File: /usr/src/linux/arch/sparc/kernel/tick14.c

1     /* tick14.c
2      * linux/arch/sparc/kernel/tick14.c
3      *
4      * Copyright (C) 1996 David Redman (djhr@tadpole.co.uk)
5      *
6      * This file handles the Sparc specific level14 ticker
7      * This is really useful for profiling OBP uses it for keyboard
8      * aborts and other stuff.
9      *
10      *
11      */
12     #include <linux/errno.h>
13     #include <linux/sched.h>
14     #include <linux/kernel.h>
15     #include <linux/param.h>
16     #include <linux/string.h>
17     #include <linux/mm.h>
18     #include <linux/timex.h>
19     
20     #include <asm/oplib.h>
21     #include <asm/segment.h>
22     #include <asm/timer.h>
23     #include <asm/mostek.h>
24     #include <asm/system.h>
25     #include <asm/irq.h>
26     #include <asm/io.h>
27     
28     extern unsigned long lvl14_save[5];
29     static unsigned long *linux_lvl14 = NULL;
30     static unsigned long obp_lvl14[4];
31      
32     void install_linux_ticker(void)
33     {
34     	unsigned long flags;
35     
36     	if (!linux_lvl14)
37     		return;
38     	save_and_cli(flags);
39     	linux_lvl14[0] =  lvl14_save[0];
40     	linux_lvl14[1] =  lvl14_save[1];
41     	linux_lvl14[2] =  lvl14_save[2];
42     	linux_lvl14[3] =  lvl14_save[3];
43     	restore_flags(flags);
44     }
45     
46     void install_obp_ticker(void)
47     {
48     	unsigned long flags;
49         
50     	if (!linux_lvl14)
51     		return;
52     	save_and_cli(flags);
53     	linux_lvl14[0] =  obp_lvl14[0];
54     	linux_lvl14[1] =  obp_lvl14[1];
55     	linux_lvl14[2] =  obp_lvl14[2];
56     	linux_lvl14[3] =  obp_lvl14[3]; 
57     	restore_flags(flags);
58     }
59     
60     void claim_ticker14(void (*handler)(int, void *, struct pt_regs *),
61     		    int irq_nr, unsigned int timeout )
62     {
63     	int cpu = smp_processor_id();
64     
65     	/* first we copy the obp handler instructions
66     	 */
67     	disable_irq(irq_nr);
68     	if (!handler)
69     		return;
70         
71     	linux_lvl14 = (unsigned long *)lvl14_save[4];
72     	obp_lvl14[0] = linux_lvl14[0];
73     	obp_lvl14[1] = linux_lvl14[1];
74     	obp_lvl14[2] = linux_lvl14[2];
75     	obp_lvl14[3] = linux_lvl14[3];
76     
77     	if (!request_irq(irq_nr,
78     			 handler,
79     			 (SA_INTERRUPT | SA_STATIC_ALLOC),
80     			 "counter14",
81     			 NULL)) {
82     		install_linux_ticker();
83     		load_profile_irq(cpu, timeout);
84     		enable_irq(irq_nr);
85     	}
86     }
87