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(dev->sdev.qirq);
  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 VIOsPAPRDevice *vty_lookup(sPAPREnvironment *spapr, target_ulong reg);
  74
  75 static target_ulong h_put_term_char(CPUState *env, sPAPREnvironment *spapr,
  76                                     target_ulong opcode, target_ulong *args)
  77 {
  78     target_ulong reg = args[0];
  79     target_ulong len = args[1];
  80     target_ulong char0_7 = args[2];
  81     target_ulong char8_15 = args[3];
  82     VIOsPAPRDevice *sdev;
  83     uint8_t buf[16];
  84
  85     sdev = vty_lookup(spapr, reg);
  86     if (!sdev) {
  87         return H_PARAMETER;
  88     }
  89
  90     if (len > 16) {
  91         return H_PARAMETER;
  92     }
  93
  94     *((uint64_t *)buf) = cpu_to_be64(char0_7);
  95     *((uint64_t *)buf + 1) = cpu_to_be64(char8_15);
  96
  97     vty_putchars(sdev, buf, len);
  98
  99     return H_SUCCESS;
 100 }
 101
 102 static target_ulong h_get_term_char(CPUState *env, sPAPREnvironment *spapr,
 103                                     target_ulong opcode, target_ulong *args)
 104 {
 105     target_ulong reg = args[0];
 106     target_ulong *len = args + 0;
 107     target_ulong *char0_7 = args + 1;
 108     target_ulong *char8_15 = args + 2;
 109     VIOsPAPRDevice *sdev;
 110     uint8_t buf[16];
 111
 112     sdev = vty_lookup(spapr, reg);
 113     if (!sdev) {
 114         return H_PARAMETER;
 115     }
 116
 117     *len = vty_getchars(sdev, buf, sizeof(buf));
 118     if (*len < 16) {
 119         memset(buf + *len, 0, 16 - *len);
 120     }
 121
 122     *char0_7 = be64_to_cpu(*((uint64_t *)buf));
 123     *char8_15 = be64_to_cpu(*((uint64_t *)buf + 1));
 124
 125     return H_SUCCESS;
 126 }
 127
 128 void spapr_vty_create(VIOsPAPRBus *bus, uint32_t reg, CharDriverState *chardev)
 129 {
 130     DeviceState *dev;
 131
 132     dev = qdev_create(&bus->bus, "spapr-vty");
 133     qdev_prop_set_uint32(dev, "reg", reg);
 134     qdev_prop_set_chr(dev, "chardev", chardev);
 135     qdev_init_nofail(dev);
 136 }
 137
 138 static Property spapr_vty_properties[] = {
 139     DEFINE_SPAPR_PROPERTIES(VIOsPAPRVTYDevice, sdev, SPAPR_VTY_BASE_ADDRESS, 0),
 140     DEFINE_PROP_CHR("chardev", VIOsPAPRVTYDevice, chardev),
 141     DEFINE_PROP_END_OF_LIST(),
 142 };
 143
 144 static void spapr_vty_class_init(ObjectClass *klass, void *data)
 145 {
 146     VIOsPAPRDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
 147
 148     k->init = spapr_vty_init;
 149     k->dt_name = "vty";
 150     k->dt_type = "serial";
 151     k->dt_compatible = "hvterm1";
 152 }
 153
 154 static DeviceInfo spapr_vty_info = {
 155     .name = "spapr-vty",
 156     .size = sizeof(VIOsPAPRVTYDevice),
 157     .props = spapr_vty_properties,
 158     .class_init = spapr_vty_class_init,
 159 };
 160
 161 VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus)
 162 {
 163     VIOsPAPRDevice *sdev, *selected;
 164     DeviceState *iter;
 165
 166     /*
 167      * To avoid the console bouncing around we want one VTY to be
 168      * the "default". We haven't really got anything to go on, so
 169      * arbitrarily choose the one with the lowest reg value.
 170      */
 171
 172     selected = NULL;
 173     QTAILQ_FOREACH(iter, &bus->bus.children, sibling) {
 174         /* Only look at VTY devices */
 175         if (!object_dynamic_cast(OBJECT(iter), "spapr-vty")) {
 176             continue;
 177         }
 178
 179         sdev = DO_UPCAST(VIOsPAPRDevice, qdev, iter);
 180
 181         /* First VTY we've found, so it is selected for now */
 182         if (!selected) {
 183             selected = sdev;
 184             continue;
 185         }
 186
 187         /* Choose VTY with lowest reg value */
 188         if (sdev->reg < selected->reg) {
 189             selected = sdev;
 190         }
 191     }
 192
 193     return selected;
 194 }
 195
 196 static VIOsPAPRDevice *vty_lookup(sPAPREnvironment *spapr, target_ulong reg)
 197 {
 198     VIOsPAPRDevice *sdev;
 199
 200     sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 201     if (!sdev && reg == 0) {
 202         /* Hack for kernel early debug, which always specifies reg==0.
 203          * We search all VIO devices, and grab the vty with the lowest
 204          * reg.  This attempts to mimic existing PowerVM behaviour
 205          * (early debug does work there, despite having no vty with
 206          * reg==0. */
 207         return spapr_vty_get_default(spapr->vio_bus);
 208     }
 209
 210     return sdev;
 211 }
 212
 213 static void spapr_vty_register(void)
 214 {
 215     spapr_register_hypercall(H_PUT_TERM_CHAR, h_put_term_char);
 216     spapr_register_hypercall(H_GET_TERM_CHAR, h_get_term_char);
 217     spapr_vio_bus_register_withprop(&spapr_vty_info);
 218 }
 219 device_init(spapr_vty_register);