Tribblix: manual page: ddi_fm_handler

DDI_FM_HANDLER_REGISTER(9F) Kernel Functions for Drivers

NAME

ddi_fm_handler_register, ddi_fm_handler_unregister - register or
unregister an error handling callback

SYNOPSIS

#include <sys/ddifm.h>

void ddi_fm_handler_register(dev_info_t *dip,
ddi_err_func_t error_handler, void *impl_data);

void ddi_fm_handler_unregister(dev_info_t *dip);

INTERFACE LEVEL

illumos DDI specific (illumos DDI)

PARAMETERS

dip
Pointer to the dev_info structure

error_handler
Pointer to an error handler callback function

impl_data
Pointer to private data for use by the caller

DESCRIPTION

The ddi_fm_handler_register() function registers an error handler
callback routine with the I/O Fault Management framework. The error
handler callback, error_handler, is called to process error
conditions detected by the system. In addition to its device
instance, dip, the error handler is called with a pointer to a fault
management error status structure, ddi_fm_error_t. For example:

int (*ddi_err_func_t)(dev_info_t *dip, ddi_fm_error_t *error_status);

A driver error handling callback is passed the following arguments:

o a pointer to the device instance registered for this
callback.

o a data structure containing common fault management data
and status for error handling.

The primary responsibilities of the error handler include:

o to check for outstanding hardware or software errors.

o where possible, to isolate the device that might have
caused the errors.

o to report errors that were detected.

During the invocation of an error handler, a device driver might
need to quiesce or suspend all I/O activities in order to check for
error conditions or status in:

o hardware control and status registers.

o outstanding I/O transactions.

o access or DMA handles.

For each error detected, the driver must formulate and post an error
report via ddi_fm_ereport_post() for problem analysis by the illumos
Fault Manager fmd(8).

For a PCI, PCI/X, or PCI Express leaf device, the pci_ereport_post()
function is provided to carry out reporting responsibilities on
behalf of the driver. In many cases, an error handler callback
function of the following form can be used:

xxx_err_cb(dev_info_t *dip, ddi_fm_error_t *errp) {
pci_ereport_post(dip, errp, NULL);
return (errp->fme_status);
}

In addition, the driver might be able to carry out further device
specific checks within the error handler.

Error handlers can be called from kernel, interrupt, or high-level
interrupt context. The interrupt block cookie returned from
ddi_fm_init() should be used to allocate and initialize any
synchronization variables and locks that might be used within the
error handler callback function. Such locks may not be held by the
driver when a device register is accessed with functions such as
ddi_get8(9F) and ddi_put8(9F).

The data structure, ddi_fm_error_t, contains an FMA protocol (format
1) ENA for the current error propagation chain, the status of the
error handler callback, an error expectation flag, and any potential
access or DMA handles associated with an error detected by the parent
nexus.

The ddi_fm_handler_unregister() function removes a previously
registered error handling callback for the device instance specified
by the dip.

CONTEXT

The ddi_fm_handler_register() and ddi_fm_handler_unregister()
functions must be called from kernel context in an attach(9E) or
detach(9E) entry point. The registered error handler, error_handler,
callback can be called from kernel, interrupt, or high level
interrupt context.

ATTRIBUTES