eeh_broadcast Kernel Service

Purpose

This service is provided for device drivers to coordinate activities during an EEH event.

Syntax

void eeh_broadcast(handle, message)
eeh_handle_t    handle;
unsigned long long message;

Parameters

Item	Description
handle	EEH handle obtained from eeh_init or eeh_init_multifunc
message	User- or kernel-defined message

Description

Because single-function drivers do not have a need for coordination, this service is intended for multifunction drivers only. If a single-function driver calls it, it is a NOP. There are two kinds of messages that can be sent among the drivers: kernel-defined messages (such as EEH_DD_SUSPEND and EEH_DD_DEAD) and the user-defined messages. See sys/eeh.h for help on how to define user messages. Kernel messages have a higher priority than user messages. Therefore, if user messages and kernel messages are both pending, the kernel messages are sent out before the user messages.

Note: Device drivers should only broadcast their own messages (that is, the user-defined message) and not the kernel messages.

Within the kernel messages, EEH_DD_DEAD has the highest priority. Multiple messages of the same kind may or may not be coalesced depending upon the relative timing. Messages are sent by invoking the callback routines. The callback routines are invoked sequentially but not in any specific order except that the last driver to receive a message will have the EEH_MASTER flag set to indicate that all other drivers have finished processing the message. Only one message is broadcast at a time—that is, all registered callback routines are called sequentially with the same message before moving on to the next message. Finally, they are invoked asynchronously at INTIODONE priority. Because they are broadcast asynchronously, a device driver must not assume on a specific timeout within which the message would arrive.

The macro EEH_BROADCAST(handle, message) is provided for device drivers to call this service.

Execution Environment

This kernel service can be called from the process or interrupt environment.

Return Values

This service has no return value.