illumos: manual page: csx

CSX_REQUESTIO(9F) Kernel Functions for Drivers CSX_REQUESTIO(9F)

NAME

csx_RequestIO, csx_ReleaseIO - request or release I/O resources for the
client

SYNOPSIS

#include <sys/pccard.h>

int32_t csx_RequestIO(client_handle_t ch, io_req_t *ir);

int32_t csx_ReleaseIO(client_handle_t ch, io_req_t *ir);

INTERFACE LEVEL

illumos DDI Specific (illumos DDI)

PARAMETERS

ch
Client handle returned from csx_RegisterClient(9F).

ir
Pointer to an io_req_t structure.

DESCRIPTION

The functions csx_RequestIO() and csx_ReleaseIO() request or release,
respectively, I/O resources for the client.

If a client requires I/O resources, csx_RequestIO() must be called to
request I/O resources from Card Services; then
csx_RequestConfiguration(9F) must be used to establish the configuration.
csx_RequestIO() can be called multiple times until a successful set of
I/O resources is found. csx_RequestConfiguration(9F) only uses the last
configuration specified.

csx_RequestIO() fails if it has already been called without a
corresponding csx_ReleaseIO().

csx_ReleaseIO() releases previously requested I/O resources. The Card
Services window resource list is adjusted by this function. Depending on
the adapter hardware, the I/O window might also be disabled.

STRUCTURE MEMBERS

The structure members of io_req_t are:

uint32_t Socket; /* socket number*/

uint32_t Baseport1.base; /* IO range base port address */
acc_handle_t Baseport1.handle; /* IO range base address
/* or port num */
uint32_t NumPorts1; /* first IO range number contiguous
/* ports */
uint32_t Attributes1; /* first IO range attributes */

uint32_t Baseport2.base; /* IO range base port address */
acc_handle_t Baseport2.handle; /* IO range base address or port num */
uint32_t NumPorts2; /* second IO range number contiguous
/* ports */
uint32_t Attributes2; /* second IO range attributes */

uint32_t IOAddrLines; /* number of IO address lines decoded */

The fields are defined as follows:

Socket
Not used in illumos, but for portability with other
Card Services implementations, it should be set to
the logical socket number.

BasePort1.base
BasePort1.handle
BasePort2.base
BasePort2.handle
Two I/O address ranges can be requested by
csx_RequestIO(). Each I/O address range is specified
by the BasePort, NumPorts, and Attributes fields. If
only a single I/O range is being requested, the
NumPorts2 field must be reset to 0.

When calling csx_RequestIO(), the BasePort.base field
specifies the first port address requested. Upon
successful return from csx_RequestIO(), the
BasePort.handle field contains an access handle,
corresponding to the first byte of the allocated I/O
window, which the client must use when accessing the
PC Card's I/O space via the common access functions.
A client must not make any assumptions as to the
format of the returned BasePort.handle field value.

If the BasePort.base field is set to 0, Card Services
returns an I/O resource based on the available I/O
resources and the number of contiguous ports
requested. When BasePort.base is 0, Card Services
aligns the returned resource in the host system's I/O
address space on a boundary that is a multiple of the
number of contiguous ports requested, rounded up to
the nearest power of two. For example, if a client
requests two I/O ports, the resource returned will be
a multiple of two. If a client requests five
contiguous I/O ports, the resource returned will be a
multiple of eight.

If multiple ranges are being requested, at least one
of the BasePort.base fields must be non-zero.

NumPorts
This field is the number of contiguous ports being
requested.

Attributes
This field is bit-mapped. The following bits are
defined:

IO_DATA_WIDTH_8
I/O resource uses 8-bit
data path.

IO_DATA_WIDTH_16
I/O resource uses 16-bit
data path.

WIN_ACC_NEVER_SWAP
Host endian byte ordering.

WIN_ACC_BIG_ENDIAN
Big endian byte ordering

WIN_ACC_LITTLE_ENDIAN
Little endian byte
ordering.

WIN_ACC_STRICT_ORDER
Program ordering
references.

WIN_ACC_UNORDERED_OK
May re-order references.

WIN_ACC_MERGING_OK
Merge stores to
consecutive locations.

WIN_ACC_LOADCACHING_OK
May cache load operations.

WIN_ACC_STORECACHING_OK
May cache store
operations.

For some combinations of host system busses and
adapter hardware, the width of an I/O resource can
not be set via RequestIO(); on those systems, the
host bus cycle access type determines the I/O
resource data path width on a per-cycle basis.

WIN_ACC_BIG_ENDIAN and WIN_ACC_LITTLE ENDIAN describe
the endian characteristics of the device as big
endian or little endian, respectively. Even though
most of the devices will have the same endian
characteristics as their busses, there are examples
of devices with an I/O processor that has opposite
endian characteristics of the busses. When
WIN_ACC_BIG_ENDIAN or WIN_ACC_LITTLE ENDIAN is set,
byte swapping will automatically be performed by the
system if the host machine and the device data
formats have opposite endian characteristics. The
implementation may take advantage of hardware
platform byte swapping capabilities.

When WIN_ACC_NEVER_SWAP is specified, byte swapping
will not be invoked in the data access functions. The
ability to specify the order in which the CPU will
reference data is provided by the following
Attributes bits. Only one of the following bits may
be specified:

WIN_ACC_STRICT_ORDER

The data references must be issued by a CPU in
program order. Strict ordering is the default
behavior.

WIN_ACC_UNORDERED_OK

The CPU may re-order the data references. This
includes all kinds of re-ordering (that is, a
load followed by a store may be replaced by a
store followed by a load).

WIN_ACC_MERGING_OK

The CPU may merge individual stores to
consecutive locations. For example, the CPU may
turn two consecutive byte stores into one
halfword store. It may also batch individual
loads. For example, the CPU may turn two
consecutive byte loads into one halfword load.
IO_MERGING_OK_ACC also implies re-ordering.

WIN_ACC_LOADCACHING_OK

The CPU may cache the data it fetches and reuse
it until another store occurs. The default
behavior is to fetch new data on every load.
WIN_ACC_LOADCACHING_OK also implies merging and
re-ordering.

WIN_ACC_STORECACHING_OK

The CPU may keep the data in the cache and push
it to the device (perhaps with other data) at a
later time. The default behavior is to push the
data right away. WIN_ACC_STORECACHING_OK also
implies load caching, merging, and re-ordering.

These values are advisory, not mandatory. For
example, data can be ordered without being merged or
cached, even though a driver requests unordered,
merged and cached together. All other bits in the
Attributes field must be set to 0.

IOAddrLines
This field is the number of I/O address lines decoded
by the PC Card in the specified socket.

On some systems, multiple calls to csx_RequestIO() with different
BasePort, NumPorts, and/or IOAddrLines values will have to be made to
find an acceptable combination of parameters that can be used by Card
Services to allocate I/O resources for the client. (See NOTES).

RETURN VALUES

CS_SUCCESS
Successful operation.

CS_BAD_ATTRIBUTE
Invalid Attributes specified.

CS_BAD_BASE
BasePort value is invalid.

CS_BAD_HANDLE
Client handle is invalid.

CS_CONFIGURATION_LOCKED
csx_RequestConfiguration(9F) has already been
done.

CS_IN_USE
csx_RequestIO() has already been done without
a corresponding csx_ReleaseIO().

CS_NO_CARD
No PC Card in socket.

CS_BAD_WINDOW
Unable to allocate I/O resources.

CS_OUT_OF_RESOURCE
Unable to allocate I/O resources.

CS_UNSUPPORTED_FUNCTION
No PCMCIA hardware installed.

CONTEXT

These functions may be called from user or kernel context.

NOTES

It is important for clients to try to use the minimum amount of I/O
resources necessary. One way to do this is for the client to parse the
CIS of the PC Card and call csx_RequestIO() first with any IOAddrLines
values that are 0 or that specify a minimum number of address lines
necessary to decode the I/O space on the PC Card. Also, if no convenient
minimum number of address lines can be used to decode the I/O space on
the PC Card, it is important to try to avoid system conflicts with well-
known architectural hardware features.

July 19, 1996 CSX_REQUESTIO(9F)