xref: /openbmc/qemu/hw/char/spapr_vty.c (revision 2993683b)
1 #include "hw/qdev.h"
2 #include "sysemu/char.h"
3 #include "hw/ppc/spapr.h"
4 #include "hw/ppc/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 #define TYPE_VIO_SPAPR_VTY_DEVICE "spapr-vty"
16 #define VIO_SPAPR_VTY_DEVICE(obj) \
17      OBJECT_CHECK(VIOsPAPRVTYDevice, (obj), TYPE_VIO_SPAPR_VTY_DEVICE)
18 
19 static int vty_can_receive(void *opaque)
20 {
21     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(opaque);
22 
23     return (dev->in - dev->out) < VTERM_BUFSIZE;
24 }
25 
26 static void vty_receive(void *opaque, const uint8_t *buf, int size)
27 {
28     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(opaque);
29     int i;
30 
31     if ((dev->in == dev->out) && size) {
32         /* toggle line to simulate edge interrupt */
33         qemu_irq_pulse(spapr_vio_qirq(&dev->sdev));
34     }
35     for (i = 0; i < size; i++) {
36         assert((dev->in - dev->out) < VTERM_BUFSIZE);
37         dev->buf[dev->in++ % VTERM_BUFSIZE] = buf[i];
38     }
39 }
40 
41 static int vty_getchars(VIOsPAPRDevice *sdev, uint8_t *buf, int max)
42 {
43     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(sdev);
44     int n = 0;
45 
46     while ((n < max) && (dev->out != dev->in)) {
47         buf[n++] = dev->buf[dev->out++ % VTERM_BUFSIZE];
48     }
49 
50     return n;
51 }
52 
53 void vty_putchars(VIOsPAPRDevice *sdev, uint8_t *buf, int len)
54 {
55     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(sdev);
56 
57     /* FIXME: should check the qemu_chr_fe_write() return value */
58     qemu_chr_fe_write(dev->chardev, buf, len);
59 }
60 
61 static int spapr_vty_init(VIOsPAPRDevice *sdev)
62 {
63     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(sdev);
64 
65     if (!dev->chardev) {
66         fprintf(stderr, "spapr-vty: Can't create vty without a chardev!\n");
67         exit(1);
68     }
69 
70     qemu_chr_add_handlers(dev->chardev, vty_can_receive,
71                           vty_receive, NULL, dev);
72 
73     return 0;
74 }
75 
76 /* Forward declaration */
77 static target_ulong h_put_term_char(PowerPCCPU *cpu, sPAPREnvironment *spapr,
78                                     target_ulong opcode, target_ulong *args)
79 {
80     target_ulong reg = args[0];
81     target_ulong len = args[1];
82     target_ulong char0_7 = args[2];
83     target_ulong char8_15 = args[3];
84     VIOsPAPRDevice *sdev;
85     uint8_t buf[16];
86 
87     sdev = vty_lookup(spapr, reg);
88     if (!sdev) {
89         return H_PARAMETER;
90     }
91 
92     if (len > 16) {
93         return H_PARAMETER;
94     }
95 
96     *((uint64_t *)buf) = cpu_to_be64(char0_7);
97     *((uint64_t *)buf + 1) = cpu_to_be64(char8_15);
98 
99     vty_putchars(sdev, buf, len);
100 
101     return H_SUCCESS;
102 }
103 
104 static target_ulong h_get_term_char(PowerPCCPU *cpu, sPAPREnvironment *spapr,
105                                     target_ulong opcode, target_ulong *args)
106 {
107     target_ulong reg = args[0];
108     target_ulong *len = args + 0;
109     target_ulong *char0_7 = args + 1;
110     target_ulong *char8_15 = args + 2;
111     VIOsPAPRDevice *sdev;
112     uint8_t buf[16];
113 
114     sdev = vty_lookup(spapr, reg);
115     if (!sdev) {
116         return H_PARAMETER;
117     }
118 
119     *len = vty_getchars(sdev, buf, sizeof(buf));
120     if (*len < 16) {
121         memset(buf + *len, 0, 16 - *len);
122     }
123 
124     *char0_7 = be64_to_cpu(*((uint64_t *)buf));
125     *char8_15 = be64_to_cpu(*((uint64_t *)buf + 1));
126 
127     return H_SUCCESS;
128 }
129 
130 void spapr_vty_create(VIOsPAPRBus *bus, CharDriverState *chardev)
131 {
132     DeviceState *dev;
133 
134     dev = qdev_create(&bus->bus, "spapr-vty");
135     qdev_prop_set_chr(dev, "chardev", chardev);
136     qdev_init_nofail(dev);
137 }
138 
139 static Property spapr_vty_properties[] = {
140     DEFINE_SPAPR_PROPERTIES(VIOsPAPRVTYDevice, sdev),
141     DEFINE_PROP_CHR("chardev", VIOsPAPRVTYDevice, chardev),
142     DEFINE_PROP_END_OF_LIST(),
143 };
144 
145 static void spapr_vty_class_init(ObjectClass *klass, void *data)
146 {
147     DeviceClass *dc = DEVICE_CLASS(klass);
148     VIOsPAPRDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
149 
150     k->init = spapr_vty_init;
151     k->dt_name = "vty";
152     k->dt_type = "serial";
153     k->dt_compatible = "hvterm1";
154     dc->props = spapr_vty_properties;
155 }
156 
157 static const TypeInfo spapr_vty_info = {
158     .name          = TYPE_VIO_SPAPR_VTY_DEVICE,
159     .parent        = TYPE_VIO_SPAPR_DEVICE,
160     .instance_size = sizeof(VIOsPAPRVTYDevice),
161     .class_init    = spapr_vty_class_init,
162 };
163 
164 VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus)
165 {
166     VIOsPAPRDevice *sdev, *selected;
167     BusChild *kid;
168 
169     /*
170      * To avoid the console bouncing around we want one VTY to be
171      * the "default". We haven't really got anything to go on, so
172      * arbitrarily choose the one with the lowest reg value.
173      */
174 
175     selected = NULL;
176     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
177         DeviceState *iter = kid->child;
178 
179         /* Only look at VTY devices */
180         if (!object_dynamic_cast(OBJECT(iter), "spapr-vty")) {
181             continue;
182         }
183 
184         sdev = VIO_SPAPR_DEVICE(iter);
185 
186         /* First VTY we've found, so it is selected for now */
187         if (!selected) {
188             selected = sdev;
189             continue;
190         }
191 
192         /* Choose VTY with lowest reg value */
193         if (sdev->reg < selected->reg) {
194             selected = sdev;
195         }
196     }
197 
198     return selected;
199 }
200 
201 VIOsPAPRDevice *vty_lookup(sPAPREnvironment *spapr, target_ulong reg)
202 {
203     VIOsPAPRDevice *sdev;
204 
205     sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
206     if (!sdev && reg == 0) {
207         /* Hack for kernel early debug, which always specifies reg==0.
208          * We search all VIO devices, and grab the vty with the lowest
209          * reg.  This attempts to mimic existing PowerVM behaviour
210          * (early debug does work there, despite having no vty with
211          * reg==0. */
212         return spapr_vty_get_default(spapr->vio_bus);
213     }
214 
215     return sdev;
216 }
217 
218 static void spapr_vty_register_types(void)
219 {
220     spapr_register_hypercall(H_PUT_TERM_CHAR, h_put_term_char);
221     spapr_register_hypercall(H_GET_TERM_CHAR, h_get_term_char);
222     type_register_static(&spapr_vty_info);
223 }
224 
225 type_init(spapr_vty_register_types)
226