xref: /openbmc/linux/drivers/tty/hvc/hvc_vio.c (revision 8cb5d748)
1 /*
2  * vio driver interface to hvc_console.c
3  *
4  * This code was moved here to allow the remaining code to be reused as a
5  * generic polling mode with semi-reliable transport driver core to the
6  * console and tty subsystems.
7  *
8  *
9  * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
10  * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
11  * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
12  * Copyright (C) 2004 IBM Corporation
13  *
14  * Additional Author(s):
15  *  Ryan S. Arnold <rsa@us.ibm.com>
16  *
17  * This program is free software; you can redistribute it and/or modify
18  * it under the terms of the GNU General Public License as published by
19  * the Free Software Foundation; either version 2 of the License, or
20  * (at your option) any later version.
21  *
22  * This program is distributed in the hope that it will be useful,
23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
25  * GNU General Public License for more details.
26  *
27  * You should have received a copy of the GNU General Public License
28  * along with this program; if not, write to the Free Software
29  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
30  *
31  * TODO:
32  *
33  *   - handle error in sending hvsi protocol packets
34  *   - retry nego on subsequent sends ?
35  */
36 
37 #undef DEBUG
38 
39 #include <linux/types.h>
40 #include <linux/init.h>
41 #include <linux/delay.h>
42 #include <linux/slab.h>
43 #include <linux/console.h>
44 
45 #include <asm/hvconsole.h>
46 #include <asm/vio.h>
47 #include <asm/prom.h>
48 #include <asm/hvsi.h>
49 #include <asm/udbg.h>
50 #include <asm/machdep.h>
51 
52 #include "hvc_console.h"
53 
54 static const char hvc_driver_name[] = "hvc_console";
55 
56 static const struct vio_device_id hvc_driver_table[] = {
57 	{"serial", "hvterm1"},
58 #ifndef HVC_OLD_HVSI
59 	{"serial", "hvterm-protocol"},
60 #endif
61 	{ "", "" }
62 };
63 
64 typedef enum hv_protocol {
65 	HV_PROTOCOL_RAW,
66 	HV_PROTOCOL_HVSI
67 } hv_protocol_t;
68 
69 struct hvterm_priv {
70 	u32			termno;	/* HV term number */
71 	hv_protocol_t		proto;	/* Raw data or HVSI packets */
72 	struct hvsi_priv	hvsi;	/* HVSI specific data */
73 	spinlock_t		buf_lock;
74 	char			buf[SIZE_VIO_GET_CHARS];
75 	int			left;
76 	int			offset;
77 };
78 static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
79 /* For early boot console */
80 static struct hvterm_priv hvterm_priv0;
81 
82 static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
83 {
84 	struct hvterm_priv *pv = hvterm_privs[vtermno];
85 	unsigned long i;
86 	unsigned long flags;
87 	int got;
88 
89 	if (WARN_ON(!pv))
90 		return 0;
91 
92 	spin_lock_irqsave(&pv->buf_lock, flags);
93 
94 	if (pv->left == 0) {
95 		pv->offset = 0;
96 		pv->left = hvc_get_chars(pv->termno, pv->buf, count);
97 
98 		/*
99 		 * Work around a HV bug where it gives us a null
100 		 * after every \r.  -- paulus
101 		 */
102 		for (i = 1; i < pv->left; ++i) {
103 			if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
104 				--pv->left;
105 				if (i < pv->left) {
106 					memmove(&pv->buf[i], &pv->buf[i+1],
107 						pv->left - i);
108 				}
109 			}
110 		}
111 	}
112 
113 	got = min(count, pv->left);
114 	memcpy(buf, &pv->buf[pv->offset], got);
115 	pv->offset += got;
116 	pv->left -= got;
117 
118 	spin_unlock_irqrestore(&pv->buf_lock, flags);
119 
120 	return got;
121 }
122 
123 static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
124 {
125 	struct hvterm_priv *pv = hvterm_privs[vtermno];
126 
127 	if (WARN_ON(!pv))
128 		return 0;
129 
130 	return hvc_put_chars(pv->termno, buf, count);
131 }
132 
133 static const struct hv_ops hvterm_raw_ops = {
134 	.get_chars = hvterm_raw_get_chars,
135 	.put_chars = hvterm_raw_put_chars,
136 	.notifier_add = notifier_add_irq,
137 	.notifier_del = notifier_del_irq,
138 	.notifier_hangup = notifier_hangup_irq,
139 };
140 
141 static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
142 {
143 	struct hvterm_priv *pv = hvterm_privs[vtermno];
144 
145 	if (WARN_ON(!pv))
146 		return 0;
147 
148 	return hvsilib_get_chars(&pv->hvsi, buf, count);
149 }
150 
151 static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
152 {
153 	struct hvterm_priv *pv = hvterm_privs[vtermno];
154 
155 	if (WARN_ON(!pv))
156 		return 0;
157 
158 	return hvsilib_put_chars(&pv->hvsi, buf, count);
159 }
160 
161 static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
162 {
163 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
164 	int rc;
165 
166 	pr_devel("HVSI@%x: open !\n", pv->termno);
167 
168 	rc = notifier_add_irq(hp, data);
169 	if (rc)
170 		return rc;
171 
172 	return hvsilib_open(&pv->hvsi, hp);
173 }
174 
175 static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
176 {
177 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
178 
179 	pr_devel("HVSI@%x: do close !\n", pv->termno);
180 
181 	hvsilib_close(&pv->hvsi, hp);
182 
183 	notifier_del_irq(hp, data);
184 }
185 
186 void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
187 {
188 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
189 
190 	pr_devel("HVSI@%x: do hangup !\n", pv->termno);
191 
192 	hvsilib_close(&pv->hvsi, hp);
193 
194 	notifier_hangup_irq(hp, data);
195 }
196 
197 static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
198 {
199 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
200 
201 	if (!pv)
202 		return -EINVAL;
203 	return pv->hvsi.mctrl;
204 }
205 
206 static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
207 				unsigned int clear)
208 {
209 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
210 
211 	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
212 		 pv->termno, set, clear);
213 
214 	if (set & TIOCM_DTR)
215 		hvsilib_write_mctrl(&pv->hvsi, 1);
216 	else if (clear & TIOCM_DTR)
217 		hvsilib_write_mctrl(&pv->hvsi, 0);
218 
219 	return 0;
220 }
221 
222 static const struct hv_ops hvterm_hvsi_ops = {
223 	.get_chars = hvterm_hvsi_get_chars,
224 	.put_chars = hvterm_hvsi_put_chars,
225 	.notifier_add = hvterm_hvsi_open,
226 	.notifier_del = hvterm_hvsi_close,
227 	.notifier_hangup = hvterm_hvsi_hangup,
228 	.tiocmget = hvterm_hvsi_tiocmget,
229 	.tiocmset = hvterm_hvsi_tiocmset,
230 };
231 
232 static void udbg_hvc_putc(char c)
233 {
234 	int count = -1;
235 
236 	if (!hvterm_privs[0])
237 		return;
238 
239 	if (c == '\n')
240 		udbg_hvc_putc('\r');
241 
242 	do {
243 		switch(hvterm_privs[0]->proto) {
244 		case HV_PROTOCOL_RAW:
245 			count = hvterm_raw_put_chars(0, &c, 1);
246 			break;
247 		case HV_PROTOCOL_HVSI:
248 			count = hvterm_hvsi_put_chars(0, &c, 1);
249 			break;
250 		}
251 	} while(count == 0);
252 }
253 
254 static int udbg_hvc_getc_poll(void)
255 {
256 	int rc = 0;
257 	char c;
258 
259 	if (!hvterm_privs[0])
260 		return -1;
261 
262 	switch(hvterm_privs[0]->proto) {
263 	case HV_PROTOCOL_RAW:
264 		rc = hvterm_raw_get_chars(0, &c, 1);
265 		break;
266 	case HV_PROTOCOL_HVSI:
267 		rc = hvterm_hvsi_get_chars(0, &c, 1);
268 		break;
269 	}
270 	if (!rc)
271 		return -1;
272 	return c;
273 }
274 
275 static int udbg_hvc_getc(void)
276 {
277 	int ch;
278 
279 	if (!hvterm_privs[0])
280 		return -1;
281 
282 	for (;;) {
283 		ch = udbg_hvc_getc_poll();
284 		if (ch == -1) {
285 			/* This shouldn't be needed...but... */
286 			volatile unsigned long delay;
287 			for (delay=0; delay < 2000000; delay++)
288 				;
289 		} else {
290 			return ch;
291 		}
292 	}
293 }
294 
295 static int hvc_vio_probe(struct vio_dev *vdev,
296 				   const struct vio_device_id *id)
297 {
298 	const struct hv_ops *ops;
299 	struct hvc_struct *hp;
300 	struct hvterm_priv *pv;
301 	hv_protocol_t proto;
302 	int i, termno = -1;
303 
304 	/* probed with invalid parameters. */
305 	if (!vdev || !id)
306 		return -EPERM;
307 
308 	if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
309 		proto = HV_PROTOCOL_RAW;
310 		ops = &hvterm_raw_ops;
311 	} else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
312 		proto = HV_PROTOCOL_HVSI;
313 		ops = &hvterm_hvsi_ops;
314 	} else {
315 		pr_err("hvc_vio: Unknown protocol for %pOF\n", vdev->dev.of_node);
316 		return -ENXIO;
317 	}
318 
319 	pr_devel("hvc_vio_probe() device %pOF, using %s protocol\n",
320 		 vdev->dev.of_node,
321 		 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
322 
323 	/* Is it our boot one ? */
324 	if (hvterm_privs[0] == &hvterm_priv0 &&
325 	    vdev->unit_address == hvterm_priv0.termno) {
326 		pv = hvterm_privs[0];
327 		termno = 0;
328 		pr_devel("->boot console, using termno 0\n");
329 	}
330 	/* nope, allocate a new one */
331 	else {
332 		for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
333 			if (!hvterm_privs[i])
334 				termno = i;
335 		pr_devel("->non-boot console, using termno %d\n", termno);
336 		if (termno < 0)
337 			return -ENODEV;
338 		pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
339 		if (!pv)
340 			return -ENOMEM;
341 		pv->termno = vdev->unit_address;
342 		pv->proto = proto;
343 		spin_lock_init(&pv->buf_lock);
344 		hvterm_privs[termno] = pv;
345 		hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
346 			     pv->termno, 0);
347 	}
348 
349 	hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
350 	if (IS_ERR(hp))
351 		return PTR_ERR(hp);
352 	dev_set_drvdata(&vdev->dev, hp);
353 
354 	/* register udbg if it's not there already for console 0 */
355 	if (hp->index == 0 && !udbg_putc) {
356 		udbg_putc = udbg_hvc_putc;
357 		udbg_getc = udbg_hvc_getc;
358 		udbg_getc_poll = udbg_hvc_getc_poll;
359 	}
360 
361 	return 0;
362 }
363 
364 static struct vio_driver hvc_vio_driver = {
365 	.id_table	= hvc_driver_table,
366 	.probe		= hvc_vio_probe,
367 	.name		= hvc_driver_name,
368 	.driver = {
369 		.suppress_bind_attrs	= true,
370 	},
371 };
372 
373 static int __init hvc_vio_init(void)
374 {
375 	int rc;
376 
377 	/* Register as a vio device to receive callbacks */
378 	rc = vio_register_driver(&hvc_vio_driver);
379 
380 	return rc;
381 }
382 device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */
383 
384 void __init hvc_vio_init_early(void)
385 {
386 	const __be32 *termno;
387 	const char *name;
388 	const struct hv_ops *ops;
389 
390 	/* find the boot console from /chosen/stdout */
391 	if (!of_stdout)
392 		return;
393 	name = of_get_property(of_stdout, "name", NULL);
394 	if (!name) {
395 		printk(KERN_WARNING "stdout node missing 'name' property!\n");
396 		return;
397 	}
398 
399 	/* Check if it's a virtual terminal */
400 	if (strncmp(name, "vty", 3) != 0)
401 		return;
402 	termno = of_get_property(of_stdout, "reg", NULL);
403 	if (termno == NULL)
404 		return;
405 	hvterm_priv0.termno = of_read_number(termno, 1);
406 	spin_lock_init(&hvterm_priv0.buf_lock);
407 	hvterm_privs[0] = &hvterm_priv0;
408 
409 	/* Check the protocol */
410 	if (of_device_is_compatible(of_stdout, "hvterm1")) {
411 		hvterm_priv0.proto = HV_PROTOCOL_RAW;
412 		ops = &hvterm_raw_ops;
413 	}
414 	else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) {
415 		hvterm_priv0.proto = HV_PROTOCOL_HVSI;
416 		ops = &hvterm_hvsi_ops;
417 		hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
418 			     hvterm_priv0.termno, 1);
419 		/* HVSI, perform the handshake now */
420 		hvsilib_establish(&hvterm_priv0.hvsi);
421 	} else
422 		return;
423 	udbg_putc = udbg_hvc_putc;
424 	udbg_getc = udbg_hvc_getc;
425 	udbg_getc_poll = udbg_hvc_getc_poll;
426 #ifdef HVC_OLD_HVSI
427 	/* When using the old HVSI driver don't register the HVC
428 	 * backend for HVSI, only do udbg
429 	 */
430 	if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
431 		return;
432 #endif
433 	/* Check whether the user has requested a different console. */
434 	if (!strstr(boot_command_line, "console="))
435 		add_preferred_console("hvc", 0, NULL);
436 	hvc_instantiate(0, 0, ops);
437 }
438 
439 /* call this from early_init() for a working debug console on
440  * vterm capable LPAR machines
441  */
442 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
443 void __init udbg_init_debug_lpar(void)
444 {
445 	/*
446 	 * If we're running as a hypervisor then we definitely can't call the
447 	 * hypervisor to print debug output (we *are* the hypervisor), so don't
448 	 * register if we detect that MSR_HV=1.
449 	 */
450 	if (mfmsr() & MSR_HV)
451 		return;
452 
453 	hvterm_privs[0] = &hvterm_priv0;
454 	hvterm_priv0.termno = 0;
455 	hvterm_priv0.proto = HV_PROTOCOL_RAW;
456 	spin_lock_init(&hvterm_priv0.buf_lock);
457 	udbg_putc = udbg_hvc_putc;
458 	udbg_getc = udbg_hvc_getc;
459 	udbg_getc_poll = udbg_hvc_getc_poll;
460 }
461 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
462 
463 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
464 void __init udbg_init_debug_lpar_hvsi(void)
465 {
466 	/* See comment above in udbg_init_debug_lpar() */
467 	if (mfmsr() & MSR_HV)
468 		return;
469 
470 	hvterm_privs[0] = &hvterm_priv0;
471 	hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
472 	hvterm_priv0.proto = HV_PROTOCOL_HVSI;
473 	spin_lock_init(&hvterm_priv0.buf_lock);
474 	udbg_putc = udbg_hvc_putc;
475 	udbg_getc = udbg_hvc_getc;
476 	udbg_getc_poll = udbg_hvc_getc_poll;
477 	hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
478 		     hvterm_priv0.termno, 1);
479 	hvsilib_establish(&hvterm_priv0.hvsi);
480 }
481 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */
482