freebsd-nq/sys/i386/include/pmap_nopae.h
Konstantin Belousov 9a52756044 i386: Merge PAE and non-PAE pmaps into same kernel.
Effectively all i386 kernels now have two pmaps compiled in: one
managing PAE pagetables, and another non-PAE. The implementation is
selected at cold time depending on the CPU features. The vm_paddr_t is
always 64bit now. As result, nx bit can be used on all capable CPUs.

Option PAE only affects the bus_addr_t: it is still 32bit for non-PAE
configs, for drivers compatibility. Kernel layout, esp. max kernel
address, low memory PDEs and max user address (same as trampoline
start) are now same for PAE and for non-PAE regardless of the type of
page tables used.

Non-PAE kernel (when using PAE pagetables) can handle physical memory
up to 24G now, larger memory requires re-tuning the KVA consumers and
instead the code caps the maximum at 24G. Unfortunately, a lot of
drivers do not use busdma(9) properly so by default even 4G barrier is
not easy. There are two tunables added: hw.above4g_allow and
hw.above24g_allow, the first one is kept enabled for now to evaluate
the status on HEAD, second is only for dev use.

i386 now creates three freelists if there is any memory above 4G, to
allow proper bounce pages allocation. Also, VM_KMEM_SIZE_SCALE changed
from 3 to 1.

The PAE_TABLES kernel config option is retired.

In collaboarion with: pho
Discussed with:	emaste
Reviewed by:	markj
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D18894
2019-01-30 02:07:13 +00:00

101 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_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