Motorola MCP750 Specifications Page 194

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D
evice Driver Programming
11-20
primed Medium priority (recommended)
prilo Low priority
Drivers can use these values to request a priority appropriate to a given type of
device or to request a priority that is high, medium or low relative to other activities
within the kernel. In general, it is recommended that you use the primed value.
lkp is a pointer to a spin lock which must be locked when SV_WAIT is called. The
spin lock is released (atomically) as the calling LWP goes to sleep. No spin lock—
basic locks or read/write locks—can be held across calls to this routine.
The SV_WAIT routine has no return value.
The SV_WAIT_SIG routine is specified as follows:
#include <sys/types.h>
#include <sys/ksynch.h>
#include <sys/ddi.h>
bool_t SV_WAIT_SIG(svp
,
priority
,
lkp)
sv_t *svp
;
int priority
;
lock_t
*
lkp
;
where:
svp is a pointer to the synchronization variable on which to sleep.
priority is a hint to the scheduler on the priority at which to schedule the LWP upon
wake up. It allows the driver to temporarily boost the priority of an LWP which is in
the timesharing class as a a reward for voluntarily blocking itself. Valid priority val-
ues are:
pridisk Priority appropriate to disk driver
prinet Priority appropriate to network driver
pritty Priority appropriate to tty driver
pritape Priority appropriate to tape driver
prihi High priority
primed Medium priority (recommended)
prilo Low priority
Drivers can use these values to request a priority appropriate to a given type of
device or to request a priority that is high, medium or low relative to other activities
within the kernel. In general, it is recommended that you use the primed value.
lkp is a pointer to a spin lock which must be locked when SV_WAIT_SIG is called.
The spin lock is released (atomically) as the calling LWP goes to sleep. No spin
lock—basic locks or read/write locks—can be held across calls to this routine.
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