OpenRISC: Memory management

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

11 files changed, 1328 insertions, 0 deletions

diff --git a/arch/openrisc/include/asm/cache.h b/arch/openrisc/include/asm/cache.h
new file mode 100644
index 000000000000..4ce7a01a252d
--- /dev/null
+++ b/arch/openrisc/include/asm/cache.h
@@ -0,0 +1,29 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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.
+ */
+
+#ifndef __ASM_OPENRISC_CACHE_H
+#define __ASM_OPENRISC_CACHE_H
+
+/* FIXME: How can we replace these with values from the CPU...
+ * they shouldn't be hard-coded!
+ */
+
+#define L1_CACHE_BYTES 16
+#define L1_CACHE_SHIFT 4
+
+#endif /* __ASM_OPENRISC_CACHE_H */
diff --git a/arch/openrisc/include/asm/fixmap.h b/arch/openrisc/include/asm/fixmap.h
new file mode 100644
index 000000000000..52733416c1f3
--- /dev/null
+++ b/arch/openrisc/include/asm/fixmap.h
@@ -0,0 +1,87 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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.
+ */
+
+#ifndef __ASM_OPENRISC_FIXMAP_H
+#define __ASM_OPENRISC_FIXMAP_H
+
+/* Why exactly do we need 2 empty pages between the top of the fixed
+ * addresses and the top of virtual memory?  Something is using that
+ * memory space but not sure what right now... If you find it, leave
+ * a comment here.
+ */
+#define FIXADDR_TOP     ((unsigned long) (-2*PAGE_SIZE))
+
+#include <linux/kernel.h>
+#include <asm/page.h>
+
+/*
+ * On OpenRISC we use these special fixed_addresses for doing ioremap
+ * early in the boot process before memory initialization is complete.
+ * This is used, in particular, by the early serial console code.
+ *
+ * It's not really 'fixmap', per se, but fits loosely into the same
+ * paradigm.
+ */
+enum fixed_addresses {
+        /*
+         * FIX_IOREMAP entries are useful for mapping physical address
+         * space before ioremap() is useable, e.g. really early in boot
+         * before kmalloc() is working.
+         */
+#define FIX_N_IOREMAPS  32
+        FIX_IOREMAP_BEGIN,
+        FIX_IOREMAP_END = FIX_IOREMAP_BEGIN + FIX_N_IOREMAPS - 1,
+        __end_of_fixed_addresses
+};
+
+#define FIXADDR_SIZE            (__end_of_fixed_addresses << PAGE_SHIFT)
+/* FIXADDR_BOTTOM might be a better name here... */
+#define FIXADDR_START           (FIXADDR_TOP - FIXADDR_SIZE)
+
+#define __fix_to_virt(x)        (FIXADDR_TOP - ((x) << PAGE_SHIFT))
+#define __virt_to_fix(x)        ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
+
+/*
+ * 'index to address' translation. If anyone tries to use the idx
+ * directly without tranlation, we catch the bug with a NULL-deference
+ * kernel oops. Illegal ranges of incoming indices are caught too.
+ */
+static __always_inline unsigned long fix_to_virt(const unsigned int idx)
+{
+        /*
+         * this branch gets completely eliminated after inlining,
+         * except when someone tries to use fixaddr indices in an
+         * illegal way. (such as mixing up address types or using
+         * out-of-range indices).
+         *
+         * If it doesn't get removed, the linker will complain
+         * loudly with a reasonably clear error message..
+         */
+        if (idx >= __end_of_fixed_addresses)
+                BUG();
+
+        return __fix_to_virt(idx);
+}
+
+static inline unsigned long virt_to_fix(const unsigned long vaddr)
+{
+        BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
+        return __virt_to_fix(vaddr);
+}
+
+#endif
diff --git a/arch/openrisc/include/asm/memblock.h b/arch/openrisc/include/asm/memblock.h
new file mode 100644
index 000000000000..bbe5a1c788cb
--- /dev/null
+++ b/arch/openrisc/include/asm/memblock.h
@@ -0,0 +1,24 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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.
+ */
+
+#ifndef __ASM_OPENRISC_MEMBLOCK_H
+#define __ASM_OPENRISC_MEMBLOCK_H
+
+/* empty */
+
+#endif /* __ASM_OPENRISC_MEMBLOCK_H */
diff --git a/arch/openrisc/include/asm/mmu.h b/arch/openrisc/include/asm/mmu.h
new file mode 100644
index 000000000000..d069bc2ddfa4
--- /dev/null
+++ b/arch/openrisc/include/asm/mmu.h
@@ -0,0 +1,26 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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.
+ */
+
+#ifndef __ASM_OPENRISC_MMU_H
+#define __ASM_OPENRISC_MMU_H
+
+#ifndef __ASSEMBLY__
+typedef unsigned long mm_context_t;
+#endif
+
+#endif
diff --git a/arch/openrisc/include/asm/mmu_context.h b/arch/openrisc/include/asm/mmu_context.h
new file mode 100644
index 000000000000..e94b814d2e3c
--- /dev/null
+++ b/arch/openrisc/include/asm/mmu_context.h
@@ -0,0 +1,43 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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.
+ */
+
+#ifndef __ASM_OPENRISC_MMU_CONTEXT_H
+#define __ASM_OPENRISC_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>
+
+extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
+extern void destroy_context(struct mm_struct *mm);
+extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+                      struct task_struct *tsk);
+
+#define deactivate_mm(tsk, mm)  do { } while (0)
+
+#define activate_mm(prev, next) switch_mm((prev), (next), NULL)
+
+/* current active pgd - this is similar to other processors pgd
+ * registers like cr3 on the i386
+ */
+
+extern volatile pgd_t *current_pgd;   /* defined in arch/openrisc/mm/fault.c */
+
+static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+{
+}
+
+#endif
diff --git a/arch/openrisc/include/asm/page.h b/arch/openrisc/include/asm/page.h
new file mode 100644
index 000000000000..b041b344b229
--- /dev/null
+++ b/arch/openrisc/include/asm/page.h
@@ -0,0 +1,110 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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.
+ */
+
+#ifndef __ASM_OPENRISC_PAGE_H
+#define __ASM_OPENRISC_PAGE_H
+
+
+/* PAGE_SHIFT determines the page size */
+
+#define PAGE_SHIFT      13
+#ifdef __ASSEMBLY__
+#define PAGE_SIZE       (1 << PAGE_SHIFT)
+#else
+#define PAGE_SIZE       (1UL << PAGE_SHIFT)
+#endif
+#define PAGE_MASK       (~(PAGE_SIZE-1))
+
+#define PAGE_OFFSET     0xc0000000
+#define KERNELBASE      PAGE_OFFSET
+
+/* This is not necessarily the right place for this, but it's needed by
+ * drivers/of/fdt.c
+ */
+#include <asm/setup.h>
+
+#ifndef __ASSEMBLY__
+
+#define get_user_page(vaddr)            __get_free_page(GFP_KERNEL)
+#define free_user_page(page, addr)      free_page(addr)
+
+#define clear_page(page)        memset((page), 0, PAGE_SIZE)
+#define copy_page(to, from)     memcpy((to), (from), PAGE_SIZE)
+
+#define clear_user_page(page, vaddr, pg)        clear_page(page)
+#define copy_user_page(to, from, vaddr, pg)     copy_page(to, from)
+
+/*
+ * These are used to make use of C type-checking..
+ */
+typedef struct {
+        unsigned long pte;
+} pte_t;
+typedef struct {
+        unsigned long pgd;
+} pgd_t;
+typedef struct {
+        unsigned long pgprot;
+} pgprot_t;
+typedef struct page *pgtable_t;
+
+#define pte_val(x)      ((x).pte)
+#define pgd_val(x)      ((x).pgd)
+#define pgprot_val(x)   ((x).pgprot)
+
+#define __pte(x)        ((pte_t) { (x) })
+#define __pgd(x)        ((pgd_t) { (x) })
+#define __pgprot(x)     ((pgprot_t) { (x) })
+
+extern unsigned long memory_start;
+extern unsigned long memory_end;
+
+#endif /* !__ASSEMBLY__ */
+
+
+#ifndef __ASSEMBLY__
+
+#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET))
+#define __pa(x) ((unsigned long) (x) - PAGE_OFFSET)
+
+#define virt_to_pfn(kaddr)      (__pa(kaddr) >> PAGE_SHIFT)
+#define pfn_to_virt(pfn)        __va((pfn) << PAGE_SHIFT)
+
+#define virt_to_page(addr) \
+        (mem_map + (((unsigned long)(addr)-PAGE_OFFSET) >> PAGE_SHIFT))
+#define page_to_virt(page) \
+        ((((page) - mem_map) << PAGE_SHIFT) + PAGE_OFFSET)
+
+#define page_to_phys(page)      ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
+
+#define pfn_valid(pfn)          ((pfn) < max_mapnr)
+
+#define virt_addr_valid(kaddr)  (((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
+                                ((void *)(kaddr) < (void *)memory_end))
+
+#endif /* __ASSEMBLY__ */
+
+
+#define VM_DATA_DEFAULT_FLAGS   (VM_READ | VM_WRITE | VM_EXEC | \
+                                 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+
+
+#include <asm-generic/memory_model.h>
+#include <asm-generic/getorder.h>
+
+#endif /* __ASM_OPENRISC_PAGE_H */
diff --git a/arch/openrisc/include/asm/pgalloc.h b/arch/openrisc/include/asm/pgalloc.h
new file mode 100644
index 000000000000..05c39ecd2efd
--- /dev/null
+++ b/arch/openrisc/include/asm/pgalloc.h
@@ -0,0 +1,102 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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.
+ */
+
+#ifndef __ASM_OPENRISC_PGALLOC_H
+#define __ASM_OPENRISC_PGALLOC_H
+
+#include <asm/page.h>
+#include <linux/threads.h>
+#include <linux/mm.h>
+#include <linux/memblock.h>
+#include <linux/bootmem.h>
+
+extern int mem_init_done;
+
+#define pmd_populate_kernel(mm, pmd, pte) \
+        set_pmd(pmd, __pmd(_KERNPG_TABLE + __pa(pte)))
+
+static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
+                                struct page *pte)
+{
+        set_pmd(pmd, __pmd(_KERNPG_TABLE +
+                     ((unsigned long)page_to_pfn(pte) <<
+                     (unsigned long) PAGE_SHIFT)));
+}
+
+/*
+ * Allocate and free page tables.
+ */
+static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+        pgd_t *ret = (pgd_t *)__get_free_page(GFP_KERNEL);
+
+        if (ret) {
+                memset(ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
+                memcpy(ret + USER_PTRS_PER_PGD,
+                       swapper_pg_dir + USER_PTRS_PER_PGD,
+                       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+
+        }
+        return ret;
+}
+
+#if 0
+/* FIXME: This seems to be the preferred style, but we are using
+ * current_pgd (from mm->pgd) to load kernel pages so we need it
+ * initialized.  This needs to be looked into.
+ */
+extern inline pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+        return (pgd_t *)get_zeroed_page(GFP_KERNEL);
+}
+#endif
+
+static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+        free_page((unsigned long)pgd);
+}
+
+extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address);
+
+static inline struct page *pte_alloc_one(struct mm_struct *mm,
+                                         unsigned long address)
+{
+        struct page *pte;
+        pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
+        if (pte)
+                clear_page(page_address(pte));
+        return pte;
+}
+
+static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
+{
+        free_page((unsigned long)pte);
+}
+
+static inline void pte_free(struct mm_struct *mm, struct page *pte)
+{
+        __free_page(pte);
+}
+
+
+#define __pte_free_tlb(tlb, pte, addr) tlb_remove_page((tlb), (pte))
+#define pmd_pgtable(pmd) pmd_page(pmd)
+
+#define check_pgt_cache()          do { } while (0)
+
+#endif
diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h
new file mode 100644
index 000000000000..043505d7f684
--- /dev/null
+++ b/arch/openrisc/include/asm/pgtable.h
@@ -0,0 +1,463 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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.
+ */
+
+/* or32 pgtable.h - macros and functions to manipulate page tables
+ *
+ * Based on:
+ * include/asm-cris/pgtable.h
+ */
+
+#ifndef __ASM_OPENRISC_PGTABLE_H
+#define __ASM_OPENRISC_PGTABLE_H
+
+#include <asm-generic/pgtable-nopmd.h>
+
+#ifndef __ASSEMBLY__
+#include <asm/mmu.h>
+#include <asm/fixmap.h>
+
+/*
+ * The Linux memory management assumes a three-level page table setup. On
+ * or32, we use that, but "fold" the mid level into the top-level page
+ * table. Since the MMU TLB is software loaded through an interrupt, it
+ * supports any page table structure, so we could have used a three-level
+ * setup, but for the amounts of memory we normally use, a two-level is
+ * probably more efficient.
+ *
+ * This file contains the functions and defines necessary to modify and use
+ * the or32 page table tree.
+ */
+
+extern void paging_init(void);
+
+/* Certain architectures need to do special things when pte's
+ * within a page table are directly modified.  Thus, the following
+ * hook is made available.
+ */
+#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval))
+#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
+/*
+ * (pmds are folded into pgds so this doesn't get actually called,
+ * but the define is needed for a generic inline function.)
+ */
+#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)
+
+#define PGDIR_SHIFT     (PAGE_SHIFT + (PAGE_SHIFT-2))
+#define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
+#define PGDIR_MASK      (~(PGDIR_SIZE-1))
+
+/*
+ * entries per page directory level: we use a two-level, so
+ * we don't really have any PMD directory physically.
+ * pointers are 4 bytes so we can use the page size and
+ * divide it by 4 (shift by 2).
+ */
+#define PTRS_PER_PTE    (1UL << (PAGE_SHIFT-2))
+
+#define PTRS_PER_PGD    (1UL << (PAGE_SHIFT-2))
+
+/* calculate how many PGD entries a user-level program can use
+ * the first mappable virtual address is 0
+ * (TASK_SIZE is the maximum virtual address space)
+ */
+
+#define USER_PTRS_PER_PGD       (TASK_SIZE/PGDIR_SIZE)
+#define FIRST_USER_ADDRESS      0
+
+/*
+ * Kernels own virtual memory area.
+ */
+
+/*
+ * The size and location of the vmalloc area are chosen so that modules
+ * placed in this area aren't more than a 28-bit signed offset from any
+ * kernel functions that they may need.  This greatly simplifies handling
+ * of the relocations for l.j and l.jal instructions as we don't need to
+ * introduce any trampolines for reaching "distant" code.
+ *
+ * 64 MB of vmalloc area is comparable to what's available on other arches.
+ */
+
+#define VMALLOC_START   (PAGE_OFFSET-0x04000000)
+#define VMALLOC_END     (PAGE_OFFSET)
+#define VMALLOC_VMADDR(x) ((unsigned long)(x))
+
+/* Define some higher level generic page attributes.
+ *
+ * If you change _PAGE_CI definition be sure to change it in
+ * io.h for ioremap_nocache() too.
+ */
+
+/*
+ * An OR32 PTE looks like this:
+ *
+ * |  31 ... 10 |  9  |  8 ... 6  |  5  |  4  |  3  |  2  |  1  |  0  |
+ *  Phys pg.num    L     PP Index    D     A    WOM   WBC   CI    CC
+ *
+ *  L  : link
+ *  PPI: Page protection index
+ *  D  : Dirty
+ *  A  : Accessed
+ *  WOM: Weakly ordered memory
+ *  WBC: Write-back cache
+ *  CI : Cache inhibit
+ *  CC : Cache coherent
+ *
+ * The protection bits below should correspond to the layout of the actual
+ * PTE as per above
+ */
+
+#define _PAGE_CC       0x001 /* software: pte contains a translation */
+#define _PAGE_CI       0x002 /* cache inhibit          */
+#define _PAGE_WBC      0x004 /* write back cache       */
+#define _PAGE_FILE     0x004 /* set: pagecache, unset: swap (when !PRESENT) */
+#define _PAGE_WOM      0x008 /* weakly ordered memory  */
+
+#define _PAGE_A        0x010 /* accessed               */
+#define _PAGE_D        0x020 /* dirty                  */
+#define _PAGE_URE      0x040 /* user read enable       */
+#define _PAGE_UWE      0x080 /* user write enable      */
+
+#define _PAGE_SRE      0x100 /* superuser read enable  */
+#define _PAGE_SWE      0x200 /* superuser write enable */
+#define _PAGE_EXEC     0x400 /* software: page is executable */
+#define _PAGE_U_SHARED 0x800 /* software: page is shared in user space */
+
+/* 0x001 is cache coherency bit, which should always be set to
+ *       1 - for SMP (when we support it)
+ *       0 - otherwise
+ *
+ * we just reuse this bit in software for _PAGE_PRESENT and
+ * force it to 0 when loading it into TLB.
+ */
+#define _PAGE_PRESENT  _PAGE_CC
+#define _PAGE_USER     _PAGE_URE
+#define _PAGE_WRITE    (_PAGE_UWE | _PAGE_SWE)
+#define _PAGE_DIRTY    _PAGE_D
+#define _PAGE_ACCESSED _PAGE_A
+#define _PAGE_NO_CACHE _PAGE_CI
+#define _PAGE_SHARED   _PAGE_U_SHARED
+#define _PAGE_READ     (_PAGE_URE | _PAGE_SRE)
+
+#define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define _PAGE_BASE     (_PAGE_PRESENT | _PAGE_ACCESSED)
+#define _PAGE_ALL      (_PAGE_PRESENT | _PAGE_ACCESSED)
+#define _KERNPG_TABLE \
+        (_PAGE_BASE | _PAGE_SRE | _PAGE_SWE | _PAGE_ACCESSED | _PAGE_DIRTY)
+
+#define PAGE_NONE       __pgprot(_PAGE_ALL)
+#define PAGE_READONLY   __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE)
+#define PAGE_READONLY_X __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC)
+#define PAGE_SHARED \
+        __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \
+                 | _PAGE_SHARED)
+#define PAGE_SHARED_X \
+        __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \
+                 | _PAGE_SHARED | _PAGE_EXEC)
+#define PAGE_COPY       __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE)
+#define PAGE_COPY_X     __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC)
+
+#define PAGE_KERNEL \
+        __pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \
+                 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC)
+#define PAGE_KERNEL_RO \
+        __pgprot(_PAGE_ALL | _PAGE_SRE \
+                 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC)
+#define PAGE_KERNEL_NOCACHE \
+        __pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \
+                 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC | _PAGE_CI)
+
+#define __P000  PAGE_NONE
+#define __P001  PAGE_READONLY_X
+#define __P010  PAGE_COPY
+#define __P011  PAGE_COPY_X
+#define __P100  PAGE_READONLY
+#define __P101  PAGE_READONLY_X
+#define __P110  PAGE_COPY
+#define __P111  PAGE_COPY_X
+
+#define __S000  PAGE_NONE
+#define __S001  PAGE_READONLY_X
+#define __S010  PAGE_SHARED
+#define __S011  PAGE_SHARED_X
+#define __S100  PAGE_READONLY
+#define __S101  PAGE_READONLY_X
+#define __S110  PAGE_SHARED
+#define __S111  PAGE_SHARED_X
+
+/* zero page used for uninitialized stuff */
+extern unsigned long empty_zero_page[2048];
+#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
+
+/* number of bits that fit into a memory pointer */
+#define BITS_PER_PTR                    (8*sizeof(unsigned long))
+
+/* to align the pointer to a pointer address */
+#define PTR_MASK                        (~(sizeof(void *)-1))
+
+/* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
+/* 64-bit machines, beware!  SRB. */
+#define SIZEOF_PTR_LOG2                 2
+
+/* to find an entry in a page-table */
+#define PAGE_PTR(address) \
+((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)
+
+/* to set the page-dir */
+#define SET_PAGE_DIR(tsk, pgdir)
+
+#define pte_none(x)     (!pte_val(x))
+#define pte_present(x)  (pte_val(x) & _PAGE_PRESENT)
+#define pte_clear(mm, addr, xp) do { pte_val(*(xp)) = 0; } while (0)
+
+#define pmd_none(x)     (!pmd_val(x))
+#define pmd_bad(x)      ((pmd_val(x) & (~PAGE_MASK)) != _KERNPG_TABLE)
+#define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
+#define pmd_clear(xp)   do { pmd_val(*(xp)) = 0; } while (0)
+
+/*
+ * The following only work if pte_present() is true.
+ * Undefined behaviour if not..
+ */
+
+static inline int pte_read(pte_t pte)  { return pte_val(pte) & _PAGE_READ; }
+static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
+static inline int pte_exec(pte_t pte)  { return pte_val(pte) & _PAGE_EXEC; }
+static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
+static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
+static inline int pte_file(pte_t pte)  { return pte_val(pte) & _PAGE_FILE; }
+static inline int pte_special(pte_t pte) { return 0; }
+static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
+
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+        pte_val(pte) &= ~(_PAGE_WRITE);
+        return pte;
+}
+
+static inline pte_t pte_rdprotect(pte_t pte)
+{
+        pte_val(pte) &= ~(_PAGE_READ);
+        return pte;
+}
+
+static inline pte_t pte_exprotect(pte_t pte)
+{
+        pte_val(pte) &= ~(_PAGE_EXEC);
+        return pte;
+}
+
+static inline pte_t pte_mkclean(pte_t pte)
+{
+        pte_val(pte) &= ~(_PAGE_DIRTY);
+        return pte;
+}
+
+static inline pte_t pte_mkold(pte_t pte)
+{
+        pte_val(pte) &= ~(_PAGE_ACCESSED);
+        return pte;
+}
+
+static inline pte_t pte_mkwrite(pte_t pte)
+{
+        pte_val(pte) |= _PAGE_WRITE;
+        return pte;
+}
+
+static inline pte_t pte_mkread(pte_t pte)
+{
+        pte_val(pte) |= _PAGE_READ;
+        return pte;
+}
+
+static inline pte_t pte_mkexec(pte_t pte)
+{
+        pte_val(pte) |= _PAGE_EXEC;
+        return pte;
+}
+
+static inline pte_t pte_mkdirty(pte_t pte)
+{
+        pte_val(pte) |= _PAGE_DIRTY;
+        return pte;
+}
+
+static inline pte_t pte_mkyoung(pte_t pte)
+{
+        pte_val(pte) |= _PAGE_ACCESSED;
+        return pte;
+}
+
+/*
+ * Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ */
+
+/* What actually goes as arguments to the various functions is less than
+ * obvious, but a rule of thumb is that struct page's goes as struct page *,
+ * really physical DRAM addresses are unsigned long's, and DRAM "virtual"
+ * addresses (the 0xc0xxxxxx's) goes as void *'s.
+ */
+
+static inline pte_t __mk_pte(void *page, pgprot_t pgprot)
+{
+        pte_t pte;
+        /* the PTE needs a physical address */
+        pte_val(pte) = __pa(page) | pgprot_val(pgprot);
+        return pte;
+}
+
+#define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot))
+
+#define mk_pte_phys(physpage, pgprot) \
+({                                                                      \
+        pte_t __pte;                                                    \
+                                                                        \
+        pte_val(__pte) = (physpage) + pgprot_val(pgprot);               \
+        __pte;                                                          \
+})
+
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+        pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
+        return pte;
+}
+
+
+/*
+ * pte_val refers to a page in the 0x0xxxxxxx physical DRAM interval
+ * __pte_page(pte_val) refers to the "virtual" DRAM interval
+ * pte_pagenr refers to the page-number counted starting from the virtual
+ * DRAM start
+ */
+
+static inline unsigned long __pte_page(pte_t pte)
+{
+        /* the PTE contains a physical address */
+        return (unsigned long)__va(pte_val(pte) & PAGE_MASK);
+}
+
+#define pte_pagenr(pte)         ((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT)
+
+/* permanent address of a page */
+
+#define __page_address(page) (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
+#define pte_page(pte)           (mem_map+pte_pagenr(pte))
+
+/*
+ * only the pte's themselves need to point to physical DRAM (see above)
+ * the pagetable links are purely handled within the kernel SW and thus
+ * don't need the __pa and __va transformations.
+ */
+static inline void pmd_set(pmd_t *pmdp, pte_t *ptep)
+{
+        pmd_val(*pmdp) = _KERNPG_TABLE | (unsigned long) ptep;
+}
+
+#define pmd_page(pmd)           (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
+#define pmd_page_kernel(pmd)    ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
+
+/* to find an entry in a page-table-directory. */
+#define pgd_index(address)      ((address >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
+
+#define __pgd_offset(address)   pgd_index(address)
+
+#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
+
+/* to find an entry in a kernel page-table-directory */
+#define pgd_offset_k(address) pgd_offset(&init_mm, address)
+
+#define __pmd_offset(address) \
+        (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
+
+/*
+ * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
+ *
+ * this macro returns the index of the entry in the pte page which would
+ * control the given virtual address
+ */
+#define __pte_offset(address)                   \
+        (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
+#define pte_offset_kernel(dir, address)         \
+        ((pte_t *) pmd_page_kernel(*(dir)) +  __pte_offset(address))
+#define pte_offset_map(dir, address)            \
+        ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
+#define pte_offset_map_nested(dir, address)     \
+        pte_offset_map(dir, address)
+
+#define pte_unmap(pte)          do { } while (0)
+#define pte_unmap_nested(pte)   do { } while (0)
+#define pte_pfn(x)              ((unsigned long)(((x).pte)) >> PAGE_SHIFT)
+#define pfn_pte(pfn, prot)  __pte((((pfn) << PAGE_SHIFT)) | pgprot_val(prot))
+
+#define pte_ERROR(e) \
+        printk(KERN_ERR "%s:%d: bad pte %p(%08lx).\n", \
+               __FILE__, __LINE__, &(e), pte_val(e))
+#define pgd_ERROR(e) \
+        printk(KERN_ERR "%s:%d: bad pgd %p(%08lx).\n", \
+               __FILE__, __LINE__, &(e), pgd_val(e))
+
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* defined in head.S */
+
+/*
+ * or32 doesn't have any external MMU info: the kernel page
+ * tables contain all the necessary information.
+ *
+ * Actually I am not sure on what this could be used for.
+ */
+static inline void update_mmu_cache(struct vm_area_struct *vma,
+        unsigned long address, pte_t *pte)
+{
+}
+
+/* __PHX__ FIXME, SWAP, this probably doesn't work */
+
+/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */
+/* Since the PAGE_PRESENT bit is bit 4, we can use the bits above */
+
+#define __swp_type(x)                   (((x).val >> 5) & 0x7f)
+#define __swp_offset(x)                 ((x).val >> 12)
+#define __swp_entry(type, offset) \
+        ((swp_entry_t) { ((type) << 5) | ((offset) << 12) })
+#define __pte_to_swp_entry(pte)         ((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
+
+/* Encode and decode a nonlinear file mapping entry */
+
+#define PTE_FILE_MAX_BITS               26
+#define pte_to_pgoff(x)                 (pte_val(x) >> 6)
+#define pgoff_to_pte(x)                 __pte(((x) << 6) | _PAGE_FILE)
+
+#define kern_addr_valid(addr)           (1)
+
+#define io_remap_pfn_range(vma, vaddr, pfn, size, prot)         \
+        remap_pfn_range(vma, vaddr, pfn, size, prot)
+
+#include <asm-generic/pgtable.h>
+
+/*
+ * No page table caches to initialise
+ */
+#define pgtable_cache_init()            do { } while (0)
+#define io_remap_page_range             remap_page_range
+
+typedef pte_t *pte_addr_t;
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_OPENRISC_PGTABLE_H */
diff --git a/arch/openrisc/include/asm/tlb.h b/arch/openrisc/include/asm/tlb.h
new file mode 100644
index 000000000000..fa4376a4515d
--- /dev/null
+++ b/arch/openrisc/include/asm/tlb.h
@@ -0,0 +1,34 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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.
+ */
+
+#ifndef __ASM_OPENRISC_TLB_H__
+#define __ASM_OPENRISC_TLB_H__
+
+/*
+ * or32 doesn't need any special per-pte or
+ * per-vma handling..
+ */
+#define tlb_start_vma(tlb, vma) do { } while (0)
+#define tlb_end_vma(tlb, vma) do { } while (0)
+#define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0)
+
+#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm)
+#include <linux/pagemap.h>
+#include <asm-generic/tlb.h>
+
+#endif /* __ASM_OPENRISC_TLB_H__ */
diff --git a/arch/openrisc/include/asm/tlbflush.h b/arch/openrisc/include/asm/tlbflush.h
new file mode 100644
index 000000000000..6a2accd6cb67
--- /dev/null
+++ b/arch/openrisc/include/asm/tlbflush.h
@@ -0,0 +1,55 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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.
+ */
+
+#ifndef __ASM_OPENRISC_TLBFLUSH_H
+#define __ASM_OPENRISC_TLBFLUSH_H
+
+#include <linux/mm.h>
+#include <asm/processor.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/current.h>
+#include <linux/sched.h>
+
+/*
+ *  - flush_tlb() flushes the current mm struct TLBs
+ *  - flush_tlb_all() flushes all processes TLBs
+ *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
+ *  - flush_tlb_page(vma, vmaddr) flushes one page
+ *  - flush_tlb_range(mm, start, end) flushes a range of pages
+ */
+
+void flush_tlb_all(void);
+void flush_tlb_mm(struct mm_struct *mm);
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr);
+void flush_tlb_range(struct vm_area_struct *vma,
+                     unsigned long start,
+                     unsigned long end);
+
+static inline void flush_tlb(void)
+{
+        flush_tlb_mm(current->mm);
+}
+
+static inline void flush_tlb_kernel_range(unsigned long start,
+                                          unsigned long end)
+{
+        flush_tlb_range(NULL, start, end);
+}
+
+#endif /* __ASM_OPENRISC_TLBFLUSH_H */
diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h
new file mode 100644
index 000000000000..c310e45b538e
--- /dev/null
+++ b/arch/openrisc/include/asm/uaccess.h
@@ -0,0 +1,355 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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.
+ */
+
+#ifndef __ASM_OPENRISC_UACCESS_H
+#define __ASM_OPENRISC_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/errno.h>
+#include <linux/thread_info.h>
+#include <linux/prefetch.h>
+#include <linux/string.h>
+#include <linux/thread_info.h>
+#include <asm/page.h>
+
+#define VERIFY_READ     0
+#define VERIFY_WRITE    1
+
+/*
+ * The fs value determines whether argument validity checking should be
+ * performed or not.  If get_fs() == USER_DS, checking is performed, with
+ * get_fs() == KERNEL_DS, checking is bypassed.
+ *
+ * For historical reasons, these macros are grossly misnamed.
+ */
+
+/* addr_limit is the maximum accessible address for the task. we misuse
+ * the KERNEL_DS and USER_DS values to both assign and compare the
+ * addr_limit values through the equally misnamed get/set_fs macros.
+ * (see above)
+ */
+
+#define KERNEL_DS       (~0UL)
+#define get_ds()        (KERNEL_DS)
+
+#define USER_DS         (TASK_SIZE)
+#define get_fs()        (current_thread_info()->addr_limit)
+#define set_fs(x)       (current_thread_info()->addr_limit = (x))
+
+#define segment_eq(a, b)        ((a) == (b))
+
+/* Ensure that the range from addr to addr+size is all within the process'
+ * address space
+ */
+#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size))
+
+/* Ensure that addr is below task's addr_limit */
+#define __addr_ok(addr) ((unsigned long) addr < get_fs())
+
+#define access_ok(type, addr, size) \
+        __range_ok((unsigned long)addr, (unsigned long)size)
+
+/*
+ * The exception table consists of pairs of addresses: the first is the
+ * address of an instruction that is allowed to fault, and the second is
+ * the address at which the program should continue.  No registers are
+ * modified, so it is entirely up to the continuation code to figure out
+ * what to do.
+ *
+ * All the routines below use bits of fixup code that are out of line
+ * with the main instruction path.  This means when everything is well,
+ * we don't even have to jump over them.  Further, they do not intrude
+ * on our cache or tlb entries.
+ */
+
+struct exception_table_entry {
+        unsigned long insn, fixup;
+};
+
+/* Returns 0 if exception not found and fixup otherwise.  */
+extern unsigned long search_exception_table(unsigned long);
+extern void sort_exception_table(void);
+
+/*
+ * These are the main single-value transfer routines.  They automatically
+ * use the right size if we just have the right pointer type.
+ *
+ * This gets kind of ugly. We want to return _two_ values in "get_user()"
+ * and yet we don't want to do any pointers, because that is too much
+ * of a performance impact. Thus we have a few rather ugly macros here,
+ * and hide all the uglyness from the user.
+ *
+ * The "__xxx" versions of the user access functions are versions that
+ * do not verify the address space, that must have been done previously
+ * with a separate "access_ok()" call (this is used when we do multiple
+ * accesses to the same area of user memory).
+ *
+ * As we use the same address space for kernel and user data on the
+ * PowerPC, we can just do these as direct assignments.  (Of course, the
+ * exception handling means that it's no longer "just"...)
+ */
+#define get_user(x, ptr) \
+        __get_user_check((x), (ptr), sizeof(*(ptr)))
+#define put_user(x, ptr) \
+        __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+
+#define __get_user(x, ptr) \
+        __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
+#define __put_user(x, ptr) \
+        __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+
+extern long __put_user_bad(void);
+
+#define __put_user_nocheck(x, ptr, size)                \
+({                                                      \
+        long __pu_err;                                  \
+        __put_user_size((x), (ptr), (size), __pu_err);  \
+        __pu_err;                                       \
+})
+
+#define __put_user_check(x, ptr, size)                                  \
+({                                                                      \
+        long __pu_err = -EFAULT;                                        \
+        __typeof__(*(ptr)) *__pu_addr = (ptr);                          \
+        if (access_ok(VERIFY_WRITE, __pu_addr, size))                   \
+                __put_user_size((x), __pu_addr, (size), __pu_err);      \
+        __pu_err;                                                       \
+})
+
+#define __put_user_size(x, ptr, size, retval)                           \
+do {                                                                    \
+        retval = 0;                                                     \
+        switch (size) {                                                 \
+        case 1: __put_user_asm(x, ptr, retval, "l.sb"); break;          \
+        case 2: __put_user_asm(x, ptr, retval, "l.sh"); break;          \
+        case 4: __put_user_asm(x, ptr, retval, "l.sw"); break;          \
+        case 8: __put_user_asm2(x, ptr, retval); break;                 \
+        default: __put_user_bad();                                      \
+        }                                                               \
+} while (0)
+
+struct __large_struct {
+        unsigned long buf[100];
+};
+#define __m(x) (*(struct __large_struct *)(x))
+
+/*
+ * We don't tell gcc that we are accessing memory, but this is OK
+ * because we do not write to any memory gcc knows about, so there
+ * are no aliasing issues.
+ */
+#define __put_user_asm(x, addr, err, op)                        \
+        __asm__ __volatile__(                                   \
+                "1:     "op" 0(%2),%1\n"                        \
+                "2:\n"                                          \
+                ".section .fixup,\"ax\"\n"                      \
+                "3:     l.addi %0,r0,%3\n"                      \
+                "       l.j 2b\n"                               \
+                "       l.nop\n"                                \
+                ".previous\n"                                   \
+                ".section __ex_table,\"a\"\n"                   \
+                "       .align 2\n"                             \
+                "       .long 1b,3b\n"                          \
+                ".previous"                                     \
+                : "=r"(err)                                     \
+                : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
+
+#define __put_user_asm2(x, addr, err)                           \
+        __asm__ __volatile__(                                   \
+                "1:     l.sw 0(%2),%1\n"                        \
+                "2:     l.sw 4(%2),%H1\n"                       \
+                "3:\n"                                          \
+                ".section .fixup,\"ax\"\n"                      \
+                "4:     l.addi %0,r0,%3\n"                      \
+                "       l.j 3b\n"                               \
+                "       l.nop\n"                                \
+                ".previous\n"                                   \
+                ".section __ex_table,\"a\"\n"                   \
+                "       .align 2\n"                             \
+                "       .long 1b,4b\n"                          \
+                "       .long 2b,4b\n"                          \
+                ".previous"                                     \
+                : "=r"(err)                                     \
+                : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
+
+#define __get_user_nocheck(x, ptr, size)                        \
+({                                                              \
+        long __gu_err, __gu_val;                                \
+        __get_user_size(__gu_val, (ptr), (size), __gu_err);     \
+        (x) = (__typeof__(*(ptr)))__gu_val;                     \
+        __gu_err;                                               \
+})
+
+#define __get_user_check(x, ptr, size)                                  \
+({                                                                      \
+        long __gu_err = -EFAULT, __gu_val = 0;                          \
+        const __typeof__(*(ptr)) * __gu_addr = (ptr);                   \
+        if (access_ok(VERIFY_READ, __gu_addr, size))                    \
+                __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
+        (x) = (__typeof__(*(ptr)))__gu_val;                             \
+        __gu_err;                                                       \
+})
+
+extern long __get_user_bad(void);
+
+#define __get_user_size(x, ptr, size, retval)                           \
+do {                                                                    \
+        retval = 0;                                                     \
+        switch (size) {                                                 \
+        case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break;         \
+        case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break;         \
+        case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break;         \
+        case 8: __get_user_asm2(x, ptr, retval);                        \
+        default: (x) = __get_user_bad();                                \
+        }                                                               \
+} while (0)
+
+#define __get_user_asm(x, addr, err, op)                \
+        __asm__ __volatile__(                           \
+                "1:     "op" %1,0(%2)\n"                \
+                "2:\n"                                  \
+                ".section .fixup,\"ax\"\n"              \
+                "3:     l.addi %0,r0,%3\n"              \
+                "       l.addi %1,r0,0\n"               \
+                "       l.j 2b\n"                       \
+                "       l.nop\n"                        \
+                ".previous\n"                           \
+                ".section __ex_table,\"a\"\n"           \
+                "       .align 2\n"                     \
+                "       .long 1b,3b\n"                  \
+                ".previous"                             \
+                : "=r"(err), "=r"(x)                    \
+                : "r"(addr), "i"(-EFAULT), "0"(err))
+
+#define __get_user_asm2(x, addr, err)                   \
+        __asm__ __volatile__(                           \
+                "1:     l.lwz %1,0(%2)\n"               \
+                "2:     l.lwz %H1,4(%2)\n"              \
+                "3:\n"                                  \
+                ".section .fixup,\"ax\"\n"              \
+                "4:     l.addi %0,r0,%3\n"              \
+                "       l.addi %1,r0,0\n"               \
+                "       l.addi %H1,r0,0\n"              \
+                "       l.j 3b\n"                       \
+                "       l.nop\n"                        \
+                ".previous\n"                           \
+                ".section __ex_table,\"a\"\n"           \
+                "       .align 2\n"                     \
+                "       .long 1b,4b\n"                  \
+                "       .long 2b,4b\n"                  \
+                ".previous"                             \
+                : "=r"(err), "=&r"(x)                   \
+                : "r"(addr), "i"(-EFAULT), "0"(err))
+
+/* more complex routines */
+
+extern unsigned long __must_check
+__copy_tofrom_user(void *to, const void *from, unsigned long size);
+
+#define __copy_from_user(to, from, size) \
+        __copy_tofrom_user(to, from, size)
+#define __copy_to_user(to, from, size) \
+        __copy_tofrom_user(to, from, size)
+
+#define __copy_to_user_inatomic __copy_to_user
+#define __copy_from_user_inatomic __copy_from_user
+
+static inline unsigned long
+copy_from_user(void *to, const void *from, unsigned long n)
+{
+        unsigned long over;
+
+        if (access_ok(VERIFY_READ, from, n))
+                return __copy_tofrom_user(to, from, n);
+        if ((unsigned long)from < TASK_SIZE) {
+                over = (unsigned long)from + n - TASK_SIZE;
+                return __copy_tofrom_user(to, from, n - over) + over;
+        }
+        return n;
+}
+
+static inline unsigned long
+copy_to_user(void *to, const void *from, unsigned long n)
+{
+        unsigned long over;
+
+        if (access_ok(VERIFY_WRITE, to, n))
+                return __copy_tofrom_user(to, from, n);
+        if ((unsigned long)to < TASK_SIZE) {
+                over = (unsigned long)to + n - TASK_SIZE;
+                return __copy_tofrom_user(to, from, n - over) + over;
+        }
+        return n;
+}
+
+extern unsigned long __clear_user(void *addr, unsigned long size);
+
+static inline __must_check unsigned long
+clear_user(void *addr, unsigned long size)
+{
+
+        if (access_ok(VERIFY_WRITE, addr, size))
+                return __clear_user(addr, size);
+        if ((unsigned long)addr < TASK_SIZE) {
+                unsigned long over = (unsigned long)addr + size - TASK_SIZE;
+                return __clear_user(addr, size - over) + over;
+        }
+        return size;
+}
+
+extern int __strncpy_from_user(char *dst, const char *src, long count);
+
+static inline long strncpy_from_user(char *dst, const char *src, long count)
+{
+        if (access_ok(VERIFY_READ, src, 1))
+                return __strncpy_from_user(dst, src, count);
+        return -EFAULT;
+}
+
+/*
+ * Return the size of a string (including the ending 0)
+ *
+ * Return 0 for error
+ */
+
+extern int __strnlen_user(const char *str, long len, unsigned long top);
+
+/*
+ * Returns the length of the string at str (including the null byte),
+ * or 0 if we hit a page we can't access,
+ * or something > len if we didn't find a null byte.
+ *
+ * The `top' parameter to __strnlen_user is to make sure that
+ * we can never overflow from the user area into kernel space.
+ */
+static inline long strnlen_user(const char __user *str, long len)
+{
+        unsigned long top = (unsigned long)get_fs();
+        unsigned long res = 0;
+
+        if (__addr_ok(str))
+                res = __strnlen_user(str, len, top);
+
+        return res;
+}
+
+#define strlen_user(str) strnlen_user(str, TASK_SIZE-1)
+
+#endif /* __ASM_OPENRISC_UACCESS_H */