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 static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count) 111 { 112 struct hvterm_priv *pv = hvterm_privs[vtermno]; 113 114 if (WARN_ON(!pv)) 115 return 0; 116 117 return hvc_put_chars(pv->termno, buf, count); 118 } 119 120 static const struct hv_ops hvterm_raw_ops = { 121 .get_chars = hvterm_raw_get_chars, 122 .put_chars = hvterm_raw_put_chars, 123 .notifier_add = notifier_add_irq, 124 .notifier_del = notifier_del_irq, 125 .notifier_hangup = notifier_hangup_irq, 126 }; 127 128 static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count) 129 { 130 struct hvterm_priv *pv = hvterm_privs[vtermno]; 131 132 if (WARN_ON(!pv)) 133 return 0; 134 135 return hvsilib_get_chars(&pv->hvsi, buf, count); 136 } 137 138 static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count) 139 { 140 struct hvterm_priv *pv = hvterm_privs[vtermno]; 141 142 if (WARN_ON(!pv)) 143 return 0; 144 145 return hvsilib_put_chars(&pv->hvsi, buf, count); 146 } 147 148 static int hvterm_hvsi_open(struct hvc_struct *hp, int data) 149 { 150 struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; 151 int rc; 152 153 pr_devel("HVSI@%x: open !\n", pv->termno); 154 155 rc = notifier_add_irq(hp, data); 156 if (rc) 157 return rc; 158 159 return hvsilib_open(&pv->hvsi, hp); 160 } 161 162 static void hvterm_hvsi_close(struct hvc_struct *hp, int data) 163 { 164 struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; 165 166 pr_devel("HVSI@%x: do close !\n", pv->termno); 167 168 hvsilib_close(&pv->hvsi, hp); 169 170 notifier_del_irq(hp, data); 171 } 172 173 void hvterm_hvsi_hangup(struct hvc_struct *hp, int data) 174 { 175 struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; 176 177 pr_devel("HVSI@%x: do hangup !\n", pv->termno); 178 179 hvsilib_close(&pv->hvsi, hp); 180 181 notifier_hangup_irq(hp, data); 182 } 183 184 static int hvterm_hvsi_tiocmget(struct hvc_struct *hp) 185 { 186 struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; 187 188 if (!pv) 189 return -EINVAL; 190 return pv->hvsi.mctrl; 191 } 192 193 static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set, 194 unsigned int clear) 195 { 196 struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; 197 198 pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n", 199 pv->termno, set, clear); 200 201 if (set & TIOCM_DTR) 202 hvsilib_write_mctrl(&pv->hvsi, 1); 203 else if (clear & TIOCM_DTR) 204 hvsilib_write_mctrl(&pv->hvsi, 0); 205 206 return 0; 207 } 208 209 static const struct hv_ops hvterm_hvsi_ops = { 210 .get_chars = hvterm_hvsi_get_chars, 211 .put_chars = hvterm_hvsi_put_chars, 212 .notifier_add = hvterm_hvsi_open, 213 .notifier_del = hvterm_hvsi_close, 214 .notifier_hangup = hvterm_hvsi_hangup, 215 .tiocmget = hvterm_hvsi_tiocmget, 216 .tiocmset = hvterm_hvsi_tiocmset, 217 }; 218 219 static void udbg_hvc_putc(char c) 220 { 221 int count = -1; 222 223 if (!hvterm_privs[0]) 224 return; 225 226 if (c == '\n') 227 udbg_hvc_putc('\r'); 228 229 do { 230 switch(hvterm_privs[0]->proto) { 231 case HV_PROTOCOL_RAW: 232 count = hvterm_raw_put_chars(0, &c, 1); 233 break; 234 case HV_PROTOCOL_HVSI: 235 count = hvterm_hvsi_put_chars(0, &c, 1); 236 break; 237 } 238 } while(count == 0); 239 } 240 241 static int udbg_hvc_getc_poll(void) 242 { 243 int rc = 0; 244 char c; 245 246 if (!hvterm_privs[0]) 247 return -1; 248 249 switch(hvterm_privs[0]->proto) { 250 case HV_PROTOCOL_RAW: 251 rc = hvterm_raw_get_chars(0, &c, 1); 252 break; 253 case HV_PROTOCOL_HVSI: 254 rc = hvterm_hvsi_get_chars(0, &c, 1); 255 break; 256 } 257 if (!rc) 258 return -1; 259 return c; 260 } 261 262 static int udbg_hvc_getc(void) 263 { 264 int ch; 265 266 if (!hvterm_privs[0]) 267 return -1; 268 269 for (;;) { 270 ch = udbg_hvc_getc_poll(); 271 if (ch == -1) { 272 /* This shouldn't be needed...but... */ 273 volatile unsigned long delay; 274 for (delay=0; delay < 2000000; delay++) 275 ; 276 } else { 277 return ch; 278 } 279 } 280 } 281 282 static int hvc_vio_probe(struct vio_dev *vdev, 283 const struct vio_device_id *id) 284 { 285 const struct hv_ops *ops; 286 struct hvc_struct *hp; 287 struct hvterm_priv *pv; 288 hv_protocol_t proto; 289 int i, termno = -1; 290 291 /* probed with invalid parameters. */ 292 if (!vdev || !id) 293 return -EPERM; 294 295 if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) { 296 proto = HV_PROTOCOL_RAW; 297 ops = &hvterm_raw_ops; 298 } else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) { 299 proto = HV_PROTOCOL_HVSI; 300 ops = &hvterm_hvsi_ops; 301 } else { 302 pr_err("hvc_vio: Unknown protocol for %pOF\n", vdev->dev.of_node); 303 return -ENXIO; 304 } 305 306 pr_devel("hvc_vio_probe() device %pOF, using %s protocol\n", 307 vdev->dev.of_node, 308 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi"); 309 310 /* Is it our boot one ? */ 311 if (hvterm_privs[0] == &hvterm_priv0 && 312 vdev->unit_address == hvterm_priv0.termno) { 313 pv = hvterm_privs[0]; 314 termno = 0; 315 pr_devel("->boot console, using termno 0\n"); 316 } 317 /* nope, allocate a new one */ 318 else { 319 for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++) 320 if (!hvterm_privs[i]) 321 termno = i; 322 pr_devel("->non-boot console, using termno %d\n", termno); 323 if (termno < 0) 324 return -ENODEV; 325 pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL); 326 if (!pv) 327 return -ENOMEM; 328 pv->termno = vdev->unit_address; 329 pv->proto = proto; 330 spin_lock_init(&pv->buf_lock); 331 hvterm_privs[termno] = pv; 332 hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars, 333 pv->termno, 0); 334 } 335 336 hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS); 337 if (IS_ERR(hp)) 338 return PTR_ERR(hp); 339 dev_set_drvdata(&vdev->dev, hp); 340 341 /* register udbg if it's not there already for console 0 */ 342 if (hp->index == 0 && !udbg_putc) { 343 udbg_putc = udbg_hvc_putc; 344 udbg_getc = udbg_hvc_getc; 345 udbg_getc_poll = udbg_hvc_getc_poll; 346 } 347 348 return 0; 349 } 350 351 static struct vio_driver hvc_vio_driver = { 352 .id_table = hvc_driver_table, 353 .probe = hvc_vio_probe, 354 .name = hvc_driver_name, 355 .driver = { 356 .suppress_bind_attrs = true, 357 }, 358 }; 359 360 static int __init hvc_vio_init(void) 361 { 362 int rc; 363 364 /* Register as a vio device to receive callbacks */ 365 rc = vio_register_driver(&hvc_vio_driver); 366 367 return rc; 368 } 369 device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */ 370 371 void __init hvc_vio_init_early(void) 372 { 373 const __be32 *termno; 374 const char *name; 375 const struct hv_ops *ops; 376 377 /* find the boot console from /chosen/stdout */ 378 if (!of_stdout) 379 return; 380 name = of_get_property(of_stdout, "name", NULL); 381 if (!name) { 382 printk(KERN_WARNING "stdout node missing 'name' property!\n"); 383 return; 384 } 385 386 /* Check if it's a virtual terminal */ 387 if (strncmp(name, "vty", 3) != 0) 388 return; 389 termno = of_get_property(of_stdout, "reg", NULL); 390 if (termno == NULL) 391 return; 392 hvterm_priv0.termno = of_read_number(termno, 1); 393 spin_lock_init(&hvterm_priv0.buf_lock); 394 hvterm_privs[0] = &hvterm_priv0; 395 396 /* Check the protocol */ 397 if (of_device_is_compatible(of_stdout, "hvterm1")) { 398 hvterm_priv0.proto = HV_PROTOCOL_RAW; 399 ops = &hvterm_raw_ops; 400 } 401 else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) { 402 hvterm_priv0.proto = HV_PROTOCOL_HVSI; 403 ops = &hvterm_hvsi_ops; 404 hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars, 405 hvterm_priv0.termno, 1); 406 /* HVSI, perform the handshake now */ 407 hvsilib_establish(&hvterm_priv0.hvsi); 408 } else 409 return; 410 udbg_putc = udbg_hvc_putc; 411 udbg_getc = udbg_hvc_getc; 412 udbg_getc_poll = udbg_hvc_getc_poll; 413 #ifdef HVC_OLD_HVSI 414 /* When using the old HVSI driver don't register the HVC 415 * backend for HVSI, only do udbg 416 */ 417 if (hvterm_priv0.proto == HV_PROTOCOL_HVSI) 418 return; 419 #endif 420 /* Check whether the user has requested a different console. */ 421 if (!strstr(boot_command_line, "console=")) 422 add_preferred_console("hvc", 0, NULL); 423 hvc_instantiate(0, 0, ops); 424 } 425 426 /* call this from early_init() for a working debug console on 427 * vterm capable LPAR machines 428 */ 429 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR 430 void __init udbg_init_debug_lpar(void) 431 { 432 /* 433 * If we're running as a hypervisor then we definitely can't call the 434 * hypervisor to print debug output (we *are* the hypervisor), so don't 435 * register if we detect that MSR_HV=1. 436 */ 437 if (mfmsr() & MSR_HV) 438 return; 439 440 hvterm_privs[0] = &hvterm_priv0; 441 hvterm_priv0.termno = 0; 442 hvterm_priv0.proto = HV_PROTOCOL_RAW; 443 spin_lock_init(&hvterm_priv0.buf_lock); 444 udbg_putc = udbg_hvc_putc; 445 udbg_getc = udbg_hvc_getc; 446 udbg_getc_poll = udbg_hvc_getc_poll; 447 } 448 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */ 449 450 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI 451 void __init udbg_init_debug_lpar_hvsi(void) 452 { 453 /* See comment above in udbg_init_debug_lpar() */ 454 if (mfmsr() & MSR_HV) 455 return; 456 457 hvterm_privs[0] = &hvterm_priv0; 458 hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO; 459 hvterm_priv0.proto = HV_PROTOCOL_HVSI; 460 spin_lock_init(&hvterm_priv0.buf_lock); 461 udbg_putc = udbg_hvc_putc; 462 udbg_getc = udbg_hvc_getc; 463 udbg_getc_poll = udbg_hvc_getc_poll; 464 hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars, 465 hvterm_priv0.termno, 1); 466 hvsilib_establish(&hvterm_priv0.hvsi); 467 } 468 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */ 469