ddi_model_convert_from(9FKernel Functions for Driverddi_model_convert_from(9F)NAMEddi_model_convert_from - determine data model type mismatch
SYNOPSIS
#include <sys/ddi.h>
#include <sys/sunddi.h>
uint_tddi_model_convert_from(uint_t model);
INTERFACE LEVEL
Solaris DDI specific (Solaris DDI).
PARAMETERS
model The data model type of the current thread.
DESCRIPTIONddi_model_convert_from() is used to determine if the current thread
uses a different C Language Type Model than the device driver. The
64-bit version of Solaris will require a 64-bit kernel to support both
64-bit and 32-bit user mode programs. The difference between a 32-bit
program and a 64-bit program is in its C Language Type Model: a 32-bit
program is ILP32 (integer, longs, and pointers are 32-bit) and a 64-bit
program is LP64 (longs and pointers are 64-bit). There are a number of
driver entry points such as ioctl(9E) and mmap(9E) where it is neces‐
sary to identify the C Language Type Model of the user-mode originator
of an kernel event. For example any data which flows between programs
and the device driver or vice versa need to be identical in format. A
64-bit device driver may need to modify the format of the data before
sending it to a 32-bit application. ddi_model_convert_from() is used to
determine if data that is passed between the device driver and the
application requires reformatting to any non-native data model.
RETURN VALUES
DDI_MODEL_ILP32 A conversion to/from ILP32 is neces‐
sary.
DDI_MODEL_NONE No conversion is necessary. Current
thread and driver use the same data
model.
CONTEXTddi_model_convert_from() can be called from any context.
EXAMPLES
Example 1: : Using ddi_model_convert_from() in the ioctl() entry point
to support both 32-bit and 64-bit applications.
The following is an example how to use ddi_model_convert_from() in the
ioctl() entry point to support both 32-bit and 64-bit applications.
struct passargs32 {
int len;
caddr32_t addr;
};
struct passargs {
int len;
caddr_t addr;
};
xxioctl(dev_t dev, int cmd, intptr_t arg, int mode,
cred_t *credp, int *rvalp) {
struct passargs pa;
switch (ddi_model_convert_from(mode & FMODELS)) {
case DDI_MODEL_ILP32:
{
struct passargs32 pa32;
ddi_copyin(arg, &pa32, sizeof (struct passargs32), mode);
pa.len = pa32.len;
pa.address = pa32.address;
break;
}
case DDI_MODEL_NONE:
ddi_copyin(arg, &pa, sizeof (struct passargs), mode);
break;
}
do_ioctl(&pa);
....
}
SEE ALSOioctl(9E), mmap(9E), ddi_mmap_get_model(9F)
Writing Device Drivers
SunOS 5.10 8 Feb 2001 ddi_model_convert_from(9F)
