include/nucleus/vdso.h

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#ifndef _XENO_NUCLEUS_VDSO_H
#define _XENO_NUCLEUS_VDSO_H

#include <nucleus/types.h>

/*
 * Data shared between Xenomai kernel/userland and the Linux kernel/userland
 * on the global semaphore heap. The features element indicates which data are
 * shared. Notice that struct xnvdso may only grow, but never shrink.
 */
struct xnvdso {
        unsigned long long features;

        /* Embed domain specific structures that describe the
         * shared data here */
};

/*
 * For each shared feature, add a flag below. For now, the set is still
 * empty.
 */
/*
#define XNVDSO_FEAT_A   0x0000000000000001ULL
#define XNVDSO_FEAT_B   0x0000000000000002ULL
#define XNVDSO_FEAT_C   0x0000000000000004ULL
#define XNVDSO_FEATURES (XNVDSO_FEAT_A | XNVDSO_FEAT_B | XVDSO_FEAT_C)
*/
#define XNVDSO_FEAT_DROP_U_MODE 0x0000000000000001ULL
#define XNVDSO_FEATURES (XNVDSO_FEAT_DROP_U_MODE)

extern struct xnvdso *nkvdso;

static inline int xnvdso_test_feature(unsigned long long feature)
{
        return testbits(nkvdso->features, feature);
}

extern void xnheap_init_vdso(void);
#endif /* _XENO_NUCLEUS_VDSO_H */