linux/drivers/usb/early/xhci-dbc.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/**
   3 * xhci-dbc.c - xHCI debug capability early driver
   4 *
   5 * Copyright (C) 2016 Intel Corporation
   6 *
   7 * Author: Lu Baolu <baolu.lu@linux.intel.com>
   8 */
   9
  10#define pr_fmt(fmt)     KBUILD_MODNAME ":%s: " fmt, __func__
  11
  12#include <linux/console.h>
  13#include <linux/pci_regs.h>
  14#include <linux/pci_ids.h>
  15#include <linux/memblock.h>
  16#include <linux/io.h>
  17#include <asm/pci-direct.h>
  18#include <asm/fixmap.h>
  19#include <linux/bcd.h>
  20#include <linux/export.h>
  21#include <linux/version.h>
  22#include <linux/module.h>
  23#include <linux/delay.h>
  24#include <linux/kthread.h>
  25
  26#include "../host/xhci.h"
  27#include "xhci-dbc.h"
  28
  29static struct xdbc_state xdbc;
  30static bool early_console_keep;
  31
  32#ifdef XDBC_TRACE
  33#define xdbc_trace      trace_printk
  34#else
  35static inline void xdbc_trace(const char *fmt, ...) { }
  36#endif /* XDBC_TRACE */
  37
  38static void __iomem * __init xdbc_map_pci_mmio(u32 bus, u32 dev, u32 func)
  39{
  40        u64 val64, sz64, mask64;
  41        void __iomem *base;
  42        u32 val, sz;
  43        u8 byte;
  44
  45        val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
  46        write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, ~0);
  47        sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
  48        write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, val);
  49
  50        if (val == 0xffffffff || sz == 0xffffffff) {
  51                pr_notice("invalid mmio bar\n");
  52                return NULL;
  53        }
  54
  55        val64   = val & PCI_BASE_ADDRESS_MEM_MASK;
  56        sz64    = sz & PCI_BASE_ADDRESS_MEM_MASK;
  57        mask64  = PCI_BASE_ADDRESS_MEM_MASK;
  58
  59        if ((val & PCI_BASE_ADDRESS_MEM_TYPE_MASK) == PCI_BASE_ADDRESS_MEM_TYPE_64) {
  60                val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
  61                write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, ~0);
  62                sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
  63                write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, val);
  64
  65                val64   |= (u64)val << 32;
  66                sz64    |= (u64)sz << 32;
  67                mask64  |= ~0ULL << 32;
  68        }
  69
  70        sz64 &= mask64;
  71
  72        if (!sz64) {
  73                pr_notice("invalid mmio address\n");
  74                return NULL;
  75        }
  76
  77        sz64 = 1ULL << __ffs64(sz64);
  78
  79        /* Check if the mem space is enabled: */
  80        byte = read_pci_config_byte(bus, dev, func, PCI_COMMAND);
  81        if (!(byte & PCI_COMMAND_MEMORY)) {
  82                byte |= PCI_COMMAND_MEMORY;
  83                write_pci_config_byte(bus, dev, func, PCI_COMMAND, byte);
  84        }
  85
  86        xdbc.xhci_start = val64;
  87        xdbc.xhci_length = sz64;
  88        base = early_ioremap(val64, sz64);
  89
  90        return base;
  91}
  92
  93static void * __init xdbc_get_page(dma_addr_t *dma_addr)
  94{
  95        void *virt;
  96
  97        virt = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
  98        if (!virt)
  99                return NULL;
 100
 101        if (dma_addr)
 102                *dma_addr = (dma_addr_t)__pa(virt);
 103
 104        return virt;
 105}
 106
 107static u32 __init xdbc_find_dbgp(int xdbc_num, u32 *b, u32 *d, u32 *f)
 108{
 109        u32 bus, dev, func, class;
 110
 111        for (bus = 0; bus < XDBC_PCI_MAX_BUSES; bus++) {
 112                for (dev = 0; dev < XDBC_PCI_MAX_DEVICES; dev++) {
 113                        for (func = 0; func < XDBC_PCI_MAX_FUNCTION; func++) {
 114
 115                                class = read_pci_config(bus, dev, func, PCI_CLASS_REVISION);
 116                                if ((class >> 8) != PCI_CLASS_SERIAL_USB_XHCI)
 117                                        continue;
 118
 119                                if (xdbc_num-- != 0)
 120                                        continue;
 121
 122                                *b = bus;
 123                                *d = dev;
 124                                *f = func;
 125
 126                                return 0;
 127                        }
 128                }
 129        }
 130
 131        return -1;
 132}
 133
 134static int handshake(void __iomem *ptr, u32 mask, u32 done, int wait, int delay)
 135{
 136        u32 result;
 137
 138        do {
 139                result = readl(ptr);
 140                result &= mask;
 141                if (result == done)
 142                        return 0;
 143                udelay(delay);
 144                wait -= delay;
 145        } while (wait > 0);
 146
 147        return -ETIMEDOUT;
 148}
 149
 150static void __init xdbc_bios_handoff(void)
 151{
 152        int offset, timeout;
 153        u32 val;
 154
 155        offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_LEGACY);
 156        val = readl(xdbc.xhci_base + offset);
 157
 158        if (val & XHCI_HC_BIOS_OWNED) {
 159                writel(val | XHCI_HC_OS_OWNED, xdbc.xhci_base + offset);
 160                timeout = handshake(xdbc.xhci_base + offset, XHCI_HC_BIOS_OWNED, 0, 5000, 10);
 161
 162                if (timeout) {
 163                        pr_notice("failed to hand over xHCI control from BIOS\n");
 164                        writel(val & ~XHCI_HC_BIOS_OWNED, xdbc.xhci_base + offset);
 165                }
 166        }
 167
 168        /* Disable BIOS SMIs and clear all SMI events: */
 169        val = readl(xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
 170        val &= XHCI_LEGACY_DISABLE_SMI;
 171        val |= XHCI_LEGACY_SMI_EVENTS;
 172        writel(val, xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
 173}
 174
 175static int __init
 176xdbc_alloc_ring(struct xdbc_segment *seg, struct xdbc_ring *ring)
 177{
 178        seg->trbs = xdbc_get_page(&seg->dma);
 179        if (!seg->trbs)
 180                return -ENOMEM;
 181
 182        ring->segment = seg;
 183
 184        return 0;
 185}
 186
 187static void __init xdbc_free_ring(struct xdbc_ring *ring)
 188{
 189        struct xdbc_segment *seg = ring->segment;
 190
 191        if (!seg)
 192                return;
 193
 194        memblock_free(seg->dma, PAGE_SIZE);
 195        ring->segment = NULL;
 196}
 197
 198static void xdbc_reset_ring(struct xdbc_ring *ring)
 199{
 200        struct xdbc_segment *seg = ring->segment;
 201        struct xdbc_trb *link_trb;
 202
 203        memset(seg->trbs, 0, PAGE_SIZE);
 204
 205        ring->enqueue = seg->trbs;
 206        ring->dequeue = seg->trbs;
 207        ring->cycle_state = 1;
 208
 209        if (ring != &xdbc.evt_ring) {
 210                link_trb = &seg->trbs[XDBC_TRBS_PER_SEGMENT - 1];
 211                link_trb->field[0] = cpu_to_le32(lower_32_bits(seg->dma));
 212                link_trb->field[1] = cpu_to_le32(upper_32_bits(seg->dma));
 213                link_trb->field[3] = cpu_to_le32(TRB_TYPE(TRB_LINK)) | cpu_to_le32(LINK_TOGGLE);
 214        }
 215}
 216
 217static inline void xdbc_put_utf16(u16 *s, const char *c, size_t size)
 218{
 219        int i;
 220
 221        for (i = 0; i < size; i++)
 222                s[i] = cpu_to_le16(c[i]);
 223}
 224
 225static void xdbc_mem_init(void)
 226{
 227        struct xdbc_ep_context *ep_in, *ep_out;
 228        struct usb_string_descriptor *s_desc;
 229        struct xdbc_erst_entry *entry;
 230        struct xdbc_strings *strings;
 231        struct xdbc_context *ctx;
 232        unsigned int max_burst;
 233        u32 string_length;
 234        int index = 0;
 235        u32 dev_info;
 236
 237        xdbc_reset_ring(&xdbc.evt_ring);
 238        xdbc_reset_ring(&xdbc.in_ring);
 239        xdbc_reset_ring(&xdbc.out_ring);
 240        memset(xdbc.table_base, 0, PAGE_SIZE);
 241        memset(xdbc.out_buf, 0, PAGE_SIZE);
 242
 243        /* Initialize event ring segment table: */
 244        xdbc.erst_size  = 16;
 245        xdbc.erst_base  = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
 246        xdbc.erst_dma   = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
 247
 248        index += XDBC_ERST_ENTRY_NUM;
 249        entry = (struct xdbc_erst_entry *)xdbc.erst_base;
 250
 251        entry->seg_addr         = cpu_to_le64(xdbc.evt_seg.dma);
 252        entry->seg_size         = cpu_to_le32(XDBC_TRBS_PER_SEGMENT);
 253        entry->__reserved_0     = 0;
 254
 255        /* Initialize ERST registers: */
 256        writel(1, &xdbc.xdbc_reg->ersts);
 257        xdbc_write64(xdbc.erst_dma, &xdbc.xdbc_reg->erstba);
 258        xdbc_write64(xdbc.evt_seg.dma, &xdbc.xdbc_reg->erdp);
 259
 260        /* Debug capability contexts: */
 261        xdbc.dbcc_size  = 64 * 3;
 262        xdbc.dbcc_base  = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
 263        xdbc.dbcc_dma   = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
 264
 265        index += XDBC_DBCC_ENTRY_NUM;
 266
 267        /* Popluate the strings: */
 268        xdbc.string_size = sizeof(struct xdbc_strings);
 269        xdbc.string_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
 270        xdbc.string_dma  = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
 271        strings          = (struct xdbc_strings *)xdbc.string_base;
 272
 273        index += XDBC_STRING_ENTRY_NUM;
 274
 275        /* Serial string: */
 276        s_desc                  = (struct usb_string_descriptor *)strings->serial;
 277        s_desc->bLength         = (strlen(XDBC_STRING_SERIAL) + 1) * 2;
 278        s_desc->bDescriptorType = USB_DT_STRING;
 279
 280        xdbc_put_utf16(s_desc->wData, XDBC_STRING_SERIAL, strlen(XDBC_STRING_SERIAL));
 281        string_length = s_desc->bLength;
 282        string_length <<= 8;
 283
 284        /* Product string: */
 285        s_desc                  = (struct usb_string_descriptor *)strings->product;
 286        s_desc->bLength         = (strlen(XDBC_STRING_PRODUCT) + 1) * 2;
 287        s_desc->bDescriptorType = USB_DT_STRING;
 288
 289        xdbc_put_utf16(s_desc->wData, XDBC_STRING_PRODUCT, strlen(XDBC_STRING_PRODUCT));
 290        string_length += s_desc->bLength;
 291        string_length <<= 8;
 292
 293        /* Manufacture string: */
 294        s_desc                  = (struct usb_string_descriptor *)strings->manufacturer;
 295        s_desc->bLength         = (strlen(XDBC_STRING_MANUFACTURER) + 1) * 2;
 296        s_desc->bDescriptorType = USB_DT_STRING;
 297
 298        xdbc_put_utf16(s_desc->wData, XDBC_STRING_MANUFACTURER, strlen(XDBC_STRING_MANUFACTURER));
 299        string_length += s_desc->bLength;
 300        string_length <<= 8;
 301
 302        /* String0: */
 303        strings->string0[0]     = 4;
 304        strings->string0[1]     = USB_DT_STRING;
 305        strings->string0[2]     = 0x09;
 306        strings->string0[3]     = 0x04;
 307
 308        string_length += 4;
 309
 310        /* Populate info Context: */
 311        ctx = (struct xdbc_context *)xdbc.dbcc_base;
 312
 313        ctx->info.string0       = cpu_to_le64(xdbc.string_dma);
 314        ctx->info.manufacturer  = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH);
 315        ctx->info.product       = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 2);
 316        ctx->info.serial        = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 3);
 317        ctx->info.length        = cpu_to_le32(string_length);
 318
 319        /* Populate bulk out endpoint context: */
 320        max_burst = DEBUG_MAX_BURST(readl(&xdbc.xdbc_reg->control));
 321        ep_out = (struct xdbc_ep_context *)&ctx->out;
 322
 323        ep_out->ep_info1        = 0;
 324        ep_out->ep_info2        = cpu_to_le32(EP_TYPE(BULK_OUT_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
 325        ep_out->deq             = cpu_to_le64(xdbc.out_seg.dma | xdbc.out_ring.cycle_state);
 326
 327        /* Populate bulk in endpoint context: */
 328        ep_in = (struct xdbc_ep_context *)&ctx->in;
 329
 330        ep_in->ep_info1         = 0;
 331        ep_in->ep_info2         = cpu_to_le32(EP_TYPE(BULK_IN_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
 332        ep_in->deq              = cpu_to_le64(xdbc.in_seg.dma | xdbc.in_ring.cycle_state);
 333
 334        /* Set DbC context and info registers: */
 335        xdbc_write64(xdbc.dbcc_dma, &xdbc.xdbc_reg->dccp);
 336
 337        dev_info = cpu_to_le32((XDBC_VENDOR_ID << 16) | XDBC_PROTOCOL);
 338        writel(dev_info, &xdbc.xdbc_reg->devinfo1);
 339
 340        dev_info = cpu_to_le32((XDBC_DEVICE_REV << 16) | XDBC_PRODUCT_ID);
 341        writel(dev_info, &xdbc.xdbc_reg->devinfo2);
 342
 343        xdbc.in_buf = xdbc.out_buf + XDBC_MAX_PACKET;
 344        xdbc.in_dma = xdbc.out_dma + XDBC_MAX_PACKET;
 345}
 346
 347static void xdbc_do_reset_debug_port(u32 id, u32 count)
 348{
 349        void __iomem *ops_reg;
 350        void __iomem *portsc;
 351        u32 val, cap_length;
 352        int i;
 353
 354        cap_length = readl(xdbc.xhci_base) & 0xff;
 355        ops_reg = xdbc.xhci_base + cap_length;
 356
 357        id--;
 358        for (i = id; i < (id + count); i++) {
 359                portsc = ops_reg + 0x400 + i * 0x10;
 360                val = readl(portsc);
 361                if (!(val & PORT_CONNECT))
 362                        writel(val | PORT_RESET, portsc);
 363        }
 364}
 365
 366static void xdbc_reset_debug_port(void)
 367{
 368        u32 val, port_offset, port_count;
 369        int offset = 0;
 370
 371        do {
 372                offset = xhci_find_next_ext_cap(xdbc.xhci_base, offset, XHCI_EXT_CAPS_PROTOCOL);
 373                if (!offset)
 374                        break;
 375
 376                val = readl(xdbc.xhci_base + offset);
 377                if (XHCI_EXT_PORT_MAJOR(val) != 0x3)
 378                        continue;
 379
 380                val = readl(xdbc.xhci_base + offset + 8);
 381                port_offset = XHCI_EXT_PORT_OFF(val);
 382                port_count = XHCI_EXT_PORT_COUNT(val);
 383
 384                xdbc_do_reset_debug_port(port_offset, port_count);
 385        } while (1);
 386}
 387
 388static void
 389xdbc_queue_trb(struct xdbc_ring *ring, u32 field1, u32 field2, u32 field3, u32 field4)
 390{
 391        struct xdbc_trb *trb, *link_trb;
 392
 393        trb = ring->enqueue;
 394        trb->field[0] = cpu_to_le32(field1);
 395        trb->field[1] = cpu_to_le32(field2);
 396        trb->field[2] = cpu_to_le32(field3);
 397        trb->field[3] = cpu_to_le32(field4);
 398
 399        ++(ring->enqueue);
 400        if (ring->enqueue >= &ring->segment->trbs[TRBS_PER_SEGMENT - 1]) {
 401                link_trb = ring->enqueue;
 402                if (ring->cycle_state)
 403                        link_trb->field[3] |= cpu_to_le32(TRB_CYCLE);
 404                else
 405                        link_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
 406
 407                ring->enqueue = ring->segment->trbs;
 408                ring->cycle_state ^= 1;
 409        }
 410}
 411
 412static void xdbc_ring_doorbell(int target)
 413{
 414        writel(DOOR_BELL_TARGET(target), &xdbc.xdbc_reg->doorbell);
 415}
 416
 417static int xdbc_start(void)
 418{
 419        u32 ctrl, status;
 420        int ret;
 421
 422        ctrl = readl(&xdbc.xdbc_reg->control);
 423        writel(ctrl | CTRL_DBC_ENABLE | CTRL_PORT_ENABLE, &xdbc.xdbc_reg->control);
 424        ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, CTRL_DBC_ENABLE, 100000, 100);
 425        if (ret) {
 426                xdbc_trace("failed to initialize hardware\n");
 427                return ret;
 428        }
 429
 430        /* Reset port to avoid bus hang: */
 431        if (xdbc.vendor == PCI_VENDOR_ID_INTEL)
 432                xdbc_reset_debug_port();
 433
 434        /* Wait for port connection: */
 435        ret = handshake(&xdbc.xdbc_reg->portsc, PORTSC_CONN_STATUS, PORTSC_CONN_STATUS, 5000000, 100);
 436        if (ret) {
 437                xdbc_trace("waiting for connection timed out\n");
 438                return ret;
 439        }
 440
 441        /* Wait for debug device to be configured: */
 442        ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_RUN, CTRL_DBC_RUN, 5000000, 100);
 443        if (ret) {
 444                xdbc_trace("waiting for device configuration timed out\n");
 445                return ret;
 446        }
 447
 448        /* Check port number: */
 449        status = readl(&xdbc.xdbc_reg->status);
 450        if (!DCST_DEBUG_PORT(status)) {
 451                xdbc_trace("invalid root hub port number\n");
 452                return -ENODEV;
 453        }
 454
 455        xdbc.port_number = DCST_DEBUG_PORT(status);
 456
 457        xdbc_trace("DbC is running now, control 0x%08x port ID %d\n",
 458                   readl(&xdbc.xdbc_reg->control), xdbc.port_number);
 459
 460        return 0;
 461}
 462
 463static int xdbc_bulk_transfer(void *data, int size, bool read)
 464{
 465        struct xdbc_ring *ring;
 466        struct xdbc_trb *trb;
 467        u32 length, control;
 468        u32 cycle;
 469        u64 addr;
 470
 471        if (size > XDBC_MAX_PACKET) {
 472                xdbc_trace("bad parameter, size %d\n", size);
 473                return -EINVAL;
 474        }
 475
 476        if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED) ||
 477            !(xdbc.flags & XDBC_FLAGS_CONFIGURED) ||
 478            (!read && (xdbc.flags & XDBC_FLAGS_OUT_STALL)) ||
 479            (read && (xdbc.flags & XDBC_FLAGS_IN_STALL))) {
 480
 481                xdbc_trace("connection not ready, flags %08x\n", xdbc.flags);
 482                return -EIO;
 483        }
 484
 485        ring = (read ? &xdbc.in_ring : &xdbc.out_ring);
 486        trb = ring->enqueue;
 487        cycle = ring->cycle_state;
 488        length = TRB_LEN(size);
 489        control = TRB_TYPE(TRB_NORMAL) | TRB_IOC;
 490
 491        if (cycle)
 492                control &= cpu_to_le32(~TRB_CYCLE);
 493        else
 494                control |= cpu_to_le32(TRB_CYCLE);
 495
 496        if (read) {
 497                memset(xdbc.in_buf, 0, XDBC_MAX_PACKET);
 498                addr = xdbc.in_dma;
 499                xdbc.flags |= XDBC_FLAGS_IN_PROCESS;
 500        } else {
 501                memset(xdbc.out_buf, 0, XDBC_MAX_PACKET);
 502                memcpy(xdbc.out_buf, data, size);
 503                addr = xdbc.out_dma;
 504                xdbc.flags |= XDBC_FLAGS_OUT_PROCESS;
 505        }
 506
 507        xdbc_queue_trb(ring, lower_32_bits(addr), upper_32_bits(addr), length, control);
 508
 509        /*
 510         * Add a barrier between writes of trb fields and flipping
 511         * the cycle bit:
 512         */
 513        wmb();
 514        if (cycle)
 515                trb->field[3] |= cpu_to_le32(cycle);
 516        else
 517                trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
 518
 519        xdbc_ring_doorbell(read ? IN_EP_DOORBELL : OUT_EP_DOORBELL);
 520
 521        return size;
 522}
 523
 524static int xdbc_handle_external_reset(void)
 525{
 526        int ret = 0;
 527
 528        xdbc.flags = 0;
 529        writel(0, &xdbc.xdbc_reg->control);
 530        ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 10);
 531        if (ret)
 532                goto reset_out;
 533
 534        xdbc_mem_init();
 535
 536        ret = xdbc_start();
 537        if (ret < 0)
 538                goto reset_out;
 539
 540        xdbc_trace("dbc recovered\n");
 541
 542        xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
 543
 544        xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
 545
 546        return 0;
 547
 548reset_out:
 549        xdbc_trace("failed to recover from external reset\n");
 550        return ret;
 551}
 552
 553static int __init xdbc_early_setup(void)
 554{
 555        int ret;
 556
 557        writel(0, &xdbc.xdbc_reg->control);
 558        ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 100);
 559        if (ret)
 560                return ret;
 561
 562        /* Allocate the table page: */
 563        xdbc.table_base = xdbc_get_page(&xdbc.table_dma);
 564        if (!xdbc.table_base)
 565                return -ENOMEM;
 566
 567        /* Get and store the transfer buffer: */
 568        xdbc.out_buf = xdbc_get_page(&xdbc.out_dma);
 569        if (!xdbc.out_buf)
 570                return -ENOMEM;
 571
 572        /* Allocate the event ring: */
 573        ret = xdbc_alloc_ring(&xdbc.evt_seg, &xdbc.evt_ring);
 574        if (ret < 0)
 575                return ret;
 576
 577        /* Allocate IN/OUT endpoint transfer rings: */
 578        ret = xdbc_alloc_ring(&xdbc.in_seg, &xdbc.in_ring);
 579        if (ret < 0)
 580                return ret;
 581
 582        ret = xdbc_alloc_ring(&xdbc.out_seg, &xdbc.out_ring);
 583        if (ret < 0)
 584                return ret;
 585
 586        xdbc_mem_init();
 587
 588        ret = xdbc_start();
 589        if (ret < 0) {
 590                writel(0, &xdbc.xdbc_reg->control);
 591                return ret;
 592        }
 593
 594        xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
 595
 596        xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
 597
 598        return 0;
 599}
 600
 601int __init early_xdbc_parse_parameter(char *s)
 602{
 603        unsigned long dbgp_num = 0;
 604        u32 bus, dev, func, offset;
 605        int ret;
 606
 607        if (!early_pci_allowed())
 608                return -EPERM;
 609
 610        if (strstr(s, "keep"))
 611                early_console_keep = true;
 612
 613        if (xdbc.xdbc_reg)
 614                return 0;
 615
 616        if (*s && kstrtoul(s, 0, &dbgp_num))
 617                dbgp_num = 0;
 618
 619        pr_notice("dbgp_num: %lu\n", dbgp_num);
 620
 621        /* Locate the host controller: */
 622        ret = xdbc_find_dbgp(dbgp_num, &bus, &dev, &func);
 623        if (ret) {
 624                pr_notice("failed to locate xhci host\n");
 625                return -ENODEV;
 626        }
 627
 628        xdbc.vendor     = read_pci_config_16(bus, dev, func, PCI_VENDOR_ID);
 629        xdbc.device     = read_pci_config_16(bus, dev, func, PCI_DEVICE_ID);
 630        xdbc.bus        = bus;
 631        xdbc.dev        = dev;
 632        xdbc.func       = func;
 633
 634        /* Map the IO memory: */
 635        xdbc.xhci_base = xdbc_map_pci_mmio(bus, dev, func);
 636        if (!xdbc.xhci_base)
 637                return -EINVAL;
 638
 639        /* Locate DbC registers: */
 640        offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
 641        if (!offset) {
 642                pr_notice("xhci host doesn't support debug capability\n");
 643                early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
 644                xdbc.xhci_base = NULL;
 645                xdbc.xhci_length = 0;
 646
 647                return -ENODEV;
 648        }
 649        xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
 650
 651        return 0;
 652}
 653
 654int __init early_xdbc_setup_hardware(void)
 655{
 656        int ret;
 657
 658        if (!xdbc.xdbc_reg)
 659                return -ENODEV;
 660
 661        xdbc_bios_handoff();
 662
 663        raw_spin_lock_init(&xdbc.lock);
 664
 665        ret = xdbc_early_setup();
 666        if (ret) {
 667                pr_notice("failed to setup the connection to host\n");
 668
 669                xdbc_free_ring(&xdbc.evt_ring);
 670                xdbc_free_ring(&xdbc.out_ring);
 671                xdbc_free_ring(&xdbc.in_ring);
 672
 673                if (xdbc.table_dma)
 674                        memblock_free(xdbc.table_dma, PAGE_SIZE);
 675
 676                if (xdbc.out_dma)
 677                        memblock_free(xdbc.out_dma, PAGE_SIZE);
 678
 679                xdbc.table_base = NULL;
 680                xdbc.out_buf = NULL;
 681        }
 682
 683        return ret;
 684}
 685
 686static void xdbc_handle_port_status(struct xdbc_trb *evt_trb)
 687{
 688        u32 port_reg;
 689
 690        port_reg = readl(&xdbc.xdbc_reg->portsc);
 691        if (port_reg & PORTSC_CONN_CHANGE) {
 692                xdbc_trace("connect status change event\n");
 693
 694                /* Check whether cable unplugged: */
 695                if (!(port_reg & PORTSC_CONN_STATUS)) {
 696                        xdbc.flags = 0;
 697                        xdbc_trace("cable unplugged\n");
 698                }
 699        }
 700
 701        if (port_reg & PORTSC_RESET_CHANGE)
 702                xdbc_trace("port reset change event\n");
 703
 704        if (port_reg & PORTSC_LINK_CHANGE)
 705                xdbc_trace("port link status change event\n");
 706
 707        if (port_reg & PORTSC_CONFIG_CHANGE)
 708                xdbc_trace("config error change\n");
 709
 710        /* Write back the value to clear RW1C bits: */
 711        writel(port_reg, &xdbc.xdbc_reg->portsc);
 712}
 713
 714static void xdbc_handle_tx_event(struct xdbc_trb *evt_trb)
 715{
 716        u32 comp_code;
 717        int ep_id;
 718
 719        comp_code       = GET_COMP_CODE(le32_to_cpu(evt_trb->field[2]));
 720        ep_id           = TRB_TO_EP_ID(le32_to_cpu(evt_trb->field[3]));
 721
 722        switch (comp_code) {
 723        case COMP_SUCCESS:
 724        case COMP_SHORT_PACKET:
 725                break;
 726        case COMP_TRB_ERROR:
 727        case COMP_BABBLE_DETECTED_ERROR:
 728        case COMP_USB_TRANSACTION_ERROR:
 729        case COMP_STALL_ERROR:
 730        default:
 731                if (ep_id == XDBC_EPID_OUT)
 732                        xdbc.flags |= XDBC_FLAGS_OUT_STALL;
 733                if (ep_id == XDBC_EPID_IN)
 734                        xdbc.flags |= XDBC_FLAGS_IN_STALL;
 735
 736                xdbc_trace("endpoint %d stalled\n", ep_id);
 737                break;
 738        }
 739
 740        if (ep_id == XDBC_EPID_IN) {
 741                xdbc.flags &= ~XDBC_FLAGS_IN_PROCESS;
 742                xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
 743        } else if (ep_id == XDBC_EPID_OUT) {
 744                xdbc.flags &= ~XDBC_FLAGS_OUT_PROCESS;
 745        } else {
 746                xdbc_trace("invalid endpoint id %d\n", ep_id);
 747        }
 748}
 749
 750static void xdbc_handle_events(void)
 751{
 752        struct xdbc_trb *evt_trb;
 753        bool update_erdp = false;
 754        u32 reg;
 755        u8 cmd;
 756
 757        cmd = read_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND);
 758        if (!(cmd & PCI_COMMAND_MASTER)) {
 759                cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
 760                write_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND, cmd);
 761        }
 762
 763        if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
 764                return;
 765
 766        /* Handle external reset events: */
 767        reg = readl(&xdbc.xdbc_reg->control);
 768        if (!(reg & CTRL_DBC_ENABLE)) {
 769                if (xdbc_handle_external_reset()) {
 770                        xdbc_trace("failed to recover connection\n");
 771                        return;
 772                }
 773        }
 774
 775        /* Handle configure-exit event: */
 776        reg = readl(&xdbc.xdbc_reg->control);
 777        if (reg & CTRL_DBC_RUN_CHANGE) {
 778                writel(reg, &xdbc.xdbc_reg->control);
 779                if (reg & CTRL_DBC_RUN)
 780                        xdbc.flags |= XDBC_FLAGS_CONFIGURED;
 781                else
 782                        xdbc.flags &= ~XDBC_FLAGS_CONFIGURED;
 783        }
 784
 785        /* Handle endpoint stall event: */
 786        reg = readl(&xdbc.xdbc_reg->control);
 787        if (reg & CTRL_HALT_IN_TR) {
 788                xdbc.flags |= XDBC_FLAGS_IN_STALL;
 789        } else {
 790                xdbc.flags &= ~XDBC_FLAGS_IN_STALL;
 791                if (!(xdbc.flags & XDBC_FLAGS_IN_PROCESS))
 792                        xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
 793        }
 794
 795        if (reg & CTRL_HALT_OUT_TR)
 796                xdbc.flags |= XDBC_FLAGS_OUT_STALL;
 797        else
 798                xdbc.flags &= ~XDBC_FLAGS_OUT_STALL;
 799
 800        /* Handle the events in the event ring: */
 801        evt_trb = xdbc.evt_ring.dequeue;
 802        while ((le32_to_cpu(evt_trb->field[3]) & TRB_CYCLE) == xdbc.evt_ring.cycle_state) {
 803                /*
 804                 * Add a barrier between reading the cycle flag and any
 805                 * reads of the event's flags/data below:
 806                 */
 807                rmb();
 808
 809                switch ((le32_to_cpu(evt_trb->field[3]) & TRB_TYPE_BITMASK)) {
 810                case TRB_TYPE(TRB_PORT_STATUS):
 811                        xdbc_handle_port_status(evt_trb);
 812                        break;
 813                case TRB_TYPE(TRB_TRANSFER):
 814                        xdbc_handle_tx_event(evt_trb);
 815                        break;
 816                default:
 817                        break;
 818                }
 819
 820                ++(xdbc.evt_ring.dequeue);
 821                if (xdbc.evt_ring.dequeue == &xdbc.evt_seg.trbs[TRBS_PER_SEGMENT]) {
 822                        xdbc.evt_ring.dequeue = xdbc.evt_seg.trbs;
 823                        xdbc.evt_ring.cycle_state ^= 1;
 824                }
 825
 826                evt_trb = xdbc.evt_ring.dequeue;
 827                update_erdp = true;
 828        }
 829
 830        /* Update event ring dequeue pointer: */
 831        if (update_erdp)
 832                xdbc_write64(__pa(xdbc.evt_ring.dequeue), &xdbc.xdbc_reg->erdp);
 833}
 834
 835static int xdbc_bulk_write(const char *bytes, int size)
 836{
 837        int ret, timeout = 0;
 838        unsigned long flags;
 839
 840retry:
 841        if (in_nmi()) {
 842                if (!raw_spin_trylock_irqsave(&xdbc.lock, flags))
 843                        return -EAGAIN;
 844        } else {
 845                raw_spin_lock_irqsave(&xdbc.lock, flags);
 846        }
 847
 848        xdbc_handle_events();
 849
 850        /* Check completion of the previous request: */
 851        if ((xdbc.flags & XDBC_FLAGS_OUT_PROCESS) && (timeout < 2000000)) {
 852                raw_spin_unlock_irqrestore(&xdbc.lock, flags);
 853                udelay(100);
 854                timeout += 100;
 855                goto retry;
 856        }
 857
 858        if (xdbc.flags & XDBC_FLAGS_OUT_PROCESS) {
 859                raw_spin_unlock_irqrestore(&xdbc.lock, flags);
 860                xdbc_trace("previous transfer not completed yet\n");
 861
 862                return -ETIMEDOUT;
 863        }
 864
 865        ret = xdbc_bulk_transfer((void *)bytes, size, false);
 866        raw_spin_unlock_irqrestore(&xdbc.lock, flags);
 867
 868        return ret;
 869}
 870
 871static void early_xdbc_write(struct console *con, const char *str, u32 n)
 872{
 873        static char buf[XDBC_MAX_PACKET];
 874        int chunk, ret;
 875        int use_cr = 0;
 876
 877        if (!xdbc.xdbc_reg)
 878                return;
 879        memset(buf, 0, XDBC_MAX_PACKET);
 880        while (n > 0) {
 881                for (chunk = 0; chunk < XDBC_MAX_PACKET && n > 0; str++, chunk++, n--) {
 882
 883                        if (!use_cr && *str == '\n') {
 884                                use_cr = 1;
 885                                buf[chunk] = '\r';
 886                                str--;
 887                                n++;
 888                                continue;
 889                        }
 890
 891                        if (use_cr)
 892                                use_cr = 0;
 893                        buf[chunk] = *str;
 894                }
 895
 896                if (chunk > 0) {
 897                        ret = xdbc_bulk_write(buf, chunk);
 898                        if (ret < 0)
 899                                xdbc_trace("missed message {%s}\n", buf);
 900                }
 901        }
 902}
 903
 904static struct console early_xdbc_console = {
 905        .name           = "earlyxdbc",
 906        .write          = early_xdbc_write,
 907        .flags          = CON_PRINTBUFFER,
 908        .index          = -1,
 909};
 910
 911void __init early_xdbc_register_console(void)
 912{
 913        if (early_console)
 914                return;
 915
 916        early_console = &early_xdbc_console;
 917        if (early_console_keep)
 918                early_console->flags &= ~CON_BOOT;
 919        else
 920                early_console->flags |= CON_BOOT;
 921        register_console(early_console);
 922}
 923
 924static void xdbc_unregister_console(void)
 925{
 926        if (early_xdbc_console.flags & CON_ENABLED)
 927                unregister_console(&early_xdbc_console);
 928}
 929
 930static int xdbc_scrub_function(void *ptr)
 931{
 932        unsigned long flags;
 933
 934        while (true) {
 935                raw_spin_lock_irqsave(&xdbc.lock, flags);
 936                xdbc_handle_events();
 937
 938                if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED)) {
 939                        raw_spin_unlock_irqrestore(&xdbc.lock, flags);
 940                        break;
 941                }
 942
 943                raw_spin_unlock_irqrestore(&xdbc.lock, flags);
 944                schedule_timeout_interruptible(1);
 945        }
 946
 947        xdbc_unregister_console();
 948        writel(0, &xdbc.xdbc_reg->control);
 949        xdbc_trace("dbc scrub function exits\n");
 950
 951        return 0;
 952}
 953
 954static int __init xdbc_init(void)
 955{
 956        unsigned long flags;
 957        void __iomem *base;
 958        int ret = 0;
 959        u32 offset;
 960
 961        if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
 962                return 0;
 963
 964        /*
 965         * It's time to shut down the DbC, so that the debug
 966         * port can be reused by the host controller:
 967         */
 968        if (early_xdbc_console.index == -1 ||
 969            (early_xdbc_console.flags & CON_BOOT)) {
 970                xdbc_trace("hardware not used anymore\n");
 971                goto free_and_quit;
 972        }
 973
 974        base = ioremap_nocache(xdbc.xhci_start, xdbc.xhci_length);
 975        if (!base) {
 976                xdbc_trace("failed to remap the io address\n");
 977                ret = -ENOMEM;
 978                goto free_and_quit;
 979        }
 980
 981        raw_spin_lock_irqsave(&xdbc.lock, flags);
 982        early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
 983        xdbc.xhci_base = base;
 984        offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
 985        xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
 986        raw_spin_unlock_irqrestore(&xdbc.lock, flags);
 987
 988        kthread_run(xdbc_scrub_function, NULL, "%s", "xdbc");
 989
 990        return 0;
 991
 992free_and_quit:
 993        xdbc_free_ring(&xdbc.evt_ring);
 994        xdbc_free_ring(&xdbc.out_ring);
 995        xdbc_free_ring(&xdbc.in_ring);
 996        memblock_free(xdbc.table_dma, PAGE_SIZE);
 997        memblock_free(xdbc.out_dma, PAGE_SIZE);
 998        writel(0, &xdbc.xdbc_reg->control);
 999        early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
1000
1001        return ret;
1002}
1003subsys_initcall(xdbc_init);
1004