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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2004, 2011
4 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
5 * Holger Smolinski <Holger.Smolinski@de.ibm.com>,
6 * Thomas Spatzier <tspat@de.ibm.com>,
7 *
8 * This file contains interrupt related functions.
9 */
10
11#include <linux/kernel_stat.h>
12#include <linux/interrupt.h>
13#include <linux/seq_file.h>
14#include <linux/proc_fs.h>
15#include <linux/profile.h>
16#include <linux/export.h>
17#include <linux/kernel.h>
18#include <linux/ftrace.h>
19#include <linux/errno.h>
20#include <linux/slab.h>
21#include <linux/init.h>
22#include <linux/cpu.h>
23#include <linux/irq.h>
24#include <asm/irq_regs.h>
25#include <asm/cputime.h>
26#include <asm/lowcore.h>
27#include <asm/irq.h>
28#include <asm/hw_irq.h>
29#include "entry.h"
30
31DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
32EXPORT_PER_CPU_SYMBOL_GPL(irq_stat);
33
34struct irq_class {
35 int irq;
36 char *name;
37 char *desc;
38};
39
40/*
41 * The list of "main" irq classes on s390. This is the list of interrupts
42 * that appear both in /proc/stat ("intr" line) and /proc/interrupts.
43 * Historically only external and I/O interrupts have been part of /proc/stat.
44 * We can't add the split external and I/O sub classes since the first field
45 * in the "intr" line in /proc/stat is supposed to be the sum of all other
46 * fields.
47 * Since the external and I/O interrupt fields are already sums we would end
48 * up with having a sum which accounts each interrupt twice.
49 */
50static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = {
51 {.irq = EXT_INTERRUPT, .name = "EXT"},
52 {.irq = IO_INTERRUPT, .name = "I/O"},
53 {.irq = THIN_INTERRUPT, .name = "AIO"},
54};
55
56/*
57 * The list of split external and I/O interrupts that appear only in
58 * /proc/interrupts.
59 * In addition this list contains non external / I/O events like NMIs.
60 */
61static const struct irq_class irqclass_sub_desc[] = {
62 {.irq = IRQEXT_CLK, .name = "CLK", .desc = "[EXT] Clock Comparator"},
63 {.irq = IRQEXT_EXC, .name = "EXC", .desc = "[EXT] External Call"},
64 {.irq = IRQEXT_EMS, .name = "EMS", .desc = "[EXT] Emergency Signal"},
65 {.irq = IRQEXT_TMR, .name = "TMR", .desc = "[EXT] CPU Timer"},
66 {.irq = IRQEXT_TLA, .name = "TAL", .desc = "[EXT] Timing Alert"},
67 {.irq = IRQEXT_PFL, .name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
68 {.irq = IRQEXT_DSD, .name = "DSD", .desc = "[EXT] DASD Diag"},
69 {.irq = IRQEXT_VRT, .name = "VRT", .desc = "[EXT] Virtio"},
70 {.irq = IRQEXT_SCP, .name = "SCP", .desc = "[EXT] Service Call"},
71 {.irq = IRQEXT_IUC, .name = "IUC", .desc = "[EXT] IUCV"},
72 {.irq = IRQEXT_CMS, .name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
73 {.irq = IRQEXT_CMC, .name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
74 {.irq = IRQEXT_FTP, .name = "FTP", .desc = "[EXT] HMC FTP Service"},
75 {.irq = IRQIO_CIO, .name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
76 {.irq = IRQIO_QAI, .name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt"},
77 {.irq = IRQIO_DAS, .name = "DAS", .desc = "[I/O] DASD"},
78 {.irq = IRQIO_C15, .name = "C15", .desc = "[I/O] 3215"},
79 {.irq = IRQIO_C70, .name = "C70", .desc = "[I/O] 3270"},
80 {.irq = IRQIO_TAP, .name = "TAP", .desc = "[I/O] Tape"},
81 {.irq = IRQIO_VMR, .name = "VMR", .desc = "[I/O] Unit Record Devices"},
82 {.irq = IRQIO_LCS, .name = "LCS", .desc = "[I/O] LCS"},
83 {.irq = IRQIO_CTC, .name = "CTC", .desc = "[I/O] CTC"},
84 {.irq = IRQIO_APB, .name = "APB", .desc = "[I/O] AP Bus"},
85 {.irq = IRQIO_ADM, .name = "ADM", .desc = "[I/O] EADM Subchannel"},
86 {.irq = IRQIO_CSC, .name = "CSC", .desc = "[I/O] CHSC Subchannel"},
87 {.irq = IRQIO_PCI, .name = "PCI", .desc = "[I/O] PCI Interrupt" },
88 {.irq = IRQIO_MSI, .name = "MSI", .desc = "[I/O] MSI Interrupt" },
89 {.irq = IRQIO_VIR, .name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
90 {.irq = IRQIO_VAI, .name = "VAI", .desc = "[I/O] Virtual I/O Devices AI"},
91 {.irq = NMI_NMI, .name = "NMI", .desc = "[NMI] Machine Check"},
92 {.irq = CPU_RST, .name = "RST", .desc = "[CPU] CPU Restart"},
93};
94
95void __init init_IRQ(void)
96{
97 BUILD_BUG_ON(ARRAY_SIZE(irqclass_sub_desc) != NR_ARCH_IRQS);
98 init_cio_interrupts();
99 init_airq_interrupts();
100 init_ext_interrupts();
101}
102
103void do_IRQ(struct pt_regs *regs, int irq)
104{
105 struct pt_regs *old_regs;
106
107 old_regs = set_irq_regs(regs);
108 irq_enter();
109 if (tod_after_eq(S390_lowcore.int_clock,
110 S390_lowcore.clock_comparator))
111 /* Serve timer interrupts first. */
112 clock_comparator_work();
113 generic_handle_irq(irq);
114 irq_exit();
115 set_irq_regs(old_regs);
116}
117
118/*
119 * show_interrupts is needed by /proc/interrupts.
120 */
121int show_interrupts(struct seq_file *p, void *v)
122{
123 int index = *(loff_t *) v;
124 int cpu, irq;
125
126 get_online_cpus();
127 if (index == 0) {
128 seq_puts(p, " ");
129 for_each_online_cpu(cpu)
130 seq_printf(p, "CPU%d ", cpu);
131 seq_putc(p, '\n');
132 }
133 if (index < NR_IRQS_BASE) {
134 seq_printf(p, "%s: ", irqclass_main_desc[index].name);
135 irq = irqclass_main_desc[index].irq;
136 for_each_online_cpu(cpu)
137 seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
138 seq_putc(p, '\n');
139 goto out;
140 }
141 if (index > NR_IRQS_BASE)
142 goto out;
143
144 for (index = 0; index < NR_ARCH_IRQS; index++) {
145 seq_printf(p, "%s: ", irqclass_sub_desc[index].name);
146 irq = irqclass_sub_desc[index].irq;
147 for_each_online_cpu(cpu)
148 seq_printf(p, "%10u ",
149 per_cpu(irq_stat, cpu).irqs[irq]);
150 if (irqclass_sub_desc[index].desc)
151 seq_printf(p, " %s", irqclass_sub_desc[index].desc);
152 seq_putc(p, '\n');
153 }
154out:
155 put_online_cpus();
156 return 0;
157}
158
159unsigned int arch_dynirq_lower_bound(unsigned int from)
160{
161 return from < NR_IRQS_BASE ? NR_IRQS_BASE : from;
162}
163
164/*
165 * Switch to the asynchronous interrupt stack for softirq execution.
166 */
167void do_softirq_own_stack(void)
168{
169 unsigned long old, new;
170
171 old = current_stack_pointer();
172 /* Check against async. stack address range. */
173 new = S390_lowcore.async_stack;
174 if (((new - old) >> (PAGE_SHIFT + THREAD_SIZE_ORDER)) != 0) {
175 /* Need to switch to the async. stack. */
176 new -= STACK_FRAME_OVERHEAD;
177 ((struct stack_frame *) new)->back_chain = old;
178 asm volatile(" la 15,0(%0)\n"
179 " brasl 14,__do_softirq\n"
180 " la 15,0(%1)\n"
181 : : "a" (new), "a" (old)
182 : "0", "1", "2", "3", "4", "5", "14",
183 "cc", "memory" );
184 } else {
185 /* We are already on the async stack. */
186 __do_softirq();
187 }
188}
189
190/*
191 * ext_int_hash[index] is the list head for all external interrupts that hash
192 * to this index.
193 */
194static struct hlist_head ext_int_hash[32] ____cacheline_aligned;
195
196struct ext_int_info {
197 ext_int_handler_t handler;
198 struct hlist_node entry;
199 struct rcu_head rcu;
200 u16 code;
201};
202
203/* ext_int_hash_lock protects the handler lists for external interrupts */
204static DEFINE_SPINLOCK(ext_int_hash_lock);
205
206static inline int ext_hash(u16 code)
207{
208 BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash)));
209
210 return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1);
211}
212
213int register_external_irq(u16 code, ext_int_handler_t handler)
214{
215 struct ext_int_info *p;
216 unsigned long flags;
217 int index;
218
219 p = kmalloc(sizeof(*p), GFP_ATOMIC);
220 if (!p)
221 return -ENOMEM;
222 p->code = code;
223 p->handler = handler;
224 index = ext_hash(code);
225
226 spin_lock_irqsave(&ext_int_hash_lock, flags);
227 hlist_add_head_rcu(&p->entry, &ext_int_hash[index]);
228 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
229 return 0;
230}
231EXPORT_SYMBOL(register_external_irq);
232
233int unregister_external_irq(u16 code, ext_int_handler_t handler)
234{
235 struct ext_int_info *p;
236 unsigned long flags;
237 int index = ext_hash(code);
238
239 spin_lock_irqsave(&ext_int_hash_lock, flags);
240 hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
241 if (p->code == code && p->handler == handler) {
242 hlist_del_rcu(&p->entry);
243 kfree_rcu(p, rcu);
244 }
245 }
246 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
247 return 0;
248}
249EXPORT_SYMBOL(unregister_external_irq);
250
251static irqreturn_t do_ext_interrupt(int irq, void *dummy)
252{
253 struct pt_regs *regs = get_irq_regs();
254 struct ext_code ext_code;
255 struct ext_int_info *p;
256 int index;
257
258 ext_code = *(struct ext_code *) ®s->int_code;
259 if (ext_code.code != EXT_IRQ_CLK_COMP)
260 set_cpu_flag(CIF_NOHZ_DELAY);
261
262 index = ext_hash(ext_code.code);
263 rcu_read_lock();
264 hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
265 if (unlikely(p->code != ext_code.code))
266 continue;
267 p->handler(ext_code, regs->int_parm, regs->int_parm_long);
268 }
269 rcu_read_unlock();
270 return IRQ_HANDLED;
271}
272
273static struct irqaction external_interrupt = {
274 .name = "EXT",
275 .handler = do_ext_interrupt,
276};
277
278void __init init_ext_interrupts(void)
279{
280 int idx;
281
282 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
283 INIT_HLIST_HEAD(&ext_int_hash[idx]);
284
285 irq_set_chip_and_handler(EXT_INTERRUPT,
286 &dummy_irq_chip, handle_percpu_irq);
287 setup_irq(EXT_INTERRUPT, &external_interrupt);
288}
289
290static DEFINE_SPINLOCK(irq_subclass_lock);
291static unsigned char irq_subclass_refcount[64];
292
293void irq_subclass_register(enum irq_subclass subclass)
294{
295 spin_lock(&irq_subclass_lock);
296 if (!irq_subclass_refcount[subclass])
297 ctl_set_bit(0, subclass);
298 irq_subclass_refcount[subclass]++;
299 spin_unlock(&irq_subclass_lock);
300}
301EXPORT_SYMBOL(irq_subclass_register);
302
303void irq_subclass_unregister(enum irq_subclass subclass)
304{
305 spin_lock(&irq_subclass_lock);
306 irq_subclass_refcount[subclass]--;
307 if (!irq_subclass_refcount[subclass])
308 ctl_clear_bit(0, subclass);
309 spin_unlock(&irq_subclass_lock);
310}
311EXPORT_SYMBOL(irq_subclass_unregister);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2004, 2011
4 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
5 * Holger Smolinski <Holger.Smolinski@de.ibm.com>,
6 * Thomas Spatzier <tspat@de.ibm.com>,
7 *
8 * This file contains interrupt related functions.
9 */
10
11#include <linux/kernel_stat.h>
12#include <linux/interrupt.h>
13#include <linux/seq_file.h>
14#include <linux/proc_fs.h>
15#include <linux/profile.h>
16#include <linux/export.h>
17#include <linux/kernel.h>
18#include <linux/ftrace.h>
19#include <linux/errno.h>
20#include <linux/slab.h>
21#include <linux/init.h>
22#include <linux/cpu.h>
23#include <linux/irq.h>
24#include <linux/entry-common.h>
25#include <asm/irq_regs.h>
26#include <asm/cputime.h>
27#include <asm/lowcore.h>
28#include <asm/irq.h>
29#include <asm/hw_irq.h>
30#include <asm/stacktrace.h>
31#include <asm/softirq_stack.h>
32#include "entry.h"
33
34DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
35EXPORT_PER_CPU_SYMBOL_GPL(irq_stat);
36
37struct irq_class {
38 int irq;
39 char *name;
40 char *desc;
41};
42
43/*
44 * The list of "main" irq classes on s390. This is the list of interrupts
45 * that appear both in /proc/stat ("intr" line) and /proc/interrupts.
46 * Historically only external and I/O interrupts have been part of /proc/stat.
47 * We can't add the split external and I/O sub classes since the first field
48 * in the "intr" line in /proc/stat is supposed to be the sum of all other
49 * fields.
50 * Since the external and I/O interrupt fields are already sums we would end
51 * up with having a sum which accounts each interrupt twice.
52 */
53static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = {
54 {.irq = EXT_INTERRUPT, .name = "EXT"},
55 {.irq = IO_INTERRUPT, .name = "I/O"},
56 {.irq = THIN_INTERRUPT, .name = "AIO"},
57};
58
59/*
60 * The list of split external and I/O interrupts that appear only in
61 * /proc/interrupts.
62 * In addition this list contains non external / I/O events like NMIs.
63 */
64static const struct irq_class irqclass_sub_desc[] = {
65 {.irq = IRQEXT_CLK, .name = "CLK", .desc = "[EXT] Clock Comparator"},
66 {.irq = IRQEXT_EXC, .name = "EXC", .desc = "[EXT] External Call"},
67 {.irq = IRQEXT_EMS, .name = "EMS", .desc = "[EXT] Emergency Signal"},
68 {.irq = IRQEXT_TMR, .name = "TMR", .desc = "[EXT] CPU Timer"},
69 {.irq = IRQEXT_TLA, .name = "TAL", .desc = "[EXT] Timing Alert"},
70 {.irq = IRQEXT_PFL, .name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
71 {.irq = IRQEXT_DSD, .name = "DSD", .desc = "[EXT] DASD Diag"},
72 {.irq = IRQEXT_VRT, .name = "VRT", .desc = "[EXT] Virtio"},
73 {.irq = IRQEXT_SCP, .name = "SCP", .desc = "[EXT] Service Call"},
74 {.irq = IRQEXT_IUC, .name = "IUC", .desc = "[EXT] IUCV"},
75 {.irq = IRQEXT_CMS, .name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
76 {.irq = IRQEXT_CMC, .name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
77 {.irq = IRQEXT_FTP, .name = "FTP", .desc = "[EXT] HMC FTP Service"},
78 {.irq = IRQIO_CIO, .name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
79 {.irq = IRQIO_DAS, .name = "DAS", .desc = "[I/O] DASD"},
80 {.irq = IRQIO_C15, .name = "C15", .desc = "[I/O] 3215"},
81 {.irq = IRQIO_C70, .name = "C70", .desc = "[I/O] 3270"},
82 {.irq = IRQIO_TAP, .name = "TAP", .desc = "[I/O] Tape"},
83 {.irq = IRQIO_VMR, .name = "VMR", .desc = "[I/O] Unit Record Devices"},
84 {.irq = IRQIO_LCS, .name = "LCS", .desc = "[I/O] LCS"},
85 {.irq = IRQIO_CTC, .name = "CTC", .desc = "[I/O] CTC"},
86 {.irq = IRQIO_ADM, .name = "ADM", .desc = "[I/O] EADM Subchannel"},
87 {.irq = IRQIO_CSC, .name = "CSC", .desc = "[I/O] CHSC Subchannel"},
88 {.irq = IRQIO_VIR, .name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
89 {.irq = IRQIO_QAI, .name = "QAI", .desc = "[AIO] QDIO Adapter Interrupt"},
90 {.irq = IRQIO_APB, .name = "APB", .desc = "[AIO] AP Bus"},
91 {.irq = IRQIO_PCF, .name = "PCF", .desc = "[AIO] PCI Floating Interrupt"},
92 {.irq = IRQIO_PCD, .name = "PCD", .desc = "[AIO] PCI Directed Interrupt"},
93 {.irq = IRQIO_MSI, .name = "MSI", .desc = "[AIO] MSI Interrupt"},
94 {.irq = IRQIO_VAI, .name = "VAI", .desc = "[AIO] Virtual I/O Devices AI"},
95 {.irq = IRQIO_GAL, .name = "GAL", .desc = "[AIO] GIB Alert"},
96 {.irq = NMI_NMI, .name = "NMI", .desc = "[NMI] Machine Check"},
97 {.irq = CPU_RST, .name = "RST", .desc = "[CPU] CPU Restart"},
98};
99
100static void do_IRQ(struct pt_regs *regs, int irq)
101{
102 if (tod_after_eq(S390_lowcore.int_clock,
103 S390_lowcore.clock_comparator))
104 /* Serve timer interrupts first. */
105 clock_comparator_work();
106 generic_handle_irq(irq);
107}
108
109static int on_async_stack(void)
110{
111 unsigned long frame = current_frame_address();
112
113 return ((S390_lowcore.async_stack ^ frame) & ~(THREAD_SIZE - 1)) == 0;
114}
115
116static void do_irq_async(struct pt_regs *regs, int irq)
117{
118 if (on_async_stack()) {
119 do_IRQ(regs, irq);
120 } else {
121 call_on_stack(2, S390_lowcore.async_stack, void, do_IRQ,
122 struct pt_regs *, regs, int, irq);
123 }
124}
125
126static int irq_pending(struct pt_regs *regs)
127{
128 int cc;
129
130 asm volatile("tpi 0\n"
131 "ipm %0" : "=d" (cc) : : "cc");
132 return cc >> 28;
133}
134
135void noinstr do_io_irq(struct pt_regs *regs)
136{
137 irqentry_state_t state = irqentry_enter(regs);
138 struct pt_regs *old_regs = set_irq_regs(regs);
139 int from_idle;
140
141 irq_enter();
142
143 if (user_mode(regs))
144 update_timer_sys();
145
146 from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit;
147 if (from_idle)
148 account_idle_time_irq();
149
150 do {
151 regs->tpi_info = S390_lowcore.tpi_info;
152 if (S390_lowcore.tpi_info.adapter_IO)
153 do_irq_async(regs, THIN_INTERRUPT);
154 else
155 do_irq_async(regs, IO_INTERRUPT);
156 } while (MACHINE_IS_LPAR && irq_pending(regs));
157
158 irq_exit();
159 set_irq_regs(old_regs);
160 irqentry_exit(regs, state);
161
162 if (from_idle)
163 regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
164}
165
166void noinstr do_ext_irq(struct pt_regs *regs)
167{
168 irqentry_state_t state = irqentry_enter(regs);
169 struct pt_regs *old_regs = set_irq_regs(regs);
170 int from_idle;
171
172 irq_enter();
173
174 if (user_mode(regs))
175 update_timer_sys();
176
177 regs->int_code = S390_lowcore.ext_int_code_addr;
178 regs->int_parm = S390_lowcore.ext_params;
179 regs->int_parm_long = S390_lowcore.ext_params2;
180
181 from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit;
182 if (from_idle)
183 account_idle_time_irq();
184
185 do_irq_async(regs, EXT_INTERRUPT);
186
187 irq_exit();
188 set_irq_regs(old_regs);
189 irqentry_exit(regs, state);
190
191 if (from_idle)
192 regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
193}
194
195static void show_msi_interrupt(struct seq_file *p, int irq)
196{
197 struct irq_desc *desc;
198 unsigned long flags;
199 int cpu;
200
201 irq_lock_sparse();
202 desc = irq_to_desc(irq);
203 if (!desc)
204 goto out;
205
206 raw_spin_lock_irqsave(&desc->lock, flags);
207 seq_printf(p, "%3d: ", irq);
208 for_each_online_cpu(cpu)
209 seq_printf(p, "%10u ", irq_desc_kstat_cpu(desc, cpu));
210
211 if (desc->irq_data.chip)
212 seq_printf(p, " %8s", desc->irq_data.chip->name);
213
214 if (desc->action)
215 seq_printf(p, " %s", desc->action->name);
216
217 seq_putc(p, '\n');
218 raw_spin_unlock_irqrestore(&desc->lock, flags);
219out:
220 irq_unlock_sparse();
221}
222
223/*
224 * show_interrupts is needed by /proc/interrupts.
225 */
226int show_interrupts(struct seq_file *p, void *v)
227{
228 int index = *(loff_t *) v;
229 int cpu, irq;
230
231 get_online_cpus();
232 if (index == 0) {
233 seq_puts(p, " ");
234 for_each_online_cpu(cpu)
235 seq_printf(p, "CPU%-8d", cpu);
236 seq_putc(p, '\n');
237 }
238 if (index < NR_IRQS_BASE) {
239 seq_printf(p, "%s: ", irqclass_main_desc[index].name);
240 irq = irqclass_main_desc[index].irq;
241 for_each_online_cpu(cpu)
242 seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
243 seq_putc(p, '\n');
244 goto out;
245 }
246 if (index < nr_irqs) {
247 show_msi_interrupt(p, index);
248 goto out;
249 }
250 for (index = 0; index < NR_ARCH_IRQS; index++) {
251 seq_printf(p, "%s: ", irqclass_sub_desc[index].name);
252 irq = irqclass_sub_desc[index].irq;
253 for_each_online_cpu(cpu)
254 seq_printf(p, "%10u ",
255 per_cpu(irq_stat, cpu).irqs[irq]);
256 if (irqclass_sub_desc[index].desc)
257 seq_printf(p, " %s", irqclass_sub_desc[index].desc);
258 seq_putc(p, '\n');
259 }
260out:
261 put_online_cpus();
262 return 0;
263}
264
265unsigned int arch_dynirq_lower_bound(unsigned int from)
266{
267 return from < NR_IRQS_BASE ? NR_IRQS_BASE : from;
268}
269
270/*
271 * ext_int_hash[index] is the list head for all external interrupts that hash
272 * to this index.
273 */
274static struct hlist_head ext_int_hash[32] ____cacheline_aligned;
275
276struct ext_int_info {
277 ext_int_handler_t handler;
278 struct hlist_node entry;
279 struct rcu_head rcu;
280 u16 code;
281};
282
283/* ext_int_hash_lock protects the handler lists for external interrupts */
284static DEFINE_SPINLOCK(ext_int_hash_lock);
285
286static inline int ext_hash(u16 code)
287{
288 BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash)));
289
290 return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1);
291}
292
293int register_external_irq(u16 code, ext_int_handler_t handler)
294{
295 struct ext_int_info *p;
296 unsigned long flags;
297 int index;
298
299 p = kmalloc(sizeof(*p), GFP_ATOMIC);
300 if (!p)
301 return -ENOMEM;
302 p->code = code;
303 p->handler = handler;
304 index = ext_hash(code);
305
306 spin_lock_irqsave(&ext_int_hash_lock, flags);
307 hlist_add_head_rcu(&p->entry, &ext_int_hash[index]);
308 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
309 return 0;
310}
311EXPORT_SYMBOL(register_external_irq);
312
313int unregister_external_irq(u16 code, ext_int_handler_t handler)
314{
315 struct ext_int_info *p;
316 unsigned long flags;
317 int index = ext_hash(code);
318
319 spin_lock_irqsave(&ext_int_hash_lock, flags);
320 hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
321 if (p->code == code && p->handler == handler) {
322 hlist_del_rcu(&p->entry);
323 kfree_rcu(p, rcu);
324 }
325 }
326 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
327 return 0;
328}
329EXPORT_SYMBOL(unregister_external_irq);
330
331static irqreturn_t do_ext_interrupt(int irq, void *dummy)
332{
333 struct pt_regs *regs = get_irq_regs();
334 struct ext_code ext_code;
335 struct ext_int_info *p;
336 int index;
337
338 ext_code = *(struct ext_code *) ®s->int_code;
339 if (ext_code.code != EXT_IRQ_CLK_COMP)
340 set_cpu_flag(CIF_NOHZ_DELAY);
341
342 index = ext_hash(ext_code.code);
343 rcu_read_lock();
344 hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
345 if (unlikely(p->code != ext_code.code))
346 continue;
347 p->handler(ext_code, regs->int_parm, regs->int_parm_long);
348 }
349 rcu_read_unlock();
350 return IRQ_HANDLED;
351}
352
353static void __init init_ext_interrupts(void)
354{
355 int idx;
356
357 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
358 INIT_HLIST_HEAD(&ext_int_hash[idx]);
359
360 irq_set_chip_and_handler(EXT_INTERRUPT,
361 &dummy_irq_chip, handle_percpu_irq);
362 if (request_irq(EXT_INTERRUPT, do_ext_interrupt, 0, "EXT", NULL))
363 panic("Failed to register EXT interrupt\n");
364}
365
366void __init init_IRQ(void)
367{
368 BUILD_BUG_ON(ARRAY_SIZE(irqclass_sub_desc) != NR_ARCH_IRQS);
369 init_cio_interrupts();
370 init_airq_interrupts();
371 init_ext_interrupts();
372}
373
374static DEFINE_SPINLOCK(irq_subclass_lock);
375static unsigned char irq_subclass_refcount[64];
376
377void irq_subclass_register(enum irq_subclass subclass)
378{
379 spin_lock(&irq_subclass_lock);
380 if (!irq_subclass_refcount[subclass])
381 ctl_set_bit(0, subclass);
382 irq_subclass_refcount[subclass]++;
383 spin_unlock(&irq_subclass_lock);
384}
385EXPORT_SYMBOL(irq_subclass_register);
386
387void irq_subclass_unregister(enum irq_subclass subclass)
388{
389 spin_lock(&irq_subclass_lock);
390 irq_subclass_refcount[subclass]--;
391 if (!irq_subclass_refcount[subclass])
392 ctl_clear_bit(0, subclass);
393 spin_unlock(&irq_subclass_lock);
394}
395EXPORT_SYMBOL(irq_subclass_unregister);