xref: /openbmc/linux/arch/s390/kernel/irq.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  *    Copyright IBM Corp. 2004,2010
3  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
4  *		 Thomas Spatzier (tspat@de.ibm.com)
5  *
6  * This file contains interrupt related functions.
7  */
8 
9 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <linux/kernel_stat.h>
12 #include <linux/interrupt.h>
13 #include <linux/seq_file.h>
14 #include <linux/cpu.h>
15 #include <linux/proc_fs.h>
16 #include <linux/profile.h>
17 
18 struct irq_class {
19 	char *name;
20 	char *desc;
21 };
22 
23 static const struct irq_class intrclass_names[] = {
24 	{.name = "EXT" },
25 	{.name = "I/O" },
26 	{.name = "CLK", .desc = "[EXT] Clock Comparator" },
27 	{.name = "IPI", .desc = "[EXT] Signal Processor" },
28 	{.name = "TMR", .desc = "[EXT] CPU Timer" },
29 	{.name = "TAL", .desc = "[EXT] Timing Alert" },
30 	{.name = "PFL", .desc = "[EXT] Pseudo Page Fault" },
31 	{.name = "DSD", .desc = "[EXT] DASD Diag" },
32 	{.name = "VRT", .desc = "[EXT] Virtio" },
33 	{.name = "SCP", .desc = "[EXT] Service Call" },
34 	{.name = "IUC", .desc = "[EXT] IUCV" },
35 	{.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt" },
36 	{.name = "QDI", .desc = "[I/O] QDIO Interrupt" },
37 	{.name = "DAS", .desc = "[I/O] DASD" },
38 	{.name = "C15", .desc = "[I/O] 3215" },
39 	{.name = "C70", .desc = "[I/O] 3270" },
40 	{.name = "TAP", .desc = "[I/O] Tape" },
41 	{.name = "VMR", .desc = "[I/O] Unit Record Devices" },
42 	{.name = "LCS", .desc = "[I/O] LCS" },
43 	{.name = "CLW", .desc = "[I/O] CLAW" },
44 	{.name = "CTC", .desc = "[I/O] CTC" },
45 	{.name = "APB", .desc = "[I/O] AP Bus" },
46 	{.name = "NMI", .desc = "[NMI] Machine Check" },
47 };
48 
49 /*
50  * show_interrupts is needed by /proc/interrupts.
51  */
52 int show_interrupts(struct seq_file *p, void *v)
53 {
54 	int i = *(loff_t *) v, j;
55 
56 	get_online_cpus();
57 	if (i == 0) {
58 		seq_puts(p, "           ");
59 		for_each_online_cpu(j)
60 			seq_printf(p, "CPU%d       ",j);
61 		seq_putc(p, '\n');
62 	}
63 
64 	if (i < NR_IRQS) {
65 		seq_printf(p, "%s: ", intrclass_names[i].name);
66 #ifndef CONFIG_SMP
67 		seq_printf(p, "%10u ", kstat_irqs(i));
68 #else
69 		for_each_online_cpu(j)
70 			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
71 #endif
72 		if (intrclass_names[i].desc)
73 			seq_printf(p, "  %s", intrclass_names[i].desc);
74                 seq_putc(p, '\n');
75         }
76 	put_online_cpus();
77         return 0;
78 }
79 
80 /*
81  * For compatibilty only. S/390 specific setup of interrupts et al. is done
82  * much later in init_channel_subsystem().
83  */
84 void __init
85 init_IRQ(void)
86 {
87 	/* nothing... */
88 }
89 
90 /*
91  * Switch to the asynchronous interrupt stack for softirq execution.
92  */
93 asmlinkage void do_softirq(void)
94 {
95 	unsigned long flags, old, new;
96 
97 	if (in_interrupt())
98 		return;
99 
100 	local_irq_save(flags);
101 
102 	if (local_softirq_pending()) {
103 		/* Get current stack pointer. */
104 		asm volatile("la %0,0(15)" : "=a" (old));
105 		/* Check against async. stack address range. */
106 		new = S390_lowcore.async_stack;
107 		if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
108 			/* Need to switch to the async. stack. */
109 			new -= STACK_FRAME_OVERHEAD;
110 			((struct stack_frame *) new)->back_chain = old;
111 
112 			asm volatile("   la    15,0(%0)\n"
113 				     "   basr  14,%2\n"
114 				     "   la    15,0(%1)\n"
115 				     : : "a" (new), "a" (old),
116 				         "a" (__do_softirq)
117 				     : "0", "1", "2", "3", "4", "5", "14",
118 				       "cc", "memory" );
119 		} else
120 			/* We are already on the async stack. */
121 			__do_softirq();
122 	}
123 
124 	local_irq_restore(flags);
125 }
126 
127 #ifdef CONFIG_PROC_FS
128 void init_irq_proc(void)
129 {
130 	struct proc_dir_entry *root_irq_dir;
131 
132 	root_irq_dir = proc_mkdir("irq", NULL);
133 	create_prof_cpu_mask(root_irq_dir);
134 }
135 #endif
136