QUIESCE(9E)QUIESCE(9E)NAMEquiesce - quiesce a device
SYNOPSIS
#include <sys/ddi.h>
#include <sys/sunddi.h>
int prefixquiesce(dev_info_t *dip);
int ddi_quiesce_not_needed(dev_info_t *dip);
INTERFACE LEVEL
Solaris DDI specific (Solaris DDI)
PARAMETERS
dip
A pointer to the device's dev_info structure.
DESCRIPTION
The quiesce() function quiesces a device so that the device no longer
generates interrupts, modifies or accesses memory. The driver should
reset the device to a hardware state from which the device can be cor‐
rectly configured by the driver's attach() routine without a system
power cycle or being configured by the firmware. For devices with a
defined reset state configuration, the driver should return that device
to that state as part of the quiesce operation. Fast Reboot, where
firmware is bypassed when booting to a new OS image, is such a case.
quiesce() is only called for an attached device instance as one of the
final operations of a reboot sequence, and no other thread can be
active for this device. The system guarantees that no other driver
entry point is active or invoked while quiesce() is invoked. The system
also guarantees that no timeout or taskq is invoked. The system is sin‐
gle-threaded and can not be interrupted. Therefore, the driver's qui‐
esce() implementation must not use locks or timeouts, or rely on them
being called. The driver must discard all outstanding I/O instead of
waiting for completion. At the conclusion of the quiesce() operation,
the driver must guarantee that the device no longer has access to mem‐
ory or interrupts.
The only DDI interfaces that can be called by the quiesce() implementa‐
tion are non-blocking functions, such as the ddi_get*() and ddi_put*()
functions.
If quiesce() determines a particular instance of the device cannot be
quiesced when requested because of some exceptional condition, qui‐
esce() returns DDI_FAILURE. This rarely happens.
If a driver has previously implemented the obsolete reset() interface,
its functionality must be merged into quiesce(). The driver's reset()
routine is no longer called if an implementation of quiesce() is
present.
ddi_quiesce_not_needed() always returns DDI_SUCCESS. A driver can set
its devo_quiesce device function to ddi_quiesce_not_needed() to indi‐
cate that the device it manages does not need to be quiesced.
RETURN VALUESquiesce() returns the following:
DDI_SUCCESS
The device has been successfully quiesced.
DDI_FAILURE
The operation failed.
CONTEXT
This function is called from kernel context only.
SEE ALSOreboot(1M), uadmin(1M), uadmin(2), attach(9E), detach(9E),
ddi_add_intr(9F), ddi_map_regs(9F), pci_config_setup(9F), timeout(9F),
dev_ops(9S)NOTES
When quiesce() is called, the system is single-threaded, therefore the
driver's quiesce() implementation must not be blocked. For example, the
implementation must not create or tear down mappings, call FMA func‐
tions, or create or cancel callbacks.
Sep 16, 2008 QUIESCE(9E)
