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 | u8 buf[SIZE_VIO_GET_CHARS]; |
62 | size_t left; |
63 | size_t 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 ssize_t hvterm_raw_get_chars(uint32_t vtermno, u8 *buf, size_t count) |
70 | { |
71 | struct hvterm_priv *pv = hvterm_privs[vtermno]; |
72 | unsigned long i; |
73 | unsigned long flags; |
74 | size_t 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 ssize_t hvterm_raw_put_chars(uint32_t vtermno, const u8 *buf, |
119 | size_t count) |
120 | { |
121 | struct hvterm_priv *pv = hvterm_privs[vtermno]; |
122 | |
123 | if (WARN_ON(!pv)) |
124 | return 0; |
125 | |
126 | return hvc_put_chars(pv->termno, buf, count); |
127 | } |
128 | |
129 | static const struct hv_ops hvterm_raw_ops = { |
130 | .get_chars = hvterm_raw_get_chars, |
131 | .put_chars = hvterm_raw_put_chars, |
132 | .notifier_add = notifier_add_irq, |
133 | .notifier_del = notifier_del_irq, |
134 | .notifier_hangup = notifier_hangup_irq, |
135 | }; |
136 | |
137 | static ssize_t hvterm_hvsi_get_chars(uint32_t vtermno, u8 *buf, size_t count) |
138 | { |
139 | struct hvterm_priv *pv = hvterm_privs[vtermno]; |
140 | |
141 | if (WARN_ON(!pv)) |
142 | return 0; |
143 | |
144 | return hvsilib_get_chars(&pv->hvsi, buf, count); |
145 | } |
146 | |
147 | static ssize_t hvterm_hvsi_put_chars(uint32_t vtermno, const u8 *buf, |
148 | size_t count) |
149 | { |
150 | struct hvterm_priv *pv = hvterm_privs[vtermno]; |
151 | |
152 | if (WARN_ON(!pv)) |
153 | return 0; |
154 | |
155 | return hvsilib_put_chars(&pv->hvsi, buf, count); |
156 | } |
157 | |
158 | static int hvterm_hvsi_open(struct hvc_struct *hp, int data) |
159 | { |
160 | struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; |
161 | int rc; |
162 | |
163 | pr_devel("HVSI@%x: open !\n" , pv->termno); |
164 | |
165 | rc = notifier_add_irq(hp, data); |
166 | if (rc) |
167 | return rc; |
168 | |
169 | return hvsilib_open(&pv->hvsi, hp); |
170 | } |
171 | |
172 | static void hvterm_hvsi_close(struct hvc_struct *hp, int data) |
173 | { |
174 | struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; |
175 | |
176 | pr_devel("HVSI@%x: do close !\n" , pv->termno); |
177 | |
178 | hvsilib_close(&pv->hvsi, hp); |
179 | |
180 | notifier_del_irq(hp, data); |
181 | } |
182 | |
183 | static void hvterm_hvsi_hangup(struct hvc_struct *hp, int data) |
184 | { |
185 | struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; |
186 | |
187 | pr_devel("HVSI@%x: do hangup !\n" , pv->termno); |
188 | |
189 | hvsilib_close(&pv->hvsi, hp); |
190 | |
191 | notifier_hangup_irq(hp, data); |
192 | } |
193 | |
194 | static int hvterm_hvsi_tiocmget(struct hvc_struct *hp) |
195 | { |
196 | struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; |
197 | |
198 | if (!pv) |
199 | return -EINVAL; |
200 | return pv->hvsi.mctrl; |
201 | } |
202 | |
203 | static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set, |
204 | unsigned int clear) |
205 | { |
206 | struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; |
207 | |
208 | pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n" , |
209 | pv->termno, set, clear); |
210 | |
211 | if (set & TIOCM_DTR) |
212 | hvsilib_write_mctrl(&pv->hvsi, 1); |
213 | else if (clear & TIOCM_DTR) |
214 | hvsilib_write_mctrl(&pv->hvsi, 0); |
215 | |
216 | return 0; |
217 | } |
218 | |
219 | static const struct hv_ops hvterm_hvsi_ops = { |
220 | .get_chars = hvterm_hvsi_get_chars, |
221 | .put_chars = hvterm_hvsi_put_chars, |
222 | .notifier_add = hvterm_hvsi_open, |
223 | .notifier_del = hvterm_hvsi_close, |
224 | .notifier_hangup = hvterm_hvsi_hangup, |
225 | .tiocmget = hvterm_hvsi_tiocmget, |
226 | .tiocmset = hvterm_hvsi_tiocmset, |
227 | }; |
228 | |
229 | static void udbg_hvc_putc(char c) |
230 | { |
231 | int count = -1; |
232 | unsigned char bounce_buffer[16]; |
233 | |
234 | if (!hvterm_privs[0]) |
235 | return; |
236 | |
237 | if (c == '\n') |
238 | udbg_hvc_putc(c: '\r'); |
239 | |
240 | do { |
241 | switch(hvterm_privs[0]->proto) { |
242 | case HV_PROTOCOL_RAW: |
243 | /* |
244 | * hvterm_raw_put_chars requires at least a 16-byte |
245 | * buffer, so go via the bounce buffer |
246 | */ |
247 | bounce_buffer[0] = c; |
248 | count = hvterm_raw_put_chars(vtermno: 0, buf: bounce_buffer, count: 1); |
249 | break; |
250 | case HV_PROTOCOL_HVSI: |
251 | count = hvterm_hvsi_put_chars(vtermno: 0, buf: &c, count: 1); |
252 | break; |
253 | } |
254 | } while (count == 0 || count == -EAGAIN); |
255 | } |
256 | |
257 | static int udbg_hvc_getc_poll(void) |
258 | { |
259 | int rc = 0; |
260 | char c; |
261 | |
262 | if (!hvterm_privs[0]) |
263 | return -1; |
264 | |
265 | switch(hvterm_privs[0]->proto) { |
266 | case HV_PROTOCOL_RAW: |
267 | rc = hvterm_raw_get_chars(vtermno: 0, buf: &c, count: 1); |
268 | break; |
269 | case HV_PROTOCOL_HVSI: |
270 | rc = hvterm_hvsi_get_chars(vtermno: 0, buf: &c, count: 1); |
271 | break; |
272 | } |
273 | if (!rc) |
274 | return -1; |
275 | return c; |
276 | } |
277 | |
278 | static int udbg_hvc_getc(void) |
279 | { |
280 | int ch; |
281 | |
282 | if (!hvterm_privs[0]) |
283 | return -1; |
284 | |
285 | for (;;) { |
286 | ch = udbg_hvc_getc_poll(); |
287 | if (ch == -1) { |
288 | /* This shouldn't be needed...but... */ |
289 | volatile unsigned long delay; |
290 | for (delay=0; delay < 2000000; delay++) |
291 | ; |
292 | } else { |
293 | return ch; |
294 | } |
295 | } |
296 | } |
297 | |
298 | static int hvc_vio_probe(struct vio_dev *vdev, |
299 | const struct vio_device_id *id) |
300 | { |
301 | const struct hv_ops *ops; |
302 | struct hvc_struct *hp; |
303 | struct hvterm_priv *pv; |
304 | hv_protocol_t proto; |
305 | int i, termno = -1; |
306 | |
307 | /* probed with invalid parameters. */ |
308 | if (!vdev || !id) |
309 | return -EPERM; |
310 | |
311 | if (of_device_is_compatible(device: vdev->dev.of_node, "hvterm1" )) { |
312 | proto = HV_PROTOCOL_RAW; |
313 | ops = &hvterm_raw_ops; |
314 | } else if (of_device_is_compatible(device: vdev->dev.of_node, "hvterm-protocol" )) { |
315 | proto = HV_PROTOCOL_HVSI; |
316 | ops = &hvterm_hvsi_ops; |
317 | } else { |
318 | pr_err("hvc_vio: Unknown protocol for %pOF\n" , vdev->dev.of_node); |
319 | return -ENXIO; |
320 | } |
321 | |
322 | pr_devel("hvc_vio_probe() device %pOF, using %s protocol\n" , |
323 | vdev->dev.of_node, |
324 | proto == HV_PROTOCOL_RAW ? "raw" : "hvsi" ); |
325 | |
326 | /* Is it our boot one ? */ |
327 | if (hvterm_privs[0] == &hvterm_priv0 && |
328 | vdev->unit_address == hvterm_priv0.termno) { |
329 | pv = hvterm_privs[0]; |
330 | termno = 0; |
331 | pr_devel("->boot console, using termno 0\n" ); |
332 | } |
333 | /* nope, allocate a new one */ |
334 | else { |
335 | for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++) |
336 | if (!hvterm_privs[i]) |
337 | termno = i; |
338 | pr_devel("->non-boot console, using termno %d\n" , termno); |
339 | if (termno < 0) |
340 | return -ENODEV; |
341 | pv = kzalloc(size: sizeof(struct hvterm_priv), GFP_KERNEL); |
342 | if (!pv) |
343 | return -ENOMEM; |
344 | pv->termno = vdev->unit_address; |
345 | pv->proto = proto; |
346 | spin_lock_init(&pv->buf_lock); |
347 | hvterm_privs[termno] = pv; |
348 | hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars, |
349 | pv->termno, 0); |
350 | } |
351 | |
352 | hp = hvc_alloc(vtermno: termno, data: vdev->irq, ops, outbuf_size: MAX_VIO_PUT_CHARS); |
353 | if (IS_ERR(ptr: hp)) |
354 | return PTR_ERR(ptr: hp); |
355 | dev_set_drvdata(dev: &vdev->dev, data: hp); |
356 | |
357 | /* register udbg if it's not there already for console 0 */ |
358 | if (hp->index == 0 && !udbg_putc) { |
359 | udbg_putc = udbg_hvc_putc; |
360 | udbg_getc = udbg_hvc_getc; |
361 | udbg_getc_poll = udbg_hvc_getc_poll; |
362 | } |
363 | |
364 | return 0; |
365 | } |
366 | |
367 | static struct vio_driver hvc_vio_driver = { |
368 | .id_table = hvc_driver_table, |
369 | .probe = hvc_vio_probe, |
370 | .name = hvc_driver_name, |
371 | .driver = { |
372 | .suppress_bind_attrs = true, |
373 | }, |
374 | }; |
375 | |
376 | static int __init hvc_vio_init(void) |
377 | { |
378 | int rc; |
379 | |
380 | /* Register as a vio device to receive callbacks */ |
381 | rc = vio_register_driver(&hvc_vio_driver); |
382 | |
383 | return rc; |
384 | } |
385 | device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */ |
386 | |
387 | void __init hvc_vio_init_early(void) |
388 | { |
389 | const __be32 *termno; |
390 | const struct hv_ops *ops; |
391 | |
392 | /* find the boot console from /chosen/stdout */ |
393 | /* Check if it's a virtual terminal */ |
394 | if (!of_node_name_prefix(np: of_stdout, prefix: "vty" )) |
395 | return; |
396 | termno = of_get_property(node: of_stdout, name: "reg" , NULL); |
397 | if (termno == NULL) |
398 | return; |
399 | hvterm_priv0.termno = of_read_number(cell: termno, size: 1); |
400 | spin_lock_init(&hvterm_priv0.buf_lock); |
401 | hvterm_privs[0] = &hvterm_priv0; |
402 | |
403 | /* Check the protocol */ |
404 | if (of_device_is_compatible(device: of_stdout, "hvterm1" )) { |
405 | hvterm_priv0.proto = HV_PROTOCOL_RAW; |
406 | ops = &hvterm_raw_ops; |
407 | } |
408 | else if (of_device_is_compatible(device: of_stdout, "hvterm-protocol" )) { |
409 | hvterm_priv0.proto = HV_PROTOCOL_HVSI; |
410 | ops = &hvterm_hvsi_ops; |
411 | hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars, |
412 | hvterm_priv0.termno, 1); |
413 | /* HVSI, perform the handshake now */ |
414 | hvsilib_establish(&hvterm_priv0.hvsi); |
415 | } else |
416 | return; |
417 | udbg_putc = udbg_hvc_putc; |
418 | udbg_getc = udbg_hvc_getc; |
419 | udbg_getc_poll = udbg_hvc_getc_poll; |
420 | #ifdef HVC_OLD_HVSI |
421 | /* When using the old HVSI driver don't register the HVC |
422 | * backend for HVSI, only do udbg |
423 | */ |
424 | if (hvterm_priv0.proto == HV_PROTOCOL_HVSI) |
425 | return; |
426 | #endif |
427 | /* Check whether the user has requested a different console. */ |
428 | if (!strstr(boot_command_line, "console=" )) |
429 | add_preferred_console(name: "hvc" , idx: 0, NULL); |
430 | hvc_instantiate(vtermno: 0, index: 0, ops); |
431 | } |
432 | |
433 | /* call this from early_init() for a working debug console on |
434 | * vterm capable LPAR machines |
435 | */ |
436 | #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR |
437 | void __init udbg_init_debug_lpar(void) |
438 | { |
439 | /* |
440 | * If we're running as a hypervisor then we definitely can't call the |
441 | * hypervisor to print debug output (we *are* the hypervisor), so don't |
442 | * register if we detect that MSR_HV=1. |
443 | */ |
444 | if (mfmsr() & MSR_HV) |
445 | return; |
446 | |
447 | hvterm_privs[0] = &hvterm_priv0; |
448 | hvterm_priv0.termno = 0; |
449 | hvterm_priv0.proto = HV_PROTOCOL_RAW; |
450 | spin_lock_init(&hvterm_priv0.buf_lock); |
451 | udbg_putc = udbg_hvc_putc; |
452 | udbg_getc = udbg_hvc_getc; |
453 | udbg_getc_poll = udbg_hvc_getc_poll; |
454 | } |
455 | #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */ |
456 | |
457 | #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI |
458 | void __init udbg_init_debug_lpar_hvsi(void) |
459 | { |
460 | /* See comment above in udbg_init_debug_lpar() */ |
461 | if (mfmsr() & MSR_HV) |
462 | return; |
463 | |
464 | hvterm_privs[0] = &hvterm_priv0; |
465 | hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO; |
466 | hvterm_priv0.proto = HV_PROTOCOL_HVSI; |
467 | spin_lock_init(&hvterm_priv0.buf_lock); |
468 | udbg_putc = udbg_hvc_putc; |
469 | udbg_getc = udbg_hvc_getc; |
470 | udbg_getc_poll = udbg_hvc_getc_poll; |
471 | hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars, |
472 | hvterm_priv0.termno, 1); |
473 | hvsilib_establish(&hvterm_priv0.hvsi); |
474 | } |
475 | #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */ |
476 | |