xref: /openbmc/qemu/hw/char/spapr_vty.c (revision 3aff6c2f)
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     qemu_chr_accept_input(dev->chardev);
51 
52     return n;
53 }
54 
55 void vty_putchars(VIOsPAPRDevice *sdev, uint8_t *buf, int len)
56 {
57     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(sdev);
58 
59     /* FIXME: should check the qemu_chr_fe_write() return value */
60     qemu_chr_fe_write(dev->chardev, buf, len);
61 }
62 
63 static int spapr_vty_init(VIOsPAPRDevice *sdev)
64 {
65     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(sdev);
66 
67     if (!dev->chardev) {
68         fprintf(stderr, "spapr-vty: Can't create vty without a chardev!\n");
69         exit(1);
70     }
71 
72     qemu_chr_add_handlers(dev->chardev, vty_can_receive,
73                           vty_receive, NULL, dev);
74 
75     return 0;
76 }
77 
78 /* Forward declaration */
79 static target_ulong h_put_term_char(PowerPCCPU *cpu, sPAPREnvironment *spapr,
80                                     target_ulong opcode, target_ulong *args)
81 {
82     target_ulong reg = args[0];
83     target_ulong len = args[1];
84     target_ulong char0_7 = args[2];
85     target_ulong char8_15 = args[3];
86     VIOsPAPRDevice *sdev;
87     uint8_t buf[16];
88 
89     sdev = vty_lookup(spapr, reg);
90     if (!sdev) {
91         return H_PARAMETER;
92     }
93 
94     if (len > 16) {
95         return H_PARAMETER;
96     }
97 
98     *((uint64_t *)buf) = cpu_to_be64(char0_7);
99     *((uint64_t *)buf + 1) = cpu_to_be64(char8_15);
100 
101     vty_putchars(sdev, buf, len);
102 
103     return H_SUCCESS;
104 }
105 
106 static target_ulong h_get_term_char(PowerPCCPU *cpu, sPAPREnvironment *spapr,
107                                     target_ulong opcode, target_ulong *args)
108 {
109     target_ulong reg = args[0];
110     target_ulong *len = args + 0;
111     target_ulong *char0_7 = args + 1;
112     target_ulong *char8_15 = args + 2;
113     VIOsPAPRDevice *sdev;
114     uint8_t buf[16];
115 
116     sdev = vty_lookup(spapr, reg);
117     if (!sdev) {
118         return H_PARAMETER;
119     }
120 
121     *len = vty_getchars(sdev, buf, sizeof(buf));
122     if (*len < 16) {
123         memset(buf + *len, 0, 16 - *len);
124     }
125 
126     *char0_7 = be64_to_cpu(*((uint64_t *)buf));
127     *char8_15 = be64_to_cpu(*((uint64_t *)buf + 1));
128 
129     return H_SUCCESS;
130 }
131 
132 void spapr_vty_create(VIOsPAPRBus *bus, CharDriverState *chardev)
133 {
134     DeviceState *dev;
135 
136     dev = qdev_create(&bus->bus, "spapr-vty");
137     qdev_prop_set_chr(dev, "chardev", chardev);
138     qdev_init_nofail(dev);
139 }
140 
141 static Property spapr_vty_properties[] = {
142     DEFINE_SPAPR_PROPERTIES(VIOsPAPRVTYDevice, sdev),
143     DEFINE_PROP_CHR("chardev", VIOsPAPRVTYDevice, chardev),
144     DEFINE_PROP_END_OF_LIST(),
145 };
146 
147 static const VMStateDescription vmstate_spapr_vty = {
148     .name = "spapr_vty",
149     .version_id = 1,
150     .minimum_version_id = 1,
151     .fields = (VMStateField[]) {
152         VMSTATE_SPAPR_VIO(sdev, VIOsPAPRVTYDevice),
153 
154         VMSTATE_UINT32(in, VIOsPAPRVTYDevice),
155         VMSTATE_UINT32(out, VIOsPAPRVTYDevice),
156         VMSTATE_BUFFER(buf, VIOsPAPRVTYDevice),
157         VMSTATE_END_OF_LIST()
158     },
159 };
160 
161 static void spapr_vty_class_init(ObjectClass *klass, void *data)
162 {
163     DeviceClass *dc = DEVICE_CLASS(klass);
164     VIOsPAPRDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
165 
166     k->init = spapr_vty_init;
167     k->dt_name = "vty";
168     k->dt_type = "serial";
169     k->dt_compatible = "hvterm1";
170     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
171     dc->props = spapr_vty_properties;
172     dc->vmsd = &vmstate_spapr_vty;
173 }
174 
175 static const TypeInfo spapr_vty_info = {
176     .name          = TYPE_VIO_SPAPR_VTY_DEVICE,
177     .parent        = TYPE_VIO_SPAPR_DEVICE,
178     .instance_size = sizeof(VIOsPAPRVTYDevice),
179     .class_init    = spapr_vty_class_init,
180 };
181 
182 VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus)
183 {
184     VIOsPAPRDevice *sdev, *selected;
185     BusChild *kid;
186 
187     /*
188      * To avoid the console bouncing around we want one VTY to be
189      * the "default". We haven't really got anything to go on, so
190      * arbitrarily choose the one with the lowest reg value.
191      */
192 
193     selected = NULL;
194     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
195         DeviceState *iter = kid->child;
196 
197         /* Only look at VTY devices */
198         if (!object_dynamic_cast(OBJECT(iter), "spapr-vty")) {
199             continue;
200         }
201 
202         sdev = VIO_SPAPR_DEVICE(iter);
203 
204         /* First VTY we've found, so it is selected for now */
205         if (!selected) {
206             selected = sdev;
207             continue;
208         }
209 
210         /* Choose VTY with lowest reg value */
211         if (sdev->reg < selected->reg) {
212             selected = sdev;
213         }
214     }
215 
216     return selected;
217 }
218 
219 VIOsPAPRDevice *vty_lookup(sPAPREnvironment *spapr, target_ulong reg)
220 {
221     VIOsPAPRDevice *sdev;
222 
223     sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
224     if (!sdev && reg == 0) {
225         /* Hack for kernel early debug, which always specifies reg==0.
226          * We search all VIO devices, and grab the vty with the lowest
227          * reg.  This attempts to mimic existing PowerVM behaviour
228          * (early debug does work there, despite having no vty with
229          * reg==0. */
230         return spapr_vty_get_default(spapr->vio_bus);
231     }
232 
233     return sdev;
234 }
235 
236 static void spapr_vty_register_types(void)
237 {
238     spapr_register_hypercall(H_PUT_TERM_CHAR, h_put_term_char);
239     spapr_register_hypercall(H_GET_TERM_CHAR, h_get_term_char);
240     type_register_static(&spapr_vty_info);
241 }
242 
243 type_init(spapr_vty_register_types)
244