1 // SPDX-License-Identifier: GPL-2.0+
3 * vio driver interface to hvc_console.c
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.
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
15 * Additional Author(s):
16 * Ryan S. Arnold <rsa@us.ibm.com>
20 * - handle error in sending hvsi protocol packets
21 * - retry nego on subsequent sends ?
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>
32 #include <asm/hvconsole.h>
37 #include <asm/machdep.h>
39 #include "hvc_console.h"
41 static const char hvc_driver_name[] = "hvc_console";
43 static const struct vio_device_id hvc_driver_table[] = {
44 {"serial", "hvterm1"},
46 {"serial", "hvterm-protocol"},
51 typedef enum hv_protocol {
57 u32 termno; /* HV term number */
58 hv_protocol_t proto; /* Raw data or HVSI packets */
59 struct hvsi_priv hvsi; /* HVSI specific data */
61 char buf[SIZE_VIO_GET_CHARS];
65 static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
66 /* For early boot console */
67 static struct hvterm_priv hvterm_priv0;
69 static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
71 struct hvterm_priv *pv = hvterm_privs[vtermno];
79 spin_lock_irqsave(&pv->buf_lock, flags);
83 pv->left = hvc_get_chars(pv->termno, pv->buf, count);
86 * Work around a HV bug where it gives us a null
87 * after every \r. -- paulus
89 for (i = 1; i < pv->left; ++i) {
90 if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
93 memmove(&pv->buf[i], &pv->buf[i+1],
100 got = min(count, pv->left);
101 memcpy(buf, &pv->buf[pv->offset], got);
105 spin_unlock_irqrestore(&pv->buf_lock, flags);
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.
118 static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
120 struct hvterm_priv *pv = hvterm_privs[vtermno];
125 return hvc_put_chars(pv->termno, buf, count);
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,
136 static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
138 struct hvterm_priv *pv = hvterm_privs[vtermno];
143 return hvsilib_get_chars(&pv->hvsi, buf, count);
146 static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
148 struct hvterm_priv *pv = hvterm_privs[vtermno];
153 return hvsilib_put_chars(&pv->hvsi, buf, count);
156 static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
158 struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
161 pr_devel("HVSI@%x: open !\n", pv->termno);
163 rc = notifier_add_irq(hp, data);
167 return hvsilib_open(&pv->hvsi, hp);
170 static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
172 struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
174 pr_devel("HVSI@%x: do close !\n", pv->termno);
176 hvsilib_close(&pv->hvsi, hp);
178 notifier_del_irq(hp, data);
181 void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
183 struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
185 pr_devel("HVSI@%x: do hangup !\n", pv->termno);
187 hvsilib_close(&pv->hvsi, hp);
189 notifier_hangup_irq(hp, data);
192 static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
194 struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
198 return pv->hvsi.mctrl;
201 static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
204 struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
206 pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
207 pv->termno, set, clear);
210 hvsilib_write_mctrl(&pv->hvsi, 1);
211 else if (clear & TIOCM_DTR)
212 hvsilib_write_mctrl(&pv->hvsi, 0);
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,
227 static void udbg_hvc_putc(char c)
230 unsigned char bounce_buffer[16];
232 if (!hvterm_privs[0])
239 switch(hvterm_privs[0]->proto) {
240 case HV_PROTOCOL_RAW:
242 * hvterm_raw_put_chars requires at least a 16-byte
243 * buffer, so go via the bounce buffer
245 bounce_buffer[0] = c;
246 count = hvterm_raw_put_chars(0, bounce_buffer, 1);
248 case HV_PROTOCOL_HVSI:
249 count = hvterm_hvsi_put_chars(0, &c, 1);
255 static int udbg_hvc_getc_poll(void)
260 if (!hvterm_privs[0])
263 switch(hvterm_privs[0]->proto) {
264 case HV_PROTOCOL_RAW:
265 rc = hvterm_raw_get_chars(0, &c, 1);
267 case HV_PROTOCOL_HVSI:
268 rc = hvterm_hvsi_get_chars(0, &c, 1);
276 static int udbg_hvc_getc(void)
280 if (!hvterm_privs[0])
284 ch = udbg_hvc_getc_poll();
286 /* This shouldn't be needed...but... */
287 volatile unsigned long delay;
288 for (delay=0; delay < 2000000; delay++)
296 static int hvc_vio_probe(struct vio_dev *vdev,
297 const struct vio_device_id *id)
299 const struct hv_ops *ops;
300 struct hvc_struct *hp;
301 struct hvterm_priv *pv;
305 /* probed with invalid parameters. */
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;
316 pr_err("hvc_vio: Unknown protocol for %pOF\n", vdev->dev.of_node);
320 pr_devel("hvc_vio_probe() device %pOF, using %s protocol\n",
322 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
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];
329 pr_devel("->boot console, using termno 0\n");
331 /* nope, allocate a new one */
333 for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
334 if (!hvterm_privs[i])
336 pr_devel("->non-boot console, using termno %d\n", termno);
339 pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
342 pv->termno = vdev->unit_address;
344 spin_lock_init(&pv->buf_lock);
345 hvterm_privs[termno] = pv;
346 hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
350 hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
353 dev_set_drvdata(&vdev->dev, hp);
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;
365 static struct vio_driver hvc_vio_driver = {
366 .id_table = hvc_driver_table,
367 .probe = hvc_vio_probe,
368 .name = hvc_driver_name,
370 .suppress_bind_attrs = true,
374 static int __init hvc_vio_init(void)
378 /* Register as a vio device to receive callbacks */
379 rc = vio_register_driver(&hvc_vio_driver);
383 device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */
385 void __init hvc_vio_init_early(void)
387 const __be32 *termno;
389 const struct hv_ops *ops;
391 /* find the boot console from /chosen/stdout */
394 name = of_get_property(of_stdout, "name", NULL);
396 printk(KERN_WARNING "stdout node missing 'name' property!\n");
400 /* Check if it's a virtual terminal */
401 if (strncmp(name, "vty", 3) != 0)
403 termno = of_get_property(of_stdout, "reg", NULL);
406 hvterm_priv0.termno = of_read_number(termno, 1);
407 spin_lock_init(&hvterm_priv0.buf_lock);
408 hvterm_privs[0] = &hvterm_priv0;
410 /* Check the protocol */
411 if (of_device_is_compatible(of_stdout, "hvterm1")) {
412 hvterm_priv0.proto = HV_PROTOCOL_RAW;
413 ops = &hvterm_raw_ops;
415 else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) {
416 hvterm_priv0.proto = HV_PROTOCOL_HVSI;
417 ops = &hvterm_hvsi_ops;
418 hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
419 hvterm_priv0.termno, 1);
420 /* HVSI, perform the handshake now */
421 hvsilib_establish(&hvterm_priv0.hvsi);
424 udbg_putc = udbg_hvc_putc;
425 udbg_getc = udbg_hvc_getc;
426 udbg_getc_poll = udbg_hvc_getc_poll;
428 /* When using the old HVSI driver don't register the HVC
429 * backend for HVSI, only do udbg
431 if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
434 /* Check whether the user has requested a different console. */
435 if (!strstr(boot_command_line, "console="))
436 add_preferred_console("hvc", 0, NULL);
437 hvc_instantiate(0, 0, ops);
440 /* call this from early_init() for a working debug console on
441 * vterm capable LPAR machines
443 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
444 void __init udbg_init_debug_lpar(void)
447 * If we're running as a hypervisor then we definitely can't call the
448 * hypervisor to print debug output (we *are* the hypervisor), so don't
449 * register if we detect that MSR_HV=1.
451 if (mfmsr() & MSR_HV)
454 hvterm_privs[0] = &hvterm_priv0;
455 hvterm_priv0.termno = 0;
456 hvterm_priv0.proto = HV_PROTOCOL_RAW;
457 spin_lock_init(&hvterm_priv0.buf_lock);
458 udbg_putc = udbg_hvc_putc;
459 udbg_getc = udbg_hvc_getc;
460 udbg_getc_poll = udbg_hvc_getc_poll;
462 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
464 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
465 void __init udbg_init_debug_lpar_hvsi(void)
467 /* See comment above in udbg_init_debug_lpar() */
468 if (mfmsr() & MSR_HV)
471 hvterm_privs[0] = &hvterm_priv0;
472 hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
473 hvterm_priv0.proto = HV_PROTOCOL_HVSI;
474 spin_lock_init(&hvterm_priv0.buf_lock);
475 udbg_putc = udbg_hvc_putc;
476 udbg_getc = udbg_hvc_getc;
477 udbg_getc_poll = udbg_hvc_getc_poll;
478 hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
479 hvterm_priv0.termno, 1);
480 hvsilib_establish(&hvterm_priv0.hvsi);
482 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */