VME(9) BSD Kernel Developer's Manual VME(9)NAME
VME, vme_probe, vme_space_map, vme_space_unmap, vme_intr_map,
vme_intr_establish, vme_intr_disestablish, vme_intr_evcnt,
vme_dmamap_create, vme_dmamap_destroy, vme_dmamem_alloc, vme_dmamem_free,
vme_space_alloc, vme_space_free, vme_space_get — Versa Module Euroboard
bus
SYNOPSIS
#include <sys/bus.h>
#include <dev/vme/vmereg.h>
#include <dev/vme/vmevar.h>
int
vme_probe(void *vc, vme_addr_t vmeaddr, vme_size_t len, vme_am_t am,
vme_datasize_t datasize, int (*callback)(), void *arg);
int
vme_space_map(void *vc, vme_addr_t vmeaddr, vme_size_t len, vme_am_t am,
vme_datasize_t datasize, vme_swap_t swap, bus_space_tag_t *tag,
bus_space_handle_t *handle, vme_mapresc_t *resc);
void
vme_space_unmap(void *vc, vme_mapresc_t resc);
int
vme_intr_map(void *vc, int level, int vector,
vme_intr_handle_t *handlep);
void *
vme_intr_establish(void *vc, vme_intr_handle_t handle, int prio,
int (*func)(void *), void *arg);
void
vme_intr_disestablish(void *vc, void *cookie);
const struct evcnt *
vme_intr_evcnt(void *vc, vme_intr_handle_t handle);
int
vme_dmamap_create(void *vc, vme_size_t size, vme_am_t am,
vme_datasize_t datasize, vme_swap_t swap, int nsegs,
vme_size_t segsz, vme_addr_t bound, int flags, bus_dmamap_t *map);
void
vme_dmamap_destroy(void *vc, bus_dmamap_t map);
int
vme_dmamem_alloc(void *vc, vme_size_t size, vme_am_t am,
vme_datasize_t datasize, vme_swap_t swap, bus_dma_segment_t *segs,
int nsegs, int *rsegs, int flags);
void
vme_dmamem_free(void *vc, bus_dma_segment_t *segs, int nsegs);
int
vme_space_alloc(struct vmebus_softc *tag, vme_addr_t addr,
vme_size_t size, vme_am_t ams);
void
vme_space_free(void *vc, vme_addr_t addr, vme_size_t size, vme_am_t ams);
int
vme_space_get(void *vc, vme_size_t size, vme_am_t ams, u_long align,
vme_addr_t *addr);
DESCRIPTION
The VME bus provides support for VME devices. The VME bus is a high-per‐
formance backplane bus for use in computer systems. It is based on the
VMEbus specification initially released by the VMEbus International Trade
Association (VITA) in August of 1982. It has since undergone IEC and
IEEE standardisation.
The VME bus supports 8, 16, and 32-bit transfers over non-multiplexed
32-bit data and address paths. The latest revisions allow 64-bit, multi‐
plexed transfers. It supports asynchronous, fully handshaken transfers
at speeds up to 80 MB/sec. It has a master-slave architecture, encourag‐
ing multiprocessing and supports up to seven interrupt levels.
DATA TYPES
Drivers attached to the VME bus will make use of the following data
types:
vme_chipset_tag_t
An opaque type identifying the bus controller.
vme_addr_t
Addresses on the bus.
vme_am_t
Address modifiers. Valid values are VME_AM_A32, VME_AM_A16,
VME_AM_A24, VME_AM_USERDEF (user/vendor definable), VME_AM_MBO,
VME_AM_SUPER, VME_AM_USER, VME_AM_DATA, VME_AM_PRG, VME_AM_BLT32
and VME_AM_BLT64.
vme_datasize_t
The datasize of the address space. Valid values are VME_D8,
VME_D16, and VME_D32.
vme_mapresc_t
Generic placeholder for any resources needed for a mapping.
vme_intr_handle_t
An opaque type describing an interrupt mapping.
vme_swap_t
Hardware swap capabilities for controlling data endianness.
Valid values have not been specified yet.
struct vme_range
A structure used to describe an address range on the VME bus.
It contains the following members:
vme_addr_t offset;
vme_size_t size;
vme_am_t am;
struct vme_attach_args
A structure used to inform the driver of the device properties.
It contains the following members:
vme_chipset_tag_t va_vct;
bus_dma_tag_t va_bdt;
int ivector;
int ilevel;
int numcfranges;
struct vme_range r[VME_MAXCFRANGES];
FUNCTIONS
vme_probe(vc, vmeaddr, len, am, datasize, callback, arg)
Probes the VME space managed by controller vc at address
vmeaddr, length len, with address modifiers am and datasize
datasize for a device. If a VME device is found, the function
callback() (if it is not NULL) is called to perform device-spe‐
cific identification. callback() is called with the argument
arg, and the bus-space tag and bus-space handle for accessing
the VME space mapping and should return a nonzero positive inte‐
ger for a positive device match.
vme_space_map(vc, vmeaddr, len, am, datasize, swap, tag, handle, resc)
Maps the VME space managed by controller vc at address vmeaddr,
length len, with address modifiers am, datasize datasize and
endianness swap for a device. If the mapping is successful tag
contains the bus-space tag and handle contains the bus-space
handle for accessing the VME space mapping. resc contains the
resources for the mappings. vme_space_map() returns 0 on suc‐
cess, and nonzero on error.
vme_space_unmap(vc, resc)
Unmaps the VME space mapping managed by controller vc and
resources resc.
vme_intr_map(vc, level, vector, handlep)
Sets handlep to a machine-dependent value which identifies a
particular interrupt source at level level and vector vector on
the controller vc. vme_intr_map() returns zero on success, and
nonzero on failure.
vme_intr_establish(vc, handle, prio, func, arg)
Establishes the interrupt handler handlep. When the device
interrupts, func() will be called with a single argument arg and
will run at the interrupt priority level prio. The return value
of vme_intr_establish() may be saved and passed to
vme_intr_disestablish().
vme_intr_disestablish(vc, cookie)
Disables the interrupt handler when the driver is no longer
interested in interrupts from the device. cookie is the value
returned by vme_intr_establish().
vme_intr_evcnt(vc, handle)
Increment the interrupt event counter for the interrupt speci‐
fied by handle.
vme_dmamap_create(vc, size, am, datasize, swap, nsegs, segsz, bound,
flags, map)
Allocates a DMA handle and initializes it according to the
parameters provided. The VME-specific parameters describe the
address-space modifiers am, datasize datasize, and endianness
swap. The remaining parameters are described in bus_dma(9).
vme_dmamap_destroy(vc, map)
Frees all resources associated with a given DMA handle. The
parameters are described in bus_dma(9).
vme_dmamem_alloc(vc, size, am, datasize, swap, segs, nsegs, rsegs, flags)
Allocates memory that is “DMA safe” for the VME bus managed by
controller vc. The VME-specific parameters describe the
address-space modifiers am, datasize datasize, and endianness
swap. The remaining parameters are described in bus_dma(9).
vme_dmamem_free(vc, segs, nsegs)
Frees memory previously allocated by vme_dmamem_alloc() for the
VME space managed by controller vc.
vme_space_alloc(tag, addr, size, ams)
Allocate VME space for the bus-space tag at address addr of size
size and address-space modifiers ams. vme_space_alloc() returns
EINVAL on invalid inputs.
vme_space_free(vc, addr, size, ams)
Deallocate VME space for the bus-space tag at address addr of
size size and address-space modifiers ams.
vme_space_get(vc, size, ams, align, addr)
Returns EINVAL on invalid inputs.
AUTOCONFIGURATION
The VME bus is an indirect-connection bus. During autoconfiguration each
driver is required to probe the bus for the presence of a device. A VME
driver will receive a pointer to a struct vme_attach_args hinting at
"locations" (address ranges) on the VME bus where the device may be
located. The driver should check the number of address ranges, allocate
the address space of these ranges using vme_space_alloc(), and probe the
address space for the device using vme_probe().
During driver attach the driver should also map the address ranges using
vme_space_map(). The interrupt locators in struct vme_attach_args are
used by vme_intr_map() and vme_intr_establish().
DMA SUPPORT
Extensive DMA facilities are provided.
CODE REFERENCES
The VME subsystem itself is implemented within the file
sys/dev/vme/vme.c.
SEE ALSOvme(4), autoconf(9), bus_dma(9), bus_space(9), driver(9)HISTORY
The machine-independent VME subsystem appeared in NetBSD 1.5.
BUGS
This page is incomplete.
BSD June 12, 2001 BSD
