xref: /openbmc/qemu/hw/char/spapr_vty.c (revision dccfcd0e)
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 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(spapr_vio_qirq(&dev->sdev));
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 target_ulong h_put_term_char(PowerPCCPU *cpu, sPAPREnvironment *spapr,
74                                     target_ulong opcode, target_ulong *args)
75 {
76     target_ulong reg = args[0];
77     target_ulong len = args[1];
78     target_ulong char0_7 = args[2];
79     target_ulong char8_15 = args[3];
80     VIOsPAPRDevice *sdev;
81     uint8_t buf[16];
82 
83     sdev = vty_lookup(spapr, reg);
84     if (!sdev) {
85         return H_PARAMETER;
86     }
87 
88     if (len > 16) {
89         return H_PARAMETER;
90     }
91 
92     *((uint64_t *)buf) = cpu_to_be64(char0_7);
93     *((uint64_t *)buf + 1) = cpu_to_be64(char8_15);
94 
95     vty_putchars(sdev, buf, len);
96 
97     return H_SUCCESS;
98 }
99 
100 static target_ulong h_get_term_char(PowerPCCPU *cpu, sPAPREnvironment *spapr,
101                                     target_ulong opcode, target_ulong *args)
102 {
103     target_ulong reg = args[0];
104     target_ulong *len = args + 0;
105     target_ulong *char0_7 = args + 1;
106     target_ulong *char8_15 = args + 2;
107     VIOsPAPRDevice *sdev;
108     uint8_t buf[16];
109 
110     sdev = vty_lookup(spapr, reg);
111     if (!sdev) {
112         return H_PARAMETER;
113     }
114 
115     *len = vty_getchars(sdev, buf, sizeof(buf));
116     if (*len < 16) {
117         memset(buf + *len, 0, 16 - *len);
118     }
119 
120     *char0_7 = be64_to_cpu(*((uint64_t *)buf));
121     *char8_15 = be64_to_cpu(*((uint64_t *)buf + 1));
122 
123     return H_SUCCESS;
124 }
125 
126 void spapr_vty_create(VIOsPAPRBus *bus, CharDriverState *chardev)
127 {
128     DeviceState *dev;
129 
130     dev = qdev_create(&bus->bus, "spapr-vty");
131     qdev_prop_set_chr(dev, "chardev", chardev);
132     qdev_init_nofail(dev);
133 }
134 
135 static Property spapr_vty_properties[] = {
136     DEFINE_SPAPR_PROPERTIES(VIOsPAPRVTYDevice, sdev),
137     DEFINE_PROP_CHR("chardev", VIOsPAPRVTYDevice, chardev),
138     DEFINE_PROP_END_OF_LIST(),
139 };
140 
141 static void spapr_vty_class_init(ObjectClass *klass, void *data)
142 {
143     DeviceClass *dc = DEVICE_CLASS(klass);
144     VIOsPAPRDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
145 
146     k->init = spapr_vty_init;
147     k->dt_name = "vty";
148     k->dt_type = "serial";
149     k->dt_compatible = "hvterm1";
150     dc->props = spapr_vty_properties;
151 }
152 
153 static const TypeInfo spapr_vty_info = {
154     .name          = "spapr-vty",
155     .parent        = TYPE_VIO_SPAPR_DEVICE,
156     .instance_size = sizeof(VIOsPAPRVTYDevice),
157     .class_init    = spapr_vty_class_init,
158 };
159 
160 VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus)
161 {
162     VIOsPAPRDevice *sdev, *selected;
163     BusChild *kid;
164 
165     /*
166      * To avoid the console bouncing around we want one VTY to be
167      * the "default". We haven't really got anything to go on, so
168      * arbitrarily choose the one with the lowest reg value.
169      */
170 
171     selected = NULL;
172     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
173         DeviceState *iter = kid->child;
174 
175         /* Only look at VTY devices */
176         if (!object_dynamic_cast(OBJECT(iter), "spapr-vty")) {
177             continue;
178         }
179 
180         sdev = DO_UPCAST(VIOsPAPRDevice, qdev, iter);
181 
182         /* First VTY we've found, so it is selected for now */
183         if (!selected) {
184             selected = sdev;
185             continue;
186         }
187 
188         /* Choose VTY with lowest reg value */
189         if (sdev->reg < selected->reg) {
190             selected = sdev;
191         }
192     }
193 
194     return selected;
195 }
196 
197 VIOsPAPRDevice *vty_lookup(sPAPREnvironment *spapr, target_ulong reg)
198 {
199     VIOsPAPRDevice *sdev;
200 
201     sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
202     if (!sdev && reg == 0) {
203         /* Hack for kernel early debug, which always specifies reg==0.
204          * We search all VIO devices, and grab the vty with the lowest
205          * reg.  This attempts to mimic existing PowerVM behaviour
206          * (early debug does work there, despite having no vty with
207          * reg==0. */
208         return spapr_vty_get_default(spapr->vio_bus);
209     }
210 
211     return sdev;
212 }
213 
214 static void spapr_vty_register_types(void)
215 {
216     spapr_register_hypercall(H_PUT_TERM_CHAR, h_put_term_char);
217     spapr_register_hypercall(H_GET_TERM_CHAR, h_get_term_char);
218     type_register_static(&spapr_vty_info);
219 }
220 
221 type_init(spapr_vty_register_types)
222