xref: /freebsd/sys/i386/include/pmap_pae.h (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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 
49 #ifndef _MACHINE_PMAP_PAE_H
50 #define	_MACHINE_PMAP_PAE_H
51 
52 #define	NTRPPTD		2		/* Number of PTDs for trampoline
53 					   mapping */
54 #define	LOWPTDI		2		/* low memory map pde */
55 #define	KERNPTDI	4		/* start of kernel text pde */
56 
57 #define NPGPTD		4		/* Num of pages for page directory */
58 #define NPGPTD_SHIFT	9
59 #undef	PDRSHIFT
60 #define	PDRSHIFT	PDRSHIFT_PAE
61 #undef	NBPDR
62 #define NBPDR		(1 << PDRSHIFT_PAE)	/* bytes/page dir */
63 
64 #define	PG_FRAME	PG_FRAME_PAE
65 #define	PG_PS_FRAME	PG_PS_FRAME_PAE
66 
67 /*
68  * Size of Kernel address space.  This is the number of page table pages
69  * (4MB each) to use for the kernel.  256 pages == 1 Gigabyte.
70  * This **MUST** be a multiple of 4 (eg: 252, 256, 260, etc).
71  * For PAE, the page table page unit size is 2MB.  This means that 512 pages
72  * is 1 Gigabyte.  Double everything.  It must be a multiple of 8 for PAE.
73  */
74 #define KVA_PAGES	(512*4)
75 
76 /*
77  * The initial number of kernel page table pages that are constructed
78  * by pmap_cold() must be sufficient to map vm_page_array.  That number can
79  * be calculated as follows:
80  *     max_phys / PAGE_SIZE * sizeof(struct vm_page) / NBPDR
81  * PAE:      max_phys 16G, sizeof(vm_page) 76, NBPDR 2M, 152 page table pages.
82  * PAE_TABLES: max_phys 4G,  sizeof(vm_page) 68, NBPDR 2M, 36 page table pages.
83  * Non-PAE:  max_phys 4G,  sizeof(vm_page) 68, NBPDR 4M, 18 page table pages.
84  */
85 #ifndef NKPT
86 #define	NKPT		240
87 #endif
88 
89 typedef uint64_t pdpt_entry_t;
90 typedef uint64_t pd_entry_t;
91 typedef uint64_t pt_entry_t;
92 
93 #define	PTESHIFT	(3)
94 #define	PDESHIFT	(3)
95 
96 #define	pde_cmpset(pdep, old, new)	atomic_cmpset_64_i586(pdep, old, new)
97 #define	pte_load_store(ptep, pte)	atomic_swap_64_i586(ptep, pte)
98 #define	pte_load_clear(ptep)		atomic_swap_64_i586(ptep, 0)
99 #define	pte_store(ptep, pte)		atomic_store_rel_64_i586(ptep, pte)
100 #define	pte_store_zero(ptep, pte)		\
101 do {						\
102 	uint32_t *p;				\
103 						\
104 	MPASS((*ptep & PG_V) == 0);		\
105 	p = (void *)ptep;			\
106 	*(p + 1) = (uint32_t)(pte >> 32);	\
107 	__compiler_membar();			\
108 	*p = (uint32_t)pte;			\
109 } while (0)
110 #define	pte_load(ptep)			atomic_load_acq_64_i586(ptep)
111 
112 extern pdpt_entry_t *IdlePDPT;
113 extern pt_entry_t pg_nx;
114 extern pd_entry_t *IdlePTD_pae;	/* physical address of "Idle" state directory */
115 
116 /*
117  * KPTmap is a linear mapping of the kernel page table.  It differs from the
118  * recursive mapping in two ways: (1) it only provides access to kernel page
119  * table pages, and not user page table pages, and (2) it provides access to
120  * a kernel page table page after the corresponding virtual addresses have
121  * been promoted to a 2/4MB page mapping.
122  *
123  * KPTmap is first initialized by pmap_cold() to support just NPKT page table
124  * pages.  Later, it is reinitialized by pmap_bootstrap() to allow for
125  * expansion of the kernel page table.
126  */
127 extern pt_entry_t *KPTmap_pae;
128 
129 #endif
130