1ddi_intr_get_hilevel_pri(9KFe)rnel Functions for Drivedrdsi_intr_get_hilevel_pri(9F)
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6 ddi_intr_get_hilevel_pri - get minimum priority level for a high-level
7 interrupt
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10 #include <sys/types.h>
11 #include <sys/conf.h>
12 #include <sys/ddi.h>
13 #include <sys/sunddi.h>
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15 int ddi_intr_get_hilevel_pri(void);
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19 Solaris DDI specific (Solaris DDI).
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22 Upon a successful return, the ddi_intr_get_hilevel_pri() function
23 returns the minimum priority level for a high-level interrupt. The
24 return priority value can be used to compare to other priority values,
25 such as those returned from ddi_intr_get_pri(9F), to determine if a
26 given interrupt priority is a high-level interrupt.
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29 High-level interrupts must be handled without using system services
30 that manipulate thread or process states, because such interrupts are
31 not blocked by the scheduler.
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34 In addition, high-level interrupt handlers must take care to do a mini‐
35 mum of work because they cannot be preempted.
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38 A typical high-level interrupt handler puts data into a circular buffer
39 and schedule a soft interrupt by calling ddi_intr_trigger_softint().
40 The circular buffer can be protected by using a mutex that is properly
41 initialized for the interrupt handler.
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44 The ddi_intr_get_hilevel_pri() function can be used before calling
45 ddi_intr_add_handler() to help determine which type of interrupt han‐
46 dler can be used. Most device drivers are designed with the knowledge
47 that supported devices always generate low level interrupts. On some
48 machines, however, interrupts are high-level above the scheduler level
49 and on other machines they are not. Devices such as those those using
50 SBus interrupts or VME bus level 6 or 7 interrupts must use the
51 ddi_intr_get_hilevel_pri() function to test the type of interrupt han‐
52 dler that can be used.
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55 The ddi_intr_get_hilevel_pri() function returns the priority value for
56 a high-level interrupt.
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59 The ddi_intr_get_hilevel_pri() function can be called from either user
60 or kernel non-interrupt context.
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63 See attributes(5) for descriptions of the following attributes:
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68 ┌─────────────────────────────┬─────────────────────────────┐
69 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
70 ├─────────────────────────────┼─────────────────────────────┤
71 │Interface Stability │Committed │
72 └─────────────────────────────┴─────────────────────────────┘
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75 attributes(5), ddi_intr_add_handler(9F), ddi_intr_alloc(9F),
76 ddi_intr_enable(9F), ddi_intr_get_pri(9F), ddi_intr_trigger_soft‐
77 int(9F), mutex(9F)
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80 Writing Device Drivers
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84SunOS 5.11 07 Apr 2005 ddi_intr_get_hilevel_pri(9F)