Manual browser: vme_dmamem_alloc(9)
|VME(9)||Kernel Developer's Manual||VME(9)|
NAMEVME, 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
vme_probe(void *vc, vme_addr_t vmeaddr, vme_size_t len, vme_am_t am, vme_datasize_t datasize, int (*callback)(), void *arg);
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);
vme_space_unmap(void *vc, vme_mapresc_t resc);
vme_intr_map(void *vc, int level, int vector, vme_intr_handle_t *handlep);
vme_intr_establish(void *vc, vme_intr_handle_t handle, int prio, int (*func)(void *), void *arg);
vme_intr_disestablish(void *vc, void *cookie);
const struct evcnt *
vme_intr_evcnt(void *vc, vme_intr_handle_t handle);
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);
vme_dmamap_destroy(void *vc, bus_dmamap_t map);
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);
vme_dmamem_free(void *vc, bus_dma_segment_t *segs, int nsegs);
vme_space_alloc(struct vmebus_softc *tag, vme_addr_t addr, vme_size_t size, vme_am_t ams);
vme_space_free(void *vc, vme_addr_t addr, vme_size_t size, vme_am_t ams);
vme_space_get(void *vc, vme_size_t size, vme_am_t ams, u_long align, vme_addr_t *addr);
DESCRIPTIONThe VME bus provides support for VME devices. The VME bus is a high-performance 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, multiplexed transfers. It supports asynchronous, fully handshaken transfers at speeds up to 80 MB/sec. It has a master-slave architecture, encouraging multiprocessing and supports up to seven interrupt levels.
DATA TYPESDrivers attached to the VME bus will make use of the following data types:
- An opaque type identifying the bus controller.
- Addresses on the bus.
- 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.
- The datasize of the address space. Valid values are VME_D8, VME_D16, and VME_D32.
- Generic placeholder for any resources needed for a mapping.
- An opaque type describing an interrupt mapping.
- 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];
- 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-specific 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 integer 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 success, 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 specified 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.
AUTOCONFIGURATIONThe 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 SUPPORTExtensive DMA facilities are provided.
CODE REFERENCESThe VME subsystem itself is implemented within the file sys/dev/vme/vme.c.
HISTORYThe machine-independent VME subsystem appeared in NetBSD 1.5.
BUGSThis page is incomplete.
|June 12, 2001||NetBSD 7.0|