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gld(9f) [opensolaris man page]

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

gld, gld_mac_alloc, gld_mac_free, gld_register, gld_unregister, gld_recv, gld_sched, gld_intr - Generic LAN Driver service routines SYNOPSIS
#include <sys/gld.h> gld_mac_info_t *gld_mac_alloc(dev_info_t *dip); void gld_mac_free(gld_mac_info_t *macinfo); int gld_register(dev_info_t *dip, char *name, gld_mac_info_t *macinfo); int gld_unregister(gld_mac_info_t *macinfo); void gld_recv(gld_mac_info_t *macinfo, mblk_t *mp); void gld_sched(gld_mac_info_t *macinfo); uint_t gld_intr(caddr_t); void gld_linkstate(gld_mac_info_t *macinfo, int32_t newstate); INTERFACE LEVEL
Solaris architecture specific (Solaris DDI). PARAMETERS
macinfo Pointer to a gld_mac_info(9S) structure. dip Pointer to dev_info structure. name Device interface name. mp Pointer to a message block containing a received packet. newstate Media link state. DESCRIPTION
gld_mac_alloc() allocates a new gld_mac_info(9S) structure and returns a pointer to it. Some of the GLD-private elements of the structure may be initialized before gld_mac_alloc() returns; all other elements are initialized to zero. The device driver must initialize some structure members, as described in gld_mac_info(9S), before passing the mac_info pointer to gld_register(). gld_mac_free() frees a gld_mac_info(9S) structure previously allocated by gld_mac_alloc(). gld_register() is called from the device driver's attach(9E) routine, and is used to link the GLD-based device driver with the GLD frame- work. Before calling gld_register() the device driver's attach(9E) routine must first use gld_mac_alloc() to allocate a gld_mac_info(9S) structure, and initialize several of its structure elements. See gld_mac_info(9S) for more information. A successful call to gld_register() performs the following actions: o links the device-specific driver with the GLD system; o sets the device-specific driver's private data pointer (using ddi_set_driver_private(9F)) to point to the macinfo structure; o creates the minor device node. The device interface name passed to gld_register() must exactly match the name of the driver module as it exists in the filesystem. The driver's attach(9E) routine should return DDI_SUCCESS if gld_register() succeeds. If gld_register() returns DDI_FAILURE, the attach(9E) routine should deallocate any resources it allocated before calling gld_register() and then also return DDI_FAILURE. gld_unregister() is called by the device driver's detach(9E) function, and if successful, performs the following tasks: o ensures the device's interrupts are stopped, calling the driver's gldm_stop() routine if necessary; o removes the minor device node; o unlinks the device-specific driver from the GLD system. If gld_unregister() returns DDI_SUCCESS, the detach(9E) routine should deallocate any data structures allocated in the attach(9E) routine, using gld_mac_free() to deallocate the macinfo structure, and return DDI_SUCCESS. If gld_unregister() returns DDI_FAILURE, the driver's detach(9E) routine must leave the device operational and return DDI_FAILURE. gld_recv() is called by the driver's interrupt handler to pass a received packet upstream. The driver must construct and pass a STREAMS M_DATA message containing the raw packet. gld_recv() determines which STREAMS queues, if any, should receive a copy of the packet, dupli- cating it if necessary. It then formats a DL_UNITDATA_IND message, if required, and passes the data up all appropriate streams. The driver should avoid holding mutex or other locks during the call to gld_recv(). In particular, locks that could be taken by a transmit thread may not be held during a call to gld_recv(): the interrupt thread that calls gld_recv() may in some cases carry out processing that includes sending an outgoing packet, resulting in a call to the driver's gldm_send() routine. If the gldm_send() routine were to try to acquire a mutex being held by the gldm_intr() routine at the time it calls gld_recv(), this could result in a panic due to recursive mutex entry. gld_sched() is called by the device driver to reschedule stalled outbound packets. Whenever the driver's gldm_send() routine has returned GLD_NORESOURCES, the driver must later call gld_sched() to inform the GLD framework that it should retry the packets that previously could not be sent. gld_sched() should be called as soon as possible after resources are again available, to ensure that GLD resumes passing out- bound packets to the driver's gldm_send() routine in a timely way. (If the driver's gldm_stop() routine is called, the driver is absolved from this obligation until it later again returns GLD_NORESOURCES from its gldm_send() routine; however, extra calls to gld_sched() will not cause incorrect operation.) gld_intr() is GLD's main interrupt handler. Normally it is specified as the interrupt routine in the device driver's call to ddi_add_intr(9F). The argument to the interrupt handler (specified as int_handler_arg in the call to ddi_add_intr(9F)) must be a pointer to the gld_mac_info(9S) structure. gld_intr() will, when appropriate, call the device driver's gldm_intr() function, passing that pointer to the gld_mac_info(9S) structure. However, if the driver uses a high-level interrupt, it must provide its own high-level interrupt handler, and trigger a soft interrupt from within that. In this case, gld_intr() may be specified as the soft interrupt handler in the call to ddi_add_softintr(). gld_linkstate() is called by the device driver to notify GLD of changes in the media link state. The newstate argument should be set to one of the following: GLD_LINKSTATE_DOWN The media link is unavailable. GLD_LINKSTATE_UP The media link is unavailable. GLD_LINKSTATE_UNKNOWN The status of the media link is unknown. If a driver calls gld_linkstate(), it must also set the GLD_CAP_LINKSTATE bit in the gldm_capabilties field of the gld_mac_info(9S) structure. RETURN VALUES
gld_mac_alloc() returns a pointer to a new gld_mac_info(9S) structure. gld_register() and gld_unregister() return: DDI_SUCCESS on success. DDI_FAILURE on failure. gld_intr() returns a value appropriate for an interrupt handler. SEE ALSO
gld(7D), gld(9E), gld_mac_info(9S), gld_stats(9S), dlpi(7P), attach(9E), ddi_add_intr(9F). Writing Device Drivers SunOS 5.11 28 Aug 2003 gld(9F)
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