Commit | Line | Data |
---|---|---|
2d4b8473 FW |
1 | #ifndef LINUX_PREEMPT_MASK_H |
2 | #define LINUX_PREEMPT_MASK_H | |
3 | ||
4 | #include <linux/preempt.h> | |
5 | #include <asm/hardirq.h> | |
6 | ||
7 | /* | |
8 | * We put the hardirq and softirq counter into the preemption | |
9 | * counter. The bitmask has the following meaning: | |
10 | * | |
11 | * - bits 0-7 are the preemption count (max preemption depth: 256) | |
12 | * - bits 8-15 are the softirq count (max # of softirqs: 256) | |
13 | * | |
14 | * The hardirq count can in theory reach the same as NR_IRQS. | |
15 | * In reality, the number of nested IRQS is limited to the stack | |
16 | * size as well. For archs with over 1000 IRQS it is not practical | |
17 | * to expect that they will all nest. We give a max of 10 bits for | |
18 | * hardirq nesting. An arch may choose to give less than 10 bits. | |
19 | * m68k expects it to be 8. | |
20 | * | |
21 | * - bits 16-25 are the hardirq count (max # of nested hardirqs: 1024) | |
22 | * - bit 26 is the NMI_MASK | |
23 | * - bit 27 is the PREEMPT_ACTIVE flag | |
24 | * | |
25 | * PREEMPT_MASK: 0x000000ff | |
26 | * SOFTIRQ_MASK: 0x0000ff00 | |
27 | * HARDIRQ_MASK: 0x03ff0000 | |
28 | * NMI_MASK: 0x04000000 | |
29 | */ | |
30 | #define PREEMPT_BITS 8 | |
31 | #define SOFTIRQ_BITS 8 | |
32 | #define NMI_BITS 1 | |
33 | ||
34 | #define MAX_HARDIRQ_BITS 10 | |
35 | ||
36 | #ifndef HARDIRQ_BITS | |
37 | # define HARDIRQ_BITS MAX_HARDIRQ_BITS | |
38 | #endif | |
39 | ||
40 | #if HARDIRQ_BITS > MAX_HARDIRQ_BITS | |
41 | #error HARDIRQ_BITS too high! | |
42 | #endif | |
43 | ||
44 | #define PREEMPT_SHIFT 0 | |
45 | #define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS) | |
46 | #define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS) | |
47 | #define NMI_SHIFT (HARDIRQ_SHIFT + HARDIRQ_BITS) | |
48 | ||
49 | #define __IRQ_MASK(x) ((1UL << (x))-1) | |
50 | ||
51 | #define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT) | |
52 | #define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT) | |
53 | #define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT) | |
54 | #define NMI_MASK (__IRQ_MASK(NMI_BITS) << NMI_SHIFT) | |
55 | ||
56 | #define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT) | |
57 | #define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT) | |
58 | #define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT) | |
59 | #define NMI_OFFSET (1UL << NMI_SHIFT) | |
60 | ||
61 | #define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET) | |
62 | ||
63 | #ifndef PREEMPT_ACTIVE | |
64 | #define PREEMPT_ACTIVE_BITS 1 | |
65 | #define PREEMPT_ACTIVE_SHIFT (NMI_SHIFT + NMI_BITS) | |
66 | #define PREEMPT_ACTIVE (__IRQ_MASK(PREEMPT_ACTIVE_BITS) << PREEMPT_ACTIVE_SHIFT) | |
67 | #endif | |
68 | ||
69 | #if PREEMPT_ACTIVE < (1 << (NMI_SHIFT + NMI_BITS)) | |
70 | #error PREEMPT_ACTIVE is too low! | |
71 | #endif | |
72 | ||
73 | #define hardirq_count() (preempt_count() & HARDIRQ_MASK) | |
74 | #define softirq_count() (preempt_count() & SOFTIRQ_MASK) | |
75 | #define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \ | |
76 | | NMI_MASK)) | |
77 | ||
78 | /* | |
79 | * Are we doing bottom half or hardware interrupt processing? | |
80 | * Are we in a softirq context? Interrupt context? | |
81 | * in_softirq - Are we currently processing softirq or have bh disabled? | |
82 | * in_serving_softirq - Are we currently processing softirq? | |
83 | */ | |
84 | #define in_irq() (hardirq_count()) | |
85 | #define in_softirq() (softirq_count()) | |
86 | #define in_interrupt() (irq_count()) | |
87 | #define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET) | |
88 | ||
89 | /* | |
90 | * Are we in NMI context? | |
91 | */ | |
92 | #define in_nmi() (preempt_count() & NMI_MASK) | |
93 | ||
94 | #if defined(CONFIG_PREEMPT_COUNT) | |
95 | # define PREEMPT_CHECK_OFFSET 1 | |
96 | #else | |
97 | # define PREEMPT_CHECK_OFFSET 0 | |
98 | #endif | |
99 | ||
100 | /* | |
101 | * Are we running in atomic context? WARNING: this macro cannot | |
102 | * always detect atomic context; in particular, it cannot know about | |
103 | * held spinlocks in non-preemptible kernels. Thus it should not be | |
104 | * used in the general case to determine whether sleeping is possible. | |
105 | * Do not use in_atomic() in driver code. | |
106 | */ | |
107 | #define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0) | |
108 | ||
109 | /* | |
110 | * Check whether we were atomic before we did preempt_disable(): | |
111 | * (used by the scheduler, *after* releasing the kernel lock) | |
112 | */ | |
113 | #define in_atomic_preempt_off() \ | |
114 | ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_CHECK_OFFSET) | |
115 | ||
116 | #ifdef CONFIG_PREEMPT_COUNT | |
117 | # define preemptible() (preempt_count() == 0 && !irqs_disabled()) | |
118 | #else | |
119 | # define preemptible() 0 | |
120 | #endif | |
121 | ||
122 | #endif /* LINUX_PREEMPT_MASK_H */ |