freebsd-skq/sys/vm/vm.h
jhb b4b2ae5652 Add new bus methods for mapping resources.
Add a pair of bus methods that can be used to "map" resources for direct
CPU access using bus_space(9).  bus_map_resource() creates a mapping and
bus_unmap_resource() releases a previously created mapping.  Mappings are
described by 'struct resource_map' object.  Pointers to these objects can
be passed as the first argument to the bus_space wrapper API used for bus
resources.

Drivers that wish to map all of a resource using default settings
(for example, using uncacheable memory attributes) do not need to change.
However, drivers that wish to use non-default settings can now do so
without jumping through hoops.

First, an RF_UNMAPPED flag is added to request that a resource is not
implicitly mapped with the default settings when it is activated.  This
permits other activation steps (such as enabling I/O or memory decoding
in a device's PCI command register) to be taken without creating a
mapping.  Right now the AGP drivers don't set RF_ACTIVE to avoid using
up a large amount of KVA to map the AGP aperture on 32-bit platforms.
Once RF_UNMAPPED is supported on all platforms that support AGP this
can be changed to using RF_UNMAPPED with RF_ACTIVE instead.

Second, bus_map_resource accepts an optional structure that defines
additional settings for a given mapping.

For example, a driver can now request to map only a subset of a resource
instead of the entire range.  The AGP driver could also use this to only
map the first page of the aperture (IIRC, it calls pmap_mapdev() directly
to map the first page currently).  I will also eventually change the
PCI-PCI bridge driver to request mappings of the subset of the I/O window
resource on its parent side to create mappings for child devices rather
than passing child resources directly up to nexus to be mapped.  This
also permits bridges that do address translation to request suitable
mappings from a resource on the "upper" side of the bus when mapping
resources on the "lower" side of the bus.

Another attribute that can be specified is an alternate memory attribute
for memory-mapped resources.  This can be used to request a
Write-Combining mapping of a PCI BAR in an MI fashion.  (Currently the
drivers that do this call pmap_change_attr() directly for x86 only.)

Note that this commit only adds the MI framework.  Each platform needs
to add support for handling RF_UNMAPPED and thew new
bus_map/unmap_resource methods.  Generally speaking, any drivers that
are calling rman_set_bustag() and rman_set_bushandle() need to be
updated.

Discussed on:	arch
Reviewed by:	cem
Differential Revision:	https://reviews.freebsd.org/D5237
2016-05-20 17:57:47 +00:00

155 lines
5.2 KiB
C

/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 4. 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.
*
* @(#)vm.h 8.2 (Berkeley) 12/13/93
* @(#)vm_prot.h 8.1 (Berkeley) 6/11/93
* @(#)vm_inherit.h 8.1 (Berkeley) 6/11/93
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
*
* 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 the
* rights to redistribute these changes.
*
* $FreeBSD$
*/
#ifndef VM_H
#define VM_H
#include <machine/vm.h>
typedef char vm_inherit_t; /* inheritance codes */
#define VM_INHERIT_SHARE ((vm_inherit_t) 0)
#define VM_INHERIT_COPY ((vm_inherit_t) 1)
#define VM_INHERIT_NONE ((vm_inherit_t) 2)
#define VM_INHERIT_DEFAULT VM_INHERIT_COPY
typedef u_char vm_prot_t; /* protection codes */
#define VM_PROT_NONE ((vm_prot_t) 0x00)
#define VM_PROT_READ ((vm_prot_t) 0x01)
#define VM_PROT_WRITE ((vm_prot_t) 0x02)
#define VM_PROT_EXECUTE ((vm_prot_t) 0x04)
#define VM_PROT_COPY ((vm_prot_t) 0x08) /* copy-on-read */
#define VM_PROT_ALL (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)
#define VM_PROT_RW (VM_PROT_READ|VM_PROT_WRITE)
#define VM_PROT_DEFAULT VM_PROT_ALL
enum obj_type { OBJT_DEFAULT, OBJT_SWAP, OBJT_VNODE, OBJT_DEVICE, OBJT_PHYS,
OBJT_DEAD, OBJT_SG, OBJT_MGTDEVICE };
typedef u_char objtype_t;
union vm_map_object;
typedef union vm_map_object vm_map_object_t;
struct vm_map_entry;
typedef struct vm_map_entry *vm_map_entry_t;
struct vm_map;
typedef struct vm_map *vm_map_t;
struct vm_object;
typedef struct vm_object *vm_object_t;
#ifndef _KERNEL
/*
* This is defined in <sys/types.h> for the kernel so that non-vm kernel
* sources (mainly Mach-derived ones such as ddb) don't have to include
* vm stuff. Defining it there for applications might break things.
* Define it here for "applications" that include vm headers (e.g.,
* genassym).
*/
typedef int boolean_t;
/*
* The exact set of memory attributes is machine dependent. However,
* every machine is required to define VM_MEMATTR_DEFAULT and
* VM_MEMATTR_UNCACHEABLE.
*/
typedef char vm_memattr_t; /* memory attribute codes */
/*
* This is defined in <sys/types.h> for the kernel so that vnode_if.h
* doesn't have to include <vm/vm.h>.
*/
struct vm_page;
typedef struct vm_page *vm_page_t;
#endif /* _KERNEL */
struct vm_reserv;
typedef struct vm_reserv *vm_reserv_t;
/*
* Information passed from the machine-independant VM initialization code
* for use by machine-dependant code (mainly for MMU support)
*/
struct kva_md_info {
vm_offset_t buffer_sva;
vm_offset_t buffer_eva;
vm_offset_t clean_sva;
vm_offset_t clean_eva;
};
extern struct kva_md_info kmi;
extern void vm_ksubmap_init(struct kva_md_info *);
extern int old_mlock;
struct ucred;
int swap_reserve(vm_ooffset_t incr);
int swap_reserve_by_cred(vm_ooffset_t incr, struct ucred *cred);
void swap_reserve_force(vm_ooffset_t incr);
void swap_release(vm_ooffset_t decr);
void swap_release_by_cred(vm_ooffset_t decr, struct ucred *cred);
void swapper(void);
#endif /* VM_H */