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pmap.h revision 1.12
      1 /*	$NetBSD: pmap.h,v 1.12 2001/07/29 12:45:27 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 struct vm_page, there is a list of all currently valid virtual
    101  * mappings of that page.  An entry is a pv_entry_t, the list is pv_table.
    102  */
    103 typedef struct pv_entry {
    104 	struct pv_entry *pv_next;       /* next pv_entry */
    105 	struct pmap     *pv_pmap;        /* pmap where mapping lies */
    106 	vaddr_t         pv_va;          /* virtual address for mapping */
    107 	int             pv_flags;       /* flags */
    108 } *pv_entry_t;
    109 
    110 /*
    111  * A pv_page_info struture looks like this. It is used to contain status
    112  * information for pv_entry freelists.
    113  */
    114 struct pv_page;
    115 
    116 struct pv_page_info {
    117 	TAILQ_ENTRY(pv_page) pgi_list;
    118 	struct pv_entry *pgi_freelist;
    119 	int pgi_nfree;
    120 };
    121 
    122 /*
    123  * A pv_page itself looks like this. pv_entries are requested from the VM a
    124  * pv_page at a time.
    125  *
    126  * We also define a macro that states the number of pv_entries per page
    127  * allocated.
    128  */
    129 #define NPVPPG	((NBPG - sizeof(struct pv_page_info)) / sizeof(struct pv_entry))
    130 
    131 struct pv_page {
    132 	struct pv_page_info pvp_pgi;
    133 	struct pv_entry pvp_pv[NPVPPG];
    134 };
    135 
    136 /*
    137  * Page hooks. I'll eliminate these sometime soon :-)
    138  *
    139  * For speed we store the both the virtual address and the page table
    140  * entry address for each page hook.
    141  */
    142 typedef struct {
    143         vaddr_t va;
    144         pt_entry_t *pte;
    145 } pagehook_t;
    146 
    147 /*
    148  * Physical / virtual address structure. In a number of places (particularly
    149  * during bootstrapping) we need to keep track of the physical and virtual
    150  * addresses of various pages
    151  */
    152 typedef struct {
    153 	paddr_t pv_pa;
    154 	vaddr_t pv_va;
    155 } pv_addr_t;
    156 
    157 /*
    158  * _KERNEL specific macros, functions and prototypes
    159  */
    160 
    161 #ifdef  _KERNEL
    162 
    163 /*
    164  * Commonly referenced structures
    165  */
    166 extern pv_entry_t	pv_table;	/* Phys to virt mappings, per page. */
    167 extern struct pmap	kernel_pmap_store;
    168 extern int		pmap_debug_level; /* Only exists if PMAP_DEBUG */
    169 
    170 /*
    171  * Macros that we need to export
    172  */
    173 #define pmap_kernel()			(&kernel_pmap_store)
    174 #define pmap_update()			/* nothing (yet) */
    175 #define	pmap_resident_count(pmap)	((pmap)->pm_stats.resident_count)
    176 #define	pmap_wired_count(pmap)		((pmap)->pm_stats.wired_count)
    177 
    178 #define pmap_phys_address(ppn)		(arm_page_to_byte((ppn)))
    179 
    180 /*
    181  * Functions that we need to export
    182  */
    183 extern boolean_t pmap_testbit __P((paddr_t, int));
    184 extern void pmap_changebit __P((paddr_t, int, int));
    185 extern vaddr_t pmap_map __P((vaddr_t, vaddr_t, vaddr_t, int));
    186 extern void pmap_procwr __P((struct proc *, vaddr_t, int));
    187 #define	PMAP_NEED_PROCWR
    188 
    189 /*
    190  * Functions we use internally
    191  */
    192 extern void pmap_bootstrap __P((pd_entry_t *, pv_addr_t));
    193 extern void pmap_debug	__P((int));
    194 extern int pmap_handled_emulation __P((struct pmap *, vaddr_t));
    195 extern int pmap_modified_emulation __P((struct pmap *, vaddr_t));
    196 extern void pmap_postinit __P((void));
    197 extern pt_entry_t *pmap_pte __P((struct pmap *, vaddr_t));
    198 
    199 #endif	/* _KERNEL */
    200 
    201 /*
    202  * Useful macros and constants
    203  */
    204 
    205 /* Virtual address to page table entry */
    206 #define vtopte(va) \
    207 	((pt_entry_t *)(PROCESS_PAGE_TBLS_BASE + \
    208 	(arm_byte_to_page((unsigned int)(va)) << 2)))
    209 
    210 /* Virtual address to physical address */
    211 #define vtophys(va) \
    212 	((*vtopte(va) & PG_FRAME) | ((unsigned int)(va) & ~PG_FRAME))
    213 
    214 /* L1 and L2 page table macros */
    215 #define pmap_pde(m, v) (&((m)->pm_pdir[((vaddr_t)(v) >> PDSHIFT)&4095]))
    216 #define pmap_pte_pa(pte)	(*(pte) & PG_FRAME)
    217 #define pmap_pde_v(pde)		(*(pde) != 0)
    218 #define pmap_pte_v(pte)		(*(pte) != 0)
    219 
    220 /* Size of the kernel part of the L1 page table */
    221 #define KERNEL_PD_SIZE	\
    222 	(PD_SIZE - (KERNEL_SPACE_START >> PDSHIFT) * sizeof(pd_entry_t))
    223 
    224 #endif	/* _ARM32_PMAP_H_ */
    225