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 <linux/bitmap.h>
22 #include <asm/irq.h>
23
24 /* Bitmap of IRQ masked */
25 #define IMASK_PRIORITY 15
26
27 static DECLARE_BITMAP(imask_mask, IMASK_PRIORITY);
28 static int interrupt_priority;
29
set_interrupt_registers(int ip)30 static inline void set_interrupt_registers(int ip)
31 {
32 unsigned long __dummy;
33
34 asm volatile(
35 #ifdef CONFIG_CPU_HAS_SR_RB
36 "ldc %2, r6_bank\n\t"
37 #endif
38 "stc sr, %0\n\t"
39 "and #0xf0, %0\n\t"
40 "shlr2 %0\n\t"
41 "cmp/eq #0x3c, %0\n\t"
42 "bt/s 1f ! CLI-ed\n\t"
43 " stc sr, %0\n\t"
44 "and %1, %0\n\t"
45 "or %2, %0\n\t"
46 "ldc %0, sr\n"
47 "1:"
48 : "=&z" (__dummy)
49 : "r" (~0xf0), "r" (ip << 4)
50 : "t");
51 }
52
mask_imask_irq(struct irq_data * data)53 static void mask_imask_irq(struct irq_data *data)
54 {
55 unsigned int irq = data->irq;
56
57 clear_bit(irq, imask_mask);
58 if (interrupt_priority < IMASK_PRIORITY - irq)
59 interrupt_priority = IMASK_PRIORITY - irq;
60 set_interrupt_registers(interrupt_priority);
61 }
62
unmask_imask_irq(struct irq_data * data)63 static void unmask_imask_irq(struct irq_data *data)
64 {
65 unsigned int irq = data->irq;
66
67 set_bit(irq, imask_mask);
68 interrupt_priority = IMASK_PRIORITY -
69 find_first_zero_bit(imask_mask, IMASK_PRIORITY);
70 set_interrupt_registers(interrupt_priority);
71 }
72
73 static struct irq_chip imask_irq_chip = {
74 .name = "SR.IMASK",
75 .irq_mask = mask_imask_irq,
76 .irq_unmask = unmask_imask_irq,
77 .irq_mask_ack = mask_imask_irq,
78 };
79
make_imask_irq(unsigned int irq)80 void make_imask_irq(unsigned int irq)
81 {
82 irq_set_chip_and_handler_name(irq, &imask_irq_chip, handle_level_irq,
83 "level");
84 }
85