Root/drivers/tty/hvc/hvc_vio.c

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#include <linux/module.h>
45
46#include <asm/hvconsole.h>
47#include <asm/vio.h>
48#include <asm/prom.h>
49#include <asm/hvsi.h>
50#include <asm/udbg.h>
51
52#include "hvc_console.h"
53
54static const char hvc_driver_name[] = "hvc_console";
55
56static struct vio_device_id hvc_driver_table[] = {
57    {"serial", "hvterm1"},
58#ifndef HVC_OLD_HVSI
59    {"serial", "hvterm-protocol"},
60#endif
61    { "", "" }
62};
63MODULE_DEVICE_TABLE(vio, hvc_driver_table);
64
65typedef enum hv_protocol {
66    HV_PROTOCOL_RAW,
67    HV_PROTOCOL_HVSI
68} hv_protocol_t;
69
70struct hvterm_priv {
71    u32 termno; /* HV term number */
72    hv_protocol_t proto; /* Raw data or HVSI packets */
73    struct hvsi_priv hvsi; /* HVSI specific data */
74    spinlock_t buf_lock;
75    char buf[SIZE_VIO_GET_CHARS];
76    int left;
77    int offset;
78};
79static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
80/* For early boot console */
81static struct hvterm_priv hvterm_priv0;
82
83static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
84{
85    struct hvterm_priv *pv = hvterm_privs[vtermno];
86    unsigned long i;
87    unsigned long flags;
88    int got;
89
90    if (WARN_ON(!pv))
91        return 0;
92
93    spin_lock_irqsave(&pv->buf_lock, flags);
94
95    if (pv->left == 0) {
96        pv->offset = 0;
97        pv->left = hvc_get_chars(pv->termno, pv->buf, count);
98
99        /*
100         * Work around a HV bug where it gives us a null
101         * after every \r. -- paulus
102         */
103        for (i = 1; i < pv->left; ++i) {
104            if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
105                --pv->left;
106                if (i < pv->left) {
107                    memmove(&pv->buf[i], &pv->buf[i+1],
108                        pv->left - i);
109                }
110            }
111        }
112    }
113
114    got = min(count, pv->left);
115    memcpy(buf, &pv->buf[pv->offset], got);
116    pv->offset += got;
117    pv->left -= got;
118
119    spin_unlock_irqrestore(&pv->buf_lock, flags);
120
121    return got;
122}
123
124static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
125{
126    struct hvterm_priv *pv = hvterm_privs[vtermno];
127
128    if (WARN_ON(!pv))
129        return 0;
130
131    return hvc_put_chars(pv->termno, buf, count);
132}
133
134static const struct hv_ops hvterm_raw_ops = {
135    .get_chars = hvterm_raw_get_chars,
136    .put_chars = hvterm_raw_put_chars,
137    .notifier_add = notifier_add_irq,
138    .notifier_del = notifier_del_irq,
139    .notifier_hangup = notifier_hangup_irq,
140};
141
142static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
143{
144    struct hvterm_priv *pv = hvterm_privs[vtermno];
145
146    if (WARN_ON(!pv))
147        return 0;
148
149    return hvsilib_get_chars(&pv->hvsi, buf, count);
150}
151
152static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
153{
154    struct hvterm_priv *pv = hvterm_privs[vtermno];
155
156    if (WARN_ON(!pv))
157        return 0;
158
159    return hvsilib_put_chars(&pv->hvsi, buf, count);
160}
161
162static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
163{
164    struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
165    int rc;
166
167    pr_devel("HVSI@%x: open !\n", pv->termno);
168
169    rc = notifier_add_irq(hp, data);
170    if (rc)
171        return rc;
172
173    return hvsilib_open(&pv->hvsi, hp);
174}
175
176static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
177{
178    struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
179
180    pr_devel("HVSI@%x: do close !\n", pv->termno);
181
182    hvsilib_close(&pv->hvsi, hp);
183
184    notifier_del_irq(hp, data);
185}
186
187void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
188{
189    struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
190
191    pr_devel("HVSI@%x: do hangup !\n", pv->termno);
192
193    hvsilib_close(&pv->hvsi, hp);
194
195    notifier_hangup_irq(hp, data);
196}
197
198static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
199{
200    struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
201
202    if (!pv)
203        return -EINVAL;
204    return pv->hvsi.mctrl;
205}
206
207static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
208                unsigned int clear)
209{
210    struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
211
212    pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
213         pv->termno, set, clear);
214
215    if (set & TIOCM_DTR)
216        hvsilib_write_mctrl(&pv->hvsi, 1);
217    else if (clear & TIOCM_DTR)
218        hvsilib_write_mctrl(&pv->hvsi, 0);
219
220    return 0;
221}
222
223static const struct hv_ops hvterm_hvsi_ops = {
224    .get_chars = hvterm_hvsi_get_chars,
225    .put_chars = hvterm_hvsi_put_chars,
226    .notifier_add = hvterm_hvsi_open,
227    .notifier_del = hvterm_hvsi_close,
228    .notifier_hangup = hvterm_hvsi_hangup,
229    .tiocmget = hvterm_hvsi_tiocmget,
230    .tiocmset = hvterm_hvsi_tiocmset,
231};
232
233static void udbg_hvc_putc(char c)
234{
235    int count = -1;
236
237    if (!hvterm_privs[0])
238        return;
239
240    if (c == '\n')
241        udbg_hvc_putc('\r');
242
243    do {
244        switch(hvterm_privs[0]->proto) {
245        case HV_PROTOCOL_RAW:
246            count = hvterm_raw_put_chars(0, &c, 1);
247            break;
248        case HV_PROTOCOL_HVSI:
249            count = hvterm_hvsi_put_chars(0, &c, 1);
250            break;
251        }
252    } while(count == 0);
253}
254
255static 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(0, &c, 1);
266        break;
267    case HV_PROTOCOL_HVSI:
268        rc = hvterm_hvsi_get_chars(0, &c, 1);
269        break;
270    }
271    if (!rc)
272        return -1;
273    return c;
274}
275
276static 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
296static 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(vdev->dev.of_node, "hvterm1")) {
310        proto = HV_PROTOCOL_RAW;
311        ops = &hvterm_raw_ops;
312    } else if (of_device_is_compatible(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 %s\n", vdev->dev.of_node->full_name);
317        return -ENXIO;
318    }
319
320    pr_devel("hvc_vio_probe() device %s, using %s protocol\n",
321         vdev->dev.of_node->full_name,
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(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(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
351    if (IS_ERR(hp))
352        return PTR_ERR(hp);
353    dev_set_drvdata(&vdev->dev, 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
365static int hvc_vio_remove(struct vio_dev *vdev)
366{
367    struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
368    int rc, termno;
369
370    termno = hp->vtermno;
371    rc = hvc_remove(hp);
372    if (rc == 0) {
373        if (hvterm_privs[termno] != &hvterm_priv0)
374            kfree(hvterm_privs[termno]);
375        hvterm_privs[termno] = NULL;
376    }
377    return rc;
378}
379
380static struct vio_driver hvc_vio_driver = {
381    .id_table = hvc_driver_table,
382    .probe = hvc_vio_probe,
383    .remove = hvc_vio_remove,
384    .name = hvc_driver_name,
385};
386
387static int __init hvc_vio_init(void)
388{
389    int rc;
390
391    /* Register as a vio device to receive callbacks */
392    rc = vio_register_driver(&hvc_vio_driver);
393
394    return rc;
395}
396module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
397
398static void __exit hvc_vio_exit(void)
399{
400    vio_unregister_driver(&hvc_vio_driver);
401}
402module_exit(hvc_vio_exit);
403
404void __init hvc_vio_init_early(void)
405{
406    struct device_node *stdout_node;
407    const u32 *termno;
408    const char *name;
409    const struct hv_ops *ops;
410
411    /* find the boot console from /chosen/stdout */
412    if (!of_chosen)
413        return;
414    name = of_get_property(of_chosen, "linux,stdout-path", NULL);
415    if (name == NULL)
416        return;
417    stdout_node = of_find_node_by_path(name);
418    if (!stdout_node)
419        return;
420    name = of_get_property(stdout_node, "name", NULL);
421    if (!name) {
422        printk(KERN_WARNING "stdout node missing 'name' property!\n");
423        goto out;
424    }
425
426    /* Check if it's a virtual terminal */
427    if (strncmp(name, "vty", 3) != 0)
428        goto out;
429    termno = of_get_property(stdout_node, "reg", NULL);
430    if (termno == NULL)
431        goto out;
432    hvterm_priv0.termno = *termno;
433    spin_lock_init(&hvterm_priv0.buf_lock);
434    hvterm_privs[0] = &hvterm_priv0;
435
436    /* Check the protocol */
437    if (of_device_is_compatible(stdout_node, "hvterm1")) {
438        hvterm_priv0.proto = HV_PROTOCOL_RAW;
439        ops = &hvterm_raw_ops;
440    }
441    else if (of_device_is_compatible(stdout_node, "hvterm-protocol")) {
442        hvterm_priv0.proto = HV_PROTOCOL_HVSI;
443        ops = &hvterm_hvsi_ops;
444        hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
445                 hvterm_priv0.termno, 1);
446        /* HVSI, perform the handshake now */
447        hvsilib_establish(&hvterm_priv0.hvsi);
448    } else
449        goto out;
450    udbg_putc = udbg_hvc_putc;
451    udbg_getc = udbg_hvc_getc;
452    udbg_getc_poll = udbg_hvc_getc_poll;
453#ifdef HVC_OLD_HVSI
454    /* When using the old HVSI driver don't register the HVC
455     * backend for HVSI, only do udbg
456     */
457    if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
458        goto out;
459#endif
460    add_preferred_console("hvc", 0, NULL);
461    hvc_instantiate(0, 0, ops);
462out:
463    of_node_put(stdout_node);
464}
465
466/* call this from early_init() for a working debug console on
467 * vterm capable LPAR machines
468 */
469#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
470void __init udbg_init_debug_lpar(void)
471{
472    hvterm_privs[0] = &hvterm_priv0;
473    hvterm_priv0.termno = 0;
474    hvterm_priv0.proto = HV_PROTOCOL_RAW;
475    spin_lock_init(&hvterm_priv0.buf_lock);
476    udbg_putc = udbg_hvc_putc;
477    udbg_getc = udbg_hvc_getc;
478    udbg_getc_poll = udbg_hvc_getc_poll;
479}
480#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
481
482#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
483void __init udbg_init_debug_lpar_hvsi(void)
484{
485    hvterm_privs[0] = &hvterm_priv0;
486    hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
487    hvterm_priv0.proto = HV_PROTOCOL_HVSI;
488    spin_lock_init(&hvterm_priv0.buf_lock);
489    udbg_putc = udbg_hvc_putc;
490    udbg_getc = udbg_hvc_getc;
491    udbg_getc_poll = udbg_hvc_getc_poll;
492    hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
493             hvterm_priv0.termno, 1);
494    hvsilib_establish(&hvterm_priv0.hvsi);
495}
496#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */
497

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