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