Commit cbd15b3f authored by Ley Foon Tan's avatar Ley Foon Tan
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nios2: Page table management



This patch adds support for page table management.
Signed-off-by: default avatarLey Foon Tan <lftan@altera.com>
parent 862674d4
/*
* 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.
*
* Copyright (C) 1994 - 2001, 2003 by Ralf Baechle
* Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
*/
#ifndef _ASM_NIOS2_PGALLOC_H
#define _ASM_NIOS2_PGALLOC_H
#include <linux/mm.h>
static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
pte_t *pte)
{
set_pmd(pmd, __pmd((unsigned long)pte));
}
static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
pgtable_t pte)
{
set_pmd(pmd, __pmd((unsigned long)page_address(pte)));
}
#define pmd_pgtable(pmd) pmd_page(pmd)
/*
* Initialize a new pmd table with invalid pointers.
*/
extern void pmd_init(unsigned long page, unsigned long pagetable);
extern pgd_t *pgd_alloc(struct mm_struct *mm);
static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
free_pages((unsigned long)pgd, PGD_ORDER);
}
static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
unsigned long address)
{
pte_t *pte;
pte = (pte_t *) __get_free_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO,
PTE_ORDER);
return pte;
}
static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
unsigned long address)
{
struct page *pte;
pte = alloc_pages(GFP_KERNEL | __GFP_REPEAT, PTE_ORDER);
if (pte) {
if (!pgtable_page_ctor(pte)) {
__free_page(pte);
return NULL;
}
clear_highpage(pte);
}
return pte;
}
static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
free_pages((unsigned long)pte, PTE_ORDER);
}
static inline void pte_free(struct mm_struct *mm, struct page *pte)
{
pgtable_page_dtor(pte);
__free_pages(pte, PTE_ORDER);
}
#define __pte_free_tlb(tlb, pte, addr) \
do { \
pgtable_page_dtor(pte); \
tlb_remove_page((tlb), (pte)); \
} while (0)
#define check_pgt_cache() do { } while (0)
#endif /* _ASM_NIOS2_PGALLOC_H */
/*
* Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
* Copyright (C) 2009 Wind River Systems 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_NIOS2_PGTABLE_BITS_H
#define _ASM_NIOS2_PGTABLE_BITS_H
/*
* These are actual hardware defined protection bits in the tlbacc register
* which looks like this:
*
* 31 30 ... 26 25 24 23 22 21 20 19 18 ... 1 0
* ignored........ C R W X G PFN............
*/
#define _PAGE_GLOBAL (1<<20)
#define _PAGE_EXEC (1<<21)
#define _PAGE_WRITE (1<<22)
#define _PAGE_READ (1<<23)
#define _PAGE_CACHED (1<<24) /* C: data access cacheable */
/*
* Software defined bits. They are ignored by the hardware and always read back
* as zero, but can be written as non-zero.
*/
#define _PAGE_PRESENT (1<<25) /* PTE contains a translation */
#define _PAGE_ACCESSED (1<<26) /* page referenced */
#define _PAGE_DIRTY (1<<27) /* dirty page */
#define _PAGE_FILE (1<<28) /* PTE used for file mapping or swap */
#endif /* _ASM_NIOS2_PGTABLE_BITS_H */
/*
* Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
* Copyright (C) 2009 Wind River Systems Inc
*
* Based on asm/pgtable-32.h from mips which is:
*
* Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
* Copyright (C) 1999, 2000, 2001 Silicon Graphics, 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_NIOS2_PGTABLE_H
#define _ASM_NIOS2_PGTABLE_H
#include <linux/io.h>
#include <linux/bug.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/pgtable-bits.h>
#include <asm-generic/pgtable-nopmd.h>
#define FIRST_USER_ADDRESS 0
#define VMALLOC_START CONFIG_NIOS2_KERNEL_MMU_REGION_BASE
#define VMALLOC_END (CONFIG_NIOS2_KERNEL_REGION_BASE - 1)
struct mm_struct;
/* Helper macro */
#define MKP(x, w, r) __pgprot(_PAGE_PRESENT | _PAGE_CACHED | \
((x) ? _PAGE_EXEC : 0) | \
((r) ? _PAGE_READ : 0) | \
((w) ? _PAGE_WRITE : 0))
/*
* These are the macros that generic kernel code needs
* (to populate protection_map[])
*/
/* Remove W bit on private pages for COW support */
#define __P000 MKP(0, 0, 0)
#define __P001 MKP(0, 0, 1)
#define __P010 MKP(0, 0, 0) /* COW */
#define __P011 MKP(0, 0, 1) /* COW */
#define __P100 MKP(1, 0, 0)
#define __P101 MKP(1, 0, 1)
#define __P110 MKP(1, 0, 0) /* COW */
#define __P111 MKP(1, 0, 1) /* COW */
/* Shared pages can have exact HW mapping */
#define __S000 MKP(0, 0, 0)
#define __S001 MKP(0, 0, 1)
#define __S010 MKP(0, 1, 0)
#define __S011 MKP(0, 1, 1)
#define __S100 MKP(1, 0, 0)
#define __S101 MKP(1, 0, 1)
#define __S110 MKP(1, 1, 0)
#define __S111 MKP(1, 1, 1)
/* Used all over the kernel */
#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
_PAGE_WRITE | _PAGE_EXEC | _PAGE_GLOBAL)
#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
_PAGE_WRITE | _PAGE_ACCESSED)
#define PAGE_COPY MKP(0, 0, 1)
#define PGD_ORDER 0
#define PTE_ORDER 0
#define PTRS_PER_PGD ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
#define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
#define USER_PTRS_PER_PGD \
(CONFIG_NIOS2_KERNEL_MMU_REGION_BASE / PGDIR_SIZE)
#define PGDIR_SHIFT 22
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
/*
* ZERO_PAGE is a global shared page that is always zero: used
* for zero-mapped memory areas etc..
*/
extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
/*
* (pmds are folded into puds so this doesn't get actually called,
* but the define is needed for a generic inline function.)
*/
static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval)
{
pmdptr->pud.pgd.pgd = pmdval.pud.pgd.pgd;
}
/* to find an entry in a page-table-directory */
#define pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
#define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
static inline int pte_write(pte_t pte) \
{ return pte_val(pte) & _PAGE_WRITE; }
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; }
#define pgprot_noncached pgprot_noncached
static inline pgprot_t pgprot_noncached(pgprot_t _prot)
{
unsigned long prot = pgprot_val(_prot);
prot &= ~_PAGE_CACHED;
return __pgprot(prot);
}
static inline int pte_none(pte_t pte)
{
return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
}
static inline int pte_present(pte_t pte) \
{ return pte_val(pte) & _PAGE_PRESENT; }
/*
* The following only work if pte_present() is true.
* Undefined behaviour if not..
*/
static inline pte_t pte_wrprotect(pte_t pte)
{
pte_val(pte) &= ~_PAGE_WRITE;
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_mkdirty(pte_t pte)
{
pte_val(pte) |= _PAGE_DIRTY;
return pte;
}
static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
static inline pte_t pte_mkyoung(pte_t pte)
{
pte_val(pte) |= _PAGE_ACCESSED;
return pte;
}
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
const unsigned long mask = _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC;
pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
return pte;
}
static inline int pmd_present(pmd_t pmd)
{
return (pmd_val(pmd) != (unsigned long) invalid_pte_table)
&& (pmd_val(pmd) != 0UL);
}
static inline void pmd_clear(pmd_t *pmdp)
{
pmd_val(*pmdp) = (unsigned long) invalid_pte_table;
}
#define pte_pfn(pte) (pte_val(pte) & 0xfffff)
#define pfn_pte(pfn, prot) (__pte(pfn | pgprot_val(prot)))
#define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
/*
* Store a linux PTE into the linux page table.
*/
static inline void set_pte(pte_t *ptep, pte_t pteval)
{
*ptep = pteval;
}
static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pteval)
{
unsigned long paddr = page_to_virt(pte_page(pteval));
flush_dcache_range(paddr, paddr + PAGE_SIZE);
set_pte(ptep, pteval);
}
static inline int pmd_none(pmd_t pmd)
{
return (pmd_val(pmd) ==
(unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL);
}
#define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK)
static inline void pte_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
pte_t null;
pte_val(null) = (addr >> PAGE_SHIFT) & 0xf;
set_pte_at(mm, addr, ptep, null);
flush_tlb_one(addr);
}
/*
* Conversion functions: convert a page and protection to a page entry,
* and a page entry and page directory to the page they refer to.
*/
#define mk_pte(page, prot) (pfn_pte(page_to_pfn(page), prot))
#define pte_unmap(pte) do { } while (0)
/*
* Conversion functions: convert a page and protection to a page entry,
* and a page entry and page directory to the page they refer to.
*/
#define pmd_phys(pmd) virt_to_phys((void *)pmd_val(pmd))
#define pmd_page(pmd) (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
#define pmd_page_vaddr(pmd) pmd_val(pmd)
#define pte_offset_map(dir, addr) \
((pte_t *) page_address(pmd_page(*dir)) + \
(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
/* to find an entry in a kernel page-table-directory */
#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
/* Get the address to the PTE for a vaddr in specific directory */
#define pte_offset_kernel(dir, addr) \
((pte_t *) pmd_page_vaddr(*(dir)) + \
(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
#define pte_ERROR(e) \
pr_err("%s:%d: bad pte %08lx.\n", \
__FILE__, __LINE__, pte_val(e))
#define pgd_ERROR(e) \
pr_err("%s:%d: bad pgd %08lx.\n", \
__FILE__, __LINE__, pgd_val(e))
/*
* Encode and decode a swap entry (must be !pte_none(pte) && !pte_present(pte)
* && !pte_file(pte)):
*
* 31 30 29 28 27 26 25 24 23 22 21 20 19 18 ... 1 0
* 0 0 0 0 type. 0 0 0 0 0 0 offset.........
*
* This gives us up to 2**2 = 4 swap files and 2**20 * 4K = 4G per swap file.
*
* Note that the offset field is always non-zero, thus !pte_none(pte) is always
* true.
*/
#define __swp_type(swp) (((swp).val >> 26) & 0x3)
#define __swp_offset(swp) ((swp).val & 0xfffff)
#define __swp_entry(type, off) ((swp_entry_t) { (((type) & 0x3) << 26) \
| ((off) & 0xfffff) })
#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
/* Encode and decode a nonlinear file mapping entry */
#define PTE_FILE_MAX_BITS 25
#define pte_to_pgoff(pte) (pte_val(pte) & 0x1ffffff)
#define pgoff_to_pte(off) __pte(((off) & 0x1ffffff) | _PAGE_FILE)
#define kern_addr_valid(addr) (1)
#include <asm-generic/pgtable.h>
#define pgtable_cache_init() do { } while (0)
extern void __init paging_init(void);
extern void __init mmu_init(void);
extern void update_mmu_cache(struct vm_area_struct *vma,
unsigned long address, pte_t *pte);
#endif /* _ASM_NIOS2_PGTABLE_H */
/*
* Copyright (C) 2009 Wind River Systems Inc
* Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
*
* 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.
*/
#include <linux/mm.h>
#include <linux/sched.h>
#include <asm/pgtable.h>
#include <asm/cpuinfo.h>
/* pteaddr:
* ptbase | vpn* | zero
* 31-22 | 21-2 | 1-0
*
* *vpn is preserved on double fault
*
* tlbacc:
* IG |*flags| pfn
* 31-25|24-20 | 19-0
*
* *crwxg
*
* tlbmisc:
* resv |way |rd | we|pid |dbl|bad|perm|d
* 31-24 |23-20 |19 | 20|17-4|3 |2 |1 |0
*
*/
/*
* Initialize a new pgd / pmd table with invalid pointers.
*/
static void pgd_init(pgd_t *pgd)
{
unsigned long *p = (unsigned long *) pgd;
int i;
for (i = 0; i < USER_PTRS_PER_PGD; i += 8) {
p[i + 0] = (unsigned long) invalid_pte_table;
p[i + 1] = (unsigned long) invalid_pte_table;
p[i + 2] = (unsigned long) invalid_pte_table;
p[i + 3] = (unsigned long) invalid_pte_table;
p[i + 4] = (unsigned long) invalid_pte_table;
p[i + 5] = (unsigned long) invalid_pte_table;
p[i + 6] = (unsigned long) invalid_pte_table;
p[i + 7] = (unsigned long) invalid_pte_table;
}
}
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *ret, *init;
ret = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_ORDER);
if (ret) {
init = pgd_offset(&init_mm, 0UL);
pgd_init(ret);
memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
}
return ret;
}
void __init pagetable_init(void)
{
/* Initialize the entire pgd. */
pgd_init(swapper_pg_dir);
pgd_init(swapper_pg_dir + USER_PTRS_PER_PGD);
}
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