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kernel-ark/arch/openrisc/include/asm/pgtable.h
Jonas Bonn 61e85e3675 OpenRISC: Memory management 
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2011-07-22 18:46:28 +02:00

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/*
* 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 */
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