1/*-
  2 * SPDX-License-Identifier: BSD-3-Clause
  3 *
  4 * Copyright (c) 1991 Regents of the University of California.
  5 * All rights reserved.
  6 *
  7 * Copyright (c) 2018 The FreeBSD Foundation
  8 * All rights reserved.
  9 *
 10 * This code is derived from software contributed to Berkeley by
 11 * the Systems Programming Group of the University of Utah Computer
 12 * Science Department and William Jolitz of UUNET Technologies Inc.
 13 *
 14 * Portions of this software were developed by
 15 * Konstantin Belousov <kib@FreeBSD.org> under sponsorship from
 16 * the FreeBSD Foundation.
 17 *
 18 * Redistribution and use in source and binary forms, with or without
 19 * modification, are permitted provided that the following conditions
 20 * are met:
 21 * 1. Redistributions of source code must retain the above copyright
 22 *    notice, this list of conditions and the following disclaimer.
 23 * 2. Redistributions in binary form must reproduce the above copyright
 24 *    notice, this list of conditions and the following disclaimer in the
 25 *    documentation and/or other materials provided with the distribution.
 26 * 3. Neither the name of the University nor the names of its contributors
 27 *    may be used to endorse or promote products derived from this software
 28 *    without specific prior written permission.
 29 *
 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 33 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 40 * SUCH DAMAGE.
 41 *
 42 * Derived from hp300 version by Mike Hibler, this version by William
 43 * Jolitz uses a recursive map [a pde points to the page directory] to
 44 * map the page tables using the pagetables themselves. This is done to
 45 * reduce the impact on kernel virtual memory for lots of sparse address
 46 * space, and to reduce the cost of memory to each process.
 47 *
 48 *	from: hp300: @(#)pmap.h	7.2 (Berkeley) 12/16/90
 49 *	from: @(#)pmap.h	7.4 (Berkeley) 5/12/91
 50 */
 51
 52#ifndef _MACHINE_PMAP_PAE_H
 53#define	_MACHINE_PMAP_PAE_H
 54
 55#define	NTRPPTD		2		/* Number of PTDs for trampoline
 56					   mapping */
 57#define	LOWPTDI		2		/* low memory map pde */
 58#define	KERNPTDI	4		/* start of kernel text pde */
 59
 60#define NPGPTD		4		/* Num of pages for page directory */
 61#define NPGPTD_SHIFT	9
 62#undef	PDRSHIFT
 63#define	PDRSHIFT	PDRSHIFT_PAE
 64#undef	NBPDR
 65#define NBPDR		(1 << PDRSHIFT_PAE)	/* bytes/page dir */
 66
 67#define	PG_FRAME	PG_FRAME_PAE
 68#define	PG_PS_FRAME	PG_PS_FRAME_PAE
 69
 70/*
 71 * Size of Kernel address space.  This is the number of page table pages
 72 * (4MB each) to use for the kernel.  256 pages == 1 Gigabyte.
 73 * This **MUST** be a multiple of 4 (eg: 252, 256, 260, etc).
 74 * For PAE, the page table page unit size is 2MB.  This means that 512 pages
 75 * is 1 Gigabyte.  Double everything.  It must be a multiple of 8 for PAE.
 76 */
 77#define KVA_PAGES	(512*4)
 78
 79/*
 80 * The initial number of kernel page table pages that are constructed
 81 * by pmap_cold() must be sufficient to map vm_page_array.  That number can
 82 * be calculated as follows:
 83 *     max_phys / PAGE_SIZE * sizeof(struct vm_page) / NBPDR
 84 * PAE:      max_phys 16G, sizeof(vm_page) 76, NBPDR 2M, 152 page table pages.
 85 * PAE_TABLES: max_phys 4G,  sizeof(vm_page) 68, NBPDR 2M, 36 page table pages.
 86 * Non-PAE:  max_phys 4G,  sizeof(vm_page) 68, NBPDR 4M, 18 page table pages.
 87 */
 88#ifndef NKPT
 89#define	NKPT		240
 90#endif
 91
 92typedef uint64_t pdpt_entry_t;
 93typedef uint64_t pd_entry_t;
 94typedef uint64_t pt_entry_t;
 95
 96#define	PTESHIFT	(3)
 97#define	PDESHIFT	(3)
 98
 99#define	pde_cmpset(pdep, old, new)	atomic_cmpset_64_i586(pdep, old, new)
100#define	pte_load_store(ptep, pte)	atomic_swap_64_i586(ptep, pte)
101#define	pte_load_clear(ptep)		atomic_swap_64_i586(ptep, 0)
102#define	pte_store(ptep, pte)		atomic_store_rel_64_i586(ptep, pte)
103#define	pte_store_zero(ptep, pte)		\
104do {						\
105	uint32_t *p;				\
106						\
107	MPASS((*ptep & PG_V) == 0);		\
108	p = (void *)ptep;			\
109	*(p + 1) = (uint32_t)(pte >> 32);	\
110	__compiler_membar();			\
111	*p = (uint32_t)pte;			\
112} while (0)
113#define	pte_load(ptep)			atomic_load_acq_64_i586(ptep)
114
115extern pdpt_entry_t *IdlePDPT;
116extern pt_entry_t pg_nx;
117extern pd_entry_t *IdlePTD_pae;	/* physical address of "Idle" state directory */
118
119/*
120 * KPTmap is a linear mapping of the kernel page table.  It differs from the
121 * recursive mapping in two ways: (1) it only provides access to kernel page
122 * table pages, and not user page table pages, and (2) it provides access to
123 * a kernel page table page after the corresponding virtual addresses have
124 * been promoted to a 2/4MB page mapping.
125 *
126 * KPTmap is first initialized by pmap_cold() to support just NPKT page table
127 * pages.  Later, it is reinitialized by pmap_bootstrap() to allow for
128 * expansion of the kernel page table.
129 */
130extern pt_entry_t *KPTmap_pae;
131
132#endif