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1// SPDX-License-Identifier: GPL-2.0+2/*3 * vio driver interface to hvc_console.c4 *5 * This code was moved here to allow the remaining code to be reused as a6 * generic polling mode with semi-reliable transport driver core to the7 * console and tty subsystems.8 *9 *10 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM11 * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM12 * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.13 * Copyright (C) 2004 IBM Corporation14 *15 * Additional Author(s):16 * Ryan S. Arnold <rsa@us.ibm.com>17 *18 * TODO:19 *20 * - handle error in sending hvsi protocol packets21 * - retry nego on subsequent sends ?22 */23 24#undef DEBUG25 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 41static const char hvc_driver_name[] = "hvc_console";42 43static const struct vio_device_id hvc_driver_table[] = {44 {"serial", "hvterm1"},45#ifndef HVC_OLD_HVSI46 {"serial", "hvterm-protocol"},47#endif48 { "", "" }49};50 51typedef enum hv_protocol {52 HV_PROTOCOL_RAW,53 HV_PROTOCOL_HVSI54} hv_protocol_t;55 56struct 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};65static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];66/* For early boot console */67static struct hvterm_priv hvterm_priv0;68 69static 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 null87 * after every \r. -- paulus88 */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(&pv->buf_lock, flags);106 107 return got;108}109 110/**111 * hvterm_raw_put_chars: send characters to firmware for given vterm adapter112 * @vtermno: The virtual terminal number.113 * @buf: The characters to send. Because of the underlying hypercall in114 * hvc_put_chars(), this buffer must be at least 16 bytes long, even if115 * you are sending fewer chars.116 * @count: number of chars to send.117 */118static 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 129static 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 137static 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 147static 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 158static 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 172static 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 183static 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 194static 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 203static 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 219static 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 229static 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('\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-byte245 * buffer, so go via the bounce buffer246 */247 bounce_buffer[0] = c;248 count = hvterm_raw_put_chars(0, bounce_buffer, 1);249 break;250 case HV_PROTOCOL_HVSI:251 count = hvterm_hvsi_put_chars(0, &c, 1);252 break;253 }254 } while (count == 0 || count == -EAGAIN);255}256 257static 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(0, &c, 1);268 break;269 case HV_PROTOCOL_HVSI:270 rc = hvterm_hvsi_get_chars(0, &c, 1);271 break;272 }273 if (!rc)274 return -1;275 return c;276}277 278static 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 298static 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(vdev->dev.of_node, "hvterm1")) {312 proto = HV_PROTOCOL_RAW;313 ops = &hvterm_raw_ops;314 } else if (of_device_is_compatible(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(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(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);353 if (IS_ERR(hp))354 return PTR_ERR(hp);355 dev_set_drvdata(&vdev->dev, 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 367static 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 376static 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}385device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */386 387void __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(of_stdout, "vty"))395 return;396 termno = of_get_property(of_stdout, "reg", NULL);397 if (termno == NULL)398 return;399 hvterm_priv0.termno = of_read_number(termno, 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(of_stdout, "hvterm1")) {405 hvterm_priv0.proto = HV_PROTOCOL_RAW;406 ops = &hvterm_raw_ops;407 }408 else if (of_device_is_compatible(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 } else416 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_HVSI421 /* When using the old HVSI driver don't register the HVC422 * backend for HVSI, only do udbg423 */424 if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)425 return;426#endif427 /* Check whether the user has requested a different console. */428 if (!strstr(boot_command_line, "console="))429 add_preferred_console("hvc", 0, NULL);430 hvc_instantiate(0, 0, ops);431}432 433/* call this from early_init() for a working debug console on434 * vterm capable LPAR machines435 */436#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR437void __init udbg_init_debug_lpar(void)438{439 /*440 * If we're running as a hypervisor then we definitely can't call the441 * hypervisor to print debug output (we *are* the hypervisor), so don't442 * 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_HVSI458void __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