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 32 #include <asm/hvconsole.h> 33 #include <asm/vio.h> 34 #include <asm/prom.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 char buf[SIZE_VIO_GET_CHARS]; 62 int left; 63 int 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 int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count) 70 { 71 struct hvterm_priv *pv = hvterm_privs[vtermno]; 72 unsigned long i; 73 unsigned long flags; 74 int 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(&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 int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count) 119 { 120 struct hvterm_priv *pv = hvterm_privs[vtermno]; 121 122 if (WARN_ON(!pv)) 123 return 0; 124 125 return hvc_put_chars(pv->termno, buf, count); 126 } 127 128 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, 134 }; 135 136 static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count) 137 { 138 struct hvterm_priv *pv = hvterm_privs[vtermno]; 139 140 if (WARN_ON(!pv)) 141 return 0; 142 143 return hvsilib_get_chars(&pv->hvsi, buf, count); 144 } 145 146 static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count) 147 { 148 struct hvterm_priv *pv = hvterm_privs[vtermno]; 149 150 if (WARN_ON(!pv)) 151 return 0; 152 153 return hvsilib_put_chars(&pv->hvsi, buf, count); 154 } 155 156 static int hvterm_hvsi_open(struct hvc_struct *hp, int data) 157 { 158 struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; 159 int rc; 160 161 pr_devel("HVSI@%x: open !\n", pv->termno); 162 163 rc = notifier_add_irq(hp, data); 164 if (rc) 165 return rc; 166 167 return hvsilib_open(&pv->hvsi, hp); 168 } 169 170 static void hvterm_hvsi_close(struct hvc_struct *hp, int data) 171 { 172 struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; 173 174 pr_devel("HVSI@%x: do close !\n", pv->termno); 175 176 hvsilib_close(&pv->hvsi, hp); 177 178 notifier_del_irq(hp, data); 179 } 180 181 static void hvterm_hvsi_hangup(struct hvc_struct *hp, int data) 182 { 183 struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; 184 185 pr_devel("HVSI@%x: do hangup !\n", pv->termno); 186 187 hvsilib_close(&pv->hvsi, hp); 188 189 notifier_hangup_irq(hp, data); 190 } 191 192 static int hvterm_hvsi_tiocmget(struct hvc_struct *hp) 193 { 194 struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; 195 196 if (!pv) 197 return -EINVAL; 198 return pv->hvsi.mctrl; 199 } 200 201 static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set, 202 unsigned int clear) 203 { 204 struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; 205 206 pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n", 207 pv->termno, set, clear); 208 209 if (set & TIOCM_DTR) 210 hvsilib_write_mctrl(&pv->hvsi, 1); 211 else if (clear & TIOCM_DTR) 212 hvsilib_write_mctrl(&pv->hvsi, 0); 213 214 return 0; 215 } 216 217 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, 225 }; 226 227 static void udbg_hvc_putc(char c) 228 { 229 int count = -1; 230 unsigned char bounce_buffer[16]; 231 232 if (!hvterm_privs[0]) 233 return; 234 235 if (c == '\n') 236 udbg_hvc_putc('\r'); 237 238 do { 239 switch(hvterm_privs[0]->proto) { 240 case HV_PROTOCOL_RAW: 241 /* 242 * hvterm_raw_put_chars requires at least a 16-byte 243 * buffer, so go via the bounce buffer 244 */ 245 bounce_buffer[0] = c; 246 count = hvterm_raw_put_chars(0, bounce_buffer, 1); 247 break; 248 case HV_PROTOCOL_HVSI: 249 count = hvterm_hvsi_put_chars(0, &c, 1); 250 break; 251 } 252 } while (count == 0 || count == -EAGAIN); 253 } 254 255 static 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 } 275 276 static 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 } 295 296 static 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 %pOF\n", vdev->dev.of_node); 317 return -ENXIO; 318 } 319 320 pr_devel("hvc_vio_probe() device %pOF, using %s protocol\n", 321 vdev->dev.of_node, 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 } 364 365 static struct vio_driver hvc_vio_driver = { 366 .id_table = hvc_driver_table, 367 .probe = hvc_vio_probe, 368 .name = hvc_driver_name, 369 .driver = { 370 .suppress_bind_attrs = true, 371 }, 372 }; 373 374 static int __init hvc_vio_init(void) 375 { 376 int rc; 377 378 /* Register as a vio device to receive callbacks */ 379 rc = vio_register_driver(&hvc_vio_driver); 380 381 return rc; 382 } 383 device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */ 384 385 void __init hvc_vio_init_early(void) 386 { 387 const __be32 *termno; 388 const struct hv_ops *ops; 389 390 /* find the boot console from /chosen/stdout */ 391 /* Check if it's a virtual terminal */ 392 if (!of_node_name_prefix(of_stdout, "vty")) 393 return; 394 termno = of_get_property(of_stdout, "reg", NULL); 395 if (termno == NULL) 396 return; 397 hvterm_priv0.termno = of_read_number(termno, 1); 398 spin_lock_init(&hvterm_priv0.buf_lock); 399 hvterm_privs[0] = &hvterm_priv0; 400 401 /* Check the protocol */ 402 if (of_device_is_compatible(of_stdout, "hvterm1")) { 403 hvterm_priv0.proto = HV_PROTOCOL_RAW; 404 ops = &hvterm_raw_ops; 405 } 406 else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) { 407 hvterm_priv0.proto = HV_PROTOCOL_HVSI; 408 ops = &hvterm_hvsi_ops; 409 hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars, 410 hvterm_priv0.termno, 1); 411 /* HVSI, perform the handshake now */ 412 hvsilib_establish(&hvterm_priv0.hvsi); 413 } else 414 return; 415 udbg_putc = udbg_hvc_putc; 416 udbg_getc = udbg_hvc_getc; 417 udbg_getc_poll = udbg_hvc_getc_poll; 418 #ifdef HVC_OLD_HVSI 419 /* When using the old HVSI driver don't register the HVC 420 * backend for HVSI, only do udbg 421 */ 422 if (hvterm_priv0.proto == HV_PROTOCOL_HVSI) 423 return; 424 #endif 425 /* Check whether the user has requested a different console. */ 426 if (!strstr(boot_command_line, "console=")) 427 add_preferred_console("hvc", 0, NULL); 428 hvc_instantiate(0, 0, ops); 429 } 430 431 /* call this from early_init() for a working debug console on 432 * vterm capable LPAR machines 433 */ 434 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR 435 void __init udbg_init_debug_lpar(void) 436 { 437 /* 438 * If we're running as a hypervisor then we definitely can't call the 439 * hypervisor to print debug output (we *are* the hypervisor), so don't 440 * register if we detect that MSR_HV=1. 441 */ 442 if (mfmsr() & MSR_HV) 443 return; 444 445 hvterm_privs[0] = &hvterm_priv0; 446 hvterm_priv0.termno = 0; 447 hvterm_priv0.proto = HV_PROTOCOL_RAW; 448 spin_lock_init(&hvterm_priv0.buf_lock); 449 udbg_putc = udbg_hvc_putc; 450 udbg_getc = udbg_hvc_getc; 451 udbg_getc_poll = udbg_hvc_getc_poll; 452 } 453 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */ 454 455 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI 456 void __init udbg_init_debug_lpar_hvsi(void) 457 { 458 /* See comment above in udbg_init_debug_lpar() */ 459 if (mfmsr() & MSR_HV) 460 return; 461 462 hvterm_privs[0] = &hvterm_priv0; 463 hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO; 464 hvterm_priv0.proto = HV_PROTOCOL_HVSI; 465 spin_lock_init(&hvterm_priv0.buf_lock); 466 udbg_putc = udbg_hvc_putc; 467 udbg_getc = udbg_hvc_getc; 468 udbg_getc_poll = udbg_hvc_getc_poll; 469 hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars, 470 hvterm_priv0.termno, 1); 471 hvsilib_establish(&hvterm_priv0.hvsi); 472 } 473 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */ 474