DDI_LOG_SYSEVENT(9F) Kernel Functions for Drivers DDI_LOG_SYSEVENT(9F)

ddi_log_sysevent - log system event for drivers

#include <sys/ddi.h>
#include <sys/sunddi.h>
int ddi_log_sysevent(dev_info_t *dip, char *vendor,
     char *class, char *subclass, nvlist_t *attr_list,
     sysevent_id_t *eidp, int sleep_flag);

illumos DDI specific (illumos DDI).

dip
A pointer to the dev_info node for this driver.

vendor

A pointer to a string defining the vendor. Third-party drivers should use their company's stock symbol (or similarly enduring identifier). Sun-supplied drivers should use DDI_VENDOR_SUNW.

class

A pointer to a string defining the event class.

subclass

A pointer to a string defining the event subclass.

attr_list

A pointer to an nvlist_t, listing the name-value attributes associated with the event or NULL if there are no such attributes for this event.

eidp

The address of a sysevent_id_t structure in which the event's sequence number and timestamp are returned if the event is successfully queued. May be NULL if this information is not of interest. See below for the definition of sysevent_id_t.

sleep_flag

Indicates how a caller wants to handle the possibility of resources not being available. If sleep_flag is DDI_NOSLEEP, the caller does not care if the allocation fails or the queue is full and can handle a failure appropriately. If sleep_flag is DDI_SLEEP, the caller wishes to have the allocation and queuing routines wait for resources to become available.

The ddi_log_sysevent() function causes a system event, of the specified class and subclass, to be generated on behalf of the driver and queued for delivery to syseventd, the user-land sysevent daemon.

The publisher string for the event is constructed using the vendor name and driver name, with the format:


"<vendor>:kern:<driver-name>"

The two fields of eidp, eid_seq and eid_ts, are sufficient to uniquely identify an event.

The structure members of sysevent_id_t are:


     uint64_t   eid_seq;        /* sysevent sequence number */
     hrtime_t   eid_ts;         /* sysevent timestamp */

The ddi_log_sysevent() function returns:

DDI_SUCCESS

The event has been queued for delivery successfully.

DDI_ENOMEM

There is not enough memory to queue the system event at this time. DDI_ENOMEM cannot be returned when sleep_flag is DDI_SLEEP.

DDI_EBUSY

The system event queue is full at this time. DDI_EBUSY cannot be returned when sleep_flag is DDI_SLEEP.

DDI_ETRANSPORT

The syseventd daemon is not responding and events cannot be queued or delivered at this time. DDI_ETRANSPORT can be returned even when sleep_flag is DDI_SLEEP.

DDI_ECONTEXT

sleep_flag is DDI_SLEEP and the driver is running in interrupt context.

ddi_log_sysevent supports the following data types:

DATA_TYPE_BYTE


DATA_TYPE_INT16


DATA_TYPE_UINT16


DATA_TYPE_INT32


DATA_TYPE_UINT32


DATA_TYPE_INT64


DATA_TYPE_UINT64


DATA_TYPE_STRING


DATA_TYPE_BYTE_ARRAY


DATA_TYPE_INT16_ARRAY


DATA_TYPE_UINT16_ARRAY


DATA_TYPE_INT32_ARRAY


DATA_TYPE_UINT32_ARRAY


DATA_TYPE_INT64_ARRAY


DATA_TYPE_UINT64_ARRAY

The ddi_log_sysevent() function can be called from user, interrupt, or kernel context, except when sleep_flag is DDI_SLEEP, in which case it cannot be called from interrupt context.

Example 1 Logging System Event with No Attributes


    if (ddi_log_sysevent(dip, DDI_VENDOR_SUNW, "class", "subclass",
        NULL, NULL, DDI_SLEEP) != DDI_SUCCESS) {
        cmn_err(CE_WARN, "error logging system event\n");
    }

Example 2 Logging System Event with Two Name/Value Attributes, an Integer and a String


nvlist_t    *attr_list;
sysevent_id_t   eid;
if (nvlist_alloc(&attr_list, NV_UNIQUE_NAME_TYPE, KM_SLEEP) == 0)
{
    err = nvlist_add_uint32(attr_list, int_name, int_value);
    if (err == 0)
        err = nvlist_add_string(attr_list, str_name, str_value);
    if (err == 0)
        err = ddi_log_sysevent(dip, DDI_VENDOR_SUNW,
          "class", "subclass", attr_list, &eid, DDI_SLEEP);
    if (err != DDI_SUCCESS)
        cmn_err(CE_WARN, "error logging system event\n");
    nvlist_free(attr_list);
    }

Example 3 Use Timeout to Handle nvlist and System Event Resource Allocation Failures

Since no blocking calls are made, this example would be useable from a driver needing to generate an event from interrupt context.


static int
    xx_se_timeout_handler(xx_state_t *xx)
    {
        xx->xx_timeoutid = (xx_generate_event(xx) ?
            timeout(xx_se_timeout_handler, xx, 4) : 0);
    }
    static int
    xx_generate_event(xx_state_t *xx)
    {
        int err;
        err = nvlist_alloc(&xx->xx_ev_attrlist, NV_UNIQUE_NAME_TYPE, 0);
        if (err != 0)
            return (1);
        err = nvlist_add_uint32(&xx->xx_ev_attrlist,
            xx->xx_ev_name, xx->xx_ev_value);
        if (err != 0) {
            nvlist_free(xx->xx_ev_attrlist);
            return(1);
        }
        err = ddi_log_sysevent(xx->xx_dip, DDI_VENDOR_SUNW,
            xx->xx_ev_class, xx->xx_ev_sbclass,
            xx->xx_ev_attrlist, NULL, DDI_NOSLEEP);
        nvlist_free(xx->xx_ev_attrlist);
        if (err == DDI_SUCCESS || err == DDI_ETRANSPORT) {
            if (err == DDI_ETRANSPORT)
                cmn_err(CE_WARN, "cannot log system event\n");
            return (0);
        }
        return (1);
    }

syseventd(1M), attributes(5), nvlist_add_boolean(9F), nvlist_alloc(9F)

Writing Device Drivers

January 16, 2006 OmniOS