NetBSD-5.0.2/share/man/man4/agp.4
.\" $NetBSD: agp.4,v 1.12 2008/04/30 13:10:53 martin Exp $
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.\" Copyright (c) 2001 The NetBSD Foundation, Inc.
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Gregory McGarry.
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.Dd September 11, 2001
.Dt AGP 4
.Os
.Sh NAME
.Nm agp
.Nd accelerated graphics port driver
.Sh SYNOPSIS
.Cd "agp* at pchb?"
.Sh DESCRIPTION
The
.Nm
driver provides machine-independent support for the accelerated
graphics port (AGP) found on many PC-based and PCI systems. The AGP
specification was designed by Intel.
.Pp
The AGP chipset is positioned between the PCI-Host bridge and the
graphics accelerator to provide a high-performance dedicated graphics
bus for moving large amounts of data directly from host memory to the
graphics accelerator. The specification currently supports a peak
bandwidth of 528 MB/s. AGP uses a Graphics Address Remapping Table
(GART) to provide a physically-contiguous view of scattered pages in
host memory for DMA transfers.
.Pp
The
.Nm
driver supports the following chipsets:
.Pp
.Bl -dash -compact -offset indent
.It
ALI M1541 host-to-AGP bridge
.It
AMD 751 and 761 host-to-AGP bridges
.It
Intel 82810, 82810-DC100, 82810E, and 82815 SVGA controllers
.It
SiS 5591 host-to-AGP bridge
.It
VIA
.El
.Pp
The
.Nm
driver also provides an interface to user processes for use by X
servers. A user process communicates to the device initially by means
of
.Xr ioctl 2
calls. The calls supported are:
.Bl -tag -width indent
.It Dv AGPIOC_INFO
Get AGP information, setting the members in the
.Em agp_info
structure as defined in \*[Lt]sys/agpio.h\*[Gt]:
.Bd -literal
typedef struct _agp_info {
agp_version version; /* version of the driver */
uint32_t bridge_id; /* bridge vendor/device */
uint32_t agp_mode; /* mode info of bridge */
off_t aper_base; /* base of aperture */
size_t aper_size; /* size of aperture */
size_t pg_total; /* max pages (swap + system) */
size_t pg_system; /* max pages (system) */
size_t pg_used; /* current pages used */
} agp_info;
.Ed
.It Dv AGPIOC_ACQUIRE
Acquire AGP.
.It Dv AGPIOC_RELEASE
Release AGP.
.It Dv AGPIOC_SETUP
Set up AGP, using the members in the
.Em agp_setup
structure as defined in \*[Lt]sys/agpio.h\*[Gt]:
.Bd -literal
typedef struct _agp_setup {
uint32_t agp_mode; /* mode info of bridge */
} agp_setup;
.Ed
.It Dv AGPIOC_ALLOCATE
Allocate AGP space, using and setting the members in the
.Em agp_allocate
structure as defined in \*[Lt]sys/agpio.h\*[Gt]:
.Bd -literal
typedef struct _agp_allocate {
int key; /* tag of allocation */
size_t pg_count; /* number of pages */
uint32_t type; /* 0 == normal, other devspec */
paddr_t physical; /* device specific (some devices
* need a phys address of the
* actual page behind the gatt
* table) */
} agp_allocate;
.Ed
.It Dv AGPIOC_DEALLOCATE
Deallocate AGP space.
.It Dv AGPIOC_BIND
Bind AGP space, using the members in the
.Em agp_bind
structure as defined in \*[Lt]sys/agpio.h\*[Gt]:
.Bd -literal
typedef struct _agp_bind {
int key; /* tag of allocation */
off_t pg_start; /* starting page to populate */
} agp_bind;
.Ed
.It Dv AGPIOC_UNBIND
Unbind AGP space, using the members in the
.Em agp_unbind
structure as defined in \*[Lt]sys/agpio.h\*[Gt]:
.Bd -literal
typedef struct _agp_unbind {
int key; /* tag of allocation */
uint32_t priority; /* priority for paging out */
} agp_unbind;
.Ed
.El
.Sh FILES
.Bl -tag -width /dev/agpgart -compact
.It Pa /dev/agp?
AGP GART device special files
.It Pa /dev/agpgart
AGP GART device special file
.El
.Sh EXAMPLES
This short code fragment is an example of opening the AGP device
and performing some basic operations:
.Bd -literal
#include \*[Lt]sys/types.h\*[Gt]
#include \*[Lt]sys/ioctl.h\*[Gt]
#include \*[Lt]sys/agpio.h\*[Gt]
#include \*[Lt]fcntl.h\*[Gt]
#include \*[Lt]err.h\*[Gt]
int
main(int argc, char **argv)
{
int fd;
agp_info info;
agp_allocate alloc;
agp_setup setup;
agp_bind bind;
agp_unbind unbind;
fd = open("/dev/agp0", O_RDWR);
if (fd \*[Lt] 0)
err(1, "open");
if (ioctl(fd, AGPIOC_INFO, \*[Am]info) \*[Lt] 0)
err(2, "ioctl AGPIOC_INFO");
printf("version: %u.%u\\n", info.version.major,
info.version.minor);
printf("id: %x\\n", info.bridge_id);
printf("mode: %x\\n", info.agp_mode);
printf("base: %x\\n", info.aper_base);
printf("size: %uM\\n", info.aper_size);
printf("total mem: %u\\n", info.pg_total);
printf("system mem: %u\\n", info.pg_system);
printf("used mem: %u\\n\\n", info.pg_used);
setup.agp_mode = info.agp_mode;
if (ioctl(fd, AGPIOC_SETUP, \*[Am]setup) \*[Lt] 0)
err(3, "ioctl AGPIOC_SETUP");
if (ioctl(fd, AGPIOC_ACQUIRE, 0) \*[Lt] 0)
err(3, "ioctl AGPIOC_ACQUIRE");
alloc.type = 0;
alloc.pg_count = 64;
if (ioctl(fd, AGPIOC_ALLOCATE, \*[Am]alloc) \*[Lt] 0)
err(4, "ioctl AGPIOC_ALLOCATE");
printf("alloc key %d, paddr %x\\n", alloc.key, alloc.physical);
if (ioctl(fd, AGPIOC_INFO, \*[Am]info) \*[Lt] 0)
err(5, "ioctl AGPIOC_INFO");
bind.key = alloc.key;
bind.pg_start = 0x1000;
if (ioctl(fd, AGPIOC_BIND, \*[Am]bind) \*[Lt] 0)
err(6, "ioctl AGPIOC_BIND");
printf("used mem now: %u\\n\\n", info.pg_used);
unbind.key = alloc.key;
unbind.priority = 0;
if (ioctl(fd, AGPIOC_UNBIND, \*[Am]unbind) \*[Lt] 0)
err(6, "ioctl AGPIOC_BIND");
if (ioctl(fd, AGPIOC_DEALLOCATE, \*[Am]alloc.key) \*[Lt] 0)
err(6, "ioctl AGPIOC_DEALLOCATE");
if (ioctl(fd, AGPIOC_RELEASE, 0) \*[Lt] 0)
err(7, "ioctl AGPIOC_RELEASE");
close(fd);
printf("agp test successful\\n");
return 0;
}
.Ed
.Sh SEE ALSO
.Xr ioctl 2 ,
.Xr pci 4
.Sh HISTORY
The
.Nm
driver first appeared in
.Fx 4.1 .
It was adopted in
.Nx 1.6 .