xref: /linux/arch/mips/include/asm/irq.h (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1994 by Waldorf GMBH, written by Ralf Baechle
7  * Copyright (C) 1995, 96, 97, 98, 99, 2000, 01, 02, 03 by Ralf Baechle
8  */
9 #ifndef _ASM_IRQ_H
10 #define _ASM_IRQ_H
11 
12 #include <linux/linkage.h>
13 #include <linux/smp.h>
14 
15 #include <asm/mipsmtregs.h>
16 
17 #include <irq.h>
18 
19 static inline void irq_dispose_mapping(unsigned int virq)
20 {
21 }
22 
23 #ifdef CONFIG_I8259
24 static inline int irq_canonicalize(int irq)
25 {
26 	return ((irq == I8259A_IRQ_BASE + 2) ? I8259A_IRQ_BASE + 9 : irq);
27 }
28 #else
29 #define irq_canonicalize(irq) (irq)	/* Sane hardware, sane code ... */
30 #endif
31 
32 #ifdef CONFIG_MIPS_MT_SMTC
33 
34 struct irqaction;
35 
36 extern unsigned long irq_hwmask[];
37 extern int setup_irq_smtc(unsigned int irq, struct irqaction * new,
38                           unsigned long hwmask);
39 
40 static inline void smtc_im_ack_irq(unsigned int irq)
41 {
42 	if (irq_hwmask[irq] & ST0_IM)
43 		set_c0_status(irq_hwmask[irq] & ST0_IM);
44 }
45 
46 #else
47 
48 static inline void smtc_im_ack_irq(unsigned int irq)
49 {
50 }
51 
52 #endif /* CONFIG_MIPS_MT_SMTC */
53 
54 #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
55 #include <linux/cpumask.h>
56 
57 extern int plat_set_irq_affinity(struct irq_data *d,
58 				 const struct cpumask *affinity, bool force);
59 extern void smtc_forward_irq(struct irq_data *d);
60 
61 /*
62  * IRQ affinity hook invoked at the beginning of interrupt dispatch
63  * if option is enabled.
64  *
65  * Up through Linux 2.6.22 (at least) cpumask operations are very
66  * inefficient on MIPS.  Initial prototypes of SMTC IRQ affinity
67  * used a "fast path" per-IRQ-descriptor cache of affinity information
68  * to reduce latency.  As there is a project afoot to optimize the
69  * cpumask implementations, this version is optimistically assuming
70  * that cpumask.h macro overhead is reasonable during interrupt dispatch.
71  */
72 static inline int handle_on_other_cpu(unsigned int irq)
73 {
74 	struct irq_data *d = irq_get_irq_data(irq);
75 
76 	if (cpumask_test_cpu(smp_processor_id(), d->affinity))
77 		return 0;
78 	smtc_forward_irq(d);
79 	return 1;
80 }
81 
82 #else /* Not doing SMTC affinity */
83 
84 static inline int handle_on_other_cpu(unsigned int irq) { return 0; }
85 
86 #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */
87 
88 #ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
89 
90 static inline void smtc_im_backstop(unsigned int irq)
91 {
92 	if (irq_hwmask[irq] & 0x0000ff00)
93 		write_c0_tccontext(read_c0_tccontext() &
94 				   ~(irq_hwmask[irq] & 0x0000ff00));
95 }
96 
97 /*
98  * Clear interrupt mask handling "backstop" if irq_hwmask
99  * entry so indicates. This implies that the ack() or end()
100  * functions will take over re-enabling the low-level mask.
101  * Otherwise it will be done on return from exception.
102  */
103 static inline int smtc_handle_on_other_cpu(unsigned int irq)
104 {
105 	int ret = handle_on_other_cpu(irq);
106 
107 	if (!ret)
108 		smtc_im_backstop(irq);
109 	return ret;
110 }
111 
112 #else
113 
114 static inline void smtc_im_backstop(unsigned int irq) { }
115 static inline int smtc_handle_on_other_cpu(unsigned int irq)
116 {
117 	return handle_on_other_cpu(irq);
118 }
119 
120 #endif
121 
122 extern void do_IRQ(unsigned int irq);
123 
124 #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
125 
126 extern void do_IRQ_no_affinity(unsigned int irq);
127 
128 #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */
129 
130 extern void arch_init_irq(void);
131 extern void spurious_interrupt(void);
132 
133 extern int allocate_irqno(void);
134 extern void alloc_legacy_irqno(void);
135 extern void free_irqno(unsigned int irq);
136 
137 /*
138  * Before R2 the timer and performance counter interrupts were both fixed to
139  * IE7.  Since R2 their number has to be read from the c0_intctl register.
140  */
141 #define CP0_LEGACY_COMPARE_IRQ 7
142 
143 extern int cp0_compare_irq;
144 extern int cp0_compare_irq_shift;
145 extern int cp0_perfcount_irq;
146 
147 #endif /* _ASM_IRQ_H */
148