xref: /openbmc/qemu/hw/char/spapr_vty.c (revision fee5b753) 
1 #include "qemu/osdep.h"
2 #include "hw/qdev.h"
3 #include "sysemu/char.h"
4 #include "hw/ppc/spapr.h"
5 #include "hw/ppc/spapr_vio.h"
6 
7 #define VTERM_BUFSIZE   16
8 
9 typedef struct VIOsPAPRVTYDevice {
10     VIOsPAPRDevice sdev;
11     CharDriverState *chardev;
12     uint32_t in, out;
13     uint8_t buf[VTERM_BUFSIZE];
14 } VIOsPAPRVTYDevice;
15 
16 #define TYPE_VIO_SPAPR_VTY_DEVICE "spapr-vty"
17 #define VIO_SPAPR_VTY_DEVICE(obj) \
18      OBJECT_CHECK(VIOsPAPRVTYDevice, (obj), TYPE_VIO_SPAPR_VTY_DEVICE)
19 
20 static int vty_can_receive(void *opaque)
21 {
22     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(opaque);
23 
24     return (dev->in - dev->out) < VTERM_BUFSIZE;
25 }
26 
27 static void vty_receive(void *opaque, const uint8_t *buf, int size)
28 {
29     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(opaque);
30     int i;
31 
32     if ((dev->in == dev->out) && size) {
33         /* toggle line to simulate edge interrupt */
34         qemu_irq_pulse(spapr_vio_qirq(&dev->sdev));
35     }
36     for (i = 0; i < size; i++) {
37         assert((dev->in - dev->out) < VTERM_BUFSIZE);
38         dev->buf[dev->in++ % VTERM_BUFSIZE] = buf[i];
39     }
40 }
41 
42 static int vty_getchars(VIOsPAPRDevice *sdev, uint8_t *buf, int max)
43 {
44     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(sdev);
45     int n = 0;
46 
47     while ((n < max) && (dev->out != dev->in)) {
48         buf[n++] = dev->buf[dev->out++ % VTERM_BUFSIZE];
49     }
50 
51     qemu_chr_accept_input(dev->chardev);
52 
53     return n;
54 }
55 
56 void vty_putchars(VIOsPAPRDevice *sdev, uint8_t *buf, int len)
57 {
58     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(sdev);
59 
60     /* FIXME: should check the qemu_chr_fe_write() return value */
61     qemu_chr_fe_write(dev->chardev, buf, len);
62 }
63 
64 static void spapr_vty_realize(VIOsPAPRDevice *sdev, Error **errp)
65 {
66     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(sdev);
67 
68     if (!dev->chardev) {
69         error_setg(errp, "chardev property not set");
70         return;
71     }
72 
73     qemu_chr_add_handlers(dev->chardev, vty_can_receive,
74                           vty_receive, NULL, dev);
75 }
76 
77 /* Forward declaration */
78 static target_ulong h_put_term_char(PowerPCCPU *cpu, sPAPRMachineState *spapr,
79                                     target_ulong opcode, target_ulong *args)
80 {
81     target_ulong reg = args[0];
82     target_ulong len = args[1];
83     target_ulong char0_7 = args[2];
84     target_ulong char8_15 = args[3];
85     VIOsPAPRDevice *sdev;
86     uint8_t buf[16];
87 
88     sdev = vty_lookup(spapr, reg);
89     if (!sdev) {
90         return H_PARAMETER;
91     }
92 
93     if (len > 16) {
94         return H_PARAMETER;
95     }
96 
97     *((uint64_t *)buf) = cpu_to_be64(char0_7);
98     *((uint64_t *)buf + 1) = cpu_to_be64(char8_15);
99 
100     vty_putchars(sdev, buf, len);
101 
102     return H_SUCCESS;
103 }
104 
105 static target_ulong h_get_term_char(PowerPCCPU *cpu, sPAPRMachineState *spapr,
106                                     target_ulong opcode, target_ulong *args)
107 {
108     target_ulong reg = args[0];
109     target_ulong *len = args + 0;
110     target_ulong *char0_7 = args + 1;
111     target_ulong *char8_15 = args + 2;
112     VIOsPAPRDevice *sdev;
113     uint8_t buf[16];
114 
115     sdev = vty_lookup(spapr, reg);
116     if (!sdev) {
117         return H_PARAMETER;
118     }
119 
120     *len = vty_getchars(sdev, buf, sizeof(buf));
121     if (*len < 16) {
122         memset(buf + *len, 0, 16 - *len);
123     }
124 
125     *char0_7 = be64_to_cpu(*((uint64_t *)buf));
126     *char8_15 = be64_to_cpu(*((uint64_t *)buf + 1));
127 
128     return H_SUCCESS;
129 }
130 
131 void spapr_vty_create(VIOsPAPRBus *bus, CharDriverState *chardev)
132 {
133     DeviceState *dev;
134 
135     dev = qdev_create(&bus->bus, "spapr-vty");
136     qdev_prop_set_chr(dev, "chardev", chardev);
137     qdev_init_nofail(dev);
138 }
139 
140 static Property spapr_vty_properties[] = {
141     DEFINE_SPAPR_PROPERTIES(VIOsPAPRVTYDevice, sdev),
142     DEFINE_PROP_CHR("chardev", VIOsPAPRVTYDevice, chardev),
143     DEFINE_PROP_END_OF_LIST(),
144 };
145 
146 static const VMStateDescription vmstate_spapr_vty = {
147     .name = "spapr_vty",
148     .version_id = 1,
149     .minimum_version_id = 1,
150     .fields = (VMStateField[]) {
151         VMSTATE_SPAPR_VIO(sdev, VIOsPAPRVTYDevice),
152 
153         VMSTATE_UINT32(in, VIOsPAPRVTYDevice),
154         VMSTATE_UINT32(out, VIOsPAPRVTYDevice),
155         VMSTATE_BUFFER(buf, VIOsPAPRVTYDevice),
156         VMSTATE_END_OF_LIST()
157     },
158 };
159 
160 static void spapr_vty_class_init(ObjectClass *klass, void *data)
161 {
162     DeviceClass *dc = DEVICE_CLASS(klass);
163     VIOsPAPRDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
164 
165     k->realize = spapr_vty_realize;
166     k->dt_name = "vty";
167     k->dt_type = "serial";
168     k->dt_compatible = "hvterm1";
169     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
170     dc->props = spapr_vty_properties;
171     dc->vmsd = &vmstate_spapr_vty;
172 }
173 
174 static const TypeInfo spapr_vty_info = {
175     .name          = TYPE_VIO_SPAPR_VTY_DEVICE,
176     .parent        = TYPE_VIO_SPAPR_DEVICE,
177     .instance_size = sizeof(VIOsPAPRVTYDevice),
178     .class_init    = spapr_vty_class_init,
179 };
180 
181 VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus)
182 {
183     VIOsPAPRDevice *sdev, *selected;
184     BusChild *kid;
185 
186     /*
187      * To avoid the console bouncing around we want one VTY to be
188      * the "default". We haven't really got anything to go on, so
189      * arbitrarily choose the one with the lowest reg value.
190      */
191 
192     selected = NULL;
193     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
194         DeviceState *iter = kid->child;
195 
196         /* Only look at VTY devices */
197         if (!object_dynamic_cast(OBJECT(iter), TYPE_VIO_SPAPR_VTY_DEVICE)) {
198             continue;
199         }
200 
201         sdev = VIO_SPAPR_DEVICE(iter);
202 
203         /* First VTY we've found, so it is selected for now */
204         if (!selected) {
205             selected = sdev;
206             continue;
207         }
208 
209         /* Choose VTY with lowest reg value */
210         if (sdev->reg < selected->reg) {
211             selected = sdev;
212         }
213     }
214 
215     return selected;
216 }
217 
218 VIOsPAPRDevice *vty_lookup(sPAPRMachineState *spapr, target_ulong reg)
219 {
220     VIOsPAPRDevice *sdev;
221 
222     sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
223     if (!sdev && reg == 0) {
224         /* Hack for kernel early debug, which always specifies reg==0.
225          * We search all VIO devices, and grab the vty with the lowest
226          * reg.  This attempts to mimic existing PowerVM behaviour
227          * (early debug does work there, despite having no vty with
228          * reg==0. */
229         return spapr_vty_get_default(spapr->vio_bus);
230     }
231 
232     if (!object_dynamic_cast(OBJECT(sdev), TYPE_VIO_SPAPR_VTY_DEVICE)) {
233         return NULL;
234     }
235 
236     return sdev;
237 }
238 
239 static void spapr_vty_register_types(void)
240 {
241     spapr_register_hypercall(H_PUT_TERM_CHAR, h_put_term_char);
242     spapr_register_hypercall(H_GET_TERM_CHAR, h_get_term_char);
243     type_register_static(&spapr_vty_info);
244 }
245 
246 type_init(spapr_vty_register_types)
247