/*
* Copyright (c) 2003-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup kernel_mips32_mm
* @{
*/
/** @file
*/
#ifndef KERN_mips32_PAGE_H_
#define KERN_mips32_PAGE_H_
#include <arch/mm/frame.h>
#include <trace.h>
#define PAGE_WIDTH FRAME_WIDTH
#define PAGE_SIZE FRAME_SIZE
#ifndef __ASSEMBLER__
# define KSEG12PA(x) (((uintptr_t) (x)) - 0xa0000000)
# define PA2KSEG1(x) (((uintptr_t) (x)) + 0xa0000000)
# define KA2PA(x) (((uintptr_t) (x)) - 0x80000000)
# define PA2KA(x) (((uintptr_t) (x)) + 0x80000000)
#else
# define KA2PA(x) ((x) - 0x80000000)
# define PA2KA(x) ((x) + 0x80000000)
#endif
/*
* Implementation of generic 4-level page table interface.
*
* Page table layout:
* - 32-bit virtual addresses
* - Offset is 14 bits => pages are 16K long
* - PTE's use similar format as CP0 EntryLo[01] registers => PTE is therefore
* 4 bytes long
* - PTE's replace EntryLo v (valid) bit with p (present) bit
* - PTE's use only one bit to distinguish between cacheable and uncacheable
* mappings
* - PTE's define soft_valid field to ensure there is at least one 1 bit even if
* the p bit is cleared
* - PTE's make use of CP0 EntryLo's two-bit reserved field for bit W (writable)
* and bit A (accessed)
* - PTL0 has 64 entries (6 bits)
* - PTL1 is not used
* - PTL2 is not used
* - PTL3 has 4096 entries (12 bits)
*/
/* Macros describing number of entries in each level. */
#define PTL0_ENTRIES_ARCH 64
#define PTL1_ENTRIES_ARCH 0
#define PTL2_ENTRIES_ARCH 0
#define PTL3_ENTRIES_ARCH 4096
/* Macros describing size of page tables in each level. */
#define PTL0_FRAMES_ARCH 1
#define PTL1_FRAMES_ARCH 1
#define PTL2_FRAMES_ARCH 1
#define PTL3_FRAMES_ARCH 1
/* Macros calculating entry indices for each level. */
#define PTL0_INDEX_ARCH(vaddr) ((vaddr) >> 26)
#define PTL1_INDEX_ARCH(vaddr) 0
#define PTL2_INDEX_ARCH(vaddr) 0
#define PTL3_INDEX_ARCH(vaddr) (((vaddr) >> 14) & 0xfff)
/* Set accessor for PTL0 address. */
#define SET_PTL0_ADDRESS_ARCH(ptl0)
/* Get PTE address accessors for each level. */
#define GET_PTL1_ADDRESS_ARCH(ptl0, i) \
(((pte_t *) (ptl0))[(i)].pfn << 12)
#define GET_PTL2_ADDRESS_ARCH(ptl1, i) \
(ptl1)
#define GET_PTL3_ADDRESS_ARCH(ptl2, i) \
(ptl2)
#define GET_FRAME_ADDRESS_ARCH(ptl3, i) \
(((pte_t *) (ptl3))[(i)].pfn << 12)
/* Set PTE address accessors for each level. */
#define SET_PTL1_ADDRESS_ARCH(ptl0, i, a) \
(((pte_t *) (ptl0))[(i)].pfn = (a) >> 12)
#define SET_PTL2_ADDRESS_ARCH(ptl1, i, a)
#define SET_PTL3_ADDRESS_ARCH(ptl2, i, a)
#define SET_FRAME_ADDRESS_ARCH(ptl3, i, a) \
(((pte_t *) (ptl3))[(i)].pfn = (a) >> 12)
/* Get PTE flags accessors for each level. */
#define GET_PTL1_FLAGS_ARCH(ptl0, i) \
get_pt_flags((pte_t *) (ptl0), (size_t) (i))
#define GET_PTL2_FLAGS_ARCH(ptl1, i) \
PAGE_PRESENT
#define GET_PTL3_FLAGS_ARCH(ptl2, i) \
PAGE_PRESENT
#define GET_FRAME_FLAGS_ARCH(ptl3, i) \
get_pt_flags((pte_t *) (ptl3), (size_t) (i))
/* Set PTE flags accessors for each level. */
#define SET_PTL1_FLAGS_ARCH(ptl0, i, x) \
set_pt_flags((pte_t *) (ptl0), (size_t) (i), (x))
#define SET_PTL2_FLAGS_ARCH(ptl1, i, x)
#define SET_PTL3_FLAGS_ARCH(ptl2, i, x)
#define SET_FRAME_FLAGS_ARCH(ptl3, i, x) \
set_pt_flags((pte_t *) (ptl3), (size_t) (i), (x))
/* Set PTE present bit accessors for each level. */
#define SET_PTL1_PRESENT_ARCH(ptl0, i) \
set_pt_present((pte_t *) (ptl0), (size_t) (i))
#define SET_PTL2_PRESENT_ARCH(ptl1, i)
#define SET_PTL3_PRESENT_ARCH(ptl2, i)
#define SET_FRAME_PRESENT_ARCH(ptl3, i) \
set_pt_present((pte_t *) (ptl3), (size_t) (i))
/* Last-level info macros. */
#define PTE_VALID_ARCH(pte) ((pte)->soft_valid != 0)
#define PTE_PRESENT_ARCH(pte) ((pte)->p != 0)
#define PTE_GET_FRAME_ARCH(pte) ((pte)->pfn << 12)
#define PTE_WRITABLE_ARCH(pte) ((pte)->w != 0)
#define PTE_EXECUTABLE_ARCH(pte) 1
#ifndef __ASSEMBLER__
#include <mm/mm.h>
#include <arch/exception.h>
/** Page Table Entry. */
typedef struct {
unsigned g : 1; /**< Global bit. */
unsigned p : 1; /**< Present bit. */
unsigned d : 1; /**< Dirty bit. */
unsigned cacheable : 1; /**< Cacheable bit. */
unsigned : 1; /**< Unused. */
unsigned soft_valid : 1; /**< Valid content even if not present. */
unsigned pfn : 24; /**< Physical frame number. */
unsigned w : 1; /**< Page writable bit. */
unsigned a : 1; /**< Accessed bit. */
} pte_t;
_NO_TRACE static inline unsigned int get_pt_flags(pte_t *pt, size_t i)
{
pte_t *p = &pt[i];
return ((p->cacheable << PAGE_CACHEABLE_SHIFT) |
((!p->p) << PAGE_PRESENT_SHIFT) |
(1 << PAGE_USER_SHIFT) |
(1 << PAGE_READ_SHIFT) |
((p->w) << PAGE_WRITE_SHIFT) |
(1 << PAGE_EXEC_SHIFT) |
(p->g << PAGE_GLOBAL_SHIFT));
}
_NO_TRACE static inline void set_pt_flags(pte_t *pt, size_t i, int flags)
{
pte_t *p = &pt[i];
p->cacheable = (flags & PAGE_CACHEABLE) != 0;
p->p = !(flags & PAGE_NOT_PRESENT);
p->g = (flags & PAGE_GLOBAL) != 0;
p->w = (flags & PAGE_WRITE) != 0;
/*
* Ensure that valid entries have at least one bit set.
*/
p->soft_valid = 1;
}
_NO_TRACE static inline void set_pt_present(pte_t *pt, size_t i)
{
pte_t *p = &pt[i];
p->p = 1;
}
extern void page_arch_init(void);
#endif /* __ASSEMBLER__ */
#endif
/** @}
*/