
+        unsigned long tmp;
+
+        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);
+
+	/* this will put all low memory onto the freelists */
+	totalram_pages += free_all_bootmem();
+
+        /* mark usable pages in the mem_map[] and count reserved pages */
+	reservedpages = 0;
+	tmp = 0;
+	do {
+		if (tmp && (tmp & 0x1ff) == 0 && 
+                    test_access(tmp * PAGE_SIZE) == 0) {
+                        printk("2M Segment 0x%016lX not available\n",
+                               tmp * PAGE_SIZE);
+			do {
+                                set_bit(PG_reserved, &mem_map[tmp].flags);
+				reservedpages++;
+				tmp++;
+			} while (tmp < max_low_pfn && (tmp & 0x1ff));
+		} else {
+			if (PageReserved(mem_map+tmp))
+				reservedpages++;
+			tmp++;
+		}
+	} while (tmp < max_low_pfn);
+
+	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);
+}
+
+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));
+		set_page_count(virt_to_page(addr), 1);
+		free_page(addr);
+		totalram_pages++;
+        }
+        printk ("Freeing unused kernel memory: %ldk freed\n",
+		(&__init_end - &__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));
+                set_page_count(virt_to_page(start), 1);
+		free_page(start);
+		totalram_pages++;
+	}
+}
+#endif
+
+void si_meminfo(struct sysinfo *val)
+{
+        val->totalram = totalram_pages;
+	val->sharedram = 0;
+	val->freeram = nr_free_pages();
+	val->bufferram = atomic_read(&buffermem_pages);
+	val->totalhigh = 0;
+	val->freehigh = 0;
+	val->mem_unit = PAGE_SIZE;
+}
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only.  This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-indent-level: 4 
+ * c-brace-imaginary-offset: 0
+ * c-brace-offset: -4
+ * c-argdecl-indent: 4
+ * c-label-offset: -4
+ * c-continued-statement-offset: 4
+ * c-continued-brace-offset: 0
+ * indent-tabs-mode: nil
+ * tab-width: 8
+ * End:
+ */
diff --git a/arch/s390x/mm/ioremap.c b/arch/s390x/mm/ioremap.c
new file mode 100644
index 000000000..38acc4a22
--- /dev/null
+++ b/arch/s390x/mm/ioremap.c
@@ -0,0 +1,129 @@
+/*
+ *  arch/s390/mm/ioremap.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/extable.c"
+ *    (C) Copyright 1995 1996 Linus Torvalds
+ *
+ * Re-map IO memory to kernel address space so that we can access it.
+ * This is needed for high PCI addresses that aren't mapped in the
+ * 640k-1MB IO memory area on PC's
+ */
+
+#include <linux/vmalloc.h>
+#include <asm/io.h>
+#include <asm/pgalloc.h>
+
+static inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
+        unsigned long phys_addr, unsigned long flags)
+{
+        unsigned long end;
+
+        address &= ~PMD_MASK;
+        end = address + size;
+        if (end > PMD_SIZE)
+                end = PMD_SIZE;
+	if (address >= end)
+		BUG();
+        do {
+                if (!pte_none(*pte)) {
+                        printk("remap_area_pte: page already exists\n");
+			BUG();
+		}
+                set_pte(pte, mk_pte_phys(phys_addr,
+                                         __pgprot(_PAGE_PRESENT | flags)));
+                address += PAGE_SIZE;
+                phys_addr += PAGE_SIZE;
+                pte++;
+        } while (address && (address < end));
+}
+
+static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
+        unsigned long phys_addr, unsigned long flags)
+{
+	unsigned long end;
+
+	address &= ~PGDIR_MASK;
+	end = address + size;
+	if (end > PGDIR_SIZE)
+		end = PGDIR_SIZE;
+	phys_addr -= address;
+	if (address >= end)
+		BUG();
+	do {
+		pte_t * pte = pte_alloc_kernel(pmd, address);
+		if (!pte)
+			return -ENOMEM;
+		remap_area_pte(pte, address, end - address, address + phys_addr, flags);
+		address = (address + PMD_SIZE) & PMD_MASK;
+		pmd++;
+	} while (address && (address < end));
+	return 0;
+}
+
+static int remap_area_pages(unsigned long address, unsigned long phys_addr,
+				 unsigned long size, unsigned long flags)
+{
+	pgd_t * dir;
+	unsigned long end = address + size;
+
+	phys_addr -= address;
+	dir = pgd_offset(&init_mm, address);
+	flush_cache_all();
+	if (address >= end)
+		BUG();
+	do {
+		pmd_t *pmd = pmd_alloc_kernel(dir, address);
+		if (!pmd)
+			return -ENOMEM;
+		if (remap_area_pmd(pmd, address, end - address,
+					 phys_addr + address, flags))
+			return -ENOMEM;
+		set_pgdir(address, *dir);
+		address = (address + PGDIR_SIZE) & PGDIR_MASK;
+		dir++;
+	} while (address && (address < end));
+	flush_tlb_all();
+	return 0;
+}
+
+/*
+ * Generic mapping function (not visible outside):
+ */
+
+/*
+ * Remap an arbitrary physical address space into the kernel virtual
+ * address space. Needed when the kernel wants to access high addresses
+ * directly.
+ */
+void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
+{
+	void * addr;
+	struct vm_struct * area;
+
+	if (phys_addr < virt_to_phys(high_memory))
+		return phys_to_virt(phys_addr);
+	if (phys_addr & ~PAGE_MASK)
+		return NULL;
+	size = PAGE_ALIGN(size);
+	if (!size || size > phys_addr + size)
+		return NULL;
+	area = get_vm_area(size, VM_IOREMAP);
+	if (!area)
+		return NULL;
+	addr = area->addr;
+	if (remap_area_pages(VMALLOC_VMADDR(addr), phys_addr, size, flags)) {
+		vfree(addr);
+		return NULL;
+	}
+	return addr;
+}
+
+void iounmap(void *addr)
+{
+	if (addr > high_memory)
+		return vfree(addr);
+}