freebsd-skq/sys/mips/include/pmap.h
alc 6eeaee04e4 The page flag PGA_WRITEABLE is set and cleared exclusively by the pmap
layer, but it is read directly by the MI VM layer.  This change introduces
pmap_page_is_write_mapped() in order to completely encapsulate all direct
access to PGA_WRITEABLE in the pmap layer.

Aesthetics aside, I am making this change because amd64 will likely begin
using an alternative method to track write mappings, and having
pmap_page_is_write_mapped() in place allows me to make such a change
without further modification to the MI VM layer.

As an added bonus, tidy up some nearby comments concerning page flags.

Reviewed by:	kib
MFC after:	6 weeks
2012-06-16 18:56:19 +00:00

177 lines
6.2 KiB
C

/*-
* Copyright (c) 1991 Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department and William Jolitz of UUNET Technologies Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
* Derived from hp300 version by Mike Hibler, this version by William
* Jolitz uses a recursive map [a pde points to the page directory] to
* map the page tables using the pagetables themselves. This is done to
* reduce the impact on kernel virtual memory for lots of sparse address
* space, and to reduce the cost of memory to each process.
*
* from: hp300: @(#)pmap.h 7.2 (Berkeley) 12/16/90
* from: @(#)pmap.h 7.4 (Berkeley) 5/12/91
* from: src/sys/i386/include/pmap.h,v 1.65.2.2 2000/11/30 01:54:42 peter
* JNPR: pmap.h,v 1.7.2.1 2007/09/10 07:44:12 girish
* $FreeBSD$
*/
#ifndef _MACHINE_PMAP_H_
#define _MACHINE_PMAP_H_
#include <machine/vmparam.h>
#include <machine/pte.h>
#if defined(__mips_n32) || defined(__mips_n64) /* PHYSADDR_64BIT */
#define NKPT 256 /* mem > 4G, vm_page_startup needs more KPTs */
#else
#define NKPT 120 /* actual number of kernel page tables */
#endif
#ifndef LOCORE
#include <sys/queue.h>
#include <sys/_cpuset.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
/*
* Pmap stuff
*/
struct pv_entry;
struct md_page {
int pv_list_count;
int pv_flags;
TAILQ_HEAD(, pv_entry) pv_list;
};
#define PV_TABLE_MOD 0x01 /* modified */
#define PV_TABLE_REF 0x02 /* referenced */
#define ASID_BITS 8
#define ASIDGEN_BITS (32 - ASID_BITS)
#define ASIDGEN_MASK ((1 << ASIDGEN_BITS) - 1)
struct pmap {
pd_entry_t *pm_segtab; /* KVA of segment table */
TAILQ_HEAD(, pv_entry) pm_pvlist; /* list of mappings in
* pmap */
cpuset_t pm_active; /* active on cpus */
struct {
u_int32_t asid:ASID_BITS; /* TLB address space tag */
u_int32_t gen:ASIDGEN_BITS; /* its generation number */
} pm_asid[MAXSMPCPU];
struct pmap_statistics pm_stats; /* pmap statistics */
struct vm_page *pm_ptphint; /* pmap ptp hint */
struct mtx pm_mtx;
};
typedef struct pmap *pmap_t;
#ifdef _KERNEL
pt_entry_t *pmap_pte(pmap_t, vm_offset_t);
vm_paddr_t pmap_kextract(vm_offset_t va);
#define vtophys(va) pmap_kextract(((vm_offset_t) (va)))
#define pmap_asid(pmap) (pmap)->pm_asid[PCPU_GET(cpuid)].asid
extern struct pmap kernel_pmap_store;
#define kernel_pmap (&kernel_pmap_store)
#define PMAP_LOCK(pmap) mtx_lock(&(pmap)->pm_mtx)
#define PMAP_LOCK_ASSERT(pmap, type) mtx_assert(&(pmap)->pm_mtx, (type))
#define PMAP_LOCK_DESTROY(pmap) mtx_destroy(&(pmap)->pm_mtx)
#define PMAP_LOCK_INIT(pmap) mtx_init(&(pmap)->pm_mtx, "pmap", \
NULL, MTX_DEF)
#define PMAP_LOCKED(pmap) mtx_owned(&(pmap)->pm_mtx)
#define PMAP_MTX(pmap) (&(pmap)->pm_mtx)
#define PMAP_TRYLOCK(pmap) mtx_trylock(&(pmap)->pm_mtx)
#define PMAP_UNLOCK(pmap) mtx_unlock(&(pmap)->pm_mtx)
/*
* For each vm_page_t, there is a list of all currently valid virtual
* mappings of that page. An entry is a pv_entry_t, the list is pv_table.
*/
typedef struct pv_entry {
pmap_t pv_pmap; /* pmap where mapping lies */
vm_offset_t pv_va; /* virtual address for mapping */
TAILQ_ENTRY(pv_entry) pv_list;
TAILQ_ENTRY(pv_entry) pv_plist;
vm_page_t pv_ptem; /* VM page for pte */
} *pv_entry_t;
/*
* physmem_desc[] is a superset of phys_avail[] and describes all the
* memory present in the system.
*
* phys_avail[] is similar but does not include the memory stolen by
* pmap_steal_memory().
*
* Each memory region is described by a pair of elements in the array
* so we can describe up to (PHYS_AVAIL_ENTRIES / 2) distinct memory
* regions.
*/
#define PHYS_AVAIL_ENTRIES 10
extern vm_paddr_t phys_avail[PHYS_AVAIL_ENTRIES + 2];
extern vm_paddr_t physmem_desc[PHYS_AVAIL_ENTRIES + 2];
extern vm_offset_t virtual_avail;
extern vm_offset_t virtual_end;
extern vm_paddr_t dump_avail[PHYS_AVAIL_ENTRIES + 2];
#define pmap_page_get_memattr(m) VM_MEMATTR_DEFAULT
#define pmap_page_is_mapped(m) (!TAILQ_EMPTY(&(m)->md.pv_list))
#define pmap_page_is_write_mapped(m) (((m)->aflags & PGA_WRITEABLE) != 0)
#define pmap_page_set_memattr(m, ma) (void)0
void pmap_bootstrap(void);
void *pmap_mapdev(vm_paddr_t, vm_size_t);
void pmap_unmapdev(vm_offset_t, vm_size_t);
vm_offset_t pmap_steal_memory(vm_size_t size);
int page_is_managed(vm_paddr_t pa);
void pmap_kenter(vm_offset_t va, vm_paddr_t pa);
void pmap_kenter_attr(vm_offset_t va, vm_paddr_t pa, int attr);
void pmap_kremove(vm_offset_t va);
void *pmap_kenter_temporary(vm_paddr_t pa, int i);
void pmap_kenter_temporary_free(vm_paddr_t pa);
void pmap_flush_pvcache(vm_page_t m);
int pmap_emulate_modified(pmap_t pmap, vm_offset_t va);
void pmap_grow_direct_page_cache(void);
vm_page_t pmap_alloc_direct_page(unsigned int index, int req);
#endif /* _KERNEL */
#endif /* !LOCORE */
#endif /* !_MACHINE_PMAP_H_ */