freebsd-nq/sys/sparc64/include/pmap.h
Alan Cox 3cad40e517 Add pmap_clear_write() to the interface between the virtual memory
system's machine-dependent and machine-independent layers.  Once
pmap_clear_write() is implemented on all of our supported
architectures, I intend to replace all calls to pmap_page_protect() by
calls to pmap_clear_write().  Why?  Both the use and implementation of
pmap_page_protect() in our virtual memory system has subtle errors,
specifically, the management of execute permission is broken on some
architectures.  The "prot" argument to pmap_page_protect() should
behave differently from the "prot" argument to other pmap functions.
Instead of meaning, "give the specified access rights to all of the
physical page's mappings," it means "don't take away the specified
access rights from all of the physical page's mappings, but do take
away the ones that aren't specified."  However, owing to our i386
legacy, i.e., no support for no-execute rights, all but one invocation
of pmap_page_protect() specifies VM_PROT_READ only, when the intent
is, in fact, to remove only write permission.  Consequently, a
faithful implementation of pmap_page_protect(), e.g., ia64, would
remove execute permission as well as write permission.  On the other
hand, some architectures that support execute permission have
basically ignored whether or not VM_PROT_EXECUTE is passed to
pmap_page_protect(), e.g., amd64 and sparc64.  This change represents
the first step in replacing pmap_page_protect() by the less subtle
pmap_clear_write() that is already implemented on amd64, i386, and
sparc64.

Discussed with: grehan@ and marcel@
2006-07-20 17:48:41 +00:00

128 lines
4.1 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.
*
* from: hp300: @(#)pmap.h 7.2 (Berkeley) 12/16/90
* from: @(#)pmap.h 7.4 (Berkeley) 5/12/91
* from: FreeBSD: src/sys/i386/include/pmap.h,v 1.70 2000/11/30
* $FreeBSD$
*/
#ifndef _MACHINE_PMAP_H_
#define _MACHINE_PMAP_H_
#include <sys/queue.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <machine/cache.h>
#include <machine/tte.h>
#define PMAP_CONTEXT_MAX 8192
typedef struct pmap *pmap_t;
struct md_page {
TAILQ_HEAD(, tte) tte_list;
struct pmap *pmap;
uint32_t colors[DCACHE_COLORS];
int32_t color;
uint32_t flags;
};
struct pmap {
struct mtx pm_mtx;
struct tte *pm_tsb;
vm_object_t pm_tsb_obj;
u_int pm_active;
u_int pm_context[MAXCPU];
struct pmap_statistics pm_stats;
};
#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 | MTX_DUPOK)
#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)
void pmap_bootstrap(vm_offset_t ekva);
vm_paddr_t pmap_kextract(vm_offset_t va);
void pmap_kenter(vm_offset_t va, vm_page_t m);
void pmap_kremove(vm_offset_t);
void pmap_kenter_flags(vm_offset_t va, vm_paddr_t pa, u_long flags);
void pmap_kremove_flags(vm_offset_t va);
boolean_t pmap_page_is_mapped(vm_page_t m);
int pmap_cache_enter(vm_page_t m, vm_offset_t va);
void pmap_cache_remove(vm_page_t m, vm_offset_t va);
int pmap_remove_tte(struct pmap *pm1, struct pmap *pm2, struct tte *tp,
vm_offset_t va);
int pmap_protect_tte(struct pmap *pm1, struct pmap *pm2, struct tte *tp,
vm_offset_t va);
void pmap_map_tsb(void);
#define vtophys(va) pmap_kextract((vm_offset_t)(va))
extern struct pmap kernel_pmap_store;
#define kernel_pmap (&kernel_pmap_store)
extern vm_paddr_t phys_avail[];
extern vm_offset_t virtual_avail;
extern vm_offset_t virtual_end;
extern vm_paddr_t msgbuf_phys;
#ifdef PMAP_STATS
SYSCTL_DECL(_debug_pmap_stats);
#define PMAP_STATS_VAR(name) \
static long name; \
SYSCTL_LONG(_debug_pmap_stats, OID_AUTO, name, CTLFLAG_RW, \
&name, 0, "")
#define PMAP_STATS_INC(var) \
atomic_add_long(&var, 1)
#else
#define PMAP_STATS_VAR(name)
#define PMAP_STATS_INC(var)
#endif
#endif /* !_MACHINE_PMAP_H_ */