ddi_mmap_get_model(9F)

NAME

ddi_mmap_get_model − return data model type of current thread

SYNOPSIS

#include <sys/ddi.h>
#include <sys/sunddi.h> uint_t ddi_mmap_get_model(void);

INTERFACE LEVEL

Solaris DDI specific (Solaris DDI).

DESCRIPTION

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.

RETURN VALUES

DDI_MODEL_ILP32
Current thread expects 32-bit (ILP32) semantics.

DDI_MODEL_LP64
Current thread expects 64-bit (LP64) semantics.

DDI_FAILURE The ddi_mmap_get_model() function was not called from the mmap(9E) entry point.

CONTEXT

The ddi_mmap_get_model() function can only be called from the mmap(9E) driver entry point.

EXAMPLES

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;
#ifdef _MULTI_DATAMODEL
        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;
        }
#endif /∗ _MULTI_DATAMODEL ∗/
        /∗ continues along using dp ∗/
        ....
}

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