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pmap.h revision 1.13
      1 /*	$NetBSD: pmap.h,v 1.13 2001/08/11 13:20:20 chris 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 #include <machine/cpufunc.h>
     37 #include <machine/pte.h>
     38 #include <uvm/uvm_object.h>
     39 
     40 /*
     41  * a pmap describes a processes' 4GB virtual address space.  this
     42  * virtual address space can be broken up into 4096 1MB regions which
     43  * are described by PDEs in the PDP.  the PDEs are defined as follows:
     44  *
     45  * (ranges are inclusive -> exclusive, just like vm_map_entry start/end)
     46  * (the following assumes that KERNBASE is 0xf0000000)
     47  *
     48  * PDE#s	VA range		usage
     49  * 0->3835	0x0 -> 0xefc00000	user address space
     50  * 3836->3839	0xefc00000->		recursive mapping of PDP (used for
     51  *			0xf0000000	linear mapping of PTPs)
     52  * 3840->3851	0xf0000000->		kernel text address space (constant
     53  *			0xf0c00000	across all pmap's/processes)
     54  * 3852->3855	0xf0c00000->		"alternate" recursive PDP mapping
     55  *			0xf1000000	(for other pmaps)
     56  * 3856->4095	0xf1000000->		KVM and device mappings, constant
     57  *			0x00000000	across all pmaps
     58  *
     59  * The maths works out that to then map each 1MB block into 4k pages requires
     60  * 256 entries, of 4 bytes each, totaling 1k per 1MB.  However as we use 4k
     61  * pages we allocate 4 PDE's at a time, allocating the same access permissions
     62  * to them all.  This means we only need 1024 entries in the page table page
     63  * table, IE we use 1 4k page to linearly map all the other page tables used.
     64  */
     65 
     66 /*
     67  * Data structures used by pmap
     68  */
     69 
     70 /*
     71  * Structure that describes a Level 1 page table and the flags
     72  * associated with it.
     73  */
     74 struct l1pt {
     75 	SIMPLEQ_ENTRY(l1pt)	pt_queue;	/* Queue pointers */
     76 	struct pglist		pt_plist;	/* Allocated page list */
     77 	vaddr_t			pt_va;		/* Allocated virtual address */
     78 	int	                pt_flags;	/* Flags */
     79 };
     80 #define	PTFLAG_STATIC		1		/* Statically allocated */
     81 #define PTFLAG_KPT		2		/* Kernel pt's are mapped */
     82 #define PTFLAG_CLEAN		4		/* L1 is clean */
     83 
     84 /*
     85  * The pmap structure itself.
     86  */
     87 struct pmap {
     88 	struct uvm_object	pm_obj;		/* uvm_object */
     89 #define	pm_lock	pm_obj.vmobjlock
     90 	pd_entry_t		*pm_pdir;	/* KVA of page directory */
     91 	struct l1pt		*pm_l1pt;	/* L1 descriptor */
     92 	paddr_t                 pm_pptpt;	/* PA of pt's page table */
     93 	vaddr_t                 pm_vptpt;	/* VA of pt's page table */
     94 	struct pmap_statistics	pm_stats;	/* pmap statistics */
     95 };
     96 
     97 typedef struct pmap *pmap_t;
     98 
     99 /*
    100  * for each managed physical page we maintain a list of <PMAP,VA>'s
    101  * which it is mapped at.  the list is headed by a pv_head structure.
    102  * there is one pv_head per managed phys page (allocated at boot time).
    103  * the pv_head structure points to a list of pv_entry structures (each
    104  * describes one mapping).
    105  *
    106  * pv_entry's are only visible within pmap.c, so only provide a placeholder
    107  * here
    108  */
    109 
    110 struct pv_entry;
    111 
    112 struct pv_head {
    113 	struct simplelock pvh_lock;	/* locks every pv on this list */
    114 	struct pv_entry *pvh_list;	/* head of list (locked by pvh_lock) */
    115 };
    116 
    117 /*
    118  * Page hooks. I'll eliminate these sometime soon :-)
    119  *
    120  * For speed we store the both the virtual address and the page table
    121  * entry address for each page hook.
    122  */
    123 typedef struct {
    124         vaddr_t va;
    125         pt_entry_t *pte;
    126 } pagehook_t;
    127 
    128 /*
    129  * Physical / virtual address structure. In a number of places (particularly
    130  * during bootstrapping) we need to keep track of the physical and virtual
    131  * addresses of various pages
    132  */
    133 typedef struct {
    134 	paddr_t pv_pa;
    135 	vaddr_t pv_va;
    136 } pv_addr_t;
    137 
    138 /*
    139  * _KERNEL specific macros, functions and prototypes
    140  */
    141 
    142 #ifdef  _KERNEL
    143 
    144 /*
    145  * Commonly referenced structures
    146  */
    147 extern struct pv_entry	*pv_table;	/* Phys to virt mappings, per page. */
    148 extern struct pmap	kernel_pmap_store;
    149 extern int		pmap_debug_level; /* Only exists if PMAP_DEBUG */
    150 
    151 /*
    152  * Macros that we need to export
    153  */
    154 #define pmap_kernel()			(&kernel_pmap_store)
    155 #define pmap_update()			/* nothing (yet) */
    156 #define	pmap_resident_count(pmap)	((pmap)->pm_stats.resident_count)
    157 #define	pmap_wired_count(pmap)		((pmap)->pm_stats.wired_count)
    158 
    159 #define pmap_phys_address(ppn)		(arm_page_to_byte((ppn)))
    160 
    161 /*
    162  * Functions that we need to export
    163  */
    164 extern boolean_t pmap_testbit __P((paddr_t, int));
    165 extern void pmap_changebit __P((paddr_t, int, int));
    166 extern vaddr_t pmap_map __P((vaddr_t, vaddr_t, vaddr_t, int));
    167 extern void pmap_procwr __P((struct proc *, vaddr_t, int));
    168 #define	PMAP_NEED_PROCWR
    169 
    170 /*
    171  * Functions we use internally
    172  */
    173 void pmap_bootstrap __P((pd_entry_t *, pv_addr_t));
    174 void pmap_debug	__P((int));
    175 int pmap_handled_emulation __P((struct pmap *, vaddr_t));
    176 int pmap_modified_emulation __P((struct pmap *, vaddr_t));
    177 void pmap_postinit __P((void));
    178 pt_entry_t *pmap_pte __P((struct pmap *, vaddr_t));
    179 
    180 /*
    181  * Special page zero routine for use by the idle loop (no cache cleans).
    182  */
    183 boolean_t	pmap_pageidlezero __P((paddr_t));
    184 #define PMAP_PAGEIDLEZERO(pa)	pmap_pageidlezero((pa))
    185 
    186 #endif	/* _KERNEL */
    187 
    188 /*
    189  * Useful macros and constants
    190  */
    191 
    192 /* Virtual address to page table entry */
    193 #define vtopte(va) \
    194 	((pt_entry_t *)(PROCESS_PAGE_TBLS_BASE + \
    195 	(arm_byte_to_page((unsigned int)(va)) << 2)))
    196 
    197 /* Virtual address to physical address */
    198 #define vtophys(va) \
    199 	((*vtopte(va) & PG_FRAME) | ((unsigned int)(va) & ~PG_FRAME))
    200 
    201 /* L1 and L2 page table macros */
    202 #define pmap_pde(m, v) (&((m)->pm_pdir[((vaddr_t)(v) >> PDSHIFT)&4095]))
    203 #define pmap_pte_pa(pte)	(*(pte) & PG_FRAME)
    204 #define pmap_pde_v(pde)		(*(pde) != 0)
    205 #define pmap_pte_v(pte)		(*(pte) != 0)
    206 
    207 /* Size of the kernel part of the L1 page table */
    208 #define KERNEL_PD_SIZE	\
    209 	(PD_SIZE - (KERNEL_SPACE_START >> PDSHIFT) * sizeof(pd_entry_t))
    210 
    211 #endif	/* _ARM32_PMAP_H_ */
    212