freebsd-nq/sys/i386/include/param.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

168 lines
5.2 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* 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.
*
* from: @(#)param.h 5.8 (Berkeley) 6/28/91
* $FreeBSD$
*/
#ifndef _I386_INCLUDE_PARAM_H_
#define _I386_INCLUDE_PARAM_H_
#include <machine/_align.h>
/*
* Machine dependent constants for Intel 386.
*/
#define __HAVE_ACPI
#define __HAVE_PIR
#define __PCI_REROUTE_INTERRUPT
#ifndef MACHINE
#define MACHINE "i386"
#endif
#ifndef MACHINE_ARCH
#define MACHINE_ARCH "i386"
#endif
#define MID_MACHINE MID_I386
#if defined(SMP) || defined(KLD_MODULE)
#ifndef MAXCPU
#define MAXCPU 32
#endif
#else
#define MAXCPU 1
#endif /* SMP || KLD_MODULE */
#ifndef MAXMEMDOM
#define MAXMEMDOM 1
#endif
#define ALIGNBYTES _ALIGNBYTES
#define ALIGN(p) _ALIGN(p)
/*
* ALIGNED_POINTER is a boolean macro that checks whether an address
* is valid to fetch data elements of type t from on this architecture.
* This does not reflect the optimal alignment, just the possibility
* (within reasonable limits).
*/
#define ALIGNED_POINTER(p, t) 1
/*
* CACHE_LINE_SIZE is the compile-time maximum cache line size for an
* architecture. It should be used with appropriate caution.
*/
#define CACHE_LINE_SHIFT 6
#define CACHE_LINE_SIZE (1 << CACHE_LINE_SHIFT)
#define PAGE_SHIFT 12 /* LOG2(PAGE_SIZE) */
#define PAGE_SIZE (1 << PAGE_SHIFT) /* bytes/page */
#define PAGE_MASK (PAGE_SIZE - 1)
#define NPTEPG (PAGE_SIZE / sizeof(pt_entry_t))
/* Size in bytes of the page directory */
#define NBPTD (NPGPTD << PAGE_SHIFT)
/* Number of PDEs in page directory, 2048 for PAE, 1024 for non-PAE */
#define NPDEPTD (NBPTD / sizeof(pd_entry_t))
/* Number of PDEs in one page of the page directory, 512 vs. 1024 */
#define NPDEPG (PAGE_SIZE / sizeof(pd_entry_t))
#define PDRMASK (NBPDR - 1)
#ifndef PDRSHIFT
#define PDRSHIFT i386_pmap_PDRSHIFT
#endif
#ifndef NBPDR
#define NBPDR (1 << PDRSHIFT) /* bytes/page dir */
#endif
#define MAXPAGESIZES 2 /* maximum number of supported page sizes */
#define IOPAGES 2 /* pages of i/o permission bitmap */
#ifndef KSTACK_PAGES
#define KSTACK_PAGES 4 /* Includes pcb! */
#endif
#define KSTACK_GUARD_PAGES 1 /* pages of kstack guard; 0 disables */
#if KSTACK_PAGES < 4
#define TD0_KSTACK_PAGES 4
#else
#define TD0_KSTACK_PAGES KSTACK_PAGES
#endif
/*
* Ceiling on amount of swblock kva space, can be changed via
* the kern.maxswzone /boot/loader.conf variable.
*
* 276 is sizeof(struct swblock), but we do not always have a definition
* in scope for struct swblock, so we have to hardcode it. Each struct
* swblock holds metadata for 32 pages, so in theory, this is enough for
* 16 GB of swap. In practice, however, the usable amount is considerably
* lower due to fragmentation.
*/
#ifndef VM_SWZONE_SIZE_MAX
#define VM_SWZONE_SIZE_MAX (276 * 128 * 1024)
#endif
/*
* Ceiling on size of buffer cache (really only effects write queueing,
* the VM page cache is not effected), can be changed via
* the kern.maxbcache /boot/loader.conf variable.
*
* The value is equal to the size of the auto-tuned buffer map for
* the machine with 4GB of RAM, see vfs_bio.c:kern_vfs_bio_buffer_alloc().
*/
#ifndef VM_BCACHE_SIZE_MAX
#define VM_BCACHE_SIZE_MAX (7224 * 16 * 1024)
#endif
/*
* Mach derived conversion macros
*/
#define trunc_page(x) ((x) & ~PAGE_MASK)
#define round_page(x) (((x) + PAGE_MASK) & ~PAGE_MASK)
#define trunc_4mpage(x) ((x) & ~PDRMASK)
#define round_4mpage(x) ((((x)) + PDRMASK) & ~PDRMASK)
#define atop(x) ((x) >> PAGE_SHIFT)
#define ptoa(x) ((x) << PAGE_SHIFT)
#define i386_btop(x) ((x) >> PAGE_SHIFT)
#define i386_ptob(x) ((x) << PAGE_SHIFT)
#define pgtok(x) ((x) * (PAGE_SIZE / 1024))
#define INKERNEL(va) (TRUE)
#endif /* !_I386_INCLUDE_PARAM_H_ */