1/*
   2 *  PS3 virtual uart
   3 *
   4 *  Copyright (C) 2006 Sony Computer Entertainment Inc.
   5 *  Copyright 2006 Sony Corp.
   6 *
   7 *  This program is free software; you can redistribute it and/or modify
   8 *  it under the terms of the GNU General Public License as published by
   9 *  the Free Software Foundation; version 2 of the License.
  10 *
  11 *  This program is distributed in the hope that it will be useful,
  12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *  GNU General Public License for more details.
  15 *
  16 *  You should have received a copy of the GNU General Public License
  17 *  along with this program; if not, write to the Free Software
  18 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19 */
  20
  21#include <linux/kernel.h>
  22#include <linux/slab.h>
  23#include <linux/module.h>
  24#include <linux/interrupt.h>
  25#include <linux/workqueue.h>
  26#include <linux/bitops.h>
  27#include <asm/ps3.h>
  28
  29#include <asm/firmware.h>
  30#include <asm/lv1call.h>
  31
  32#include "vuart.h"
  33
  34MODULE_AUTHOR("Sony Corporation");
  35MODULE_LICENSE("GPL v2");
  36MODULE_DESCRIPTION("PS3 vuart");
  37
  38/**
  39 * vuart - An inter-partition data link service.
  40 *  port 0: PS3 AV Settings.
  41 *  port 2: PS3 System Manager.
  42 *
  43 * The vuart provides a bi-directional byte stream data link between logical
  44 * partitions.  Its primary role is as a communications link between the guest
  45 * OS and the system policy module.  The current HV does not support any
  46 * connections other than those listed.
  47 */
  48
  49enum {PORT_COUNT = 3,};
  50
  51enum vuart_param {
  52	PARAM_TX_TRIGGER = 0,
  53	PARAM_RX_TRIGGER = 1,
  54	PARAM_INTERRUPT_MASK = 2,
  55	PARAM_RX_BUF_SIZE = 3, /* read only */
  56	PARAM_RX_BYTES = 4, /* read only */
  57	PARAM_TX_BUF_SIZE = 5, /* read only */
  58	PARAM_TX_BYTES = 6, /* read only */
  59	PARAM_INTERRUPT_STATUS = 7, /* read only */
  60};
  61
  62enum vuart_interrupt_bit {
  63	INTERRUPT_BIT_TX = 0,
  64	INTERRUPT_BIT_RX = 1,
  65	INTERRUPT_BIT_DISCONNECT = 2,
  66};
  67
  68enum vuart_interrupt_mask {
  69	INTERRUPT_MASK_TX = 1,
  70	INTERRUPT_MASK_RX = 2,
  71	INTERRUPT_MASK_DISCONNECT = 4,
  72};
  73
  74/**
  75 * struct ps3_vuart_port_priv - private vuart device data.
  76 */
  77
  78struct ps3_vuart_port_priv {
  79	u64 interrupt_mask;
  80
  81	struct {
  82		spinlock_t lock;
  83		struct list_head head;
  84	} tx_list;
  85	struct {
  86		struct ps3_vuart_work work;
  87		unsigned long bytes_held;
  88		spinlock_t lock;
  89		struct list_head head;
  90	} rx_list;
  91	struct ps3_vuart_stats stats;
  92};
  93
  94static struct ps3_vuart_port_priv *to_port_priv(
  95	struct ps3_system_bus_device *dev)
  96{
  97	BUG_ON(!dev);
  98	BUG_ON(!dev->driver_priv);
  99	return (struct ps3_vuart_port_priv *)dev->driver_priv;
 100}
 101
 102/**
 103 * struct ports_bmp - bitmap indicating ports needing service.
 104 *
 105 * A 256 bit read only bitmap indicating ports needing service.  Do not write
 106 * to these bits.  Must not cross a page boundary.
 107 */
 108
 109struct ports_bmp {
 110	u64 status;
 111	u64 unused[3];
 112} __attribute__((aligned(32)));
 113
 114#define dump_ports_bmp(_b) _dump_ports_bmp(_b, __func__, __LINE__)
 115static void __maybe_unused _dump_ports_bmp(
 116	const struct ports_bmp *bmp, const char *func, int line)
 117{
 118	pr_debug("%s:%d: ports_bmp: %016llxh\n", func, line, bmp->status);
 119}
 120
 121#define dump_port_params(_b) _dump_port_params(_b, __func__, __LINE__)
 122static void __maybe_unused _dump_port_params(unsigned int port_number,
 123	const char *func, int line)
 124{
 125#if defined(DEBUG)
 126	static const char *strings[] = {
 127		"tx_trigger      ",
 128		"rx_trigger      ",
 129		"interrupt_mask  ",
 130		"rx_buf_size     ",
 131		"rx_bytes        ",
 132		"tx_buf_size     ",
 133		"tx_bytes        ",
 134		"interrupt_status",
 135	};
 136	int result;
 137	unsigned int i;
 138	u64 value;
 139
 140	for (i = 0; i < ARRAY_SIZE(strings); i++) {
 141		result = lv1_get_virtual_uart_param(port_number, i, &value);
 142
 143		if (result) {
 144			pr_debug("%s:%d: port_%u: %s failed: %s\n", func, line,
 145				port_number, strings[i], ps3_result(result));
 146			continue;
 147		}
 148		pr_debug("%s:%d: port_%u: %s = %lxh\n",
 149			func, line, port_number, strings[i], value);
 150	}
 151#endif
 152}
 153
 154struct vuart_triggers {
 155	unsigned long rx;
 156	unsigned long tx;
 157};
 158
 159int ps3_vuart_get_triggers(struct ps3_system_bus_device *dev,
 160	struct vuart_triggers *trig)
 161{
 162	int result;
 163	u64 size;
 164	u64 val;
 165	u64 tx;
 166
 167	result = lv1_get_virtual_uart_param(dev->port_number,
 168		PARAM_TX_TRIGGER, &tx);
 169	trig->tx = tx;
 170
 171	if (result) {
 172		dev_dbg(&dev->core, "%s:%d: tx_trigger failed: %s\n",
 173			__func__, __LINE__, ps3_result(result));
 174		return result;
 175	}
 176
 177	result = lv1_get_virtual_uart_param(dev->port_number,
 178		PARAM_RX_BUF_SIZE, &size);
 179
 180	if (result) {
 181		dev_dbg(&dev->core, "%s:%d: tx_buf_size failed: %s\n",
 182			__func__, __LINE__, ps3_result(result));
 183		return result;
 184	}
 185
 186	result = lv1_get_virtual_uart_param(dev->port_number,
 187		PARAM_RX_TRIGGER, &val);
 188
 189	if (result) {
 190		dev_dbg(&dev->core, "%s:%d: rx_trigger failed: %s\n",
 191			__func__, __LINE__, ps3_result(result));
 192		return result;
 193	}
 194
 195	trig->rx = size - val;
 196
 197	dev_dbg(&dev->core, "%s:%d: tx %lxh, rx %lxh\n", __func__, __LINE__,
 198		trig->tx, trig->rx);
 199
 200	return result;
 201}
 202
 203int ps3_vuart_set_triggers(struct ps3_system_bus_device *dev, unsigned int tx,
 204	unsigned int rx)
 205{
 206	int result;
 207	u64 size;
 208
 209	result = lv1_set_virtual_uart_param(dev->port_number,
 210		PARAM_TX_TRIGGER, tx);
 211
 212	if (result) {
 213		dev_dbg(&dev->core, "%s:%d: tx_trigger failed: %s\n",
 214			__func__, __LINE__, ps3_result(result));
 215		return result;
 216	}
 217
 218	result = lv1_get_virtual_uart_param(dev->port_number,
 219		PARAM_RX_BUF_SIZE, &size);
 220
 221	if (result) {
 222		dev_dbg(&dev->core, "%s:%d: tx_buf_size failed: %s\n",
 223			__func__, __LINE__, ps3_result(result));
 224		return result;
 225	}
 226
 227	result = lv1_set_virtual_uart_param(dev->port_number,
 228		PARAM_RX_TRIGGER, size - rx);
 229
 230	if (result) {
 231		dev_dbg(&dev->core, "%s:%d: rx_trigger failed: %s\n",
 232			__func__, __LINE__, ps3_result(result));
 233		return result;
 234	}
 235
 236	dev_dbg(&dev->core, "%s:%d: tx %xh, rx %xh\n", __func__, __LINE__,
 237		tx, rx);
 238
 239	return result;
 240}
 241
 242static int ps3_vuart_get_rx_bytes_waiting(struct ps3_system_bus_device *dev,
 243	u64 *bytes_waiting)
 244{
 245	int result;
 246
 247	result = lv1_get_virtual_uart_param(dev->port_number,
 248		PARAM_RX_BYTES, bytes_waiting);
 249
 250	if (result)
 251		dev_dbg(&dev->core, "%s:%d: rx_bytes failed: %s\n",
 252			__func__, __LINE__, ps3_result(result));
 253
 254	dev_dbg(&dev->core, "%s:%d: %llxh\n", __func__, __LINE__,
 255		*bytes_waiting);
 256	return result;
 257}
 258
 259/**
 260 * ps3_vuart_set_interrupt_mask - Enable/disable the port interrupt sources.
 261 * @dev: The struct ps3_system_bus_device instance.
 262 * @bmp: Logical OR of enum vuart_interrupt_mask values. A zero bit disables.
 263 */
 264
 265static int ps3_vuart_set_interrupt_mask(struct ps3_system_bus_device *dev,
 266	unsigned long mask)
 267{
 268	int result;
 269	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 270
 271	dev_dbg(&dev->core, "%s:%d: %lxh\n", __func__, __LINE__, mask);
 272
 273	priv->interrupt_mask = mask;
 274
 275	result = lv1_set_virtual_uart_param(dev->port_number,
 276		PARAM_INTERRUPT_MASK, priv->interrupt_mask);
 277
 278	if (result)
 279		dev_dbg(&dev->core, "%s:%d: interrupt_mask failed: %s\n",
 280			__func__, __LINE__, ps3_result(result));
 281
 282	return result;
 283}
 284
 285static int ps3_vuart_get_interrupt_status(struct ps3_system_bus_device *dev,
 286	unsigned long *status)
 287{
 288	int result;
 289	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 290	u64 tmp;
 291
 292	result = lv1_get_virtual_uart_param(dev->port_number,
 293		PARAM_INTERRUPT_STATUS, &tmp);
 294
 295	if (result)
 296		dev_dbg(&dev->core, "%s:%d: interrupt_status failed: %s\n",
 297			__func__, __LINE__, ps3_result(result));
 298
 299	*status = tmp & priv->interrupt_mask;
 300
 301	dev_dbg(&dev->core, "%s:%d: m %llxh, s %llxh, m&s %lxh\n",
 302		__func__, __LINE__, priv->interrupt_mask, tmp, *status);
 303
 304	return result;
 305}
 306
 307int ps3_vuart_enable_interrupt_tx(struct ps3_system_bus_device *dev)
 308{
 309	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 310
 311	return (priv->interrupt_mask & INTERRUPT_MASK_TX) ? 0
 312		: ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
 313		| INTERRUPT_MASK_TX);
 314}
 315
 316int ps3_vuart_enable_interrupt_rx(struct ps3_system_bus_device *dev)
 317{
 318	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 319
 320	return (priv->interrupt_mask & INTERRUPT_MASK_RX) ? 0
 321		: ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
 322		| INTERRUPT_MASK_RX);
 323}
 324
 325int ps3_vuart_enable_interrupt_disconnect(struct ps3_system_bus_device *dev)
 326{
 327	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 328
 329	return (priv->interrupt_mask & INTERRUPT_MASK_DISCONNECT) ? 0
 330		: ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
 331		| INTERRUPT_MASK_DISCONNECT);
 332}
 333
 334int ps3_vuart_disable_interrupt_tx(struct ps3_system_bus_device *dev)
 335{
 336	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 337
 338	return (priv->interrupt_mask & INTERRUPT_MASK_TX)
 339		? ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
 340		& ~INTERRUPT_MASK_TX) : 0;
 341}
 342
 343int ps3_vuart_disable_interrupt_rx(struct ps3_system_bus_device *dev)
 344{
 345	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 346
 347	return (priv->interrupt_mask & INTERRUPT_MASK_RX)
 348		? ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
 349		& ~INTERRUPT_MASK_RX) : 0;
 350}
 351
 352int ps3_vuart_disable_interrupt_disconnect(struct ps3_system_bus_device *dev)
 353{
 354	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 355
 356	return (priv->interrupt_mask & INTERRUPT_MASK_DISCONNECT)
 357		? ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
 358		& ~INTERRUPT_MASK_DISCONNECT) : 0;
 359}
 360
 361/**
 362 * ps3_vuart_raw_write - Low level write helper.
 363 * @dev: The struct ps3_system_bus_device instance.
 364 *
 365 * Do not call ps3_vuart_raw_write directly, use ps3_vuart_write.
 366 */
 367
 368static int ps3_vuart_raw_write(struct ps3_system_bus_device *dev,
 369	const void *buf, unsigned int bytes, u64 *bytes_written)
 370{
 371	int result;
 372	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 373
 374	result = lv1_write_virtual_uart(dev->port_number,
 375		ps3_mm_phys_to_lpar(__pa(buf)), bytes, bytes_written);
 376
 377	if (result) {
 378		dev_dbg(&dev->core, "%s:%d: lv1_write_virtual_uart failed: "
 379			"%s\n", __func__, __LINE__, ps3_result(result));
 380		return result;
 381	}
 382
 383	priv->stats.bytes_written += *bytes_written;
 384
 385	dev_dbg(&dev->core, "%s:%d: wrote %llxh/%xh=>%lxh\n", __func__, __LINE__,
 386		*bytes_written, bytes, priv->stats.bytes_written);
 387
 388	return result;
 389}
 390
 391/**
 392 * ps3_vuart_raw_read - Low level read helper.
 393 * @dev: The struct ps3_system_bus_device instance.
 394 *
 395 * Do not call ps3_vuart_raw_read directly, use ps3_vuart_read.
 396 */
 397
 398static int ps3_vuart_raw_read(struct ps3_system_bus_device *dev, void *buf,
 399	unsigned int bytes, u64 *bytes_read)
 400{
 401	int result;
 402	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 403
 404	dev_dbg(&dev->core, "%s:%d: %xh\n", __func__, __LINE__, bytes);
 405
 406	result = lv1_read_virtual_uart(dev->port_number,
 407		ps3_mm_phys_to_lpar(__pa(buf)), bytes, bytes_read);
 408
 409	if (result) {
 410		dev_dbg(&dev->core, "%s:%d: lv1_read_virtual_uart failed: %s\n",
 411			__func__, __LINE__, ps3_result(result));
 412		return result;
 413	}
 414
 415	priv->stats.bytes_read += *bytes_read;
 416
 417	dev_dbg(&dev->core, "%s:%d: read %llxh/%xh=>%lxh\n", __func__, __LINE__,
 418		*bytes_read, bytes, priv->stats.bytes_read);
 419
 420	return result;
 421}
 422
 423/**
 424 * ps3_vuart_clear_rx_bytes - Discard bytes received.
 425 * @dev: The struct ps3_system_bus_device instance.
 426 * @bytes: Max byte count to discard, zero = all pending.
 427 *
 428 * Used to clear pending rx interrupt source.  Will not block.
 429 */
 430
 431void ps3_vuart_clear_rx_bytes(struct ps3_system_bus_device *dev,
 432	unsigned int bytes)
 433{
 434	int result;
 435	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 436	u64 bytes_waiting;
 437	void *tmp;
 438
 439	result = ps3_vuart_get_rx_bytes_waiting(dev, &bytes_waiting);
 440
 441	BUG_ON(result);
 442
 443	bytes = bytes ? min(bytes, (unsigned int)bytes_waiting) : bytes_waiting;
 444
 445	dev_dbg(&dev->core, "%s:%d: %u\n", __func__, __LINE__, bytes);
 446
 447	if (!bytes)
 448		return;
 449
 450	/* Add some extra space for recently arrived data. */
 451
 452	bytes += 128;
 453
 454	tmp = kmalloc(bytes, GFP_KERNEL);
 455
 456	if (!tmp)
 457		return;
 458
 459	ps3_vuart_raw_read(dev, tmp, bytes, &bytes_waiting);
 460
 461	kfree(tmp);
 462
 463	/* Don't include these bytes in the stats. */
 464
 465	priv->stats.bytes_read -= bytes_waiting;
 466}
 467EXPORT_SYMBOL_GPL(ps3_vuart_clear_rx_bytes);
 468
 469/**
 470 * struct list_buffer - An element for a port device fifo buffer list.
 471 */
 472
 473struct list_buffer {
 474	struct list_head link;
 475	const unsigned char *head;
 476	const unsigned char *tail;
 477	unsigned long dbg_number;
 478	unsigned char data[];
 479};
 480
 481/**
 482 * ps3_vuart_write - the entry point for writing data to a port
 483 * @dev: The struct ps3_system_bus_device instance.
 484 *
 485 * If the port is idle on entry as much of the incoming data is written to
 486 * the port as the port will accept.  Otherwise a list buffer is created
 487 * and any remaning incoming data is copied to that buffer.  The buffer is
 488 * then enqueued for transmision via the transmit interrupt.
 489 */
 490
 491int ps3_vuart_write(struct ps3_system_bus_device *dev, const void *buf,
 492	unsigned int bytes)
 493{
 494	static unsigned long dbg_number;
 495	int result;
 496	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 497	unsigned long flags;
 498	struct list_buffer *lb;
 499
 500	dev_dbg(&dev->core, "%s:%d: %u(%xh) bytes\n", __func__, __LINE__,
 501		bytes, bytes);
 502
 503	spin_lock_irqsave(&priv->tx_list.lock, flags);
 504
 505	if (list_empty(&priv->tx_list.head)) {
 506		u64 bytes_written;
 507
 508		result = ps3_vuart_raw_write(dev, buf, bytes, &bytes_written);
 509
 510		spin_unlock_irqrestore(&priv->tx_list.lock, flags);
 511
 512		if (result) {
 513			dev_dbg(&dev->core,
 514				"%s:%d: ps3_vuart_raw_write failed\n",
 515				__func__, __LINE__);
 516			return result;
 517		}
 518
 519		if (bytes_written == bytes) {
 520			dev_dbg(&dev->core, "%s:%d: wrote %xh bytes\n",
 521				__func__, __LINE__, bytes);
 522			return 0;
 523		}
 524
 525		bytes -= bytes_written;
 526		buf += bytes_written;
 527	} else
 528		spin_unlock_irqrestore(&priv->tx_list.lock, flags);
 529
 530	lb = kmalloc(sizeof(struct list_buffer) + bytes, GFP_KERNEL);
 531
 532	if (!lb)
 533		return -ENOMEM;
 534
 535	memcpy(lb->data, buf, bytes);
 536	lb->head = lb->data;
 537	lb->tail = lb->data + bytes;
 538	lb->dbg_number = ++dbg_number;
 539
 540	spin_lock_irqsave(&priv->tx_list.lock, flags);
 541	list_add_tail(&lb->link, &priv->tx_list.head);
 542	ps3_vuart_enable_interrupt_tx(dev);
 543	spin_unlock_irqrestore(&priv->tx_list.lock, flags);
 544
 545	dev_dbg(&dev->core, "%s:%d: queued buf_%lu, %xh bytes\n",
 546		__func__, __LINE__, lb->dbg_number, bytes);
 547
 548	return 0;
 549}
 550EXPORT_SYMBOL_GPL(ps3_vuart_write);
 551
 552/**
 553 * ps3_vuart_queue_rx_bytes - Queue waiting bytes into the buffer list.
 554 * @dev: The struct ps3_system_bus_device instance.
 555 * @bytes_queued: Number of bytes queued to the buffer list.
 556 *
 557 * Must be called with priv->rx_list.lock held.
 558 */
 559
 560static int ps3_vuart_queue_rx_bytes(struct ps3_system_bus_device *dev,
 561	u64 *bytes_queued)
 562{
 563	static unsigned long dbg_number;
 564	int result;
 565	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 566	struct list_buffer *lb;
 567	u64 bytes;
 568
 569	*bytes_queued = 0;
 570
 571	result = ps3_vuart_get_rx_bytes_waiting(dev, &bytes);
 572	BUG_ON(result);
 573
 574	if (result)
 575		return -EIO;
 576
 577	if (!bytes)
 578		return 0;
 579
 580	/* Add some extra space for recently arrived data. */
 581
 582	bytes += 128;
 583
 584	lb = kmalloc(sizeof(struct list_buffer) + bytes, GFP_ATOMIC);
 585
 586	if (!lb)
 587		return -ENOMEM;
 588
 589	ps3_vuart_raw_read(dev, lb->data, bytes, &bytes);
 590
 591	lb->head = lb->data;
 592	lb->tail = lb->data + bytes;
 593	lb->dbg_number = ++dbg_number;
 594
 595	list_add_tail(&lb->link, &priv->rx_list.head);
 596	priv->rx_list.bytes_held += bytes;
 597
 598	dev_dbg(&dev->core, "%s:%d: buf_%lu: queued %llxh bytes\n",
 599		__func__, __LINE__, lb->dbg_number, bytes);
 600
 601	*bytes_queued = bytes;
 602
 603	return 0;
 604}
 605
 606/**
 607 * ps3_vuart_read - The entry point for reading data from a port.
 608 *
 609 * Queue data waiting at the port, and if enough bytes to satisfy the request
 610 * are held in the buffer list those bytes are dequeued and copied to the
 611 * caller's buffer.  Emptied list buffers are retiered.  If the request cannot
 612 * be statified by bytes held in the list buffers -EAGAIN is returned.
 613 */
 614
 615int ps3_vuart_read(struct ps3_system_bus_device *dev, void *buf,
 616	unsigned int bytes)
 617{
 618	int result;
 619	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 620	unsigned long flags;
 621	struct list_buffer *lb, *n;
 622	unsigned long bytes_read;
 623
 624	dev_dbg(&dev->core, "%s:%d: %u(%xh) bytes\n", __func__, __LINE__,
 625		bytes, bytes);
 626
 627	spin_lock_irqsave(&priv->rx_list.lock, flags);
 628
 629	/* Queue rx bytes here for polled reads. */
 630
 631	while (priv->rx_list.bytes_held < bytes) {
 632		u64 tmp;
 633
 634		result = ps3_vuart_queue_rx_bytes(dev, &tmp);
 635		if (result || !tmp) {
 636			dev_dbg(&dev->core, "%s:%d: starved for %lxh bytes\n",
 637				__func__, __LINE__,
 638				bytes - priv->rx_list.bytes_held);
 639			spin_unlock_irqrestore(&priv->rx_list.lock, flags);
 640			return -EAGAIN;
 641		}
 642	}
 643
 644	list_for_each_entry_safe(lb, n, &priv->rx_list.head, link) {
 645		bytes_read = min((unsigned int)(lb->tail - lb->head), bytes);
 646
 647		memcpy(buf, lb->head, bytes_read);
 648		buf += bytes_read;
 649		bytes -= bytes_read;
 650		priv->rx_list.bytes_held -= bytes_read;
 651
 652		if (bytes_read < lb->tail - lb->head) {
 653			lb->head += bytes_read;
 654			dev_dbg(&dev->core, "%s:%d: buf_%lu: dequeued %lxh "
 655				"bytes\n", __func__, __LINE__, lb->dbg_number,
 656				bytes_read);
 657			spin_unlock_irqrestore(&priv->rx_list.lock, flags);
 658			return 0;
 659		}
 660
 661		dev_dbg(&dev->core, "%s:%d: buf_%lu: free, dequeued %lxh "
 662			"bytes\n", __func__, __LINE__, lb->dbg_number,
 663			bytes_read);
 664
 665		list_del(&lb->link);
 666		kfree(lb);
 667	}
 668
 669	spin_unlock_irqrestore(&priv->rx_list.lock, flags);
 670	return 0;
 671}
 672EXPORT_SYMBOL_GPL(ps3_vuart_read);
 673
 674/**
 675 * ps3_vuart_work - Asynchronous read handler.
 676 */
 677
 678static void ps3_vuart_work(struct work_struct *work)
 679{
 680	struct ps3_system_bus_device *dev =
 681		ps3_vuart_work_to_system_bus_dev(work);
 682	struct ps3_vuart_port_driver *drv =
 683		ps3_system_bus_dev_to_vuart_drv(dev);
 684
 685	BUG_ON(!drv);
 686	drv->work(dev);
 687}
 688
 689int ps3_vuart_read_async(struct ps3_system_bus_device *dev, unsigned int bytes)
 690{
 691	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 692	unsigned long flags;
 693
 694	if (priv->rx_list.work.trigger) {
 695		dev_dbg(&dev->core, "%s:%d: warning, multiple calls\n",
 696			__func__, __LINE__);
 697		return -EAGAIN;
 698	}
 699
 700	BUG_ON(!bytes);
 701
 702	PREPARE_WORK(&priv->rx_list.work.work, ps3_vuart_work);
 703
 704	spin_lock_irqsave(&priv->rx_list.lock, flags);
 705	if (priv->rx_list.bytes_held >= bytes) {
 706		dev_dbg(&dev->core, "%s:%d: schedule_work %xh bytes\n",
 707			__func__, __LINE__, bytes);
 708		schedule_work(&priv->rx_list.work.work);
 709		spin_unlock_irqrestore(&priv->rx_list.lock, flags);
 710		return 0;
 711	}
 712
 713	priv->rx_list.work.trigger = bytes;
 714	spin_unlock_irqrestore(&priv->rx_list.lock, flags);
 715
 716	dev_dbg(&dev->core, "%s:%d: waiting for %u(%xh) bytes\n", __func__,
 717		__LINE__, bytes, bytes);
 718
 719	return 0;
 720}
 721EXPORT_SYMBOL_GPL(ps3_vuart_read_async);
 722
 723void ps3_vuart_cancel_async(struct ps3_system_bus_device *dev)
 724{
 725	to_port_priv(dev)->rx_list.work.trigger = 0;
 726}
 727EXPORT_SYMBOL_GPL(ps3_vuart_cancel_async);
 728
 729/**
 730 * ps3_vuart_handle_interrupt_tx - third stage transmit interrupt handler
 731 *
 732 * Services the transmit interrupt for the port.  Writes as much data from the
 733 * buffer list as the port will accept.  Retires any emptied list buffers and
 734 * adjusts the final list buffer state for a partial write.
 735 */
 736
 737static int ps3_vuart_handle_interrupt_tx(struct ps3_system_bus_device *dev)
 738{
 739	int result = 0;
 740	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 741	unsigned long flags;
 742	struct list_buffer *lb, *n;
 743	unsigned long bytes_total = 0;
 744
 745	dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
 746
 747	spin_lock_irqsave(&priv->tx_list.lock, flags);
 748
 749	list_for_each_entry_safe(lb, n, &priv->tx_list.head, link) {
 750
 751		u64 bytes_written;
 752
 753		result = ps3_vuart_raw_write(dev, lb->head, lb->tail - lb->head,
 754			&bytes_written);
 755
 756		if (result) {
 757			dev_dbg(&dev->core,
 758				"%s:%d: ps3_vuart_raw_write failed\n",
 759				__func__, __LINE__);
 760			break;
 761		}
 762
 763		bytes_total += bytes_written;
 764
 765		if (bytes_written < lb->tail - lb->head) {
 766			lb->head += bytes_written;
 767			dev_dbg(&dev->core,
 768				"%s:%d cleared buf_%lu, %llxh bytes\n",
 769				__func__, __LINE__, lb->dbg_number,
 770				bytes_written);
 771			goto port_full;
 772		}
 773
 774		dev_dbg(&dev->core, "%s:%d free buf_%lu\n", __func__, __LINE__,
 775			lb->dbg_number);
 776
 777		list_del(&lb->link);
 778		kfree(lb);
 779	}
 780
 781	ps3_vuart_disable_interrupt_tx(dev);
 782port_full:
 783	spin_unlock_irqrestore(&priv->tx_list.lock, flags);
 784	dev_dbg(&dev->core, "%s:%d wrote %lxh bytes total\n",
 785		__func__, __LINE__, bytes_total);
 786	return result;
 787}
 788
 789/**
 790 * ps3_vuart_handle_interrupt_rx - third stage receive interrupt handler
 791 *
 792 * Services the receive interrupt for the port.  Creates a list buffer and
 793 * copies all waiting port data to that buffer and enqueues the buffer in the
 794 * buffer list.  Buffer list data is dequeued via ps3_vuart_read.
 795 */
 796
 797static int ps3_vuart_handle_interrupt_rx(struct ps3_system_bus_device *dev)
 798{
 799	int result;
 800	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 801	unsigned long flags;
 802	u64 bytes;
 803
 804	dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
 805
 806	spin_lock_irqsave(&priv->rx_list.lock, flags);
 807	result = ps3_vuart_queue_rx_bytes(dev, &bytes);
 808
 809	if (result) {
 810		spin_unlock_irqrestore(&priv->rx_list.lock, flags);
 811		return result;
 812	}
 813
 814	if (priv->rx_list.work.trigger && priv->rx_list.bytes_held
 815		>= priv->rx_list.work.trigger) {
 816		dev_dbg(&dev->core, "%s:%d: schedule_work %lxh bytes\n",
 817			__func__, __LINE__, priv->rx_list.work.trigger);
 818		priv->rx_list.work.trigger = 0;
 819		schedule_work(&priv->rx_list.work.work);
 820	}
 821
 822	spin_unlock_irqrestore(&priv->rx_list.lock, flags);
 823	return result;
 824}
 825
 826static int ps3_vuart_handle_interrupt_disconnect(
 827	struct ps3_system_bus_device *dev)
 828{
 829	dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
 830	BUG_ON("no support");
 831	return -1;
 832}
 833
 834/**
 835 * ps3_vuart_handle_port_interrupt - second stage interrupt handler
 836 *
 837 * Services any pending interrupt types for the port.  Passes control to the
 838 * third stage type specific interrupt handler.  Returns control to the first
 839 * stage handler after one iteration.
 840 */
 841
 842static int ps3_vuart_handle_port_interrupt(struct ps3_system_bus_device *dev)
 843{
 844	int result;
 845	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
 846	unsigned long status;
 847
 848	result = ps3_vuart_get_interrupt_status(dev, &status);
 849
 850	if (result)
 851		return result;
 852
 853	dev_dbg(&dev->core, "%s:%d: status: %lxh\n", __func__, __LINE__,
 854		status);
 855
 856	if (status & INTERRUPT_MASK_DISCONNECT) {
 857		priv->stats.disconnect_interrupts++;
 858		result = ps3_vuart_handle_interrupt_disconnect(dev);
 859		if (result)
 860			ps3_vuart_disable_interrupt_disconnect(dev);
 861	}
 862
 863	if (status & INTERRUPT_MASK_TX) {
 864		priv->stats.tx_interrupts++;
 865		result = ps3_vuart_handle_interrupt_tx(dev);
 866		if (result)
 867			ps3_vuart_disable_interrupt_tx(dev);
 868	}
 869
 870	if (status & INTERRUPT_MASK_RX) {
 871		priv->stats.rx_interrupts++;
 872		result = ps3_vuart_handle_interrupt_rx(dev);
 873		if (result)
 874			ps3_vuart_disable_interrupt_rx(dev);
 875	}
 876
 877	return 0;
 878}
 879
 880struct vuart_bus_priv {
 881	struct ports_bmp *bmp;
 882	unsigned int virq;
 883	struct mutex probe_mutex;
 884	int use_count;
 885	struct ps3_system_bus_device *devices[PORT_COUNT];
 886} static vuart_bus_priv;
 887
 888/**
 889 * ps3_vuart_irq_handler - first stage interrupt handler
 890 *
 891 * Loops finding any interrupting port and its associated instance data.
 892 * Passes control to the second stage port specific interrupt handler.  Loops
 893 * until all outstanding interrupts are serviced.
 894 */
 895
 896static irqreturn_t ps3_vuart_irq_handler(int irq, void *_private)
 897{
 898	struct vuart_bus_priv *bus_priv = _private;
 899
 900	BUG_ON(!bus_priv);
 901
 902	while (1) {
 903		unsigned int port;
 904
 905		dump_ports_bmp(bus_priv->bmp);
 906
 907		port = (BITS_PER_LONG - 1) - __ilog2(bus_priv->bmp->status);
 908
 909		if (port == BITS_PER_LONG)
 910			break;
 911
 912		BUG_ON(port >= PORT_COUNT);
 913		BUG_ON(!bus_priv->devices[port]);
 914
 915		ps3_vuart_handle_port_interrupt(bus_priv->devices[port]);
 916	}
 917
 918	return IRQ_HANDLED;
 919}
 920
 921static int ps3_vuart_bus_interrupt_get(void)
 922{
 923	int result;
 924
 925	pr_debug(" -> %s:%d\n", __func__, __LINE__);
 926
 927	vuart_bus_priv.use_count++;
 928
 929	BUG_ON(vuart_bus_priv.use_count > 2);
 930
 931	if (vuart_bus_priv.use_count != 1)
 932		return 0;
 933
 934	BUG_ON(vuart_bus_priv.bmp);
 935
 936	vuart_bus_priv.bmp = kzalloc(sizeof(struct ports_bmp), GFP_KERNEL);
 937
 938	if (!vuart_bus_priv.bmp) {
 939		pr_debug("%s:%d: kzalloc failed.\n", __func__, __LINE__);
 940		result = -ENOMEM;
 941		goto fail_bmp_malloc;
 942	}
 943
 944	result = ps3_vuart_irq_setup(PS3_BINDING_CPU_ANY, vuart_bus_priv.bmp,
 945		&vuart_bus_priv.virq);
 946
 947	if (result) {
 948		pr_debug("%s:%d: ps3_vuart_irq_setup failed (%d)\n",
 949			__func__, __LINE__, result);
 950		result = -EPERM;
 951		goto fail_alloc_irq;
 952	}
 953
 954	result = request_irq(vuart_bus_priv.virq, ps3_vuart_irq_handler,
 955		IRQF_DISABLED, "vuart", &vuart_bus_priv);
 956
 957	if (result) {
 958		pr_debug("%s:%d: request_irq failed (%d)\n",
 959			__func__, __LINE__, result);
 960		goto fail_request_irq;
 961	}
 962
 963	pr_debug(" <- %s:%d: ok\n", __func__, __LINE__);
 964	return result;
 965
 966fail_request_irq:
 967	ps3_vuart_irq_destroy(vuart_bus_priv.virq);
 968	vuart_bus_priv.virq = NO_IRQ;
 969fail_alloc_irq:
 970	kfree(vuart_bus_priv.bmp);
 971	vuart_bus_priv.bmp = NULL;
 972fail_bmp_malloc:
 973	vuart_bus_priv.use_count--;
 974	pr_debug(" <- %s:%d: failed\n", __func__, __LINE__);
 975	return result;
 976}
 977
 978static int ps3_vuart_bus_interrupt_put(void)
 979{
 980	pr_debug(" -> %s:%d\n", __func__, __LINE__);
 981
 982	vuart_bus_priv.use_count--;
 983
 984	BUG_ON(vuart_bus_priv.use_count < 0);
 985
 986	if (vuart_bus_priv.use_count != 0)
 987		return 0;
 988
 989	free_irq(vuart_bus_priv.virq, &vuart_bus_priv);
 990
 991	ps3_vuart_irq_destroy(vuart_bus_priv.virq);
 992	vuart_bus_priv.virq = NO_IRQ;
 993
 994	kfree(vuart_bus_priv.bmp);
 995	vuart_bus_priv.bmp = NULL;
 996
 997	pr_debug(" <- %s:%d\n", __func__, __LINE__);
 998	return 0;
 999}
1000
1001static int ps3_vuart_probe(struct ps3_system_bus_device *dev)
1002{
1003	int result;
1004	struct ps3_vuart_port_driver *drv;
1005	struct ps3_vuart_port_priv *priv = NULL;
1006
1007	dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
1008
1009	drv = ps3_system_bus_dev_to_vuart_drv(dev);
1010
1011	dev_dbg(&dev->core, "%s:%d: (%s)\n", __func__, __LINE__,
1012		drv->core.core.name);
1013
1014	BUG_ON(!drv);
1015
1016	if (dev->port_number >= PORT_COUNT) {
1017		BUG();
1018		return -EINVAL;
1019	}
1020
1021	mutex_lock(&vuart_bus_priv.probe_mutex);
1022
1023	result = ps3_vuart_bus_interrupt_get();
1024
1025	if (result)
1026		goto fail_setup_interrupt;
1027
1028	if (vuart_bus_priv.devices[dev->port_number]) {
1029		dev_dbg(&dev->core, "%s:%d: port busy (%d)\n", __func__,
1030			__LINE__, dev->port_number);
1031		result = -EBUSY;
1032		goto fail_busy;
1033	}
1034
1035	vuart_bus_priv.devices[dev->port_number] = dev;
1036
1037	/* Setup dev->driver_priv. */
1038
1039	dev->driver_priv = kzalloc(sizeof(struct ps3_vuart_port_priv),
1040		GFP_KERNEL);
1041
1042	if (!dev->driver_priv) {
1043		result = -ENOMEM;
1044		goto fail_dev_malloc;
1045	}
1046
1047	priv = to_port_priv(dev);
1048
1049	INIT_LIST_HEAD(&priv->tx_list.head);
1050	spin_lock_init(&priv->tx_list.lock);
1051
1052	INIT_LIST_HEAD(&priv->rx_list.head);
1053	spin_lock_init(&priv->rx_list.lock);
1054
1055	INIT_WORK(&priv->rx_list.work.work, NULL);
1056	priv->rx_list.work.trigger = 0;
1057	priv->rx_list.work.dev = dev;
1058
1059	/* clear stale pending interrupts */
1060
1061	ps3_vuart_clear_rx_bytes(dev, 0);
1062
1063	ps3_vuart_set_interrupt_mask(dev, INTERRUPT_MASK_RX);
1064
1065	ps3_vuart_set_triggers(dev, 1, 1);
1066
1067	if (drv->probe)
1068		result = drv->probe(dev);
1069	else {
1070		result = 0;
1071		dev_info(&dev->core, "%s:%d: no probe method\n", __func__,
1072			__LINE__);
1073	}
1074
1075	if (result) {
1076		dev_dbg(&dev->core, "%s:%d: drv->probe failed\n",
1077			__func__, __LINE__);
1078		goto fail_probe;
1079	}
1080
1081	mutex_unlock(&vuart_bus_priv.probe_mutex);
1082
1083	return result;
1084
1085fail_probe:
1086	ps3_vuart_set_interrupt_mask(dev, 0);
1087	kfree(dev->driver_priv);
1088	dev->driver_priv = NULL;
1089fail_dev_malloc:
1090	vuart_bus_priv.devices[dev->port_number] = NULL;
1091fail_busy:
1092	ps3_vuart_bus_interrupt_put();
1093fail_setup_interrupt:
1094	mutex_unlock(&vuart_bus_priv.probe_mutex);
1095	dev_dbg(&dev->core, "%s:%d: failed\n", __func__, __LINE__);
1096	return result;
1097}
1098
1099/**
1100 * ps3_vuart_cleanup - common cleanup helper.
1101 * @dev: The struct ps3_system_bus_device instance.
1102 *
1103 * Cleans interrupts and HV resources.  Must be called with
1104 * vuart_bus_priv.probe_mutex held.  Used by ps3_vuart_remove and
1105 * ps3_vuart_shutdown.  After this call, polled reading will still work.
1106 */
1107
1108static int ps3_vuart_cleanup(struct ps3_system_bus_device *dev)
1109{
1110	dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
1111
1112	ps3_vuart_cancel_async(dev);
1113	ps3_vuart_set_interrupt_mask(dev, 0);
1114	ps3_vuart_bus_interrupt_put();
1115	return 0;
1116}
1117
1118/**
1119 * ps3_vuart_remove - Completely clean the device instance.
1120 * @dev: The struct ps3_system_bus_device instance.
1121 *
1122 * Cleans all memory, interrupts and HV resources.  After this call the
1123 * device can no longer be used.
1124 */
1125
1126static int ps3_vuart_remove(struct ps3_system_bus_device *dev)
1127{
1128	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
1129	struct ps3_vuart_port_driver *drv;
1130
1131	BUG_ON(!dev);
1132
1133	mutex_lock(&vuart_bus_priv.probe_mutex);
1134
1135	dev_dbg(&dev->core, " -> %s:%d: match_id %d\n", __func__, __LINE__,
1136		dev->match_id);
1137
1138	if (!dev->core.driver) {
1139		dev_dbg(&dev->core, "%s:%d: no driver bound\n", __func__,
1140			__LINE__);
1141		mutex_unlock(&vuart_bus_priv.probe_mutex);
1142		return 0;
1143	}
1144
1145	drv = ps3_system_bus_dev_to_vuart_drv(dev);
1146
1147	BUG_ON(!drv);
1148
1149	if (drv->remove) {
1150		drv->remove(dev);
1151	} else {
1152		dev_dbg(&dev->core, "%s:%d: no remove method\n", __func__,
1153		__LINE__);
1154		BUG();
1155	}
1156
1157	ps3_vuart_cleanup(dev);
1158
1159	vuart_bus_priv.devices[dev->port_number] = NULL;
1160	kfree(priv);
1161	priv = NULL;
1162
1163	dev_dbg(&dev->core, " <- %s:%d\n", __func__, __LINE__);
1164	mutex_unlock(&vuart_bus_priv.probe_mutex);
1165	return 0;
1166}
1167
1168/**
1169 * ps3_vuart_shutdown - Cleans interrupts and HV resources.
1170 * @dev: The struct ps3_system_bus_device instance.
1171 *
1172 * Cleans interrupts and HV resources.  After this call the
1173 * device can still be used in polling mode.  This behavior required
1174 * by sys-manager to be able to complete the device power operation
1175 * sequence.
1176 */
1177
1178static int ps3_vuart_shutdown(struct ps3_system_bus_device *dev)
1179{
1180	struct ps3_vuart_port_driver *drv;
1181
1182	BUG_ON(!dev);
1183
1184	mutex_lock(&vuart_bus_priv.probe_mutex);
1185
1186	dev_dbg(&dev->core, " -> %s:%d: match_id %d\n", __func__, __LINE__,
1187		dev->match_id);
1188
1189	if (!dev->core.driver) {
1190		dev_dbg(&dev->core, "%s:%d: no driver bound\n", __func__,
1191			__LINE__);
1192		mutex_unlock(&vuart_bus_priv.probe_mutex);
1193		return 0;
1194	}
1195
1196	drv = ps3_system_bus_dev_to_vuart_drv(dev);
1197
1198	BUG_ON(!drv);
1199
1200	if (drv->shutdown)
1201		drv->shutdown(dev);
1202	else if (drv->remove) {
1203		dev_dbg(&dev->core, "%s:%d: no shutdown, calling remove\n",
1204			__func__, __LINE__);
1205		drv->remove(dev);
1206	} else {
1207		dev_dbg(&dev->core, "%s:%d: no shutdown method\n", __func__,
1208			__LINE__);
1209		BUG();
1210	}
1211
1212	ps3_vuart_cleanup(dev);
1213
1214	dev_dbg(&dev->core, " <- %s:%d\n", __func__, __LINE__);
1215
1216	mutex_unlock(&vuart_bus_priv.probe_mutex);
1217	return 0;
1218}
1219
1220static int __init ps3_vuart_bus_init(void)
1221{
1222	pr_debug("%s:%d:\n", __func__, __LINE__);
1223
1224	if (!firmware_has_feature(FW_FEATURE_PS3_LV1))
1225		return -ENODEV;
1226
1227	mutex_init(&vuart_bus_priv.probe_mutex);
1228
1229	return 0;
1230}
1231
1232static void __exit ps3_vuart_bus_exit(void)
1233{
1234	pr_debug("%s:%d:\n", __func__, __LINE__);
1235}
1236
1237core_initcall(ps3_vuart_bus_init);
1238module_exit(ps3_vuart_bus_exit);
1239
1240/**
1241 * ps3_vuart_port_driver_register - Add a vuart port device driver.
1242 */
1243
1244int ps3_vuart_port_driver_register(struct ps3_vuart_port_driver *drv)
1245{
1246	int result;
1247
1248	pr_debug("%s:%d: (%s)\n", __func__, __LINE__, drv->core.core.name);
1249
1250	BUG_ON(!drv->core.match_id);
1251	BUG_ON(!drv->core.core.name);
1252
1253	drv->core.probe = ps3_vuart_probe;
1254	drv->core.remove = ps3_vuart_remove;
1255	drv->core.shutdown = ps3_vuart_shutdown;
1256
1257	result = ps3_system_bus_driver_register(&drv->core);
1258	return result;
1259}
1260EXPORT_SYMBOL_GPL(ps3_vuart_port_driver_register);
1261
1262/**
1263 * ps3_vuart_port_driver_unregister - Remove a vuart port device driver.
1264 */
1265
1266void ps3_vuart_port_driver_unregister(struct ps3_vuart_port_driver *drv)
1267{
1268	pr_debug("%s:%d: (%s)\n", __func__, __LINE__, drv->core.core.name);
1269	ps3_system_bus_driver_unregister(&drv->core);
1270}
1271EXPORT_SYMBOL_GPL(ps3_vuart_port_driver_unregister);