freebsd-skq/sys/i386/include/pmap_pae.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

134 lines
5.2 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_PAE_H
#define _MACHINE_PMAP_PAE_H
#define NTRPPTD 2 /* Number of PTDs for trampoline
mapping */
#define LOWPTDI 2 /* low memory map pde */
#define KERNPTDI 4 /* start of kernel text pde */
#define NPGPTD 4 /* Num of pages for page directory */
#define NPGPTD_SHIFT 9
#undef PDRSHIFT
#define PDRSHIFT PDRSHIFT_PAE
#undef NBPDR
#define NBPDR (1 << PDRSHIFT_PAE) /* bytes/page dir */
#define PG_FRAME PG_FRAME_PAE
#define PG_PS_FRAME PG_PS_FRAME_PAE
/*
* Size of Kernel address space. This is the number of page table pages
* (4MB each) to use for the kernel. 256 pages == 1 Gigabyte.
* This **MUST** be a multiple of 4 (eg: 252, 256, 260, etc).
* For PAE, the page table page unit size is 2MB. This means that 512 pages
* is 1 Gigabyte. Double everything. It must be a multiple of 8 for PAE.
*/
#define KVA_PAGES (512*4)
/*
* The initial number of kernel page table pages that are constructed
* by pmap_cold() must be sufficient to map vm_page_array. That number can
* be calculated as follows:
* max_phys / PAGE_SIZE * sizeof(struct vm_page) / NBPDR
* PAE: max_phys 16G, sizeof(vm_page) 76, NBPDR 2M, 152 page table pages.
* PAE_TABLES: max_phys 4G, sizeof(vm_page) 68, NBPDR 2M, 36 page table pages.
* Non-PAE: max_phys 4G, sizeof(vm_page) 68, NBPDR 4M, 18 page table pages.
*/
#ifndef NKPT
#define NKPT 240
#endif
typedef uint64_t pdpt_entry_t;
typedef uint64_t pd_entry_t;
typedef uint64_t pt_entry_t;
#define PTESHIFT (3)
#define PDESHIFT (3)
#define pde_cmpset(pdep, old, new) atomic_cmpset_64_i586(pdep, old, new)
#define pte_load_store(ptep, pte) atomic_swap_64_i586(ptep, pte)
#define pte_load_clear(ptep) atomic_swap_64_i586(ptep, 0)
#define pte_store(ptep, pte) atomic_store_rel_64_i586(ptep, pte)
#define pte_store_zero(ptep, pte) \
do { \
uint32_t *p; \
\
MPASS((*ptep & PG_V) == 0); \
p = (void *)ptep; \
*(p + 1) = (uint32_t)(pte >> 32); \
__compiler_membar(); \
*p = (uint32_t)pte; \
} while (0)
#define pte_load(ptep) atomic_load_acq_64_i586(ptep)
extern pdpt_entry_t *IdlePDPT;
extern pt_entry_t pg_nx;
extern pd_entry_t *IdlePTD_pae; /* physical address of "Idle" state directory */
/*
* KPTmap is a linear mapping of the kernel page table. It differs from the
* recursive mapping in two ways: (1) it only provides access to kernel page
* table pages, and not user page table pages, and (2) it provides access to
* a kernel page table page after the corresponding virtual addresses have
* been promoted to a 2/4MB page mapping.
*
* KPTmap is first initialized by pmap_cold() to support just NPKT page table
* pages. Later, it is reinitialized by pmap_bootstrap() to allow for
* expansion of the kernel page table.
*/
extern pt_entry_t *KPTmap_pae;
#endif