hw/remote/iohub.c

   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 }