NAME

cb_ops — character/block entry points structure

SYNOPSIS

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

INTERFACE LEVEL

illumos DDI specific (illumos DDI)

DESCRIPTION

The cb_ops structure contains all entry points for drivers that support both character and block entry points. All leaf device drivers that support direct user process access to a device should declare a cb_ops structure.

All drivers that safely allow multiple threads of execution in the driver at the same time must set the D_MP flag in the cb_flag field. See open(9E).

If the driver properly handles 64-bit offsets, it should also set the D_64BIT flag in the cb_flag field. This specifies that the driver will use the uio_loffset field of the uio(9S) structure.

If the driver returns EINTR from open(9E), it should also set the D_OPEN_RETURNS_EINTR flag in the cb_flag field. This lets the framework know that it is safe for the driver to return EINTR when waiting, to provide exclusion for a last-reference close(9E) call to complete before calling open(9E).

The mt-streams(9F) function describes other flags that can be set in the cb_flag field.

The cb_rev is the cb_ops structure revision number. This field must be set to CB_REV.

Non-STREAMS drivers should set cb_str to NULL.

The following DDI/DKI or DKI-only or DDI-only functions are provided in the character/block driver operations structure.

STRUCTURE MEMBERS

int  (*cb_open)(dev_t *devp, int flag, int otyp, cred_t *credp);
int  (*cb_close)(dev_t dev, int flag, int otyp, cred_t *credp);
int  (*cb_strategy)(struct buf *bp);
int  (*cb_print)(dev_t dev, char *str);
int  (*cb_dump)(dev_t dev, caddr_t addr, daddr_t blkno, int nblk);
int  (*cb_read)(dev_t dev, struct uio *uiop, cred_t *credp);
int  (*cb_write)(dev_t dev, struct uio *uiop, cred_t *credp);
int  (*cb_ioctl)(dev_t dev, int cmd, intptr_t arg, int mode,
       cred_t *credp, int *rvalp);
int  (*cb_devmap)(dev_t dev, devmap_cookie_t dhp, offset_t off,
       size_t len, size_t *maplen, uint_t model);
int  (*cb_mmap)(dev_t dev, off_t off, int prot);
int  (*cb_segmap)(dev_t dev, off_t off, struct as *asp,
       caddr_t *addrp, off_t len, unsigned int prot,
       unsigned int maxprot, unsigned int flags, cred_t *credp);
int  (*cb_chpoll)(dev_t dev, short events, int anyyet,
       short *reventsp, struct pollhead **phpp);
int  (*cb_prop_op)(dev_t dev, dev_info_t *dip,
       ddi_prop_op_t prop_op, int mod_flags,
       char *name, caddr_t valuep, int *length);
struct streamtab *cb_str;   /* streams information */
int  cb_flag;
int  cb_rev;
int  (*cb_aread)(dev_t dev, struct aio_req *aio, cred_t *credp);
int  (*cb_awrite)(dev_t dev, struct aio_req *aio, cred_t *credp);

SEE ALSO

aread(9E), awrite(9E), chpoll(9E), close(9E), dump(9E), ioctl(9E), mmap(9E), open(9E), print(9E), prop_op(9E), read(9E), segmap(9E), strategy(9E), write(9E), nochpoll(9F), nodev(9F), nulldev(9F), dev_ops(9S), qinit(9S)

Writing Device Drivers.

STREAMS Programming Guide.