Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shaggy...
[linux-2.6] / arch / sh / kernel / cpu / irq / imask.c
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
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
52 void static inline set_interrupt_registers(int ip)
53 {
54         unsigned long __dummy;
55
56         asm volatile("ldc       %2, r6_bank\n\t"
57                      "stc       sr, %0\n\t"
58                      "and       #0xf0, %0\n\t"
59                      "shlr2     %0\n\t"
60                      "cmp/eq    #0x3c, %0\n\t"
61                      "bt/s      1f      ! CLI-ed\n\t"
62                      " stc      sr, %0\n\t"
63                      "and       %1, %0\n\t"
64                      "or        %2, %0\n\t"
65                      "ldc       %0, sr\n"
66                      "1:"
67                      : "=&z" (__dummy)
68                      : "r" (~0xf0), "r" (ip << 4)
69                      : "t");
70 }
71
72 static void disable_imask_irq(unsigned int irq)
73 {
74         clear_bit(irq, &imask_mask);
75         if (interrupt_priority < IMASK_PRIORITY - irq)
76                 interrupt_priority = IMASK_PRIORITY - irq;
77
78         set_interrupt_registers(interrupt_priority);
79 }
80
81 static void enable_imask_irq(unsigned int irq)
82 {
83         set_bit(irq, &imask_mask);
84         interrupt_priority = IMASK_PRIORITY - ffz(imask_mask);
85
86         set_interrupt_registers(interrupt_priority);
87 }
88
89 static void mask_and_ack_imask(unsigned int irq)
90 {
91         disable_imask_irq(irq);
92 }
93
94 static void end_imask_irq(unsigned int irq)
95 {
96         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
97                 enable_imask_irq(irq);
98 }
99
100 static void shutdown_imask_irq(unsigned int irq)
101 {
102         /* Nothing to do */
103 }
104
105 void make_imask_irq(unsigned int irq)
106 {
107         disable_irq_nosync(irq);
108         irq_desc[irq].chip = &imask_irq_type;
109         enable_irq(irq);
110 }