hw/spapr_vty.c

   1 #include "qdev.h"
   2 #include "qemu-char.h"
   3 #include "hw/spapr.h"
   4 #include "hw/spapr_vio.h"
   5
   6 #define VTERM_BUFSIZE   16
   7
   8 typedef struct VIOsPAPRVTYDevice {
   9     VIOsPAPRDevice sdev;
  10     CharDriverState *chardev;
  11     uint32_t in, out;
  12     uint8_t buf[VTERM_BUFSIZE];
  13 } VIOsPAPRVTYDevice;
  14
  15 static int vty_can_receive(void *opaque)
  16 {
  17     VIOsPAPRVTYDevice *dev = (VIOsPAPRVTYDevice *)opaque;
  18
  19     return (dev->in - dev->out) < VTERM_BUFSIZE;
  20 }
  21
  22 static void vty_receive(void *opaque, const uint8_t *buf, int size)
  23 {
  24     VIOsPAPRVTYDevice *dev = (VIOsPAPRVTYDevice *)opaque;
  25     int i;
  26
  27     if ((dev->in == dev->out) && size) {
  28         /* toggle line to simulate edge interrupt */
  29         qemu_irq_pulse(spapr_vio_qirq(&dev->sdev));
  30     }
  31     for (i = 0; i < size; i++) {
  32         assert((dev->in - dev->out) < VTERM_BUFSIZE);
  33         dev->buf[dev->in++ % VTERM_BUFSIZE] = buf[i];
  34     }
  35 }
  36
  37 static int vty_getchars(VIOsPAPRDevice *sdev, uint8_t *buf, int max)
  38 {
  39     VIOsPAPRVTYDevice *dev = (VIOsPAPRVTYDevice *)sdev;
  40     int n = 0;
  41
  42     while ((n < max) && (dev->out != dev->in)) {
  43         buf[n++] = dev->buf[dev->out++ % VTERM_BUFSIZE];
  44     }
  45
  46     return n;
  47 }
  48
  49 void vty_putchars(VIOsPAPRDevice *sdev, uint8_t *buf, int len)
  50 {
  51     VIOsPAPRVTYDevice *dev = (VIOsPAPRVTYDevice *)sdev;
  52
  53     /* FIXME: should check the qemu_chr_fe_write() return value */
  54     qemu_chr_fe_write(dev->chardev, buf, len);
  55 }
  56
  57 static int spapr_vty_init(VIOsPAPRDevice *sdev)
  58 {
  59     VIOsPAPRVTYDevice *dev = (VIOsPAPRVTYDevice *)sdev;
  60
  61     if (!dev->chardev) {
  62         fprintf(stderr, "spapr-vty: Can't create vty without a chardev!\n");
  63         exit(1);
  64     }
  65
  66     qemu_chr_add_handlers(dev->chardev, vty_can_receive,
  67                           vty_receive, NULL, dev);
  68
  69     return 0;
  70 }
  71
  72 /* Forward declaration */
  73 static target_ulong h_put_term_char(PowerPCCPU *cpu, sPAPREnvironment *spapr,
  74                                     target_ulong opcode, target_ulong *args)
  75 {
  76     target_ulong reg = args[0];
  77     target_ulong len = args[1];
  78     target_ulong char0_7 = args[2];
  79     target_ulong char8_15 = args[3];
  80     VIOsPAPRDevice *sdev;
  81     uint8_t buf[16];
  82
  83     sdev = vty_lookup(spapr, reg);
  84     if (!sdev) {
  85         return H_PARAMETER;
  86     }
  87
  88     if (len > 16) {
  89         return H_PARAMETER;
  90     }
  91
  92     *((uint64_t *)buf) = cpu_to_be64(char0_7);
  93     *((uint64_t *)buf + 1) = cpu_to_be64(char8_15);
  94
  95     vty_putchars(sdev, buf, len);
  96
  97     return H_SUCCESS;
  98 }
  99
 100 static target_ulong h_get_term_char(PowerPCCPU *cpu, sPAPREnvironment *spapr,
 101                                     target_ulong opcode, target_ulong *args)
 102 {
 103     target_ulong reg = args[0];
 104     target_ulong *len = args + 0;
 105     target_ulong *char0_7 = args + 1;
 106     target_ulong *char8_15 = args + 2;
 107     VIOsPAPRDevice *sdev;
 108     uint8_t buf[16];
 109
 110     sdev = vty_lookup(spapr, reg);
 111     if (!sdev) {
 112         return H_PARAMETER;
 113     }
 114
 115     *len = vty_getchars(sdev, buf, sizeof(buf));
 116     if (*len < 16) {
 117         memset(buf + *len, 0, 16 - *len);
 118     }
 119
 120     *char0_7 = be64_to_cpu(*((uint64_t *)buf));
 121     *char8_15 = be64_to_cpu(*((uint64_t *)buf + 1));
 122
 123     return H_SUCCESS;
 124 }
 125
 126 void spapr_vty_create(VIOsPAPRBus *bus, CharDriverState *chardev)
 127 {
 128     DeviceState *dev;
 129
 130     dev = qdev_create(&bus->bus, "spapr-vty");
 131     qdev_prop_set_chr(dev, "chardev", chardev);
 132     qdev_init_nofail(dev);
 133 }
 134
 135 static Property spapr_vty_properties[] = {
 136     DEFINE_SPAPR_PROPERTIES(VIOsPAPRVTYDevice, sdev),
 137     DEFINE_PROP_CHR("chardev", VIOsPAPRVTYDevice, chardev),
 138     DEFINE_PROP_END_OF_LIST(),
 139 };
 140
 141 static void spapr_vty_class_init(ObjectClass *klass, void *data)
 142 {
 143     DeviceClass *dc = DEVICE_CLASS(klass);
 144     VIOsPAPRDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
 145
 146     k->init = spapr_vty_init;
 147     k->dt_name = "vty";
 148     k->dt_type = "serial";
 149     k->dt_compatible = "hvterm1";
 150     dc->props = spapr_vty_properties;
 151 }
 152
 153 static TypeInfo spapr_vty_info = {
 154     .name          = "spapr-vty",
 155     .parent        = TYPE_VIO_SPAPR_DEVICE,
 156     .instance_size = sizeof(VIOsPAPRVTYDevice),
 157     .class_init    = spapr_vty_class_init,
 158 };
 159
 160 VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus)
 161 {
 162     VIOsPAPRDevice *sdev, *selected;
 163     BusChild *kid;
 164
 165     /*
 166      * To avoid the console bouncing around we want one VTY to be
 167      * the "default". We haven't really got anything to go on, so
 168      * arbitrarily choose the one with the lowest reg value.
 169      */
 170
 171     selected = NULL;
 172     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
 173         DeviceState *iter = kid->child;
 174
 175         /* Only look at VTY devices */
 176         if (!object_dynamic_cast(OBJECT(iter), "spapr-vty")) {
 177             continue;
 178         }
 179
 180         sdev = DO_UPCAST(VIOsPAPRDevice, qdev, iter);
 181
 182         /* First VTY we've found, so it is selected for now */
 183         if (!selected) {
 184             selected = sdev;
 185             continue;
 186         }
 187
 188         /* Choose VTY with lowest reg value */
 189         if (sdev->reg < selected->reg) {
 190             selected = sdev;
 191         }
 192     }
 193
 194     return selected;
 195 }
 196
 197 VIOsPAPRDevice *vty_lookup(sPAPREnvironment *spapr, target_ulong reg)
 198 {
 199     VIOsPAPRDevice *sdev;
 200
 201     sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 202     if (!sdev && reg == 0) {
 203         /* Hack for kernel early debug, which always specifies reg==0.
 204          * We search all VIO devices, and grab the vty with the lowest
 205          * reg.  This attempts to mimic existing PowerVM behaviour
 206          * (early debug does work there, despite having no vty with
 207          * reg==0. */
 208         return spapr_vty_get_default(spapr->vio_bus);
 209     }
 210
 211     return sdev;
 212 }
 213
 214 static void spapr_vty_register_types(void)
 215 {
 216     spapr_register_hypercall(H_PUT_TERM_CHAR, h_put_term_char);
 217     spapr_register_hypercall(H_GET_TERM_CHAR, h_get_term_char);
 218     type_register_static(&spapr_vty_info);
 219 }
 220
 221 type_init(spapr_vty_register_types)