xref: /openbmc/qemu/hw/remote/iohub.c (revision 34cc54fb)
1 /*
2  * Remote IO Hub
3  *
4  * Copyright © 2018, 2021 Oracle and/or its affiliates.
5  *
6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
7  * See the COPYING file in the top-level directory.
8  *
9  */
10 
11 #include "qemu/osdep.h"
12 
13 #include "hw/pci/pci.h"
14 #include "hw/pci/pci_ids.h"
15 #include "hw/pci/pci_bus.h"
16 #include "qemu/thread.h"
17 #include "hw/remote/machine.h"
18 #include "hw/remote/iohub.h"
19 #include "qemu/main-loop.h"
20 
21 void remote_iohub_init(RemoteIOHubState *iohub)
22 {
23     int pirq;
24 
25     memset(&iohub->irqfds, 0, sizeof(iohub->irqfds));
26     memset(&iohub->resamplefds, 0, sizeof(iohub->resamplefds));
27 
28     for (pirq = 0; pirq < REMOTE_IOHUB_NB_PIRQS; pirq++) {
29         qemu_mutex_init(&iohub->irq_level_lock[pirq]);
30         iohub->irq_level[pirq] = 0;
31         event_notifier_init_fd(&iohub->irqfds[pirq], -1);
32         event_notifier_init_fd(&iohub->resamplefds[pirq], -1);
33     }
34 }
35 
36 void remote_iohub_finalize(RemoteIOHubState *iohub)
37 {
38     int pirq;
39 
40     for (pirq = 0; pirq < REMOTE_IOHUB_NB_PIRQS; pirq++) {
41         qemu_set_fd_handler(event_notifier_get_fd(&iohub->resamplefds[pirq]),
42                             NULL, NULL, NULL);
43         event_notifier_cleanup(&iohub->irqfds[pirq]);
44         event_notifier_cleanup(&iohub->resamplefds[pirq]);
45         qemu_mutex_destroy(&iohub->irq_level_lock[pirq]);
46     }
47 }
48 
49 int remote_iohub_map_irq(PCIDevice *pci_dev, int intx)
50 {
51     return pci_dev->devfn;
52 }
53 
54 void remote_iohub_set_irq(void *opaque, int pirq, int level)
55 {
56     RemoteIOHubState *iohub = opaque;
57 
58     assert(pirq >= 0);
59     assert(pirq < PCI_DEVFN_MAX);
60 
61     QEMU_LOCK_GUARD(&iohub->irq_level_lock[pirq]);
62 
63     if (level) {
64         if (++iohub->irq_level[pirq] == 1) {
65             event_notifier_set(&iohub->irqfds[pirq]);
66         }
67     } else if (iohub->irq_level[pirq] > 0) {
68         iohub->irq_level[pirq]--;
69     }
70 }
71 
72 static void intr_resample_handler(void *opaque)
73 {
74     ResampleToken *token = opaque;
75     RemoteIOHubState *iohub = token->iohub;
76     int pirq, s;
77 
78     pirq = token->pirq;
79 
80     s = event_notifier_test_and_clear(&iohub->resamplefds[pirq]);
81 
82     assert(s >= 0);
83 
84     QEMU_LOCK_GUARD(&iohub->irq_level_lock[pirq]);
85 
86     if (iohub->irq_level[pirq]) {
87         event_notifier_set(&iohub->irqfds[pirq]);
88     }
89 }
90 
91 void process_set_irqfd_msg(PCIDevice *pci_dev, MPQemuMsg *msg)
92 {
93     RemoteMachineState *machine = REMOTE_MACHINE(current_machine);
94     RemoteIOHubState *iohub = &machine->iohub;
95     int pirq, intx;
96 
97     intx = pci_get_byte(pci_dev->config + PCI_INTERRUPT_PIN) - 1;
98 
99     pirq = remote_iohub_map_irq(pci_dev, intx);
100 
101     if (event_notifier_get_fd(&iohub->irqfds[pirq]) != -1) {
102         qemu_set_fd_handler(event_notifier_get_fd(&iohub->resamplefds[pirq]),
103                             NULL, NULL, NULL);
104         event_notifier_cleanup(&iohub->irqfds[pirq]);
105         event_notifier_cleanup(&iohub->resamplefds[pirq]);
106         memset(&iohub->token[pirq], 0, sizeof(ResampleToken));
107     }
108 
109     event_notifier_init_fd(&iohub->irqfds[pirq], msg->fds[0]);
110     event_notifier_init_fd(&iohub->resamplefds[pirq], msg->fds[1]);
111 
112     iohub->token[pirq].iohub = iohub;
113     iohub->token[pirq].pirq = pirq;
114 
115     qemu_set_fd_handler(msg->fds[1], intr_resample_handler, NULL,
116                         &iohub->token[pirq]);
117 }
118