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/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 }