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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 | * | |
54197e43 TG |
14 | * The hardirq count could in theory be the same as the number of |
15 | * interrupts in the system, but we run all interrupt handlers with | |
16 | * interrupts disabled, so we cannot have nesting interrupts. Though | |
17 | * there are a few palaeontologic drivers which reenable interrupts in | |
18 | * the handler, so we need more than one bit here. | |
2d4b8473 | 19 | * |
00d1a39e TG |
20 | * PREEMPT_MASK: 0x000000ff |
21 | * SOFTIRQ_MASK: 0x0000ff00 | |
22 | * HARDIRQ_MASK: 0x000f0000 | |
23 | * NMI_MASK: 0x00100000 | |
24 | * PREEMPT_ACTIVE: 0x00200000 | |
2d4b8473 FW |
25 | */ |
26 | #define PREEMPT_BITS 8 | |
27 | #define SOFTIRQ_BITS 8 | |
54197e43 | 28 | #define HARDIRQ_BITS 4 |
2d4b8473 FW |
29 | #define NMI_BITS 1 |
30 | ||
2d4b8473 FW |
31 | #define PREEMPT_SHIFT 0 |
32 | #define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS) | |
33 | #define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS) | |
34 | #define NMI_SHIFT (HARDIRQ_SHIFT + HARDIRQ_BITS) | |
35 | ||
36 | #define __IRQ_MASK(x) ((1UL << (x))-1) | |
37 | ||
38 | #define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT) | |
39 | #define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT) | |
40 | #define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT) | |
41 | #define NMI_MASK (__IRQ_MASK(NMI_BITS) << NMI_SHIFT) | |
42 | ||
43 | #define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT) | |
44 | #define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT) | |
45 | #define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT) | |
46 | #define NMI_OFFSET (1UL << NMI_SHIFT) | |
47 | ||
48 | #define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET) | |
49 | ||
2d4b8473 FW |
50 | #define PREEMPT_ACTIVE_BITS 1 |
51 | #define PREEMPT_ACTIVE_SHIFT (NMI_SHIFT + NMI_BITS) | |
52 | #define PREEMPT_ACTIVE (__IRQ_MASK(PREEMPT_ACTIVE_BITS) << PREEMPT_ACTIVE_SHIFT) | |
2d4b8473 FW |
53 | |
54 | #define hardirq_count() (preempt_count() & HARDIRQ_MASK) | |
55 | #define softirq_count() (preempt_count() & SOFTIRQ_MASK) | |
56 | #define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \ | |
57 | | NMI_MASK)) | |
58 | ||
59 | /* | |
60 | * Are we doing bottom half or hardware interrupt processing? | |
61 | * Are we in a softirq context? Interrupt context? | |
62 | * in_softirq - Are we currently processing softirq or have bh disabled? | |
63 | * in_serving_softirq - Are we currently processing softirq? | |
64 | */ | |
65 | #define in_irq() (hardirq_count()) | |
66 | #define in_softirq() (softirq_count()) | |
67 | #define in_interrupt() (irq_count()) | |
68 | #define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET) | |
69 | ||
70 | /* | |
71 | * Are we in NMI context? | |
72 | */ | |
73 | #define in_nmi() (preempt_count() & NMI_MASK) | |
74 | ||
75 | #if defined(CONFIG_PREEMPT_COUNT) | |
76 | # define PREEMPT_CHECK_OFFSET 1 | |
77 | #else | |
78 | # define PREEMPT_CHECK_OFFSET 0 | |
79 | #endif | |
80 | ||
81 | /* | |
82 | * Are we running in atomic context? WARNING: this macro cannot | |
83 | * always detect atomic context; in particular, it cannot know about | |
84 | * held spinlocks in non-preemptible kernels. Thus it should not be | |
85 | * used in the general case to determine whether sleeping is possible. | |
86 | * Do not use in_atomic() in driver code. | |
87 | */ | |
88 | #define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0) | |
89 | ||
90 | /* | |
91 | * Check whether we were atomic before we did preempt_disable(): | |
92 | * (used by the scheduler, *after* releasing the kernel lock) | |
93 | */ | |
94 | #define in_atomic_preempt_off() \ | |
95 | ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_CHECK_OFFSET) | |
96 | ||
97 | #ifdef CONFIG_PREEMPT_COUNT | |
98 | # define preemptible() (preempt_count() == 0 && !irqs_disabled()) | |
99 | #else | |
100 | # define preemptible() 0 | |
101 | #endif | |
102 | ||
103 | #endif /* LINUX_PREEMPT_MASK_H */ |