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 #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 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 u8 buf[SIZE_VIO_GET_CHARS]; 62 size_t left; 63 size_t 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 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 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 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 } 128 129 static 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 }; 136 137 static 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 } 146 147 static 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 } 157 158 static 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 } 171 172 static 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 } 182 183 static 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 } 193 194 static 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 } 202 203 static 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 } 218 219 static 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 }; 228 229 static 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-byte 245 * buffer, so go via the bounce buffer 246 */ 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 } 256 257 static 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 } 277 278 static 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 } 297 298 static 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 } 366 367 static 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 }; 375 376 static 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 } 385 device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */ 386 387 void __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 } else 416 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_HVSI 421 /* When using the old HVSI driver don't register the HVC 422 * backend for HVSI, only do udbg 423 */ 424 if (hvterm_priv0.proto == HV_PROTOCOL_HVSI) 425 return; 426 #endif 427 /* 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 on 434 * vterm capable LPAR machines 435 */ 436 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR 437 void __init udbg_init_debug_lpar(void) 438 { 439 /* 440 * If we're running as a hypervisor then we definitely can't call the 441 * hypervisor to print debug output (we *are* the hypervisor), so don't 442 * 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_HVSI 458 void __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