1 /*
2 * arch/sh/kernel/cpu/irq/imask.c
3 *
4 * Copyright (C) 1999, 2000 Niibe Yutaka
5 *
6 * Simple interrupt handling using IMASK of SR register.
7 *
8 */
9 /* NOTE: Will not work on level 15 */
10 #include <linux/ptrace.h>
11 #include <linux/errno.h>
12 #include <linux/kernel_stat.h>
13 #include <linux/signal.h>
14 #include <linux/sched.h>
15 #include <linux/interrupt.h>
16 #include <linux/init.h>
17 #include <linux/bitops.h>
18 #include <linux/spinlock.h>
19 #include <linux/cache.h>
20 #include <linux/irq.h>
21 #include <asm/system.h>
22 #include <asm/irq.h>
23
24 /* Bitmap of IRQ masked */
25 static unsigned long imask_mask = 0x7fff;
26 static int interrupt_priority = 0;
27
28 static void enable_imask_irq(unsigned int irq);
29 static void disable_imask_irq(unsigned int irq);
30 static void shutdown_imask_irq(unsigned int irq);
31 static void mask_and_ack_imask(unsigned int);
32 static void end_imask_irq(unsigned int irq);
33
34 #define IMASK_PRIORITY 15
35
startup_imask_irq(unsigned int irq)36 static unsigned int startup_imask_irq(unsigned int irq)
37 {
38 /* Nothing to do */
39 return 0; /* never anything pending */
40 }
41
42 static struct hw_interrupt_type imask_irq_type = {
43 .typename = "SR.IMASK",
44 .startup = startup_imask_irq,
45 .shutdown = shutdown_imask_irq,
46 .enable = enable_imask_irq,
47 .disable = disable_imask_irq,
48 .ack = mask_and_ack_imask,
49 .end = end_imask_irq
50 };
51
set_interrupt_registers(int ip)52 void static inline set_interrupt_registers(int ip)
53 {
54 unsigned long __dummy;
55
56 asm volatile(
57 #ifdef CONFIG_CPU_HAS_SR_RB
58 "ldc %2, r6_bank\n\t"
59 #endif
60 "stc sr, %0\n\t"
61 "and #0xf0, %0\n\t"
62 "shlr2 %0\n\t"
63 "cmp/eq #0x3c, %0\n\t"
64 "bt/s 1f ! CLI-ed\n\t"
65 " stc sr, %0\n\t"
66 "and %1, %0\n\t"
67 "or %2, %0\n\t"
68 "ldc %0, sr\n"
69 "1:"
70 : "=&z" (__dummy)
71 : "r" (~0xf0), "r" (ip << 4)
72 : "t");
73 }
74
disable_imask_irq(unsigned int irq)75 static void disable_imask_irq(unsigned int irq)
76 {
77 clear_bit(irq, &imask_mask);
78 if (interrupt_priority < IMASK_PRIORITY - irq)
79 interrupt_priority = IMASK_PRIORITY - irq;
80
81 set_interrupt_registers(interrupt_priority);
82 }
83
enable_imask_irq(unsigned int irq)84 static void enable_imask_irq(unsigned int irq)
85 {
86 set_bit(irq, &imask_mask);
87 interrupt_priority = IMASK_PRIORITY - ffz(imask_mask);
88
89 set_interrupt_registers(interrupt_priority);
90 }
91
mask_and_ack_imask(unsigned int irq)92 static void mask_and_ack_imask(unsigned int irq)
93 {
94 disable_imask_irq(irq);
95 }
96
end_imask_irq(unsigned int irq)97 static void end_imask_irq(unsigned int irq)
98 {
99 if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
100 enable_imask_irq(irq);
101 }
102
shutdown_imask_irq(unsigned int irq)103 static void shutdown_imask_irq(unsigned int irq)
104 {
105 /* Nothing to do */
106 }
107
make_imask_irq(unsigned int irq)108 void make_imask_irq(unsigned int irq)
109 {
110 disable_irq_nosync(irq);
111 irq_desc[irq].chip = &imask_irq_type;
112 enable_irq(irq);
113 }
114