--- /dev/null
+/**
+ * xhci-dbc.c - xHCI debug capability early driver
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/console.h>
+#include <linux/pci_regs.h>
+#include <linux/pci_ids.h>
+#include <linux/bootmem.h>
+#include <linux/io.h>
+#include <asm/pci-direct.h>
+#include <asm/fixmap.h>
+#include <linux/bcd.h>
+#include <linux/export.h>
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+
+#include "../host/xhci.h"
+#include "xhci-dbc.h"
+
+static struct xdbc_state xdbc;
+static bool early_console_keep;
+
+#define XDBC_TRACE
+#ifdef XDBC_TRACE
+#define xdbc_trace trace_printk
+#else
+static inline void xdbc_trace(const char *fmt, ...) { }
+#endif /* XDBC_TRACE */
+
+static void __iomem * __init xdbc_map_pci_mmio(u32 bus, u32 dev, u32 func)
+{
+ u64 val64, sz64, mask64;
+ void __iomem *base;
+ u32 val, sz;
+ u8 byte;
+
+ val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, ~0);
+ sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, val);
+
+ if (val == 0xffffffff || sz == 0xffffffff) {
+ pr_notice("invalid mmio bar\n");
+ return NULL;
+ }
+
+ val64 = val & PCI_BASE_ADDRESS_MEM_MASK;
+ sz64 = sz & PCI_BASE_ADDRESS_MEM_MASK;
+ mask64 = PCI_BASE_ADDRESS_MEM_MASK;
+
+ if ((val & PCI_BASE_ADDRESS_MEM_TYPE_MASK) == PCI_BASE_ADDRESS_MEM_TYPE_64) {
+ val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, ~0);
+ sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, val);
+
+ val64 |= (u64)val << 32;
+ sz64 |= (u64)sz << 32;
+ mask64 |= ~0ULL << 32;
+ }
+
+ sz64 &= mask64;
+
+ if (!sz64) {
+ pr_notice("invalid mmio address\n");
+ return NULL;
+ }
+
+ sz64 = 1ULL << __ffs64(sz64);
+
+ /* Check if the mem space is enabled: */
+ byte = read_pci_config_byte(bus, dev, func, PCI_COMMAND);
+ if (!(byte & PCI_COMMAND_MEMORY)) {
+ byte |= PCI_COMMAND_MEMORY;
+ write_pci_config_byte(bus, dev, func, PCI_COMMAND, byte);
+ }
+
+ xdbc.xhci_start = val64;
+ xdbc.xhci_length = sz64;
+ base = early_ioremap(val64, sz64);
+
+ return base;
+}
+
+static void * __init xdbc_get_page(dma_addr_t *dma_addr)
+{
+ void *virt;
+
+ virt = alloc_bootmem_pages_nopanic(PAGE_SIZE);
+ if (!virt)
+ return NULL;
+
+ if (dma_addr)
+ *dma_addr = (dma_addr_t)__pa(virt);
+
+ return virt;
+}
+
+static u32 __init xdbc_find_dbgp(int xdbc_num, u32 *b, u32 *d, u32 *f)
+{
+ u32 bus, dev, func, class;
+
+ for (bus = 0; bus < XDBC_PCI_MAX_BUSES; bus++) {
+ for (dev = 0; dev < XDBC_PCI_MAX_DEVICES; dev++) {
+ for (func = 0; func < XDBC_PCI_MAX_FUNCTION; func++) {
+
+ class = read_pci_config(bus, dev, func, PCI_CLASS_REVISION);
+ if ((class >> 8) != PCI_CLASS_SERIAL_USB_XHCI)
+ continue;
+
+ if (xdbc_num-- != 0)
+ continue;
+
+ *b = bus;
+ *d = dev;
+ *f = func;
+
+ return 0;
+ }
+ }
+ }
+
+ return -1;
+}
+
+static int handshake(void __iomem *ptr, u32 mask, u32 done, int wait, int delay)
+{
+ u32 result;
+
+ do {
+ result = readl(ptr);
+ result &= mask;
+ if (result == done)
+ return 0;
+ udelay(delay);
+ wait -= delay;
+ } while (wait > 0);
+
+ return -ETIMEDOUT;
+}
+
+static void __init xdbc_bios_handoff(void)
+{
+ int offset, timeout;
+ u32 val;
+
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_LEGACY);
+ val = readl(xdbc.xhci_base + offset);
+
+ if (val & XHCI_HC_BIOS_OWNED) {
+ writel(val | XHCI_HC_OS_OWNED, xdbc.xhci_base + offset);
+ timeout = handshake(xdbc.xhci_base + offset, XHCI_HC_BIOS_OWNED, 0, 5000, 10);
+
+ if (timeout) {
+ pr_notice("failed to hand over xHCI control from BIOS\n");
+ writel(val & ~XHCI_HC_BIOS_OWNED, xdbc.xhci_base + offset);
+ }
+ }
+
+ /* Disable BIOS SMIs and clear all SMI events: */
+ val = readl(xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
+ val &= XHCI_LEGACY_DISABLE_SMI;
+ val |= XHCI_LEGACY_SMI_EVENTS;
+ writel(val, xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
+}
+
+static int __init
+xdbc_alloc_ring(struct xdbc_segment *seg, struct xdbc_ring *ring)
+{
+ seg->trbs = xdbc_get_page(&seg->dma);
+ if (!seg->trbs)
+ return -ENOMEM;
+
+ ring->segment = seg;
+
+ return 0;
+}
+
+static void __init xdbc_free_ring(struct xdbc_ring *ring)
+{
+ struct xdbc_segment *seg = ring->segment;
+
+ if (!seg)
+ return;
+
+ free_bootmem(seg->dma, PAGE_SIZE);
+ ring->segment = NULL;
+}
+
+static void xdbc_reset_ring(struct xdbc_ring *ring)
+{
+ struct xdbc_segment *seg = ring->segment;
+ struct xdbc_trb *link_trb;
+
+ memset(seg->trbs, 0, PAGE_SIZE);
+
+ ring->enqueue = seg->trbs;
+ ring->dequeue = seg->trbs;
+ ring->cycle_state = 1;
+
+ if (ring != &xdbc.evt_ring) {
+ link_trb = &seg->trbs[XDBC_TRBS_PER_SEGMENT - 1];
+ link_trb->field[0] = cpu_to_le32(lower_32_bits(seg->dma));
+ link_trb->field[1] = cpu_to_le32(upper_32_bits(seg->dma));
+ link_trb->field[3] = cpu_to_le32(TRB_TYPE(TRB_LINK)) | cpu_to_le32(LINK_TOGGLE);
+ }
+}
+
+static inline void xdbc_put_utf16(u16 *s, const char *c, size_t size)
+{
+ int i;
+
+ for (i = 0; i < size; i++)
+ s[i] = cpu_to_le16(c[i]);
+}
+
+static void xdbc_mem_init(void)
+{
+ struct xdbc_ep_context *ep_in, *ep_out;
+ struct usb_string_descriptor *s_desc;
+ struct xdbc_erst_entry *entry;
+ struct xdbc_strings *strings;
+ struct xdbc_context *ctx;
+ unsigned int max_burst;
+ u32 string_length;
+ int index = 0;
+ u32 dev_info;
+
+ xdbc_reset_ring(&xdbc.evt_ring);
+ xdbc_reset_ring(&xdbc.in_ring);
+ xdbc_reset_ring(&xdbc.out_ring);
+ memset(xdbc.table_base, 0, PAGE_SIZE);
+ memset(xdbc.out_buf, 0, PAGE_SIZE);
+
+ /* Initialize event ring segment table: */
+ xdbc.erst_size = 16;
+ xdbc.erst_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.erst_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+
+ index += XDBC_ERST_ENTRY_NUM;
+ entry = (struct xdbc_erst_entry *)xdbc.erst_base;
+
+ entry->seg_addr = cpu_to_le64(xdbc.evt_seg.dma);
+ entry->seg_size = cpu_to_le32(XDBC_TRBS_PER_SEGMENT);
+ entry->__reserved_0 = 0;
+
+ /* Initialize ERST registers: */
+ writel(1, &xdbc.xdbc_reg->ersts);
+ xdbc_write64(xdbc.erst_dma, &xdbc.xdbc_reg->erstba);
+ xdbc_write64(xdbc.evt_seg.dma, &xdbc.xdbc_reg->erdp);
+
+ /* Debug capability contexts: */
+ xdbc.dbcc_size = 64 * 3;
+ xdbc.dbcc_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.dbcc_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+
+ index += XDBC_DBCC_ENTRY_NUM;
+
+ /* Popluate the strings: */
+ xdbc.string_size = sizeof(struct xdbc_strings);
+ xdbc.string_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.string_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+ strings = (struct xdbc_strings *)xdbc.string_base;
+
+ index += XDBC_STRING_ENTRY_NUM;
+
+ /* Serial string: */
+ s_desc = (struct usb_string_descriptor *)strings->serial;
+ s_desc->bLength = (strlen(XDBC_STRING_SERIAL) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_SERIAL, strlen(XDBC_STRING_SERIAL));
+ string_length = s_desc->bLength;
+ string_length <<= 8;
+
+ /* Product string: */
+ s_desc = (struct usb_string_descriptor *)strings->product;
+ s_desc->bLength = (strlen(XDBC_STRING_PRODUCT) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_PRODUCT, strlen(XDBC_STRING_PRODUCT));
+ string_length += s_desc->bLength;
+ string_length <<= 8;
+
+ /* Manufacture string: */
+ s_desc = (struct usb_string_descriptor *)strings->manufacturer;
+ s_desc->bLength = (strlen(XDBC_STRING_MANUFACTURER) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_MANUFACTURER, strlen(XDBC_STRING_MANUFACTURER));
+ string_length += s_desc->bLength;
+ string_length <<= 8;
+
+ /* String0: */
+ strings->string0[0] = 4;
+ strings->string0[1] = USB_DT_STRING;
+ strings->string0[2] = 0x09;
+ strings->string0[3] = 0x04;
+
+ string_length += 4;
+
+ /* Populate info Context: */
+ ctx = (struct xdbc_context *)xdbc.dbcc_base;
+
+ ctx->info.string0 = cpu_to_le64(xdbc.string_dma);
+ ctx->info.manufacturer = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH);
+ ctx->info.product = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 2);
+ ctx->info.serial = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 3);
+ ctx->info.length = cpu_to_le32(string_length);
+
+ /* Populate bulk out endpoint context: */
+ max_burst = DEBUG_MAX_BURST(readl(&xdbc.xdbc_reg->control));
+ ep_out = (struct xdbc_ep_context *)&ctx->out;
+
+ ep_out->ep_info1 = 0;
+ ep_out->ep_info2 = cpu_to_le32(EP_TYPE(BULK_OUT_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
+ ep_out->deq = cpu_to_le64(xdbc.out_seg.dma | xdbc.out_ring.cycle_state);
+
+ /* Populate bulk in endpoint context: */
+ ep_in = (struct xdbc_ep_context *)&ctx->in;
+
+ ep_in->ep_info1 = 0;
+ ep_in->ep_info2 = cpu_to_le32(EP_TYPE(BULK_OUT_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
+ ep_in->deq = cpu_to_le64(xdbc.in_seg.dma | xdbc.in_ring.cycle_state);
+
+ /* Set DbC context and info registers: */
+ xdbc_write64(xdbc.dbcc_dma, &xdbc.xdbc_reg->dccp);
+
+ dev_info = cpu_to_le32((XDBC_VENDOR_ID << 16) | XDBC_PROTOCOL);
+ writel(dev_info, &xdbc.xdbc_reg->devinfo1);
+
+ dev_info = cpu_to_le32((XDBC_DEVICE_REV << 16) | XDBC_PRODUCT_ID);
+ writel(dev_info, &xdbc.xdbc_reg->devinfo2);
+
+ xdbc.in_buf = xdbc.out_buf + XDBC_MAX_PACKET;
+ xdbc.in_dma = xdbc.out_dma + XDBC_MAX_PACKET;
+}
+
+static void xdbc_do_reset_debug_port(u32 id, u32 count)
+{
+ void __iomem *ops_reg;
+ void __iomem *portsc;
+ u32 val, cap_length;
+ int i;
+
+ cap_length = readl(xdbc.xhci_base) & 0xff;
+ ops_reg = xdbc.xhci_base + cap_length;
+
+ id--;
+ for (i = id; i < (id + count); i++) {
+ portsc = ops_reg + 0x400 + i * 0x10;
+ val = readl(portsc);
+ if (!(val & PORT_CONNECT))
+ writel(val | PORT_RESET, portsc);
+ }
+}
+
+static void xdbc_reset_debug_port(void)
+{
+ u32 val, port_offset, port_count;
+ int offset = 0;
+
+ do {
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, offset, XHCI_EXT_CAPS_PROTOCOL);
+ if (!offset)
+ break;
+
+ val = readl(xdbc.xhci_base + offset);
+ if (XHCI_EXT_PORT_MAJOR(val) != 0x3)
+ continue;
+
+ val = readl(xdbc.xhci_base + offset + 8);
+ port_offset = XHCI_EXT_PORT_OFF(val);
+ port_count = XHCI_EXT_PORT_COUNT(val);
+
+ xdbc_do_reset_debug_port(port_offset, port_count);
+ } while (1);
+}
+
+static void
+xdbc_queue_trb(struct xdbc_ring *ring, u32 field1, u32 field2, u32 field3, u32 field4)
+{
+ struct xdbc_trb *trb, *link_trb;
+
+ trb = ring->enqueue;
+ trb->field[0] = cpu_to_le32(field1);
+ trb->field[1] = cpu_to_le32(field2);
+ trb->field[2] = cpu_to_le32(field3);
+ trb->field[3] = cpu_to_le32(field4);
+
+ ++(ring->enqueue);
+ if (ring->enqueue >= &ring->segment->trbs[TRBS_PER_SEGMENT - 1]) {
+ link_trb = ring->enqueue;
+ if (ring->cycle_state)
+ link_trb->field[3] |= cpu_to_le32(TRB_CYCLE);
+ else
+ link_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+ ring->enqueue = ring->segment->trbs;
+ ring->cycle_state ^= 1;
+ }
+}
+
+static void xdbc_ring_doorbell(int target)
+{
+ writel(DOOR_BELL_TARGET(target), &xdbc.xdbc_reg->doorbell);
+}
+
+static int xdbc_start(void)
+{
+ u32 ctrl, status;
+ int ret;
+
+ ctrl = readl(&xdbc.xdbc_reg->control);
+ writel(ctrl | CTRL_DBC_ENABLE | CTRL_PORT_ENABLE, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, CTRL_DBC_ENABLE, 100000, 100);
+ if (ret) {
+ xdbc_trace("failed to initialize hardware\n");
+ return ret;
+ }
+
+ /* Reset port to avoid bus hang: */
+ if (xdbc.vendor == PCI_VENDOR_ID_INTEL)
+ xdbc_reset_debug_port();
+
+ /* Wait for port connection: */
+ ret = handshake(&xdbc.xdbc_reg->portsc, PORTSC_CONN_STATUS, PORTSC_CONN_STATUS, 5000000, 100);
+ if (ret) {
+ xdbc_trace("waiting for connection timed out\n");
+ return ret;
+ }
+
+ /* Wait for debug device to be configured: */
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_RUN, CTRL_DBC_RUN, 5000000, 100);
+ if (ret) {
+ xdbc_trace("waiting for device configuration timed out\n");
+ return ret;
+ }
+
+ /* Check port number: */
+ status = readl(&xdbc.xdbc_reg->status);
+ if (!DCST_DEBUG_PORT(status)) {
+ xdbc_trace("invalid root hub port number\n");
+ return -ENODEV;
+ }
+
+ xdbc.port_number = DCST_DEBUG_PORT(status);
+
+ xdbc_trace("DbC is running now, control 0x%08x port ID %d\n",
+ readl(&xdbc.xdbc_reg->control), xdbc.port_number);
+
+ return 0;
+}
+
+static int xdbc_bulk_transfer(void *data, int size, bool read)
+{
+ struct xdbc_ring *ring;
+ struct xdbc_trb *trb;
+ u32 length, control;
+ u32 cycle;
+ u64 addr;
+
+ if (size > XDBC_MAX_PACKET) {
+ xdbc_trace("bad parameter, size %d\n", size);
+ return -EINVAL;
+ }
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED) ||
+ !(xdbc.flags & XDBC_FLAGS_CONFIGURED) ||
+ (!read && (xdbc.flags & XDBC_FLAGS_OUT_STALL)) ||
+ (read && (xdbc.flags & XDBC_FLAGS_IN_STALL))) {
+
+ xdbc_trace("connection not ready, flags %08x\n", xdbc.flags);
+ return -EIO;
+ }
+
+ ring = (read ? &xdbc.in_ring : &xdbc.out_ring);
+ trb = ring->enqueue;
+ cycle = ring->cycle_state;
+ length = TRB_LEN(size);
+ control = TRB_TYPE(TRB_NORMAL) | TRB_IOC;
+
+ if (cycle)
+ control &= cpu_to_le32(~TRB_CYCLE);
+ else
+ control |= cpu_to_le32(TRB_CYCLE);
+
+ if (read) {
+ memset(xdbc.in_buf, 0, XDBC_MAX_PACKET);
+ addr = xdbc.in_dma;
+ xdbc.flags |= XDBC_FLAGS_IN_PROCESS;
+ } else {
+ memset(xdbc.out_buf, 0, XDBC_MAX_PACKET);
+ memcpy(xdbc.out_buf, data, size);
+ addr = xdbc.out_dma;
+ xdbc.flags |= XDBC_FLAGS_OUT_PROCESS;
+ }
+
+ xdbc_queue_trb(ring, lower_32_bits(addr), upper_32_bits(addr), length, control);
+
+ /*
+ * Add a barrier between writes of trb fields and flipping
+ * the cycle bit:
+ */
+ wmb();
+ if (cycle)
+ trb->field[3] |= cpu_to_le32(cycle);
+ else
+ trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+ xdbc_ring_doorbell(read ? IN_EP_DOORBELL : OUT_EP_DOORBELL);
+
+ return size;
+}
+
+static int xdbc_handle_external_reset(void)
+{
+ int ret = 0;
+
+ xdbc.flags = 0;
+ writel(0, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 10);
+ if (ret)
+ goto reset_out;
+
+ xdbc_mem_init();
+
+ mmiowb();
+
+ ret = xdbc_start();
+ if (ret < 0)
+ goto reset_out;
+
+ xdbc_trace("dbc recovered\n");
+
+ xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
+
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+
+ return 0;
+
+reset_out:
+ xdbc_trace("failed to recover from external reset\n");
+ return ret;
+}
+
+static int __init xdbc_early_setup(void)
+{
+ int ret;
+
+ writel(0, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 100);
+ if (ret)
+ return ret;
+
+ /* Allocate the table page: */
+ xdbc.table_base = xdbc_get_page(&xdbc.table_dma);
+ if (!xdbc.table_base)
+ return -ENOMEM;
+
+ /* Get and store the transfer buffer: */
+ xdbc.out_buf = xdbc_get_page(&xdbc.out_dma);
+ if (!xdbc.out_buf)
+ return -ENOMEM;
+
+ /* Allocate the event ring: */
+ ret = xdbc_alloc_ring(&xdbc.evt_seg, &xdbc.evt_ring);
+ if (ret < 0)
+ return ret;
+
+ /* Allocate IN/OUT endpoint transfer rings: */
+ ret = xdbc_alloc_ring(&xdbc.in_seg, &xdbc.in_ring);
+ if (ret < 0)
+ return ret;
+
+ ret = xdbc_alloc_ring(&xdbc.out_seg, &xdbc.out_ring);
+ if (ret < 0)
+ return ret;
+
+ xdbc_mem_init();
+
+ mmiowb();
+
+ ret = xdbc_start();
+ if (ret < 0) {
+ writel(0, &xdbc.xdbc_reg->control);
+ return ret;
+ }
+
+ xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
+
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+
+ return 0;
+}
+
+int __init early_xdbc_parse_parameter(char *s)
+{
+ unsigned long dbgp_num = 0;
+ u32 bus, dev, func, offset;
+ int ret;
+
+ if (!early_pci_allowed())
+ return -EPERM;
+
+ if (strstr(s, "keep"))
+ early_console_keep = true;
+
+ if (xdbc.xdbc_reg)
+ return 0;
+
+ if (*s && kstrtoul(s, 0, &dbgp_num))
+ dbgp_num = 0;
+
+ pr_notice("dbgp_num: %lu\n", dbgp_num);
+
+ /* Locate the host controller: */
+ ret = xdbc_find_dbgp(dbgp_num, &bus, &dev, &func);
+ if (ret) {
+ pr_notice("failed to locate xhci host\n");
+ return -ENODEV;
+ }
+
+ xdbc.vendor = read_pci_config_16(bus, dev, func, PCI_VENDOR_ID);
+ xdbc.device = read_pci_config_16(bus, dev, func, PCI_DEVICE_ID);
+ xdbc.bus = bus;
+ xdbc.dev = dev;
+ xdbc.func = func;
+
+ /* Map the IO memory: */
+ xdbc.xhci_base = xdbc_map_pci_mmio(bus, dev, func);
+ if (!xdbc.xhci_base)
+ return -EINVAL;
+
+ /* Locate DbC registers: */
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
+ if (!offset) {
+ pr_notice("xhci host doesn't support debug capability\n");
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+ xdbc.xhci_base = NULL;
+ xdbc.xhci_length = 0;
+
+ return -ENODEV;
+ }
+ xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
+
+ return 0;
+}
+
+int __init early_xdbc_setup_hardware(void)
+{
+ int ret;
+
+ if (!xdbc.xdbc_reg)
+ return -ENODEV;
+
+ xdbc_bios_handoff();
+
+ raw_spin_lock_init(&xdbc.lock);
+
+ ret = xdbc_early_setup();
+ if (ret) {
+ pr_notice("failed to setup the connection to host\n");
+
+ xdbc_free_ring(&xdbc.evt_ring);
+ xdbc_free_ring(&xdbc.out_ring);
+ xdbc_free_ring(&xdbc.in_ring);
+
+ if (xdbc.table_dma)
+ free_bootmem(xdbc.table_dma, PAGE_SIZE);
+
+ if (xdbc.out_dma)
+ free_bootmem(xdbc.out_dma, PAGE_SIZE);
+
+ xdbc.table_base = NULL;
+ xdbc.out_buf = NULL;
+ }
+
+ return ret;
+}
+
+static void xdbc_handle_port_status(struct xdbc_trb *evt_trb)
+{
+ u32 port_reg;
+
+ port_reg = readl(&xdbc.xdbc_reg->portsc);
+ if (port_reg & PORTSC_CONN_CHANGE) {
+ xdbc_trace("connect status change event\n");
+
+ /* Check whether cable unplugged: */
+ if (!(port_reg & PORTSC_CONN_STATUS)) {
+ xdbc.flags = 0;
+ xdbc_trace("cable unplugged\n");
+ }
+ }
+
+ if (port_reg & PORTSC_RESET_CHANGE)
+ xdbc_trace("port reset change event\n");
+
+ if (port_reg & PORTSC_LINK_CHANGE)
+ xdbc_trace("port link status change event\n");
+
+ if (port_reg & PORTSC_CONFIG_CHANGE)
+ xdbc_trace("config error change\n");
+
+ /* Write back the value to clear RW1C bits: */
+ writel(port_reg, &xdbc.xdbc_reg->portsc);
+}
+
+static void xdbc_handle_tx_event(struct xdbc_trb *evt_trb)
+{
+ size_t remain_length;
+ u32 comp_code;
+ int ep_id;
+
+ comp_code = GET_COMP_CODE(le32_to_cpu(evt_trb->field[2]));
+ remain_length = EVENT_TRB_LEN(le32_to_cpu(evt_trb->field[2]));
+ ep_id = TRB_TO_EP_ID(le32_to_cpu(evt_trb->field[3]));
+
+ switch (comp_code) {
+ case COMP_SUCCESS:
+ remain_length = 0;
+ case COMP_SHORT_PACKET:
+ break;
+ case COMP_TRB_ERROR:
+ case COMP_BABBLE_DETECTED_ERROR:
+ case COMP_USB_TRANSACTION_ERROR:
+ case COMP_STALL_ERROR:
+ default:
+ if (ep_id == XDBC_EPID_OUT)
+ xdbc.flags |= XDBC_FLAGS_OUT_STALL;
+ if (ep_id == XDBC_EPID_IN)
+ xdbc.flags |= XDBC_FLAGS_IN_STALL;
+
+ xdbc_trace("endpoint %d stalled\n", ep_id);
+ break;
+ }
+
+ if (ep_id == XDBC_EPID_IN) {
+ xdbc.flags &= ~XDBC_FLAGS_IN_PROCESS;
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+ } else if (ep_id == XDBC_EPID_OUT) {
+ xdbc.flags &= ~XDBC_FLAGS_OUT_PROCESS;
+ } else {
+ xdbc_trace("invalid endpoint id %d\n", ep_id);
+ }
+}
+
+static void xdbc_handle_events(void)
+{
+ struct xdbc_trb *evt_trb;
+ bool update_erdp = false;
+ u32 reg;
+ u8 cmd;
+
+ cmd = read_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND);
+ if (!(cmd & PCI_COMMAND_MASTER)) {
+ cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
+ write_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND, cmd);
+ }
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
+ return;
+
+ /* Handle external reset events: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (!(reg & CTRL_DBC_ENABLE)) {
+ if (xdbc_handle_external_reset()) {
+ xdbc_trace("failed to recover connection\n");
+ return;
+ }
+ }
+
+ /* Handle configure-exit event: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (reg & CTRL_DBC_RUN_CHANGE) {
+ writel(reg, &xdbc.xdbc_reg->control);
+ if (reg & CTRL_DBC_RUN)
+ xdbc.flags |= XDBC_FLAGS_CONFIGURED;
+ else
+ xdbc.flags &= ~XDBC_FLAGS_CONFIGURED;
+ }
+
+ /* Handle endpoint stall event: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (reg & CTRL_HALT_IN_TR) {
+ xdbc.flags |= XDBC_FLAGS_IN_STALL;
+ } else {
+ xdbc.flags &= ~XDBC_FLAGS_IN_STALL;
+ if (!(xdbc.flags & XDBC_FLAGS_IN_PROCESS))
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+ }
+
+ if (reg & CTRL_HALT_OUT_TR)
+ xdbc.flags |= XDBC_FLAGS_OUT_STALL;
+ else
+ xdbc.flags &= ~XDBC_FLAGS_OUT_STALL;
+
+ /* Handle the events in the event ring: */
+ evt_trb = xdbc.evt_ring.dequeue;
+ while ((le32_to_cpu(evt_trb->field[3]) & TRB_CYCLE) == xdbc.evt_ring.cycle_state) {
+ /*
+ * Add a barrier between reading the cycle flag and any
+ * reads of the event's flags/data below:
+ */
+ rmb();
+
+ switch ((le32_to_cpu(evt_trb->field[3]) & TRB_TYPE_BITMASK)) {
+ case TRB_TYPE(TRB_PORT_STATUS):
+ xdbc_handle_port_status(evt_trb);
+ break;
+ case TRB_TYPE(TRB_TRANSFER):
+ xdbc_handle_tx_event(evt_trb);
+ break;
+ default:
+ break;
+ }
+
+ ++(xdbc.evt_ring.dequeue);
+ if (xdbc.evt_ring.dequeue == &xdbc.evt_seg.trbs[TRBS_PER_SEGMENT]) {
+ xdbc.evt_ring.dequeue = xdbc.evt_seg.trbs;
+ xdbc.evt_ring.cycle_state ^= 1;
+ }
+
+ evt_trb = xdbc.evt_ring.dequeue;
+ update_erdp = true;
+ }
+
+ /* Update event ring dequeue pointer: */
+ if (update_erdp)
+ xdbc_write64(__pa(xdbc.evt_ring.dequeue), &xdbc.xdbc_reg->erdp);
+}
+
+static int xdbc_bulk_write(const char *bytes, int size)
+{
+ int ret, timeout = 0;
+ unsigned long flags;
+
+retry:
+ if (in_nmi()) {
+ if (!raw_spin_trylock_irqsave(&xdbc.lock, flags))
+ return -EAGAIN;
+ } else {
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ }
+
+ xdbc_handle_events();
+
+ /* Check completion of the previous request: */
+ if ((xdbc.flags & XDBC_FLAGS_OUT_PROCESS) && (timeout < 2000000)) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ udelay(100);
+ timeout += 100;
+ goto retry;
+ }
+
+ if (xdbc.flags & XDBC_FLAGS_OUT_PROCESS) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ xdbc_trace("previous transfer not completed yet\n");
+
+ return -ETIMEDOUT;
+ }
+
+ ret = xdbc_bulk_transfer((void *)bytes, size, false);
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+
+ return ret;
+}
+
+static void early_xdbc_write(struct console *con, const char *str, u32 n)
+{
+ static char buf[XDBC_MAX_PACKET];
+ int chunk, ret;
+ int use_cr = 0;
+
+ if (!xdbc.xdbc_reg)
+ return;
+ memset(buf, 0, XDBC_MAX_PACKET);
+ while (n > 0) {
+ for (chunk = 0; chunk < XDBC_MAX_PACKET && n > 0; str++, chunk++, n--) {
+
+ if (!use_cr && *str == '\n') {
+ use_cr = 1;
+ buf[chunk] = '\r';
+ str--;
+ n++;
+ continue;
+ }
+
+ if (use_cr)
+ use_cr = 0;
+ buf[chunk] = *str;
+ }
+
+ if (chunk > 0) {
+ ret = xdbc_bulk_write(buf, chunk);
+ if (ret < 0)
+ xdbc_trace("missed message {%s}\n", buf);
+ }
+ }
+}
+
+static struct console early_xdbc_console = {
+ .name = "earlyxdbc",
+ .write = early_xdbc_write,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+};
+
+void __init early_xdbc_register_console(void)
+{
+ if (early_console)
+ return;
+
+ early_console = &early_xdbc_console;
+ if (early_console_keep)
+ early_console->flags &= ~CON_BOOT;
+ else
+ early_console->flags |= CON_BOOT;
+ register_console(early_console);
+}
+
+static void xdbc_unregister_console(void)
+{
+ if (early_xdbc_console.flags & CON_ENABLED)
+ unregister_console(&early_xdbc_console);
+}
+
+static int xdbc_scrub_function(void *ptr)
+{
+ unsigned long flags;
+
+ while (true) {
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ xdbc_handle_events();
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED)) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ break;
+ }
+
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ schedule_timeout_interruptible(1);
+ }
+
+ xdbc_unregister_console();
+ writel(0, &xdbc.xdbc_reg->control);
+ xdbc_trace("dbc scrub function exits\n");
+
+ return 0;
+}
+
+static int __init xdbc_init(void)
+{
+ unsigned long flags;
+ void __iomem *base;
+ int ret = 0;
+ u32 offset;
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
+ return 0;
+
+ /*
+ * It's time to shut down the DbC, so that the debug
+ * port can be reused by the host controller:
+ */
+ if (early_xdbc_console.index == -1 ||
+ (early_xdbc_console.flags & CON_BOOT)) {
+ xdbc_trace("hardware not used anymore\n");
+ goto free_and_quit;
+ }
+
+ base = ioremap_nocache(xdbc.xhci_start, xdbc.xhci_length);
+ if (!base) {
+ xdbc_trace("failed to remap the io address\n");
+ ret = -ENOMEM;
+ goto free_and_quit;
+ }
+
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+ xdbc.xhci_base = base;
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
+ xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+
+ kthread_run(xdbc_scrub_function, NULL, "%s", "xdbc");
+
+ return 0;
+
+free_and_quit:
+ xdbc_free_ring(&xdbc.evt_ring);
+ xdbc_free_ring(&xdbc.out_ring);
+ xdbc_free_ring(&xdbc.in_ring);
+ free_bootmem(xdbc.table_dma, PAGE_SIZE);
+ free_bootmem(xdbc.out_dma, PAGE_SIZE);
+ writel(0, &xdbc.xdbc_reg->control);
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+
+ return ret;
+}
+subsys_initcall(xdbc_init);
projects / users / willy / pagecache.git / commitdiff