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ddi_mmap_get_model - return data model type of current thread

#include <sys/ddi.h>
#include <sys/sunddi.h>



uint_t ddi_mmap_get_model(void);

illumos DDI specific (illumos DDI). ddi_mmap_get_model() returns the C Language Type Model which the current thread expects. ddi_mmap_get_model() is used in combination with ddi_model_convert_from(9F) in the mmap(9E) driver entry point to determine whether there is a data model mismatch between the current thread and the device driver. The device driver might have to adjust the shape of data structures before exporting them to a user thread which supports a different data model. DDI_MODEL_ILP32 DDI_MODEL_LP64 DDI_FAILURE The ddi_mmap_get_model() function can only be called from the mmap(9E) driver entry point. Example 1 : Using ddi_mmap_get_model()

The following is an example of the mmap(9E) entry point and how to support 32-bit and 64-bit applications with the same device driver.

struct data32 {
 int len;
 caddr32_t addr;
};

struct data {
 int len;
 caddr_t addr;
};
xxmmap(dev_t dev, off_t off, int prot) {
 struct data dtc; /* a local copy for clash resolution */
 struct data *dp = (struct data *)shared_area;

 switch (ddi_model_convert_from(ddi_mmap_get_model())) {
 case DDI_MODEL_ILP32:
 {
 struct data32 *da32p;

 da32p = (struct data32 *)shared_area;
 dp = &dtc;
 dp->len = da32p->len;
 dp->address = da32->address;
 break;
 }
 case DDI_MODEL_NONE:
 break;
 }
 /* continues along using dp */
 .\|.\|.
}

mmap (9E), ddi_model_convert_from (9F)

Writing Device Drivers