pgtable.h

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/*
 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2008-2009 PetaLogix
 * Copyright (C) 2006 Atmark Techno, Inc.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#ifndef _ASM_MICROBLAZE_PGTABLE_H
#define _ASM_MICROBLAZE_PGTABLE_H

#include <asm/setup.h>

#define io_remap_pfn_range(vma, vaddr, pfn, size, prot)     \
        remap_pfn_range(vma, vaddr, pfn, size, prot)

#ifndef __ASSEMBLY__
extern int mem_init_done;
#endif

#ifndef CONFIG_MMU

#define pgd_present(pgd)    (1) /* pages are always present on non MMU */
#define pgd_none(pgd)       (0)
#define pgd_bad(pgd)        (0)
#define pgd_clear(pgdp)
#define kern_addr_valid(addr)   (1)
#define pmd_offset(a, b)    ((void *) 0)

#define PAGE_NONE       __pgprot(0) /* these mean nothing to non MMU */
#define PAGE_SHARED     __pgprot(0) /* these mean nothing to non MMU */
#define PAGE_COPY       __pgprot(0) /* these mean nothing to non MMU */
#define PAGE_READONLY       __pgprot(0) /* these mean nothing to non MMU */
#define PAGE_KERNEL     __pgprot(0) /* these mean nothing to non MMU */

#define pgprot_noncached(x) (x)

#define __swp_type(x)       (0)
#define __swp_offset(x)     (0)
#define __swp_entry(typ, off)   ((swp_entry_t) { ((typ) | ((off) << 7)) })
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x)   ((pte_t) { (x).val })

#ifndef __ASSEMBLY__
static inline int pte_file(pte_t pte) { return 0; }
#endif /* __ASSEMBLY__ */

#define ZERO_PAGE(vaddr)    ({ BUG(); NULL; })

#define swapper_pg_dir ((pgd_t *) NULL)

#define pgtable_cache_init()    do {} while (0)

#define arch_enter_lazy_cpu_mode()  do {} while (0)

#define pgprot_noncached_wc(prot)   prot

/*
 * All 32bit addresses are effectively valid for vmalloc...
 * Sort of meaningless for non-VM targets.
 */
#define VMALLOC_START   0
#define VMALLOC_END 0xffffffff

#else /* CONFIG_MMU */

#include <asm-generic/4level-fixup.h>

#ifdef __KERNEL__
#ifndef __ASSEMBLY__

#include <linux/sched.h>
#include <linux/threads.h>
#include <asm/processor.h>      /* For TASK_SIZE */
#include <asm/mmu.h>
#include <asm/page.h>

#define FIRST_USER_ADDRESS  0

extern unsigned long va_to_phys(unsigned long address);
extern pte_t *va_to_pte(unsigned long address);

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */

static inline int pte_special(pte_t pte)    { return 0; }

static inline pte_t pte_mkspecial(pte_t pte)    { return pte; }

/* Start and end of the vmalloc area. */
/* Make sure to map the vmalloc area above the pinned kernel memory area
   of 32Mb.  */
#define VMALLOC_START   (CONFIG_KERNEL_START + CONFIG_LOWMEM_SIZE)
#define VMALLOC_END ioremap_bot

#endif /* __ASSEMBLY__ */

/*
 * Macro to mark a page protection value as "uncacheable".
 */

#define _PAGE_CACHE_CTL (_PAGE_GUARDED | _PAGE_NO_CACHE | \
                            _PAGE_WRITETHRU)

#define pgprot_noncached(prot) \
            (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
                    _PAGE_NO_CACHE | _PAGE_GUARDED))

#define pgprot_noncached_wc(prot) \
             (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
                            _PAGE_NO_CACHE))

/*
 * The MicroBlaze MMU is identical to the PPC-40x MMU, and uses a hash
 * table containing PTEs, together with a set of 16 segment registers, to
 * define the virtual to physical address mapping.
 *
 * We use the hash table as an extended TLB, i.e. a cache of currently
 * active mappings.  We maintain a two-level page table tree, much
 * like that used by the i386, for the sake of the Linux memory
 * management code.  Low-level assembler code in hashtable.S
 * (procedure hash_page) is responsible for extracting ptes from the
 * tree and putting them into the hash table when necessary, and
 * updating the accessed and modified bits in the page table tree.
 */

/*
 * The MicroBlaze processor has a TLB architecture identical to PPC-40x. The
 * instruction and data sides share a unified, 64-entry, semi-associative
 * TLB which is maintained totally under software control. In addition, the
 * instruction side has a hardware-managed, 2,4, or 8-entry, fully-associative
 * TLB which serves as a first level to the shared TLB. These two TLBs are
 * known as the UTLB and ITLB, respectively (see "mmu.h" for definitions).
 */

/*
 * The normal case is that PTEs are 32-bits and we have a 1-page
 * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages.  -- paulus
 *
 */

/* PMD_SHIFT determines the size of the area mapped by the PTE pages */
#define PMD_SHIFT   (PAGE_SHIFT + PTE_SHIFT)
#define PMD_SIZE    (1UL << PMD_SHIFT)
#define PMD_MASK    (~(PMD_SIZE-1))

/* PGDIR_SHIFT determines what a top-level page table entry can map */
#define PGDIR_SHIFT PMD_SHIFT
#define PGDIR_SIZE  (1UL << PGDIR_SHIFT)
#define PGDIR_MASK  (~(PGDIR_SIZE-1))

/*
 * entries per page directory level: our page-table tree is two-level, so
 * we don't really have any PMD directory.
 */
#define PTRS_PER_PTE    (1 << PTE_SHIFT)
#define PTRS_PER_PMD    1
#define PTRS_PER_PGD    (1 << (32 - PGDIR_SHIFT))

#define USER_PTRS_PER_PGD   (TASK_SIZE / PGDIR_SIZE)
#define FIRST_USER_PGD_NR   0

#define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT)
#define KERNEL_PGD_PTRS (PTRS_PER_PGD-USER_PGD_PTRS)

#define pte_ERROR(e) \
    printk(KERN_ERR "%s:%d: bad pte "PTE_FMT".\n", \
        __FILE__, __LINE__, pte_val(e))
#define pmd_ERROR(e) \
    printk(KERN_ERR "%s:%d: bad pmd %08lx.\n", \
        __FILE__, __LINE__, pmd_val(e))
#define pgd_ERROR(e) \
    printk(KERN_ERR "%s:%d: bad pgd %08lx.\n", \
        __FILE__, __LINE__, pgd_val(e))

/*
 * Bits in a linux-style PTE.  These match the bits in the
 * (hardware-defined) PTE as closely as possible.
 */

/* There are several potential gotchas here.  The hardware TLBLO
 * field looks like this:
 *
 * 0  1  2  3  4  ... 18 19 20 21 22 23 24 25 26 27 28 29 30 31
 * RPN.....................  0  0 EX WR ZSEL.......  W  I  M  G
 *
 * Where possible we make the Linux PTE bits match up with this
 *
 * - bits 20 and 21 must be cleared, because we use 4k pages (4xx can
 * support down to 1k pages), this is done in the TLBMiss exception
 * handler.
 * - We use only zones 0 (for kernel pages) and 1 (for user pages)
 * of the 16 available.  Bit 24-26 of the TLB are cleared in the TLB
 * miss handler.  Bit 27 is PAGE_USER, thus selecting the correct
 * zone.
 * - PRESENT *must* be in the bottom two bits because swap cache
 * entries use the top 30 bits.  Because 4xx doesn't support SMP
 * anyway, M is irrelevant so we borrow it for PAGE_PRESENT.  Bit 30
 * is cleared in the TLB miss handler before the TLB entry is loaded.
 * - All other bits of the PTE are loaded into TLBLO without
 *  * modification, leaving us only the bits 20, 21, 24, 25, 26, 30 for
 * software PTE bits.  We actually use use bits 21, 24, 25, and
 * 30 respectively for the software bits: ACCESSED, DIRTY, RW, and
 * PRESENT.
 */

/* Definitions for MicroBlaze. */
#define _PAGE_GUARDED   0x001   /* G: page is guarded from prefetch */
#define _PAGE_FILE  0x001   /* when !present: nonlinear file mapping */
#define _PAGE_PRESENT   0x002   /* software: PTE contains a translation */
#define _PAGE_NO_CACHE  0x004   /* I: caching is inhibited */
#define _PAGE_WRITETHRU 0x008   /* W: caching is write-through */
#define _PAGE_USER  0x010   /* matches one of the zone permission bits */
#define _PAGE_RW    0x040   /* software: Writes permitted */
#define _PAGE_DIRTY 0x080   /* software: dirty page */
#define _PAGE_HWWRITE   0x100   /* hardware: Dirty & RW, set in exception */
#define _PAGE_HWEXEC    0x200   /* hardware: EX permission */
#define _PAGE_ACCESSED  0x400   /* software: R: page referenced */
#define _PMD_PRESENT    PAGE_MASK

/*
 * Some bits are unused...
 */
#ifndef _PAGE_HASHPTE
#define _PAGE_HASHPTE   0
#endif
#ifndef _PTE_NONE_MASK
#define _PTE_NONE_MASK  0
#endif
#ifndef _PAGE_SHARED
#define _PAGE_SHARED    0
#endif
#ifndef _PAGE_EXEC
#define _PAGE_EXEC  0
#endif

#define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)

/*
 * Note: the _PAGE_COHERENT bit automatically gets set in the hardware
 * PTE if CONFIG_SMP is defined (hash_page does this); there is no need
 * to have it in the Linux PTE, and in fact the bit could be reused for
 * another purpose.  -- paulus.
 */
#define _PAGE_BASE  (_PAGE_PRESENT | _PAGE_ACCESSED)
#define _PAGE_WRENABLE  (_PAGE_RW | _PAGE_DIRTY | _PAGE_HWWRITE)

#define _PAGE_KERNEL \
    (_PAGE_BASE | _PAGE_WRENABLE | _PAGE_SHARED | _PAGE_HWEXEC)

#define _PAGE_IO    (_PAGE_KERNEL | _PAGE_NO_CACHE | _PAGE_GUARDED)

#define PAGE_NONE   __pgprot(_PAGE_BASE)
#define PAGE_READONLY   __pgprot(_PAGE_BASE | _PAGE_USER)
#define PAGE_READONLY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
#define PAGE_SHARED __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
#define PAGE_SHARED_X \
        __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
#define PAGE_COPY   __pgprot(_PAGE_BASE | _PAGE_USER)
#define PAGE_COPY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)

#define PAGE_KERNEL __pgprot(_PAGE_KERNEL)
#define PAGE_KERNEL_RO  __pgprot(_PAGE_BASE | _PAGE_SHARED)
#define PAGE_KERNEL_CI  __pgprot(_PAGE_IO)

/*
 * We consider execute permission the same as read.
 * Also, write permissions imply read permissions.
 */
#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

#ifndef __ASSEMBLY__
/*
 * ZERO_PAGE is a global shared page that is always zero: used
 * for zero-mapped memory areas etc..
 */
extern unsigned long empty_zero_page[1024];
#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))

#endif /* __ASSEMBLY__ */

#define pte_none(pte)       ((pte_val(pte) & ~_PTE_NONE_MASK) == 0)
#define pte_present(pte)    (pte_val(pte) & _PAGE_PRESENT)
#define pte_clear(mm, addr, ptep) \
    do { set_pte_at((mm), (addr), (ptep), __pte(0)); } while (0)

#define pmd_none(pmd)       (!pmd_val(pmd))
#define pmd_bad(pmd)        ((pmd_val(pmd) & _PMD_PRESENT) == 0)
#define pmd_present(pmd)    ((pmd_val(pmd) & _PMD_PRESENT) != 0)
#define pmd_clear(pmdp)     do { pmd_val(*(pmdp)) = 0; } while (0)

#define pte_page(x)     (mem_map + (unsigned long) \
                ((pte_val(x) - memory_start) >> PAGE_SHIFT))
#define PFN_SHIFT_OFFSET    (PAGE_SHIFT)

#define pte_pfn(x)      (pte_val(x) >> PFN_SHIFT_OFFSET)

#define pfn_pte(pfn, prot) \
    __pte(((pte_basic_t)(pfn) << PFN_SHIFT_OFFSET) | pgprot_val(prot))

#ifndef __ASSEMBLY__
/*
 * The "pgd_xxx()" functions here are trivial for a folded two-level
 * setup: the pgd is never bad, and a pmd always exists (as it's folded
 * into the pgd entry)
 */
static inline int pgd_none(pgd_t pgd)       { return 0; }
static inline int pgd_bad(pgd_t pgd)        { return 0; }
static inline int pgd_present(pgd_t pgd)    { return 1; }
#define pgd_clear(xp)               do { } while (0)
#define pgd_page(pgd) \
    ((unsigned long) __va(pgd_val(pgd) & PAGE_MASK))

/*
 * 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_USER; }
static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW; }
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 void pte_uncache(pte_t pte) { pte_val(pte) |= _PAGE_NO_CACHE; }
static inline void pte_cache(pte_t pte)   { pte_val(pte) &= ~_PAGE_NO_CACHE; }

static inline pte_t pte_rdprotect(pte_t pte) \
        { pte_val(pte) &= ~_PAGE_USER; return pte; }
static inline pte_t pte_wrprotect(pte_t pte) \
    { pte_val(pte) &= ~(_PAGE_RW | _PAGE_HWWRITE); 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 | _PAGE_HWWRITE); return pte; }
static inline pte_t pte_mkold(pte_t pte) \
    { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }

static inline pte_t pte_mkread(pte_t pte) \
    { pte_val(pte) |= _PAGE_USER; return pte; }
static inline pte_t pte_mkexec(pte_t pte) \
    { pte_val(pte) |= _PAGE_USER | _PAGE_EXEC; return pte; }
static inline pte_t pte_mkwrite(pte_t pte) \
    { pte_val(pte) |= _PAGE_RW; 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.
 */

static inline pte_t mk_pte_phys(phys_addr_t physpage, pgprot_t pgprot)
{
    pte_t pte;
    pte_val(pte) = physpage | pgprot_val(pgprot);
    return pte;
}

#define mk_pte(page, pgprot) \
({                                     \
    pte_t pte;                             \
    pte_val(pte) = (((page - mem_map) << PAGE_SHIFT) + memory_start) |  \
            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;
}

/*
 * Atomic PTE updates.
 *
 * pte_update clears and sets bit atomically, and returns
 * the old pte value.
 * The ((unsigned long)(p+1) - 4) hack is to get to the least-significant
 * 32 bits of the PTE regardless of whether PTEs are 32 or 64 bits.
 */
static inline unsigned long pte_update(pte_t *p, unsigned long clr,
                unsigned long set)
{
    unsigned long flags, old, tmp;

    raw_local_irq_save(flags);

    __asm__ __volatile__(   "lw %0, %2, r0  \n"
                "andn   %1, %0, %3  \n"
                "or %1, %1, %4  \n"
                "sw %1, %2, r0  \n"
            : "=&r" (old), "=&r" (tmp)
            : "r" ((unsigned long)(p + 1) - 4), "r" (clr), "r" (set)
            : "cc");

    raw_local_irq_restore(flags);

    return old;
}

/*
 * set_pte stores a linux PTE into the linux page table.
 */
static inline void set_pte(struct mm_struct *mm, unsigned long addr,
        pte_t *ptep, pte_t pte)
{
    *ptep = pte;
}

static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
        pte_t *ptep, pte_t pte)
{
    *ptep = pte;
}

#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
        unsigned long address, pte_t *ptep)
{
    return (pte_update(ptep, _PAGE_ACCESSED, 0) & _PAGE_ACCESSED) != 0;
}

static inline int ptep_test_and_clear_dirty(struct mm_struct *mm,
        unsigned long addr, pte_t *ptep)
{
    return (pte_update(ptep, \
        (_PAGE_DIRTY | _PAGE_HWWRITE), 0) & _PAGE_DIRTY) != 0;
}

#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
        unsigned long addr, pte_t *ptep)
{
    return __pte(pte_update(ptep, ~_PAGE_HASHPTE, 0));
}

/*static inline void ptep_set_wrprotect(struct mm_struct *mm,
        unsigned long addr, pte_t *ptep)
{
    pte_update(ptep, (_PAGE_RW | _PAGE_HWWRITE), 0);
}*/

static inline void ptep_mkdirty(struct mm_struct *mm,
        unsigned long addr, pte_t *ptep)
{
    pte_update(ptep, 0, _PAGE_DIRTY);
}

/*#define pte_same(A,B) (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0)*/

/* Convert pmd entry to page */
/* our pmd entry is an effective address of pte table*/
/* returns effective address of the pmd entry*/
#define pmd_page_kernel(pmd)    ((unsigned long) (pmd_val(pmd) & PAGE_MASK))

/* returns struct *page of the pmd entry*/
#define pmd_page(pmd)   (pfn_to_page(__pa(pmd_val(pmd)) >> PAGE_SHIFT))

/* to find an entry in a kernel page-table-directory */
#define pgd_offset_k(address) pgd_offset(&init_mm, address)

/* to find an entry in a page-table-directory */
#define pgd_index(address)   ((address) >> PGDIR_SHIFT)
#define pgd_offset(mm, address)  ((mm)->pgd + pgd_index(address))

/* Find an entry in the second-level page table.. */
static inline pmd_t *pmd_offset(pgd_t *dir, unsigned long address)
{
    return (pmd_t *) dir;
}

/* Find an entry in the third-level page table.. */
#define pte_index(address)      \
    (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
#define pte_offset_kernel(dir, addr)    \
    ((pte_t *) pmd_page_kernel(*(dir)) + pte_index(addr))
#define pte_offset_map(dir, addr)       \
    ((pte_t *) kmap_atomic(pmd_page(*(dir))) + pte_index(addr))

#define pte_unmap(pte)      kunmap_atomic(pte)

/* Encode and decode a nonlinear file mapping entry */
#define PTE_FILE_MAX_BITS   29
#define pte_to_pgoff(pte)   (pte_val(pte) >> 3)
#define pgoff_to_pte(off)   ((pte_t) { ((off) << 3) | _PAGE_FILE })

extern pgd_t swapper_pg_dir[PTRS_PER_PGD];

/*
 * Encode and decode a swap entry.
 * Note that the bits we use in a PTE for representing a swap entry
 * must not include the _PAGE_PRESENT bit, or the _PAGE_HASHPTE bit
 * (if used).  -- paulus
 */
#define __swp_type(entry)       ((entry).val & 0x3f)
#define __swp_offset(entry) ((entry).val >> 6)
#define __swp_entry(type, offset) \
        ((swp_entry_t) { (type) | ((offset) << 6) })
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) >> 2 })
#define __swp_entry_to_pte(x)   ((pte_t) { (x).val << 2 })

extern unsigned long iopa(unsigned long addr);

/* Values for nocacheflag and cmode */
/* These are not used by the APUS kernel_map, but prevents
 * compilation errors.
 */
#define IOMAP_FULL_CACHING  0
#define IOMAP_NOCACHE_SER   1
#define IOMAP_NOCACHE_NONSER    2
#define IOMAP_NO_COPYBACK   3

/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
#define kern_addr_valid(addr)   (1)

/*
 * No page table caches to initialise
 */
#define pgtable_cache_init()    do { } while (0)

void do_page_fault(struct pt_regs *regs, unsigned long address,
           unsigned long error_code);

void mapin_ram(void);
int map_page(unsigned long va, phys_addr_t pa, int flags);

extern int mem_init_done;

asmlinkage void __init mmu_init(void);

void __init *early_get_page(void);

#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */

#endif /* CONFIG_MMU */

#ifndef __ASSEMBLY__
#include <asm-generic/pgtable.h>

extern unsigned long ioremap_bot, ioremap_base;

void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *dma_handle);
void consistent_free(size_t size, void *vaddr);
void consistent_sync(void *vaddr, size_t size, int direction);
void consistent_sync_page(struct page *page, unsigned long offset,
    size_t size, int direction);

void setup_memory(void);
#endif /* __ASSEMBLY__ */

#endif /* _ASM_MICROBLAZE_PGTABLE_H */