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pmap.h revision 1.22
      1 /*	$NetBSD: pmap.h,v 1.22 2002/02/06 17:32:37 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1994,1995 Mark Brinicombe.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by Mark Brinicombe
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #ifndef	_ARM32_PMAP_H_
     34 #define	_ARM32_PMAP_H_
     35 
     36 #ifdef _KERNEL
     37 
     38 #include <arm/cpufunc.h>
     39 #include <arm/arm32/pte.h>
     40 #include <uvm/uvm_object.h>
     41 
     42 /*
     43  * a pmap describes a processes' 4GB virtual address space.  this
     44  * virtual address space can be broken up into 4096 1MB regions which
     45  * are described by PDEs in the PDP.  the PDEs are defined as follows:
     46  *
     47  * (ranges are inclusive -> exclusive, just like vm_map_entry start/end)
     48  * (the following assumes that KERNBASE is 0xf0000000)
     49  *
     50  * PDE#s	VA range		usage
     51  * 0->3835	0x0 -> 0xefc00000	user address space
     52  * 3836->3839	0xefc00000->		recursive mapping of PDP (used for
     53  *			0xf0000000	linear mapping of PTPs)
     54  * 3840->3851	0xf0000000->		kernel text address space (constant
     55  *			0xf0c00000	across all pmap's/processes)
     56  * 3852->3855	0xf0c00000->		"alternate" recursive PDP mapping
     57  *			0xf1000000	(for other pmaps)
     58  * 3856->4095	0xf1000000->		KVM and device mappings, constant
     59  *			0x00000000	across all pmaps
     60  *
     61  * The maths works out that to then map each 1MB block into 4k pages requires
     62  * 256 entries, of 4 bytes each, totaling 1k per 1MB.  However as we use 4k
     63  * pages we allocate 4 PDE's at a time, allocating the same access permissions
     64  * to them all.  This means we only need 1024 entries in the page table page
     65  * table, IE we use 1 4k page to linearly map all the other page tables used.
     66  */
     67 
     68 /*
     69  * Data structures used by pmap
     70  */
     71 
     72 /*
     73  * Structure that describes a Level 1 page table and the flags
     74  * associated with it.
     75  */
     76 struct l1pt {
     77 	SIMPLEQ_ENTRY(l1pt)	pt_queue;	/* Queue pointers */
     78 	struct pglist		pt_plist;	/* Allocated page list */
     79 	vaddr_t			pt_va;		/* Allocated virtual address */
     80 	int	                pt_flags;	/* Flags */
     81 };
     82 #define	PTFLAG_STATIC		1		/* Statically allocated */
     83 #define PTFLAG_KPT		2		/* Kernel pt's are mapped */
     84 #define PTFLAG_CLEAN		4		/* L1 is clean */
     85 
     86 /*
     87  * The pmap structure itself.
     88  */
     89 struct pmap {
     90 	struct uvm_object	pm_obj;		/* uvm_object */
     91 #define	pm_lock	pm_obj.vmobjlock
     92 	pd_entry_t		*pm_pdir;	/* KVA of page directory */
     93 	struct l1pt		*pm_l1pt;	/* L1 descriptor */
     94 	paddr_t                 pm_pptpt;	/* PA of pt's page table */
     95 	vaddr_t                 pm_vptpt;	/* VA of pt's page table */
     96 	struct pmap_statistics	pm_stats;	/* pmap statistics */
     97 };
     98 
     99 typedef struct pmap *pmap_t;
    100 
    101 /*
    102  * Page hooks. I'll eliminate these sometime soon :-)
    103  *
    104  * For speed we store the both the virtual address and the page table
    105  * entry address for each page hook.
    106  */
    107 typedef struct {
    108         vaddr_t va;
    109         pt_entry_t *pte;
    110 } pagehook_t;
    111 
    112 /*
    113  * Physical / virtual address structure. In a number of places (particularly
    114  * during bootstrapping) we need to keep track of the physical and virtual
    115  * addresses of various pages
    116  */
    117 typedef struct {
    118 	paddr_t pv_pa;
    119 	vaddr_t pv_va;
    120 } pv_addr_t;
    121 
    122 /*
    123  * _KERNEL specific macros, functions and prototypes
    124  */
    125 
    126 #ifdef  _KERNEL
    127 
    128 /*
    129  * Commonly referenced structures
    130  */
    131 extern struct pmap	kernel_pmap_store;
    132 extern int		pmap_debug_level; /* Only exists if PMAP_DEBUG */
    133 
    134 /*
    135  * Macros that we need to export
    136  */
    137 #define pmap_kernel()			(&kernel_pmap_store)
    138 #define	pmap_resident_count(pmap)	((pmap)->pm_stats.resident_count)
    139 #define	pmap_wired_count(pmap)		((pmap)->pm_stats.wired_count)
    140 
    141 #define	pmap_copy(dp, sp, da, l, sa)	/* nothing */
    142 
    143 #define	pmap_is_referenced(pg)	(((pg)->mdpage.pvh_attrs & PT_H) != 0)
    144 #define pmap_is_modified(pg)	(((pg)->mdpage.pvh_attrs & PT_M) != 0)
    145 
    146 #define pmap_phys_address(ppn)		(arm_page_to_byte((ppn)))
    147 
    148 /*
    149  * Functions that we need to export
    150  */
    151 extern vaddr_t pmap_map __P((vaddr_t, vaddr_t, vaddr_t, int));
    152 extern void pmap_procwr __P((struct proc *, vaddr_t, int));
    153 #define	PMAP_NEED_PROCWR
    154 
    155 /*
    156  * Functions we use internally
    157  */
    158 void pmap_bootstrap __P((pd_entry_t *, pv_addr_t));
    159 void pmap_debug	__P((int));
    160 int pmap_handled_emulation __P((struct pmap *, vaddr_t));
    161 int pmap_modified_emulation __P((struct pmap *, vaddr_t));
    162 void pmap_postinit __P((void));
    163 pt_entry_t *pmap_pte __P((struct pmap *, vaddr_t));
    164 
    165 /*
    166  * Special page zero routine for use by the idle loop (no cache cleans).
    167  */
    168 boolean_t	pmap_pageidlezero __P((paddr_t));
    169 #define PMAP_PAGEIDLEZERO(pa)	pmap_pageidlezero((pa))
    170 
    171 #endif	/* _KERNEL */
    172 
    173 /*
    174  * Useful macros and constants
    175  */
    176 
    177 /* Virtual address to page table entry */
    178 #define vtopte(va) \
    179 	((pt_entry_t *)(PROCESS_PAGE_TBLS_BASE + \
    180 	(arm_byte_to_page((unsigned int)(va)) << 2)))
    181 
    182 /* Virtual address to physical address */
    183 #define vtophys(va) \
    184 	((*vtopte(va) & PG_FRAME) | ((unsigned int)(va) & ~PG_FRAME))
    185 
    186 /* L1 and L2 page table macros */
    187 #define pmap_pde(m, v) (&((m)->pm_pdir[((vaddr_t)(v) >> PDSHIFT)&4095]))
    188 #define pmap_pte_pa(pte)	(*(pte) & PG_FRAME)
    189 #define pmap_pde_v(pde)		(*(pde) != 0)
    190 #define pmap_pde_section(pde)	((*(pde) & L1_MASK) == L1_SECTION)
    191 #define pmap_pde_page(pde)	((*(pde) & L1_MASK) == L1_PAGE)
    192 #define pmap_pde_fpage(pde)	((*(pde) & L1_MASK) == L1_FPAGE)
    193 
    194 #define pmap_pte_v(pte)		(*(pte) != 0)
    195 
    196 /* Size of the kernel part of the L1 page table */
    197 #define KERNEL_PD_SIZE	\
    198 	(PD_SIZE - (KERNEL_SPACE_START >> PDSHIFT) * sizeof(pd_entry_t))
    199 
    200 /*
    201  * tell MI code that the cache is virtually-indexed *and* virtually-tagged.
    202  */
    203 
    204 #define PMAP_CACHE_VIVT
    205 
    206 #endif /* _KERNEL */
    207 
    208 #endif	/* _ARM32_PMAP_H_ */
    209