KVM: fix sparse warnings: Should it be static?
[linux-2.6.git] / virt / kvm / irq_comm.c
1 /*
2  * irq_comm.c: Common API for in kernel interrupt controller
3  * Copyright (c) 2007, Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
16  * Place - Suite 330, Boston, MA 02111-1307 USA.
17  * Authors:
18  *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
19  *
20  */
21
22 #include <linux/kvm_host.h>
23
24 #include <asm/msidef.h>
25
26 #include "irq.h"
27
28 #include "ioapic.h"
29
30 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
31                            struct kvm *kvm, int level)
32 {
33 #ifdef CONFIG_X86
34         return kvm_pic_set_irq(pic_irqchip(kvm), e->irqchip.pin, level);
35 #else
36         return -1;
37 #endif
38 }
39
40 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
41                               struct kvm *kvm, int level)
42 {
43         return kvm_ioapic_set_irq(kvm->arch.vioapic, e->irqchip.pin, level);
44 }
45
46 static int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
47                        struct kvm *kvm, int level)
48 {
49         int vcpu_id, r = -1;
50         struct kvm_vcpu *vcpu;
51         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
52         int dest_id = (e->msi.address_lo & MSI_ADDR_DEST_ID_MASK)
53                         >> MSI_ADDR_DEST_ID_SHIFT;
54         int vector = (e->msi.data & MSI_DATA_VECTOR_MASK)
55                         >> MSI_DATA_VECTOR_SHIFT;
56         int dest_mode = test_bit(MSI_ADDR_DEST_MODE_SHIFT,
57                                 (unsigned long *)&e->msi.address_lo);
58         int trig_mode = test_bit(MSI_DATA_TRIGGER_SHIFT,
59                                 (unsigned long *)&e->msi.data);
60         int delivery_mode = test_bit(MSI_DATA_DELIVERY_MODE_SHIFT,
61                                 (unsigned long *)&e->msi.data);
62         u32 deliver_bitmask;
63
64         BUG_ON(!ioapic);
65
66         deliver_bitmask = kvm_ioapic_get_delivery_bitmask(ioapic,
67                                 dest_id, dest_mode);
68         /* IOAPIC delivery mode value is the same as MSI here */
69         switch (delivery_mode) {
70         case IOAPIC_LOWEST_PRIORITY:
71                 vcpu = kvm_get_lowest_prio_vcpu(ioapic->kvm, vector,
72                                 deliver_bitmask);
73                 if (vcpu != NULL)
74                         r = kvm_apic_set_irq(vcpu, vector, trig_mode);
75                 else
76                         printk(KERN_INFO "kvm: null lowest priority vcpu!\n");
77                 break;
78         case IOAPIC_FIXED:
79                 for (vcpu_id = 0; deliver_bitmask != 0; vcpu_id++) {
80                         if (!(deliver_bitmask & (1 << vcpu_id)))
81                                 continue;
82                         deliver_bitmask &= ~(1 << vcpu_id);
83                         vcpu = ioapic->kvm->vcpus[vcpu_id];
84                         if (vcpu) {
85                                 if (r < 0)
86                                         r = 0;
87                                 r += kvm_apic_set_irq(vcpu, vector, trig_mode);
88                         }
89                 }
90                 break;
91         default:
92                 break;
93         }
94         return r;
95 }
96
97 /* This should be called with the kvm->lock mutex held
98  * Return value:
99  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
100  *  = 0   Interrupt was coalesced (previous irq is still pending)
101  *  > 0   Number of CPUs interrupt was delivered to
102  */
103 int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
104 {
105         struct kvm_kernel_irq_routing_entry *e;
106         unsigned long *irq_state, sig_level;
107         int ret = -1;
108
109         if (irq < KVM_IOAPIC_NUM_PINS) {
110                 irq_state = (unsigned long *)&kvm->arch.irq_states[irq];
111
112                 /* Logical OR for level trig interrupt */
113                 if (level)
114                         set_bit(irq_source_id, irq_state);
115                 else
116                         clear_bit(irq_source_id, irq_state);
117                 sig_level = !!(*irq_state);
118         } else /* Deal with MSI/MSI-X */
119                 sig_level = 1;
120
121         /* Not possible to detect if the guest uses the PIC or the
122          * IOAPIC.  So set the bit in both. The guest will ignore
123          * writes to the unused one.
124          */
125         list_for_each_entry(e, &kvm->irq_routing, link)
126                 if (e->gsi == irq) {
127                         int r = e->set(e, kvm, sig_level);
128                         if (r < 0)
129                                 continue;
130
131                         ret = r + ((ret < 0) ? 0 : ret);
132                 }
133         return ret;
134 }
135
136 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
137 {
138         struct kvm_kernel_irq_routing_entry *e;
139         struct kvm_irq_ack_notifier *kian;
140         struct hlist_node *n;
141         unsigned gsi = pin;
142
143         list_for_each_entry(e, &kvm->irq_routing, link)
144                 if (e->irqchip.irqchip == irqchip &&
145                     e->irqchip.pin == pin) {
146                         gsi = e->gsi;
147                         break;
148                 }
149
150         hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
151                 if (kian->gsi == gsi)
152                         kian->irq_acked(kian);
153 }
154
155 void kvm_register_irq_ack_notifier(struct kvm *kvm,
156                                    struct kvm_irq_ack_notifier *kian)
157 {
158         hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
159 }
160
161 void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian)
162 {
163         hlist_del_init(&kian->link);
164 }
165
166 /* The caller must hold kvm->lock mutex */
167 int kvm_request_irq_source_id(struct kvm *kvm)
168 {
169         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
170         int irq_source_id = find_first_zero_bit(bitmap,
171                                 sizeof(kvm->arch.irq_sources_bitmap));
172
173         if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
174                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
175                 return -EFAULT;
176         }
177
178         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
179         set_bit(irq_source_id, bitmap);
180
181         return irq_source_id;
182 }
183
184 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
185 {
186         int i;
187
188         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
189
190         if (irq_source_id < 0 ||
191             irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
192                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
193                 return;
194         }
195         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
196                 clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
197         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
198 }
199
200 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
201                                     struct kvm_irq_mask_notifier *kimn)
202 {
203         kimn->irq = irq;
204         hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
205 }
206
207 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
208                                       struct kvm_irq_mask_notifier *kimn)
209 {
210         hlist_del(&kimn->link);
211 }
212
213 void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
214 {
215         struct kvm_irq_mask_notifier *kimn;
216         struct hlist_node *n;
217
218         hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
219                 if (kimn->irq == irq)
220                         kimn->func(kimn, mask);
221 }
222
223 static void __kvm_free_irq_routing(struct list_head *irq_routing)
224 {
225         struct kvm_kernel_irq_routing_entry *e, *n;
226
227         list_for_each_entry_safe(e, n, irq_routing, link)
228                 kfree(e);
229 }
230
231 void kvm_free_irq_routing(struct kvm *kvm)
232 {
233         __kvm_free_irq_routing(&kvm->irq_routing);
234 }
235
236 static int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
237                                const struct kvm_irq_routing_entry *ue)
238 {
239         int r = -EINVAL;
240         int delta;
241
242         e->gsi = ue->gsi;
243         switch (ue->type) {
244         case KVM_IRQ_ROUTING_IRQCHIP:
245                 delta = 0;
246                 switch (ue->u.irqchip.irqchip) {
247                 case KVM_IRQCHIP_PIC_MASTER:
248                         e->set = kvm_set_pic_irq;
249                         break;
250                 case KVM_IRQCHIP_PIC_SLAVE:
251                         e->set = kvm_set_pic_irq;
252                         delta = 8;
253                         break;
254                 case KVM_IRQCHIP_IOAPIC:
255                                 e->set = kvm_set_ioapic_irq;
256                         break;
257                 default:
258                         goto out;
259                 }
260                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
261                 e->irqchip.pin = ue->u.irqchip.pin + delta;
262                 break;
263         case KVM_IRQ_ROUTING_MSI:
264                 e->set = kvm_set_msi;
265                 e->msi.address_lo = ue->u.msi.address_lo;
266                 e->msi.address_hi = ue->u.msi.address_hi;
267                 e->msi.data = ue->u.msi.data;
268                 break;
269         default:
270                 goto out;
271         }
272         r = 0;
273 out:
274         return r;
275 }
276
277
278 int kvm_set_irq_routing(struct kvm *kvm,
279                         const struct kvm_irq_routing_entry *ue,
280                         unsigned nr,
281                         unsigned flags)
282 {
283         struct list_head irq_list = LIST_HEAD_INIT(irq_list);
284         struct list_head tmp = LIST_HEAD_INIT(tmp);
285         struct kvm_kernel_irq_routing_entry *e = NULL;
286         unsigned i;
287         int r;
288
289         for (i = 0; i < nr; ++i) {
290                 r = -EINVAL;
291                 if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
292                         goto out;
293                 if (ue->flags)
294                         goto out;
295                 r = -ENOMEM;
296                 e = kzalloc(sizeof(*e), GFP_KERNEL);
297                 if (!e)
298                         goto out;
299                 r = setup_routing_entry(e, ue);
300                 if (r)
301                         goto out;
302                 ++ue;
303                 list_add(&e->link, &irq_list);
304                 e = NULL;
305         }
306
307         mutex_lock(&kvm->lock);
308         list_splice(&kvm->irq_routing, &tmp);
309         INIT_LIST_HEAD(&kvm->irq_routing);
310         list_splice(&irq_list, &kvm->irq_routing);
311         INIT_LIST_HEAD(&irq_list);
312         list_splice(&tmp, &irq_list);
313         mutex_unlock(&kvm->lock);
314
315         r = 0;
316
317 out:
318         kfree(e);
319         __kvm_free_irq_routing(&irq_list);
320         return r;
321 }
322
323 #define IOAPIC_ROUTING_ENTRY(irq) \
324         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
325           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
326 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
327
328 #ifdef CONFIG_X86
329 #  define PIC_ROUTING_ENTRY(irq) \
330         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
331           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
332 #  define ROUTING_ENTRY2(irq) \
333         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
334 #else
335 #  define ROUTING_ENTRY2(irq) \
336         IOAPIC_ROUTING_ENTRY(irq)
337 #endif
338
339 static const struct kvm_irq_routing_entry default_routing[] = {
340         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
341         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
342         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
343         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
344         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
345         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
346         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
347         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
348         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
349         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
350         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
351         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
352 #ifdef CONFIG_IA64
353         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
354         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
355         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
356         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
357         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
358         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
359         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
360         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
361         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
362         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
363         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
364         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
365 #endif
366 };
367
368 int kvm_setup_default_irq_routing(struct kvm *kvm)
369 {
370         return kvm_set_irq_routing(kvm, default_routing,
371                                    ARRAY_SIZE(default_routing), 0);
372 }