xref: /openbmc/qemu/hw/remote/iohub.c (revision 6f03770d)
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 #include "qemu-common.h"
13 
14 #include "hw/pci/pci.h"
15 #include "hw/pci/pci_ids.h"
16 #include "hw/pci/pci_bus.h"
17 #include "qemu/thread.h"
18 #include "hw/boards.h"
19 #include "hw/remote/machine.h"
20 #include "hw/remote/iohub.h"
21 #include "qemu/main-loop.h"
22 
23 void remote_iohub_init(RemoteIOHubState *iohub)
24 {
25     int pirq;
26 
27     memset(&iohub->irqfds, 0, sizeof(iohub->irqfds));
28     memset(&iohub->resamplefds, 0, sizeof(iohub->resamplefds));
29 
30     for (pirq = 0; pirq < REMOTE_IOHUB_NB_PIRQS; pirq++) {
31         qemu_mutex_init(&iohub->irq_level_lock[pirq]);
32         iohub->irq_level[pirq] = 0;
33         event_notifier_init_fd(&iohub->irqfds[pirq], -1);
34         event_notifier_init_fd(&iohub->resamplefds[pirq], -1);
35     }
36 }
37 
38 void remote_iohub_finalize(RemoteIOHubState *iohub)
39 {
40     int pirq;
41 
42     for (pirq = 0; pirq < REMOTE_IOHUB_NB_PIRQS; pirq++) {
43         qemu_set_fd_handler(event_notifier_get_fd(&iohub->resamplefds[pirq]),
44                             NULL, NULL, NULL);
45         event_notifier_cleanup(&iohub->irqfds[pirq]);
46         event_notifier_cleanup(&iohub->resamplefds[pirq]);
47         qemu_mutex_destroy(&iohub->irq_level_lock[pirq]);
48     }
49 }
50 
51 int remote_iohub_map_irq(PCIDevice *pci_dev, int intx)
52 {
53     return pci_dev->devfn;
54 }
55 
56 void remote_iohub_set_irq(void *opaque, int pirq, int level)
57 {
58     RemoteIOHubState *iohub = opaque;
59 
60     assert(pirq >= 0);
61     assert(pirq < PCI_DEVFN_MAX);
62 
63     QEMU_LOCK_GUARD(&iohub->irq_level_lock[pirq]);
64 
65     if (level) {
66         if (++iohub->irq_level[pirq] == 1) {
67             event_notifier_set(&iohub->irqfds[pirq]);
68         }
69     } else if (iohub->irq_level[pirq] > 0) {
70         iohub->irq_level[pirq]--;
71     }
72 }
73 
74 static void intr_resample_handler(void *opaque)
75 {
76     ResampleToken *token = opaque;
77     RemoteIOHubState *iohub = token->iohub;
78     int pirq, s;
79 
80     pirq = token->pirq;
81 
82     s = event_notifier_test_and_clear(&iohub->resamplefds[pirq]);
83 
84     assert(s >= 0);
85 
86     QEMU_LOCK_GUARD(&iohub->irq_level_lock[pirq]);
87 
88     if (iohub->irq_level[pirq]) {
89         event_notifier_set(&iohub->irqfds[pirq]);
90     }
91 }
92 
93 void process_set_irqfd_msg(PCIDevice *pci_dev, MPQemuMsg *msg)
94 {
95     RemoteMachineState *machine = REMOTE_MACHINE(current_machine);
96     RemoteIOHubState *iohub = &machine->iohub;
97     int pirq, intx;
98 
99     intx = pci_get_byte(pci_dev->config + PCI_INTERRUPT_PIN) - 1;
100 
101     pirq = remote_iohub_map_irq(pci_dev, intx);
102 
103     if (event_notifier_get_fd(&iohub->irqfds[pirq]) != -1) {
104         qemu_set_fd_handler(event_notifier_get_fd(&iohub->resamplefds[pirq]),
105                             NULL, NULL, NULL);
106         event_notifier_cleanup(&iohub->irqfds[pirq]);
107         event_notifier_cleanup(&iohub->resamplefds[pirq]);
108         memset(&iohub->token[pirq], 0, sizeof(ResampleToken));
109     }
110 
111     event_notifier_init_fd(&iohub->irqfds[pirq], msg->fds[0]);
112     event_notifier_init_fd(&iohub->resamplefds[pirq], msg->fds[1]);
113 
114     iohub->token[pirq].iohub = iohub;
115     iohub->token[pirq].pirq = pirq;
116 
117     qemu_set_fd_handler(msg->fds[1], intr_resample_handler, NULL,
118                         &iohub->token[pirq]);
119 }
120