hw/char/spapr_vty.c

   1 #include "qemu/osdep.h"
   2 #include "qemu/error-report.h"
   3 #include "qapi/error.h"
   4 #include "qemu-common.h"
   5 #include "cpu.h"
   6 #include "hw/qdev.h"
   7 #include "chardev/char-fe.h"
   8 #include "hw/ppc/spapr.h"
   9 #include "hw/ppc/spapr_vio.h"
  10
  11 #define VTERM_BUFSIZE   16
  12
  13 typedef struct VIOsPAPRVTYDevice {
  14     VIOsPAPRDevice sdev;
  15     CharBackend chardev;
  16     uint32_t in, out;
  17     uint8_t buf[VTERM_BUFSIZE];
  18 } VIOsPAPRVTYDevice;
  19
  20 #define TYPE_VIO_SPAPR_VTY_DEVICE "spapr-vty"
  21 #define VIO_SPAPR_VTY_DEVICE(obj) \
  22      OBJECT_CHECK(VIOsPAPRVTYDevice, (obj), TYPE_VIO_SPAPR_VTY_DEVICE)
  23
  24 static int vty_can_receive(void *opaque)
  25 {
  26     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(opaque);
  27
  28     return VTERM_BUFSIZE - (dev->in - dev->out);
  29 }
  30
  31 static void vty_receive(void *opaque, const uint8_t *buf, int size)
  32 {
  33     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(opaque);
  34     int i;
  35
  36     if ((dev->in == dev->out) && size) {
  37         /* toggle line to simulate edge interrupt */
  38         qemu_irq_pulse(spapr_vio_qirq(&dev->sdev));
  39     }
  40     for (i = 0; i < size; i++) {
  41         if (dev->in - dev->out >= VTERM_BUFSIZE) {
  42             static bool reported;
  43             if (!reported) {
  44                 error_report("VTY input buffer exhausted - characters dropped."
  45                              " (input size = %i)", size);
  46                 reported = true;
  47             }
  48             break;
  49         }
  50         dev->buf[dev->in++ % VTERM_BUFSIZE] = buf[i];
  51     }
  52 }
  53
  54 static int vty_getchars(VIOsPAPRDevice *sdev, uint8_t *buf, int max)
  55 {
  56     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(sdev);
  57     int n = 0;
  58
  59     while ((n < max) && (dev->out != dev->in)) {
  60         buf[n++] = dev->buf[dev->out++ % VTERM_BUFSIZE];
  61     }
  62
  63     qemu_chr_fe_accept_input(&dev->chardev);
  64
  65     return n;
  66 }
  67
  68 void vty_putchars(VIOsPAPRDevice *sdev, uint8_t *buf, int len)
  69 {
  70     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(sdev);
  71
  72     /* XXX this blocks entire thread. Rewrite to use
  73      * qemu_chr_fe_write and background I/O callbacks */
  74     qemu_chr_fe_write_all(&dev->chardev, buf, len);
  75 }
  76
  77 static void spapr_vty_realize(VIOsPAPRDevice *sdev, Error **errp)
  78 {
  79     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(sdev);
  80
  81     if (!qemu_chr_fe_get_driver(&dev->chardev)) {
  82         error_setg(errp, "chardev property not set");
  83         return;
  84     }
  85
  86     qemu_chr_fe_set_handlers(&dev->chardev, vty_can_receive,
  87                              vty_receive, NULL, dev, NULL, true);
  88 }
  89
  90 /* Forward declaration */
  91 static target_ulong h_put_term_char(PowerPCCPU *cpu, sPAPRMachineState *spapr,
  92                                     target_ulong opcode, target_ulong *args)
  93 {
  94     target_ulong reg = args[0];
  95     target_ulong len = args[1];
  96     target_ulong char0_7 = args[2];
  97     target_ulong char8_15 = args[3];
  98     VIOsPAPRDevice *sdev;
  99     uint8_t buf[16];
 100
 101     sdev = vty_lookup(spapr, reg);
 102     if (!sdev) {
 103         return H_PARAMETER;
 104     }
 105
 106     if (len > 16) {
 107         return H_PARAMETER;
 108     }
 109
 110     *((uint64_t *)buf) = cpu_to_be64(char0_7);
 111     *((uint64_t *)buf + 1) = cpu_to_be64(char8_15);
 112
 113     vty_putchars(sdev, buf, len);
 114
 115     return H_SUCCESS;
 116 }
 117
 118 static target_ulong h_get_term_char(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 119                                     target_ulong opcode, target_ulong *args)
 120 {
 121     target_ulong reg = args[0];
 122     target_ulong *len = args + 0;
 123     target_ulong *char0_7 = args + 1;
 124     target_ulong *char8_15 = args + 2;
 125     VIOsPAPRDevice *sdev;
 126     uint8_t buf[16];
 127
 128     sdev = vty_lookup(spapr, reg);
 129     if (!sdev) {
 130         return H_PARAMETER;
 131     }
 132
 133     *len = vty_getchars(sdev, buf, sizeof(buf));
 134     if (*len < 16) {
 135         memset(buf + *len, 0, 16 - *len);
 136     }
 137
 138     *char0_7 = be64_to_cpu(*((uint64_t *)buf));
 139     *char8_15 = be64_to_cpu(*((uint64_t *)buf + 1));
 140
 141     return H_SUCCESS;
 142 }
 143
 144 void spapr_vty_create(VIOsPAPRBus *bus, Chardev *chardev)
 145 {
 146     DeviceState *dev;
 147
 148     dev = qdev_create(&bus->bus, "spapr-vty");
 149     qdev_prop_set_chr(dev, "chardev", chardev);
 150     qdev_init_nofail(dev);
 151 }
 152
 153 static Property spapr_vty_properties[] = {
 154     DEFINE_SPAPR_PROPERTIES(VIOsPAPRVTYDevice, sdev),
 155     DEFINE_PROP_CHR("chardev", VIOsPAPRVTYDevice, chardev),
 156     DEFINE_PROP_END_OF_LIST(),
 157 };
 158
 159 static const VMStateDescription vmstate_spapr_vty = {
 160     .name = "spapr_vty",
 161     .version_id = 1,
 162     .minimum_version_id = 1,
 163     .fields = (VMStateField[]) {
 164         VMSTATE_SPAPR_VIO(sdev, VIOsPAPRVTYDevice),
 165
 166         VMSTATE_UINT32(in, VIOsPAPRVTYDevice),
 167         VMSTATE_UINT32(out, VIOsPAPRVTYDevice),
 168         VMSTATE_BUFFER(buf, VIOsPAPRVTYDevice),
 169         VMSTATE_END_OF_LIST()
 170     },
 171 };
 172
 173 static void spapr_vty_class_init(ObjectClass *klass, void *data)
 174 {
 175     DeviceClass *dc = DEVICE_CLASS(klass);
 176     VIOsPAPRDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
 177
 178     k->realize = spapr_vty_realize;
 179     k->dt_name = "vty";
 180     k->dt_type = "serial";
 181     k->dt_compatible = "hvterm1";
 182     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 183     dc->props = spapr_vty_properties;
 184     dc->vmsd = &vmstate_spapr_vty;
 185 }
 186
 187 static const TypeInfo spapr_vty_info = {
 188     .name          = TYPE_VIO_SPAPR_VTY_DEVICE,
 189     .parent        = TYPE_VIO_SPAPR_DEVICE,
 190     .instance_size = sizeof(VIOsPAPRVTYDevice),
 191     .class_init    = spapr_vty_class_init,
 192 };
 193
 194 VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus)
 195 {
 196     VIOsPAPRDevice *sdev, *selected;
 197     BusChild *kid;
 198
 199     /*
 200      * To avoid the console bouncing around we want one VTY to be
 201      * the "default". We haven't really got anything to go on, so
 202      * arbitrarily choose the one with the lowest reg value.
 203      */
 204
 205     selected = NULL;
 206     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
 207         DeviceState *iter = kid->child;
 208
 209         /* Only look at VTY devices */
 210         if (!object_dynamic_cast(OBJECT(iter), TYPE_VIO_SPAPR_VTY_DEVICE)) {
 211             continue;
 212         }
 213
 214         sdev = VIO_SPAPR_DEVICE(iter);
 215
 216         /* First VTY we've found, so it is selected for now */
 217         if (!selected) {
 218             selected = sdev;
 219             continue;
 220         }
 221
 222         /* Choose VTY with lowest reg value */
 223         if (sdev->reg < selected->reg) {
 224             selected = sdev;
 225         }
 226     }
 227
 228     return selected;
 229 }
 230
 231 VIOsPAPRDevice *vty_lookup(sPAPRMachineState *spapr, target_ulong reg)
 232 {
 233     VIOsPAPRDevice *sdev;
 234
 235     sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 236     if (!sdev && reg == 0) {
 237         /* Hack for kernel early debug, which always specifies reg==0.
 238          * We search all VIO devices, and grab the vty with the lowest
 239          * reg.  This attempts to mimic existing PowerVM behaviour
 240          * (early debug does work there, despite having no vty with
 241          * reg==0. */
 242         return spapr_vty_get_default(spapr->vio_bus);
 243     }
 244
 245     if (!object_dynamic_cast(OBJECT(sdev), TYPE_VIO_SPAPR_VTY_DEVICE)) {
 246         return NULL;
 247     }
 248
 249     return sdev;
 250 }
 251
 252 static void spapr_vty_register_types(void)
 253 {
 254     spapr_register_hypercall(H_PUT_TERM_CHAR, h_put_term_char);
 255     spapr_register_hypercall(H_GET_TERM_CHAR, h_get_term_char);
 256     type_register_static(&spapr_vty_info);
 257 }
 258
 259 type_init(spapr_vty_register_types)