From f07a4c844da9f0ecae5bbee1ab94be56505f26f7 Mon Sep 17 00:00:00 2001 From: Thomas Bushnell Date: Tue, 25 Feb 1997 21:28:37 +0000 Subject: Initial source --- include/mach/vm_param.h | 98 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 include/mach/vm_param.h (limited to 'include/mach/vm_param.h') diff --git a/include/mach/vm_param.h b/include/mach/vm_param.h new file mode 100644 index 0000000..0360981 --- /dev/null +++ b/include/mach/vm_param.h @@ -0,0 +1,98 @@ +/* + * Mach Operating System + * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University + * All Rights Reserved. + * + * Permission to use, copy, modify and distribute this software and its + * documentation is hereby granted, provided that both the copyright + * notice and this permission notice appear in all copies of the + * software, derivative works or modified versions, and any portions + * thereof, and that both notices appear in supporting documentation. + * + * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" + * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR + * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. + * + * Carnegie Mellon requests users of this software to return to + * + * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU + * School of Computer Science + * Carnegie Mellon University + * Pittsburgh PA 15213-3890 + * + * any improvements or extensions that they make and grant Carnegie Mellon + * the rights to redistribute these changes. + */ +/* + * File: mach/vm_param.h + * Author: Avadis Tevanian, Jr., Michael Wayne Young + * Date: 1985 + * + * Machine independent virtual memory parameters. + * + */ + +#ifndef _MACH_VM_PARAM_H_ +#define _MACH_VM_PARAM_H_ + +#include +#include + +/* + * The machine independent pages are refered to as PAGES. A page + * is some number of hardware pages, depending on the target machine. + * + * All references to the size of a page should be done + * with PAGE_SIZE, PAGE_SHIFT, or PAGE_MASK. + * They may be implemented as either constants or variables, + * depending on more-specific code. + * If they're variables, they had better be initialized + * by the time system-independent code starts getting called. + * + * Regardless whether it is implemented with a constant or a variable, + * the PAGE_SIZE is assumed to be a power of two throughout the + * virtual memory system implementation. + * + * More-specific code must at least provide PAGE_SHIFT; + * we can calculate the others if necessary. + * (However, if PAGE_SHIFT really refers to a variable, + * PAGE_SIZE and PAGE_MASK should also be variables + * so their values don't have to be constantly recomputed.) + */ +#ifndef PAGE_SHIFT +#error mach/machine/vm_param.h needs to define PAGE_SHIFT. +#endif + +#ifndef PAGE_SIZE +#define PAGE_SIZE (1 << PAGE_SHIFT) +#endif + +#ifndef PAGE_MASK +#define PAGE_MASK (PAGE_SIZE-1) +#endif + +/* + * Convert addresses to pages and vice versa. + * No rounding is used. + */ + +#define atop(x) (((vm_size_t)(x)) >> PAGE_SHIFT) +#define ptoa(x) ((vm_offset_t)((x) << PAGE_SHIFT)) + +/* + * Round off or truncate to the nearest page. These will work + * for either addresses or counts. (i.e. 1 byte rounds to 1 page + * bytes. + */ + +#define round_page(x) ((vm_offset_t)((((vm_offset_t)(x)) + PAGE_MASK) & ~PAGE_MASK)) +#define trunc_page(x) ((vm_offset_t)(((vm_offset_t)(x)) & ~PAGE_MASK)) + +/* + * Determine whether an address is page-aligned, or a count is + * an exact page multiple. + */ + +#define page_aligned(x) ((((vm_offset_t) (x)) & PAGE_MASK) == 0) + +#endif /* _MACH_VM_PARAM_H_ */ -- cgit v1.2.3