1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * vio driver interface to hvc_console.c |
4 | * |
5 | * This code was moved here to allow the remaining code to be reused as a |
6 | * generic polling mode with semi-reliable transport driver core to the |
7 | * console and tty subsystems. |
8 | * |
9 | * |
10 | * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM |
11 | * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM |
12 | * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp. |
13 | * Copyright (C) 2004 IBM Corporation |
14 | * |
15 | * Additional Author(s): |
16 | * Ryan S. Arnold <rsa@us.ibm.com> |
17 | * |
18 | * TODO: |
19 | * |
20 | * - handle error in sending hvsi protocol packets |
21 | * - retry nego on subsequent sends ? |
22 | */ |
23 | |
24 | #undef DEBUG |
25 | |
26 | #include <linux/types.h> |
27 | #include <linux/init.h> |
28 | #include <linux/delay.h> |
29 | #include <linux/slab.h> |
30 | #include <linux/console.h> |
31 | #include <linux/of.h> |
32 | |
33 | #include <asm/hvconsole.h> |
34 | #include <asm/vio.h> |
35 | #include <asm/hvsi.h> |
36 | #include <asm/udbg.h> |
37 | #include <asm/machdep.h> |
38 | |
39 | #include "hvc_console.h" |
40 | |
41 | static const char hvc_driver_name[] = "hvc_console" ; |
42 | |
43 | static const struct vio_device_id hvc_driver_table[] = { |
44 | {"serial" , "hvterm1" }, |
45 | #ifndef HVC_OLD_HVSI |
46 | {"serial" , "hvterm-protocol" }, |
47 | #endif |
48 | { "" , "" } |
49 | }; |
50 | |
51 | typedef enum hv_protocol { |
52 | HV_PROTOCOL_RAW, |
53 | HV_PROTOCOL_HVSI |
54 | } hv_protocol_t; |
55 | |
56 | struct hvterm_priv { |
57 | u32 termno; /* HV term number */ |
58 | hv_protocol_t proto; /* Raw data or HVSI packets */ |
59 | struct hvsi_priv hvsi; /* HVSI specific data */ |
60 | spinlock_t buf_lock; |
61 | char buf[SIZE_VIO_GET_CHARS]; |
62 | int left; |
63 | int offset; |
64 | }; |
65 | static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES]; |
66 | /* For early boot console */ |
67 | static struct hvterm_priv hvterm_priv0; |
68 | |
69 | static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count) |
70 | { |
71 | struct hvterm_priv *pv = hvterm_privs[vtermno]; |
72 | unsigned long i; |
73 | unsigned long flags; |
74 | int got; |
75 | |
76 | if (WARN_ON(!pv)) |
77 | return 0; |
78 | |
79 | spin_lock_irqsave(&pv->buf_lock, flags); |
80 | |
81 | if (pv->left == 0) { |
82 | pv->offset = 0; |
83 | pv->left = hvc_get_chars(pv->termno, pv->buf, count); |
84 | |
85 | /* |
86 | * Work around a HV bug where it gives us a null |
87 | * after every \r. -- paulus |
88 | */ |
89 | for (i = 1; i < pv->left; ++i) { |
90 | if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') { |
91 | --pv->left; |
92 | if (i < pv->left) { |
93 | memmove(&pv->buf[i], &pv->buf[i+1], |
94 | pv->left - i); |
95 | } |
96 | } |
97 | } |
98 | } |
99 | |
100 | got = min(count, pv->left); |
101 | memcpy(buf, &pv->buf[pv->offset], got); |
102 | pv->offset += got; |
103 | pv->left -= got; |
104 | |
105 | spin_unlock_irqrestore(lock: &pv->buf_lock, flags); |
106 | |
107 | return got; |
108 | } |
109 | |
110 | /** |
111 | * hvterm_raw_put_chars: send characters to firmware for given vterm adapter |
112 | * @vtermno: The virtual terminal number. |
113 | * @buf: The characters to send. Because of the underlying hypercall in |
114 | * hvc_put_chars(), this buffer must be at least 16 bytes long, even if |
115 | * you are sending fewer chars. |
116 | * @count: number of chars to send. |
117 | */ |
118 | static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count) |
119 | { |
120 | struct hvterm_priv *pv = hvterm_privs[vtermno]; |
121 | |
122 | if (WARN_ON(!pv)) |
123 | return 0; |
124 | |
125 | return hvc_put_chars(pv->termno, buf, count); |
126 | } |
127 | |
128 | static const struct hv_ops hvterm_raw_ops = { |
129 | .get_chars = hvterm_raw_get_chars, |
130 | .put_chars = hvterm_raw_put_chars, |
131 | .notifier_add = notifier_add_irq, |
132 | .notifier_del = notifier_del_irq, |
133 | .notifier_hangup = notifier_hangup_irq, |
134 | }; |
135 | |
136 | static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count) |
137 | { |
138 | struct hvterm_priv *pv = hvterm_privs[vtermno]; |
139 | |
140 | if (WARN_ON(!pv)) |
141 | return 0; |
142 | |
143 | return hvsilib_get_chars(&pv->hvsi, buf, count); |
144 | } |
145 | |
146 | static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count) |
147 | { |
148 | struct hvterm_priv *pv = hvterm_privs[vtermno]; |
149 | |
150 | if (WARN_ON(!pv)) |
151 | return 0; |
152 | |
153 | return hvsilib_put_chars(&pv->hvsi, buf, count); |
154 | } |
155 | |
156 | static int hvterm_hvsi_open(struct hvc_struct *hp, int data) |
157 | { |
158 | struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; |
159 | int rc; |
160 | |
161 | pr_devel("HVSI@%x: open !\n" , pv->termno); |
162 | |
163 | rc = notifier_add_irq(hp, data); |
164 | if (rc) |
165 | return rc; |
166 | |
167 | return hvsilib_open(&pv->hvsi, hp); |
168 | } |
169 | |
170 | static void hvterm_hvsi_close(struct hvc_struct *hp, int data) |
171 | { |
172 | struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; |
173 | |
174 | pr_devel("HVSI@%x: do close !\n" , pv->termno); |
175 | |
176 | hvsilib_close(&pv->hvsi, hp); |
177 | |
178 | notifier_del_irq(hp, data); |
179 | } |
180 | |
181 | static void hvterm_hvsi_hangup(struct hvc_struct *hp, int data) |
182 | { |
183 | struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; |
184 | |
185 | pr_devel("HVSI@%x: do hangup !\n" , pv->termno); |
186 | |
187 | hvsilib_close(&pv->hvsi, hp); |
188 | |
189 | notifier_hangup_irq(hp, data); |
190 | } |
191 | |
192 | static int hvterm_hvsi_tiocmget(struct hvc_struct *hp) |
193 | { |
194 | struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; |
195 | |
196 | if (!pv) |
197 | return -EINVAL; |
198 | return pv->hvsi.mctrl; |
199 | } |
200 | |
201 | static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set, |
202 | unsigned int clear) |
203 | { |
204 | struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; |
205 | |
206 | pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n" , |
207 | pv->termno, set, clear); |
208 | |
209 | if (set & TIOCM_DTR) |
210 | hvsilib_write_mctrl(&pv->hvsi, 1); |
211 | else if (clear & TIOCM_DTR) |
212 | hvsilib_write_mctrl(&pv->hvsi, 0); |
213 | |
214 | return 0; |
215 | } |
216 | |
217 | static const struct hv_ops hvterm_hvsi_ops = { |
218 | .get_chars = hvterm_hvsi_get_chars, |
219 | .put_chars = hvterm_hvsi_put_chars, |
220 | .notifier_add = hvterm_hvsi_open, |
221 | .notifier_del = hvterm_hvsi_close, |
222 | .notifier_hangup = hvterm_hvsi_hangup, |
223 | .tiocmget = hvterm_hvsi_tiocmget, |
224 | .tiocmset = hvterm_hvsi_tiocmset, |
225 | }; |
226 | |
227 | static void udbg_hvc_putc(char c) |
228 | { |
229 | int count = -1; |
230 | unsigned char bounce_buffer[16]; |
231 | |
232 | if (!hvterm_privs[0]) |
233 | return; |
234 | |
235 | if (c == '\n') |
236 | udbg_hvc_putc(c: '\r'); |
237 | |
238 | do { |
239 | switch(hvterm_privs[0]->proto) { |
240 | case HV_PROTOCOL_RAW: |
241 | /* |
242 | * hvterm_raw_put_chars requires at least a 16-byte |
243 | * buffer, so go via the bounce buffer |
244 | */ |
245 | bounce_buffer[0] = c; |
246 | count = hvterm_raw_put_chars(vtermno: 0, buf: bounce_buffer, count: 1); |
247 | break; |
248 | case HV_PROTOCOL_HVSI: |
249 | count = hvterm_hvsi_put_chars(vtermno: 0, buf: &c, count: 1); |
250 | break; |
251 | } |
252 | } while (count == 0 || count == -EAGAIN); |
253 | } |
254 | |
255 | static int udbg_hvc_getc_poll(void) |
256 | { |
257 | int rc = 0; |
258 | char c; |
259 | |
260 | if (!hvterm_privs[0]) |
261 | return -1; |
262 | |
263 | switch(hvterm_privs[0]->proto) { |
264 | case HV_PROTOCOL_RAW: |
265 | rc = hvterm_raw_get_chars(vtermno: 0, buf: &c, count: 1); |
266 | break; |
267 | case HV_PROTOCOL_HVSI: |
268 | rc = hvterm_hvsi_get_chars(vtermno: 0, buf: &c, count: 1); |
269 | break; |
270 | } |
271 | if (!rc) |
272 | return -1; |
273 | return c; |
274 | } |
275 | |
276 | static int udbg_hvc_getc(void) |
277 | { |
278 | int ch; |
279 | |
280 | if (!hvterm_privs[0]) |
281 | return -1; |
282 | |
283 | for (;;) { |
284 | ch = udbg_hvc_getc_poll(); |
285 | if (ch == -1) { |
286 | /* This shouldn't be needed...but... */ |
287 | volatile unsigned long delay; |
288 | for (delay=0; delay < 2000000; delay++) |
289 | ; |
290 | } else { |
291 | return ch; |
292 | } |
293 | } |
294 | } |
295 | |
296 | static int hvc_vio_probe(struct vio_dev *vdev, |
297 | const struct vio_device_id *id) |
298 | { |
299 | const struct hv_ops *ops; |
300 | struct hvc_struct *hp; |
301 | struct hvterm_priv *pv; |
302 | hv_protocol_t proto; |
303 | int i, termno = -1; |
304 | |
305 | /* probed with invalid parameters. */ |
306 | if (!vdev || !id) |
307 | return -EPERM; |
308 | |
309 | if (of_device_is_compatible(device: vdev->dev.of_node, "hvterm1" )) { |
310 | proto = HV_PROTOCOL_RAW; |
311 | ops = &hvterm_raw_ops; |
312 | } else if (of_device_is_compatible(device: vdev->dev.of_node, "hvterm-protocol" )) { |
313 | proto = HV_PROTOCOL_HVSI; |
314 | ops = &hvterm_hvsi_ops; |
315 | } else { |
316 | pr_err("hvc_vio: Unknown protocol for %pOF\n" , vdev->dev.of_node); |
317 | return -ENXIO; |
318 | } |
319 | |
320 | pr_devel("hvc_vio_probe() device %pOF, using %s protocol\n" , |
321 | vdev->dev.of_node, |
322 | proto == HV_PROTOCOL_RAW ? "raw" : "hvsi" ); |
323 | |
324 | /* Is it our boot one ? */ |
325 | if (hvterm_privs[0] == &hvterm_priv0 && |
326 | vdev->unit_address == hvterm_priv0.termno) { |
327 | pv = hvterm_privs[0]; |
328 | termno = 0; |
329 | pr_devel("->boot console, using termno 0\n" ); |
330 | } |
331 | /* nope, allocate a new one */ |
332 | else { |
333 | for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++) |
334 | if (!hvterm_privs[i]) |
335 | termno = i; |
336 | pr_devel("->non-boot console, using termno %d\n" , termno); |
337 | if (termno < 0) |
338 | return -ENODEV; |
339 | pv = kzalloc(size: sizeof(struct hvterm_priv), GFP_KERNEL); |
340 | if (!pv) |
341 | return -ENOMEM; |
342 | pv->termno = vdev->unit_address; |
343 | pv->proto = proto; |
344 | spin_lock_init(&pv->buf_lock); |
345 | hvterm_privs[termno] = pv; |
346 | hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars, |
347 | pv->termno, 0); |
348 | } |
349 | |
350 | hp = hvc_alloc(vtermno: termno, data: vdev->irq, ops, outbuf_size: MAX_VIO_PUT_CHARS); |
351 | if (IS_ERR(ptr: hp)) |
352 | return PTR_ERR(ptr: hp); |
353 | dev_set_drvdata(dev: &vdev->dev, data: hp); |
354 | |
355 | /* register udbg if it's not there already for console 0 */ |
356 | if (hp->index == 0 && !udbg_putc) { |
357 | udbg_putc = udbg_hvc_putc; |
358 | udbg_getc = udbg_hvc_getc; |
359 | udbg_getc_poll = udbg_hvc_getc_poll; |
360 | } |
361 | |
362 | return 0; |
363 | } |
364 | |
365 | static struct vio_driver hvc_vio_driver = { |
366 | .id_table = hvc_driver_table, |
367 | .probe = hvc_vio_probe, |
368 | .name = hvc_driver_name, |
369 | .driver = { |
370 | .suppress_bind_attrs = true, |
371 | }, |
372 | }; |
373 | |
374 | static int __init hvc_vio_init(void) |
375 | { |
376 | int rc; |
377 | |
378 | /* Register as a vio device to receive callbacks */ |
379 | rc = vio_register_driver(&hvc_vio_driver); |
380 | |
381 | return rc; |
382 | } |
383 | device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */ |
384 | |
385 | void __init hvc_vio_init_early(void) |
386 | { |
387 | const __be32 *termno; |
388 | const struct hv_ops *ops; |
389 | |
390 | /* find the boot console from /chosen/stdout */ |
391 | /* Check if it's a virtual terminal */ |
392 | if (!of_node_name_prefix(np: of_stdout, prefix: "vty" )) |
393 | return; |
394 | termno = of_get_property(node: of_stdout, name: "reg" , NULL); |
395 | if (termno == NULL) |
396 | return; |
397 | hvterm_priv0.termno = of_read_number(cell: termno, size: 1); |
398 | spin_lock_init(&hvterm_priv0.buf_lock); |
399 | hvterm_privs[0] = &hvterm_priv0; |
400 | |
401 | /* Check the protocol */ |
402 | if (of_device_is_compatible(device: of_stdout, "hvterm1" )) { |
403 | hvterm_priv0.proto = HV_PROTOCOL_RAW; |
404 | ops = &hvterm_raw_ops; |
405 | } |
406 | else if (of_device_is_compatible(device: of_stdout, "hvterm-protocol" )) { |
407 | hvterm_priv0.proto = HV_PROTOCOL_HVSI; |
408 | ops = &hvterm_hvsi_ops; |
409 | hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars, |
410 | hvterm_priv0.termno, 1); |
411 | /* HVSI, perform the handshake now */ |
412 | hvsilib_establish(&hvterm_priv0.hvsi); |
413 | } else |
414 | return; |
415 | udbg_putc = udbg_hvc_putc; |
416 | udbg_getc = udbg_hvc_getc; |
417 | udbg_getc_poll = udbg_hvc_getc_poll; |
418 | #ifdef HVC_OLD_HVSI |
419 | /* When using the old HVSI driver don't register the HVC |
420 | * backend for HVSI, only do udbg |
421 | */ |
422 | if (hvterm_priv0.proto == HV_PROTOCOL_HVSI) |
423 | return; |
424 | #endif |
425 | /* Check whether the user has requested a different console. */ |
426 | if (!strstr(boot_command_line, "console=" )) |
427 | add_preferred_console(name: "hvc" , idx: 0, NULL); |
428 | hvc_instantiate(vtermno: 0, index: 0, ops); |
429 | } |
430 | |
431 | /* call this from early_init() for a working debug console on |
432 | * vterm capable LPAR machines |
433 | */ |
434 | #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR |
435 | void __init udbg_init_debug_lpar(void) |
436 | { |
437 | /* |
438 | * If we're running as a hypervisor then we definitely can't call the |
439 | * hypervisor to print debug output (we *are* the hypervisor), so don't |
440 | * register if we detect that MSR_HV=1. |
441 | */ |
442 | if (mfmsr() & MSR_HV) |
443 | return; |
444 | |
445 | hvterm_privs[0] = &hvterm_priv0; |
446 | hvterm_priv0.termno = 0; |
447 | hvterm_priv0.proto = HV_PROTOCOL_RAW; |
448 | spin_lock_init(&hvterm_priv0.buf_lock); |
449 | udbg_putc = udbg_hvc_putc; |
450 | udbg_getc = udbg_hvc_getc; |
451 | udbg_getc_poll = udbg_hvc_getc_poll; |
452 | } |
453 | #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */ |
454 | |
455 | #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI |
456 | void __init udbg_init_debug_lpar_hvsi(void) |
457 | { |
458 | /* See comment above in udbg_init_debug_lpar() */ |
459 | if (mfmsr() & MSR_HV) |
460 | return; |
461 | |
462 | hvterm_privs[0] = &hvterm_priv0; |
463 | hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO; |
464 | hvterm_priv0.proto = HV_PROTOCOL_HVSI; |
465 | spin_lock_init(&hvterm_priv0.buf_lock); |
466 | udbg_putc = udbg_hvc_putc; |
467 | udbg_getc = udbg_hvc_getc; |
468 | udbg_getc_poll = udbg_hvc_getc_poll; |
469 | hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars, |
470 | hvterm_priv0.termno, 1); |
471 | hvsilib_establish(&hvterm_priv0.hvsi); |
472 | } |
473 | #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */ |
474 | |