freebsd-skq/sys/i386/include/pmap_nopae.h
kib c1ebd497a3 i386 PAE: avoid atomic for pte_store() where possible.
Instead carefully write upper word, and only than the lower word with
PG_V, for previously invalid ptes.  It provides some measurable system
time saving on buildworld.

Reviewed by:	markj
Tested by:	pho
Measured by:	bde (early version)
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D19226
2019-02-26 09:45:44 +00:00

102 lines
3.6 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1991 Regents of the University of California.
* All rights reserved.
*
* Copyright (c) 2018 The FreeBSD Foundation
* 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.
*
* Portions of this software were developed by
* Konstantin Belousov <kib@FreeBSD.org> under sponsorship from
* the FreeBSD Foundation.
*
* 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.
* 3. 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
* $FreeBSD$
*/
#ifndef _MACHINE_PMAP_NOPAE_H
#define _MACHINE_PMAP_NOPAE_H
#define NTRPPTD 1
#define LOWPTDI 1
#define KERNPTDI 2
#define NPGPTD 1
#define NPGPTD_SHIFT 10
#undef PDRSHIFT
#define PDRSHIFT PDRSHIFT_NOPAE
#undef NBPDR
#define NBPDR (1 << PDRSHIFT_NOPAE) /* bytes/page dir */
#define PG_FRAME PG_FRAME_NOPAE
#define PG_PS_FRAME PG_PS_FRAME_NOPAE
#define KVA_PAGES (256*4)
#ifndef NKPT
#define NKPT 30
#endif
typedef uint32_t pd_entry_t;
typedef uint32_t pt_entry_t;
typedef uint32_t pdpt_entry_t; /* Only to keep struct pmap layout. */
#define PTESHIFT (2)
#define PDESHIFT (2)
#define pde_cmpset(pdep, old, new) atomic_cmpset_int(pdep, old, new)
#define pte_load_store(ptep, pte) atomic_swap_int(ptep, pte)
#define pte_load_clear(ptep) atomic_swap_int(ptep, 0)
#define pte_store(ptep, pte) do { \
*(u_int *)(ptep) = (u_int)(pte); \
} while (0)
#define pte_store_zero(ptep, pte) pte_store(ptep, pte)
#define pte_load(ptep) atomic_load_int(ptep)
extern pt_entry_t PTmap[];
extern pd_entry_t PTD[];
extern pd_entry_t PTDpde[];
extern pd_entry_t *IdlePTD_nopae;
extern pt_entry_t *KPTmap_nopae;
struct pmap;
pt_entry_t *__CONCAT(PMTYPE, pmap_pte)(struct pmap *, vm_offset_t) __pure2;
#endif