The _init(9E) function initializes a loadable module and is called before any other routine in the loadable module.
In a SCSI HBA, the _init(9E) function must call scsi_hba_init(9F) to inform the framework of the existence of the HBA driver before calling mod_install(9F). If scsi_hba_init(9F) returns a nonzero value, _init(9E) should return this value. Otherwise, _init(9E) must return the value returned by mod_install(9F).
The driver should initialize any required global state before calling mod_install(9F).
If mod_install(9F) fails, the _init(9E) function must free any global resources allocated and must call scsi_hba_fini(9F) before returning.
The following code sample uses a global mutex to show how to allocate data that is global to all instances of a driver. The code declares global mutex and soft-state structure information. The global mutex and soft state are initialized during _init(9E).
/* * Local static data */ static kmutex_t isp_global_mutex; static void *isp_state;
The _init(9E) function in Example 14-1 shows how a SCSI HBA driver initializes a global mutex.
int _init(void) { int err; if ((err = ddi_soft_state_init(&isp_state, sizeof (struct isp), 0)) != 0) { return (err); } if ((err = scsi_hba_init(&modlinkage)) == 0) { mutex_init(&isp_global_mutex, "isp global mutex", MUTEX_DRIVER, NULL); if ((err = mod_install(&modlinkage)) != 0) { mutex_destroy(&isp_global_mutex); scsi_hba_fini(&modlinkage); ddi_soft_state_fini(&isp_state); } } return (err); }