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21#include <linux/console.h>
22#include <linux/delay.h>
23#include <linux/err.h>
24#include <linux/init.h>
25#include <linux/types.h>
26
27#include <asm/xen/hypervisor.h>
28
29#include <xen/xen.h>
30#include <xen/page.h>
31#include <xen/events.h>
32#include <xen/interface/io/console.h>
33#include <xen/hvc-console.h>
34
35#include "hvc_console.h"
36
37#define HVC_COOKIE 0x58656e
38
39static struct hvc_struct *hvc;
40static int xencons_irq;
41
42
43
44static unsigned long console_pfn = ~0ul;
45
46static inline struct xencons_interface *xencons_interface(void)
47{
48 if (console_pfn == ~0ul)
49 return mfn_to_virt(xen_start_info->console.domU.mfn);
50 else
51 return __va(console_pfn << PAGE_SHIFT);
52}
53
54static inline void notify_daemon(void)
55{
56
57 notify_remote_via_evtchn(xen_start_info->console.domU.evtchn);
58}
59
60static int __write_console(const char *data, int len)
61{
62 struct xencons_interface *intf = xencons_interface();
63 XENCONS_RING_IDX cons, prod;
64 int sent = 0;
65
66 cons = intf->out_cons;
67 prod = intf->out_prod;
68 mb();
69 BUG_ON((prod - cons) > sizeof(intf->out));
70
71 while ((sent < len) && ((prod - cons) < sizeof(intf->out)))
72 intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++];
73
74 wmb();
75 intf->out_prod = prod;
76
77 if (sent)
78 notify_daemon();
79 return sent;
80}
81
82static int domU_write_console(uint32_t vtermno, const char *data, int len)
83{
84 int ret = len;
85
86
87
88
89
90
91
92 while (len) {
93 int sent = __write_console(data, len);
94
95 data += sent;
96 len -= sent;
97
98 if (unlikely(len))
99 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
100 }
101
102 return ret;
103}
104
105static int domU_read_console(uint32_t vtermno, char *buf, int len)
106{
107 struct xencons_interface *intf = xencons_interface();
108 XENCONS_RING_IDX cons, prod;
109 int recv = 0;
110
111 cons = intf->in_cons;
112 prod = intf->in_prod;
113 mb();
114 BUG_ON((prod - cons) > sizeof(intf->in));
115
116 while (cons != prod && recv < len)
117 buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)];
118
119 mb();
120 intf->in_cons = cons;
121
122 notify_daemon();
123 return recv;
124}
125
126static struct hv_ops domU_hvc_ops = {
127 .get_chars = domU_read_console,
128 .put_chars = domU_write_console,
129 .notifier_add = notifier_add_irq,
130 .notifier_del = notifier_del_irq,
131 .notifier_hangup = notifier_hangup_irq,
132};
133
134static int dom0_read_console(uint32_t vtermno, char *buf, int len)
135{
136 return HYPERVISOR_console_io(CONSOLEIO_read, len, buf);
137}
138
139
140
141
142
143static int dom0_write_console(uint32_t vtermno, const char *str, int len)
144{
145 int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str);
146 if (rc < 0)
147 return 0;
148
149 return len;
150}
151
152static struct hv_ops dom0_hvc_ops = {
153 .get_chars = dom0_read_console,
154 .put_chars = dom0_write_console,
155 .notifier_add = notifier_add_irq,
156 .notifier_del = notifier_del_irq,
157 .notifier_hangup = notifier_hangup_irq,
158};
159
160static int __init xen_hvc_init(void)
161{
162 struct hvc_struct *hp;
163 struct hv_ops *ops;
164
165 if (!xen_pv_domain())
166 return -ENODEV;
167
168 if (xen_initial_domain()) {
169 ops = &dom0_hvc_ops;
170 xencons_irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
171 } else {
172 if (!xen_start_info->console.domU.evtchn)
173 return -ENODEV;
174
175 ops = &domU_hvc_ops;
176 xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn);
177 }
178 if (xencons_irq < 0)
179 xencons_irq = 0;
180 else
181 irq_set_noprobe(xencons_irq);
182
183 hp = hvc_alloc(HVC_COOKIE, xencons_irq, ops, 256);
184 if (IS_ERR(hp))
185 return PTR_ERR(hp);
186
187 hvc = hp;
188
189 console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn);
190
191 return 0;
192}
193
194void xen_console_resume(void)
195{
196 if (xencons_irq)
197 rebind_evtchn_irq(xen_start_info->console.domU.evtchn, xencons_irq);
198}
199
200static void __exit xen_hvc_fini(void)
201{
202 if (hvc)
203 hvc_remove(hvc);
204}
205
206static int xen_cons_init(void)
207{
208 struct hv_ops *ops;
209
210 if (!xen_pv_domain())
211 return 0;
212
213 if (xen_initial_domain())
214 ops = &dom0_hvc_ops;
215 else
216 ops = &domU_hvc_ops;
217
218 hvc_instantiate(HVC_COOKIE, 0, ops);
219 return 0;
220}
221
222module_init(xen_hvc_init);
223module_exit(xen_hvc_fini);
224console_initcall(xen_cons_init);
225
226#ifdef CONFIG_EARLY_PRINTK
227static void xenboot_write_console(struct console *console, const char *string,
228 unsigned len)
229{
230 unsigned int linelen, off = 0;
231 const char *pos;
232
233 dom0_write_console(0, string, len);
234
235 if (xen_initial_domain())
236 return;
237
238 domU_write_console(0, "(early) ", 8);
239 while (off < len && NULL != (pos = strchr(string+off, '\n'))) {
240 linelen = pos-string+off;
241 if (off + linelen > len)
242 break;
243 domU_write_console(0, string+off, linelen);
244 domU_write_console(0, "\r\n", 2);
245 off += linelen + 1;
246 }
247 if (off < len)
248 domU_write_console(0, string+off, len-off);
249}
250
251struct console xenboot_console = {
252 .name = "xenboot",
253 .write = xenboot_write_console,
254 .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
255};
256#endif
257
258void xen_raw_console_write(const char *str)
259{
260 dom0_write_console(0, str, strlen(str));
261}
262
263void xen_raw_printk(const char *fmt, ...)
264{
265 static char buf[512];
266 va_list ap;
267
268 va_start(ap, fmt);
269 vsnprintf(buf, sizeof(buf), fmt, ap);
270 va_end(ap);
271
272 xen_raw_console_write(buf);
273}
274