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-rw-r--r--drivers/usb/host/xhci-dbgcap.c1099
1 files changed, 1099 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-dbgcap.c b/drivers/usb/host/xhci-dbgcap.c
new file mode 100644
index 000000000..f1367b53b
--- /dev/null
+++ b/drivers/usb/host/xhci-dbgcap.c
@@ -0,0 +1,1099 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * xhci-dbgcap.c - xHCI debug capability support
+ *
+ * Copyright (C) 2017 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ */
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/nls.h>
+
+#include "xhci.h"
+#include "xhci-trace.h"
+#include "xhci-dbgcap.h"
+
+static void dbc_free_ctx(struct device *dev, struct xhci_container_ctx *ctx)
+{
+ if (!ctx)
+ return;
+ dma_free_coherent(dev, ctx->size, ctx->bytes, ctx->dma);
+ kfree(ctx);
+}
+
+/* we use only one segment for DbC rings */
+static void dbc_ring_free(struct device *dev, struct xhci_ring *ring)
+{
+ if (!ring)
+ return;
+
+ if (ring->first_seg && ring->first_seg->trbs) {
+ dma_free_coherent(dev, TRB_SEGMENT_SIZE,
+ ring->first_seg->trbs,
+ ring->first_seg->dma);
+ kfree(ring->first_seg);
+ }
+ kfree(ring);
+}
+
+static u32 xhci_dbc_populate_strings(struct dbc_str_descs *strings)
+{
+ struct usb_string_descriptor *s_desc;
+ u32 string_length;
+
+ /* Serial string: */
+ s_desc = (struct usb_string_descriptor *)strings->serial;
+ utf8s_to_utf16s(DBC_STRING_SERIAL, strlen(DBC_STRING_SERIAL),
+ UTF16_LITTLE_ENDIAN, (wchar_t *)s_desc->wData,
+ DBC_MAX_STRING_LENGTH);
+
+ s_desc->bLength = (strlen(DBC_STRING_SERIAL) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+ string_length = s_desc->bLength;
+ string_length <<= 8;
+
+ /* Product string: */
+ s_desc = (struct usb_string_descriptor *)strings->product;
+ utf8s_to_utf16s(DBC_STRING_PRODUCT, strlen(DBC_STRING_PRODUCT),
+ UTF16_LITTLE_ENDIAN, (wchar_t *)s_desc->wData,
+ DBC_MAX_STRING_LENGTH);
+
+ s_desc->bLength = (strlen(DBC_STRING_PRODUCT) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+ string_length += s_desc->bLength;
+ string_length <<= 8;
+
+ /* Manufacture string: */
+ s_desc = (struct usb_string_descriptor *)strings->manufacturer;
+ utf8s_to_utf16s(DBC_STRING_MANUFACTURER,
+ strlen(DBC_STRING_MANUFACTURER),
+ UTF16_LITTLE_ENDIAN, (wchar_t *)s_desc->wData,
+ DBC_MAX_STRING_LENGTH);
+
+ s_desc->bLength = (strlen(DBC_STRING_MANUFACTURER) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+ 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;
+
+ return string_length;
+}
+
+static void xhci_dbc_init_contexts(struct xhci_dbc *dbc, u32 string_length)
+{
+ struct dbc_info_context *info;
+ struct xhci_ep_ctx *ep_ctx;
+ u32 dev_info;
+ dma_addr_t deq, dma;
+ unsigned int max_burst;
+
+ if (!dbc)
+ return;
+
+ /* Populate info Context: */
+ info = (struct dbc_info_context *)dbc->ctx->bytes;
+ dma = dbc->string_dma;
+ info->string0 = cpu_to_le64(dma);
+ info->manufacturer = cpu_to_le64(dma + DBC_MAX_STRING_LENGTH);
+ info->product = cpu_to_le64(dma + DBC_MAX_STRING_LENGTH * 2);
+ info->serial = cpu_to_le64(dma + DBC_MAX_STRING_LENGTH * 3);
+ info->length = cpu_to_le32(string_length);
+
+ /* Populate bulk out endpoint context: */
+ ep_ctx = dbc_bulkout_ctx(dbc);
+ max_burst = DBC_CTRL_MAXBURST(readl(&dbc->regs->control));
+ deq = dbc_bulkout_enq(dbc);
+ ep_ctx->ep_info = 0;
+ ep_ctx->ep_info2 = dbc_epctx_info2(BULK_OUT_EP, 1024, max_burst);
+ ep_ctx->deq = cpu_to_le64(deq | dbc->ring_out->cycle_state);
+
+ /* Populate bulk in endpoint context: */
+ ep_ctx = dbc_bulkin_ctx(dbc);
+ deq = dbc_bulkin_enq(dbc);
+ ep_ctx->ep_info = 0;
+ ep_ctx->ep_info2 = dbc_epctx_info2(BULK_IN_EP, 1024, max_burst);
+ ep_ctx->deq = cpu_to_le64(deq | dbc->ring_in->cycle_state);
+
+ /* Set DbC context and info registers: */
+ lo_hi_writeq(dbc->ctx->dma, &dbc->regs->dccp);
+
+ dev_info = cpu_to_le32((DBC_VENDOR_ID << 16) | DBC_PROTOCOL);
+ writel(dev_info, &dbc->regs->devinfo1);
+
+ dev_info = cpu_to_le32((DBC_DEVICE_REV << 16) | DBC_PRODUCT_ID);
+ writel(dev_info, &dbc->regs->devinfo2);
+}
+
+static void xhci_dbc_giveback(struct dbc_request *req, int status)
+ __releases(&dbc->lock)
+ __acquires(&dbc->lock)
+{
+ struct xhci_dbc *dbc = req->dbc;
+ struct device *dev = dbc->dev;
+
+ list_del_init(&req->list_pending);
+ req->trb_dma = 0;
+ req->trb = NULL;
+
+ if (req->status == -EINPROGRESS)
+ req->status = status;
+
+ trace_xhci_dbc_giveback_request(req);
+
+ dma_unmap_single(dev,
+ req->dma,
+ req->length,
+ dbc_ep_dma_direction(req));
+
+ /* Give back the transfer request: */
+ spin_unlock(&dbc->lock);
+ req->complete(dbc, req);
+ spin_lock(&dbc->lock);
+}
+
+static void xhci_dbc_flush_single_request(struct dbc_request *req)
+{
+ union xhci_trb *trb = req->trb;
+
+ trb->generic.field[0] = 0;
+ trb->generic.field[1] = 0;
+ trb->generic.field[2] = 0;
+ trb->generic.field[3] &= cpu_to_le32(TRB_CYCLE);
+ trb->generic.field[3] |= cpu_to_le32(TRB_TYPE(TRB_TR_NOOP));
+
+ xhci_dbc_giveback(req, -ESHUTDOWN);
+}
+
+static void xhci_dbc_flush_endpoint_requests(struct dbc_ep *dep)
+{
+ struct dbc_request *req, *tmp;
+
+ list_for_each_entry_safe(req, tmp, &dep->list_pending, list_pending)
+ xhci_dbc_flush_single_request(req);
+}
+
+static void xhci_dbc_flush_requests(struct xhci_dbc *dbc)
+{
+ xhci_dbc_flush_endpoint_requests(&dbc->eps[BULK_OUT]);
+ xhci_dbc_flush_endpoint_requests(&dbc->eps[BULK_IN]);
+}
+
+struct dbc_request *
+dbc_alloc_request(struct xhci_dbc *dbc, unsigned int direction, gfp_t flags)
+{
+ struct dbc_request *req;
+
+ if (direction != BULK_IN &&
+ direction != BULK_OUT)
+ return NULL;
+
+ if (!dbc)
+ return NULL;
+
+ req = kzalloc(sizeof(*req), flags);
+ if (!req)
+ return NULL;
+
+ req->dbc = dbc;
+ INIT_LIST_HEAD(&req->list_pending);
+ INIT_LIST_HEAD(&req->list_pool);
+ req->direction = direction;
+
+ trace_xhci_dbc_alloc_request(req);
+
+ return req;
+}
+
+void
+dbc_free_request(struct dbc_request *req)
+{
+ trace_xhci_dbc_free_request(req);
+
+ kfree(req);
+}
+
+static void
+xhci_dbc_queue_trb(struct xhci_ring *ring, u32 field1,
+ u32 field2, u32 field3, u32 field4)
+{
+ union xhci_trb *trb, *next;
+
+ trb = ring->enqueue;
+ trb->generic.field[0] = cpu_to_le32(field1);
+ trb->generic.field[1] = cpu_to_le32(field2);
+ trb->generic.field[2] = cpu_to_le32(field3);
+ trb->generic.field[3] = cpu_to_le32(field4);
+
+ trace_xhci_dbc_gadget_ep_queue(ring, &trb->generic);
+
+ ring->num_trbs_free--;
+ next = ++(ring->enqueue);
+ if (TRB_TYPE_LINK_LE32(next->link.control)) {
+ next->link.control ^= cpu_to_le32(TRB_CYCLE);
+ ring->enqueue = ring->enq_seg->trbs;
+ ring->cycle_state ^= 1;
+ }
+}
+
+static int xhci_dbc_queue_bulk_tx(struct dbc_ep *dep,
+ struct dbc_request *req)
+{
+ u64 addr;
+ union xhci_trb *trb;
+ unsigned int num_trbs;
+ struct xhci_dbc *dbc = req->dbc;
+ struct xhci_ring *ring = dep->ring;
+ u32 length, control, cycle;
+
+ num_trbs = count_trbs(req->dma, req->length);
+ WARN_ON(num_trbs != 1);
+ if (ring->num_trbs_free < num_trbs)
+ return -EBUSY;
+
+ addr = req->dma;
+ trb = ring->enqueue;
+ cycle = ring->cycle_state;
+ length = TRB_LEN(req->length);
+ control = TRB_TYPE(TRB_NORMAL) | TRB_IOC;
+
+ if (cycle)
+ control &= cpu_to_le32(~TRB_CYCLE);
+ else
+ control |= cpu_to_le32(TRB_CYCLE);
+
+ req->trb = ring->enqueue;
+ req->trb_dma = xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
+ xhci_dbc_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->generic.field[3] |= cpu_to_le32(TRB_CYCLE);
+ else
+ trb->generic.field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+ writel(DBC_DOOR_BELL_TARGET(dep->direction), &dbc->regs->doorbell);
+
+ return 0;
+}
+
+static int
+dbc_ep_do_queue(struct dbc_request *req)
+{
+ int ret;
+ struct xhci_dbc *dbc = req->dbc;
+ struct device *dev = dbc->dev;
+ struct dbc_ep *dep = &dbc->eps[req->direction];
+
+ if (!req->length || !req->buf)
+ return -EINVAL;
+
+ req->actual = 0;
+ req->status = -EINPROGRESS;
+
+ req->dma = dma_map_single(dev,
+ req->buf,
+ req->length,
+ dbc_ep_dma_direction(dep));
+ if (dma_mapping_error(dev, req->dma)) {
+ dev_err(dbc->dev, "failed to map buffer\n");
+ return -EFAULT;
+ }
+
+ ret = xhci_dbc_queue_bulk_tx(dep, req);
+ if (ret) {
+ dev_err(dbc->dev, "failed to queue trbs\n");
+ dma_unmap_single(dev,
+ req->dma,
+ req->length,
+ dbc_ep_dma_direction(dep));
+ return -EFAULT;
+ }
+
+ list_add_tail(&req->list_pending, &dep->list_pending);
+
+ return 0;
+}
+
+int dbc_ep_queue(struct dbc_request *req)
+{
+ unsigned long flags;
+ struct xhci_dbc *dbc = req->dbc;
+ int ret = -ESHUTDOWN;
+
+ if (!dbc)
+ return -ENODEV;
+
+ if (req->direction != BULK_IN &&
+ req->direction != BULK_OUT)
+ return -EINVAL;
+
+ spin_lock_irqsave(&dbc->lock, flags);
+ if (dbc->state == DS_CONFIGURED)
+ ret = dbc_ep_do_queue(req);
+ spin_unlock_irqrestore(&dbc->lock, flags);
+
+ mod_delayed_work(system_wq, &dbc->event_work, 0);
+
+ trace_xhci_dbc_queue_request(req);
+
+ return ret;
+}
+
+static inline void xhci_dbc_do_eps_init(struct xhci_dbc *dbc, bool direction)
+{
+ struct dbc_ep *dep;
+
+ dep = &dbc->eps[direction];
+ dep->dbc = dbc;
+ dep->direction = direction;
+ dep->ring = direction ? dbc->ring_in : dbc->ring_out;
+
+ INIT_LIST_HEAD(&dep->list_pending);
+}
+
+static void xhci_dbc_eps_init(struct xhci_dbc *dbc)
+{
+ xhci_dbc_do_eps_init(dbc, BULK_OUT);
+ xhci_dbc_do_eps_init(dbc, BULK_IN);
+}
+
+static void xhci_dbc_eps_exit(struct xhci_dbc *dbc)
+{
+ memset(dbc->eps, 0, sizeof(struct dbc_ep) * ARRAY_SIZE(dbc->eps));
+}
+
+static int dbc_erst_alloc(struct device *dev, struct xhci_ring *evt_ring,
+ struct xhci_erst *erst, gfp_t flags)
+{
+ erst->entries = dma_alloc_coherent(dev, sizeof(struct xhci_erst_entry),
+ &erst->erst_dma_addr, flags);
+ if (!erst->entries)
+ return -ENOMEM;
+
+ erst->num_entries = 1;
+ erst->entries[0].seg_addr = cpu_to_le64(evt_ring->first_seg->dma);
+ erst->entries[0].seg_size = cpu_to_le32(TRBS_PER_SEGMENT);
+ erst->entries[0].rsvd = 0;
+ return 0;
+}
+
+static void dbc_erst_free(struct device *dev, struct xhci_erst *erst)
+{
+ if (erst->entries)
+ dma_free_coherent(dev, sizeof(struct xhci_erst_entry),
+ erst->entries, erst->erst_dma_addr);
+ erst->entries = NULL;
+}
+
+static struct xhci_container_ctx *
+dbc_alloc_ctx(struct device *dev, gfp_t flags)
+{
+ struct xhci_container_ctx *ctx;
+
+ ctx = kzalloc(sizeof(*ctx), flags);
+ if (!ctx)
+ return NULL;
+
+ /* xhci 7.6.9, all three contexts; info, ep-out and ep-in. Each 64 bytes*/
+ ctx->size = 3 * DBC_CONTEXT_SIZE;
+ ctx->bytes = dma_alloc_coherent(dev, ctx->size, &ctx->dma, flags);
+ if (!ctx->bytes) {
+ kfree(ctx);
+ return NULL;
+ }
+ return ctx;
+}
+
+static struct xhci_ring *
+xhci_dbc_ring_alloc(struct device *dev, enum xhci_ring_type type, gfp_t flags)
+{
+ struct xhci_ring *ring;
+ struct xhci_segment *seg;
+ dma_addr_t dma;
+
+ ring = kzalloc(sizeof(*ring), flags);
+ if (!ring)
+ return NULL;
+
+ ring->num_segs = 1;
+ ring->type = type;
+
+ seg = kzalloc(sizeof(*seg), flags);
+ if (!seg)
+ goto seg_fail;
+
+ ring->first_seg = seg;
+ ring->last_seg = seg;
+ seg->next = seg;
+
+ seg->trbs = dma_alloc_coherent(dev, TRB_SEGMENT_SIZE, &dma, flags);
+ if (!seg->trbs)
+ goto dma_fail;
+
+ seg->dma = dma;
+
+ /* Only event ring does not use link TRB */
+ if (type != TYPE_EVENT) {
+ union xhci_trb *trb = &seg->trbs[TRBS_PER_SEGMENT - 1];
+
+ trb->link.segment_ptr = cpu_to_le64(dma);
+ trb->link.control = cpu_to_le32(LINK_TOGGLE | TRB_TYPE(TRB_LINK));
+ }
+ INIT_LIST_HEAD(&ring->td_list);
+ xhci_initialize_ring_info(ring, 1);
+ return ring;
+dma_fail:
+ kfree(seg);
+seg_fail:
+ kfree(ring);
+ return NULL;
+}
+
+static int xhci_dbc_mem_init(struct xhci_dbc *dbc, gfp_t flags)
+{
+ int ret;
+ dma_addr_t deq;
+ u32 string_length;
+ struct device *dev = dbc->dev;
+
+ /* Allocate various rings for events and transfers: */
+ dbc->ring_evt = xhci_dbc_ring_alloc(dev, TYPE_EVENT, flags);
+ if (!dbc->ring_evt)
+ goto evt_fail;
+
+ dbc->ring_in = xhci_dbc_ring_alloc(dev, TYPE_BULK, flags);
+ if (!dbc->ring_in)
+ goto in_fail;
+
+ dbc->ring_out = xhci_dbc_ring_alloc(dev, TYPE_BULK, flags);
+ if (!dbc->ring_out)
+ goto out_fail;
+
+ /* Allocate and populate ERST: */
+ ret = dbc_erst_alloc(dev, dbc->ring_evt, &dbc->erst, flags);
+ if (ret)
+ goto erst_fail;
+
+ /* Allocate context data structure: */
+ dbc->ctx = dbc_alloc_ctx(dev, flags); /* was sysdev, and is still */
+ if (!dbc->ctx)
+ goto ctx_fail;
+
+ /* Allocate the string table: */
+ dbc->string_size = sizeof(struct dbc_str_descs);
+ dbc->string = dma_alloc_coherent(dev, dbc->string_size,
+ &dbc->string_dma, flags);
+ if (!dbc->string)
+ goto string_fail;
+
+ /* Setup ERST register: */
+ writel(dbc->erst.erst_size, &dbc->regs->ersts);
+
+ lo_hi_writeq(dbc->erst.erst_dma_addr, &dbc->regs->erstba);
+ deq = xhci_trb_virt_to_dma(dbc->ring_evt->deq_seg,
+ dbc->ring_evt->dequeue);
+ lo_hi_writeq(deq, &dbc->regs->erdp);
+
+ /* Setup strings and contexts: */
+ string_length = xhci_dbc_populate_strings(dbc->string);
+ xhci_dbc_init_contexts(dbc, string_length);
+
+ xhci_dbc_eps_init(dbc);
+ dbc->state = DS_INITIALIZED;
+
+ return 0;
+
+string_fail:
+ dbc_free_ctx(dev, dbc->ctx);
+ dbc->ctx = NULL;
+ctx_fail:
+ dbc_erst_free(dev, &dbc->erst);
+erst_fail:
+ dbc_ring_free(dev, dbc->ring_out);
+ dbc->ring_out = NULL;
+out_fail:
+ dbc_ring_free(dev, dbc->ring_in);
+ dbc->ring_in = NULL;
+in_fail:
+ dbc_ring_free(dev, dbc->ring_evt);
+ dbc->ring_evt = NULL;
+evt_fail:
+ return -ENOMEM;
+}
+
+static void xhci_dbc_mem_cleanup(struct xhci_dbc *dbc)
+{
+ if (!dbc)
+ return;
+
+ xhci_dbc_eps_exit(dbc);
+
+ if (dbc->string) {
+ dma_free_coherent(dbc->dev, dbc->string_size,
+ dbc->string, dbc->string_dma);
+ dbc->string = NULL;
+ }
+
+ dbc_free_ctx(dbc->dev, dbc->ctx);
+ dbc->ctx = NULL;
+
+ dbc_erst_free(dbc->dev, &dbc->erst);
+ dbc_ring_free(dbc->dev, dbc->ring_out);
+ dbc_ring_free(dbc->dev, dbc->ring_in);
+ dbc_ring_free(dbc->dev, dbc->ring_evt);
+ dbc->ring_in = NULL;
+ dbc->ring_out = NULL;
+ dbc->ring_evt = NULL;
+}
+
+static int xhci_do_dbc_start(struct xhci_dbc *dbc)
+{
+ int ret;
+ u32 ctrl;
+
+ if (dbc->state != DS_DISABLED)
+ return -EINVAL;
+
+ writel(0, &dbc->regs->control);
+ ret = xhci_handshake(&dbc->regs->control,
+ DBC_CTRL_DBC_ENABLE,
+ 0, 1000);
+ if (ret)
+ return ret;
+
+ ret = xhci_dbc_mem_init(dbc, GFP_ATOMIC);
+ if (ret)
+ return ret;
+
+ ctrl = readl(&dbc->regs->control);
+ writel(ctrl | DBC_CTRL_DBC_ENABLE | DBC_CTRL_PORT_ENABLE,
+ &dbc->regs->control);
+ ret = xhci_handshake(&dbc->regs->control,
+ DBC_CTRL_DBC_ENABLE,
+ DBC_CTRL_DBC_ENABLE, 1000);
+ if (ret)
+ return ret;
+
+ dbc->state = DS_ENABLED;
+
+ return 0;
+}
+
+static int xhci_do_dbc_stop(struct xhci_dbc *dbc)
+{
+ if (dbc->state == DS_DISABLED)
+ return -1;
+
+ writel(0, &dbc->regs->control);
+ dbc->state = DS_DISABLED;
+
+ return 0;
+}
+
+static int xhci_dbc_start(struct xhci_dbc *dbc)
+{
+ int ret;
+ unsigned long flags;
+
+ WARN_ON(!dbc);
+
+ pm_runtime_get_sync(dbc->dev); /* note this was self.controller */
+
+ spin_lock_irqsave(&dbc->lock, flags);
+ ret = xhci_do_dbc_start(dbc);
+ spin_unlock_irqrestore(&dbc->lock, flags);
+
+ if (ret) {
+ pm_runtime_put(dbc->dev); /* note this was self.controller */
+ return ret;
+ }
+
+ return mod_delayed_work(system_wq, &dbc->event_work, 1);
+}
+
+static void xhci_dbc_stop(struct xhci_dbc *dbc)
+{
+ int ret;
+ unsigned long flags;
+
+ WARN_ON(!dbc);
+
+ switch (dbc->state) {
+ case DS_DISABLED:
+ return;
+ case DS_CONFIGURED:
+ case DS_STALLED:
+ if (dbc->driver->disconnect)
+ dbc->driver->disconnect(dbc);
+ break;
+ default:
+ break;
+ }
+
+ cancel_delayed_work_sync(&dbc->event_work);
+
+ spin_lock_irqsave(&dbc->lock, flags);
+ ret = xhci_do_dbc_stop(dbc);
+ spin_unlock_irqrestore(&dbc->lock, flags);
+
+ if (!ret) {
+ xhci_dbc_mem_cleanup(dbc);
+ pm_runtime_put_sync(dbc->dev); /* note, was self.controller */
+ }
+}
+
+static void
+dbc_handle_port_status(struct xhci_dbc *dbc, union xhci_trb *event)
+{
+ u32 portsc;
+
+ portsc = readl(&dbc->regs->portsc);
+ if (portsc & DBC_PORTSC_CONN_CHANGE)
+ dev_info(dbc->dev, "DbC port connect change\n");
+
+ if (portsc & DBC_PORTSC_RESET_CHANGE)
+ dev_info(dbc->dev, "DbC port reset change\n");
+
+ if (portsc & DBC_PORTSC_LINK_CHANGE)
+ dev_info(dbc->dev, "DbC port link status change\n");
+
+ if (portsc & DBC_PORTSC_CONFIG_CHANGE)
+ dev_info(dbc->dev, "DbC config error change\n");
+
+ /* Port reset change bit will be cleared in other place: */
+ writel(portsc & ~DBC_PORTSC_RESET_CHANGE, &dbc->regs->portsc);
+}
+
+static void dbc_handle_xfer_event(struct xhci_dbc *dbc, union xhci_trb *event)
+{
+ struct dbc_ep *dep;
+ struct xhci_ring *ring;
+ int ep_id;
+ int status;
+ u32 comp_code;
+ size_t remain_length;
+ struct dbc_request *req = NULL, *r;
+
+ comp_code = GET_COMP_CODE(le32_to_cpu(event->generic.field[2]));
+ remain_length = EVENT_TRB_LEN(le32_to_cpu(event->generic.field[2]));
+ ep_id = TRB_TO_EP_ID(le32_to_cpu(event->generic.field[3]));
+ dep = (ep_id == EPID_OUT) ?
+ get_out_ep(dbc) : get_in_ep(dbc);
+ ring = dep->ring;
+
+ switch (comp_code) {
+ case COMP_SUCCESS:
+ remain_length = 0;
+ fallthrough;
+ case COMP_SHORT_PACKET:
+ status = 0;
+ break;
+ case COMP_TRB_ERROR:
+ case COMP_BABBLE_DETECTED_ERROR:
+ case COMP_USB_TRANSACTION_ERROR:
+ case COMP_STALL_ERROR:
+ dev_warn(dbc->dev, "tx error %d detected\n", comp_code);
+ status = -comp_code;
+ break;
+ default:
+ dev_err(dbc->dev, "unknown tx error %d\n", comp_code);
+ status = -comp_code;
+ break;
+ }
+
+ /* Match the pending request: */
+ list_for_each_entry(r, &dep->list_pending, list_pending) {
+ if (r->trb_dma == event->trans_event.buffer) {
+ req = r;
+ break;
+ }
+ }
+
+ if (!req) {
+ dev_warn(dbc->dev, "no matched request\n");
+ return;
+ }
+
+ trace_xhci_dbc_handle_transfer(ring, &req->trb->generic);
+
+ ring->num_trbs_free++;
+ req->actual = req->length - remain_length;
+ xhci_dbc_giveback(req, status);
+}
+
+static void inc_evt_deq(struct xhci_ring *ring)
+{
+ /* If on the last TRB of the segment go back to the beginning */
+ if (ring->dequeue == &ring->deq_seg->trbs[TRBS_PER_SEGMENT - 1]) {
+ ring->cycle_state ^= 1;
+ ring->dequeue = ring->deq_seg->trbs;
+ return;
+ }
+ ring->dequeue++;
+}
+
+static enum evtreturn xhci_dbc_do_handle_events(struct xhci_dbc *dbc)
+{
+ dma_addr_t deq;
+ struct dbc_ep *dep;
+ union xhci_trb *evt;
+ u32 ctrl, portsc;
+ bool update_erdp = false;
+
+ /* DbC state machine: */
+ switch (dbc->state) {
+ case DS_DISABLED:
+ case DS_INITIALIZED:
+
+ return EVT_ERR;
+ case DS_ENABLED:
+ portsc = readl(&dbc->regs->portsc);
+ if (portsc & DBC_PORTSC_CONN_STATUS) {
+ dbc->state = DS_CONNECTED;
+ dev_info(dbc->dev, "DbC connected\n");
+ }
+
+ return EVT_DONE;
+ case DS_CONNECTED:
+ ctrl = readl(&dbc->regs->control);
+ if (ctrl & DBC_CTRL_DBC_RUN) {
+ dbc->state = DS_CONFIGURED;
+ dev_info(dbc->dev, "DbC configured\n");
+ portsc = readl(&dbc->regs->portsc);
+ writel(portsc, &dbc->regs->portsc);
+ return EVT_GSER;
+ }
+
+ return EVT_DONE;
+ case DS_CONFIGURED:
+ /* Handle cable unplug event: */
+ portsc = readl(&dbc->regs->portsc);
+ if (!(portsc & DBC_PORTSC_PORT_ENABLED) &&
+ !(portsc & DBC_PORTSC_CONN_STATUS)) {
+ dev_info(dbc->dev, "DbC cable unplugged\n");
+ dbc->state = DS_ENABLED;
+ xhci_dbc_flush_requests(dbc);
+
+ return EVT_DISC;
+ }
+
+ /* Handle debug port reset event: */
+ if (portsc & DBC_PORTSC_RESET_CHANGE) {
+ dev_info(dbc->dev, "DbC port reset\n");
+ writel(portsc, &dbc->regs->portsc);
+ dbc->state = DS_ENABLED;
+ xhci_dbc_flush_requests(dbc);
+
+ return EVT_DISC;
+ }
+
+ /* Handle endpoint stall event: */
+ ctrl = readl(&dbc->regs->control);
+ if ((ctrl & DBC_CTRL_HALT_IN_TR) ||
+ (ctrl & DBC_CTRL_HALT_OUT_TR)) {
+ dev_info(dbc->dev, "DbC Endpoint stall\n");
+ dbc->state = DS_STALLED;
+
+ if (ctrl & DBC_CTRL_HALT_IN_TR) {
+ dep = get_in_ep(dbc);
+ xhci_dbc_flush_endpoint_requests(dep);
+ }
+
+ if (ctrl & DBC_CTRL_HALT_OUT_TR) {
+ dep = get_out_ep(dbc);
+ xhci_dbc_flush_endpoint_requests(dep);
+ }
+
+ return EVT_DONE;
+ }
+
+ /* Clear DbC run change bit: */
+ if (ctrl & DBC_CTRL_DBC_RUN_CHANGE) {
+ writel(ctrl, &dbc->regs->control);
+ ctrl = readl(&dbc->regs->control);
+ }
+
+ break;
+ case DS_STALLED:
+ ctrl = readl(&dbc->regs->control);
+ if (!(ctrl & DBC_CTRL_HALT_IN_TR) &&
+ !(ctrl & DBC_CTRL_HALT_OUT_TR) &&
+ (ctrl & DBC_CTRL_DBC_RUN)) {
+ dbc->state = DS_CONFIGURED;
+ break;
+ }
+
+ return EVT_DONE;
+ default:
+ dev_err(dbc->dev, "Unknown DbC state %d\n", dbc->state);
+ break;
+ }
+
+ /* Handle the events in the event ring: */
+ evt = dbc->ring_evt->dequeue;
+ while ((le32_to_cpu(evt->event_cmd.flags) & TRB_CYCLE) ==
+ dbc->ring_evt->cycle_state) {
+ /*
+ * Add a barrier between reading the cycle flag and any
+ * reads of the event's flags/data below:
+ */
+ rmb();
+
+ trace_xhci_dbc_handle_event(dbc->ring_evt, &evt->generic);
+
+ switch (le32_to_cpu(evt->event_cmd.flags) & TRB_TYPE_BITMASK) {
+ case TRB_TYPE(TRB_PORT_STATUS):
+ dbc_handle_port_status(dbc, evt);
+ break;
+ case TRB_TYPE(TRB_TRANSFER):
+ dbc_handle_xfer_event(dbc, evt);
+ break;
+ default:
+ break;
+ }
+
+ inc_evt_deq(dbc->ring_evt);
+
+ evt = dbc->ring_evt->dequeue;
+ update_erdp = true;
+ }
+
+ /* Update event ring dequeue pointer: */
+ if (update_erdp) {
+ deq = xhci_trb_virt_to_dma(dbc->ring_evt->deq_seg,
+ dbc->ring_evt->dequeue);
+ lo_hi_writeq(deq, &dbc->regs->erdp);
+ }
+
+ return EVT_DONE;
+}
+
+static void xhci_dbc_handle_events(struct work_struct *work)
+{
+ enum evtreturn evtr;
+ struct xhci_dbc *dbc;
+ unsigned long flags;
+
+ dbc = container_of(to_delayed_work(work), struct xhci_dbc, event_work);
+
+ spin_lock_irqsave(&dbc->lock, flags);
+ evtr = xhci_dbc_do_handle_events(dbc);
+ spin_unlock_irqrestore(&dbc->lock, flags);
+
+ switch (evtr) {
+ case EVT_GSER:
+ if (dbc->driver->configure)
+ dbc->driver->configure(dbc);
+ break;
+ case EVT_DISC:
+ if (dbc->driver->disconnect)
+ dbc->driver->disconnect(dbc);
+ break;
+ case EVT_DONE:
+ break;
+ default:
+ dev_info(dbc->dev, "stop handling dbc events\n");
+ return;
+ }
+
+ mod_delayed_work(system_wq, &dbc->event_work, 1);
+}
+
+static ssize_t dbc_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const char *p;
+ struct xhci_dbc *dbc;
+ struct xhci_hcd *xhci;
+
+ xhci = hcd_to_xhci(dev_get_drvdata(dev));
+ dbc = xhci->dbc;
+
+ switch (dbc->state) {
+ case DS_DISABLED:
+ p = "disabled";
+ break;
+ case DS_INITIALIZED:
+ p = "initialized";
+ break;
+ case DS_ENABLED:
+ p = "enabled";
+ break;
+ case DS_CONNECTED:
+ p = "connected";
+ break;
+ case DS_CONFIGURED:
+ p = "configured";
+ break;
+ case DS_STALLED:
+ p = "stalled";
+ break;
+ default:
+ p = "unknown";
+ }
+
+ return sprintf(buf, "%s\n", p);
+}
+
+static ssize_t dbc_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct xhci_hcd *xhci;
+ struct xhci_dbc *dbc;
+
+ xhci = hcd_to_xhci(dev_get_drvdata(dev));
+ dbc = xhci->dbc;
+
+ if (!strncmp(buf, "enable", 6))
+ xhci_dbc_start(dbc);
+ else if (!strncmp(buf, "disable", 7))
+ xhci_dbc_stop(dbc);
+ else
+ return -EINVAL;
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(dbc);
+
+struct xhci_dbc *
+xhci_alloc_dbc(struct device *dev, void __iomem *base, const struct dbc_driver *driver)
+{
+ struct xhci_dbc *dbc;
+ int ret;
+
+ dbc = kzalloc(sizeof(*dbc), GFP_KERNEL);
+ if (!dbc)
+ return NULL;
+
+ dbc->regs = base;
+ dbc->dev = dev;
+ dbc->driver = driver;
+
+ if (readl(&dbc->regs->control) & DBC_CTRL_DBC_ENABLE)
+ goto err;
+
+ INIT_DELAYED_WORK(&dbc->event_work, xhci_dbc_handle_events);
+ spin_lock_init(&dbc->lock);
+
+ ret = device_create_file(dev, &dev_attr_dbc);
+ if (ret)
+ goto err;
+
+ return dbc;
+err:
+ kfree(dbc);
+ return NULL;
+}
+
+/* undo what xhci_alloc_dbc() did */
+void xhci_dbc_remove(struct xhci_dbc *dbc)
+{
+ if (!dbc)
+ return;
+ /* stop hw, stop wq and call dbc->ops->stop() */
+ xhci_dbc_stop(dbc);
+
+ /* remove sysfs files */
+ device_remove_file(dbc->dev, &dev_attr_dbc);
+
+ kfree(dbc);
+}
+
+
+int xhci_create_dbc_dev(struct xhci_hcd *xhci)
+{
+ struct device *dev;
+ void __iomem *base;
+ int ret;
+ int dbc_cap_offs;
+
+ /* create all parameters needed resembling a dbc device */
+ dev = xhci_to_hcd(xhci)->self.controller;
+ base = &xhci->cap_regs->hc_capbase;
+
+ dbc_cap_offs = xhci_find_next_ext_cap(base, 0, XHCI_EXT_CAPS_DEBUG);
+ if (!dbc_cap_offs)
+ return -ENODEV;
+
+ /* already allocated and in use */
+ if (xhci->dbc)
+ return -EBUSY;
+
+ ret = xhci_dbc_tty_probe(dev, base + dbc_cap_offs, xhci);
+
+ return ret;
+}
+
+void xhci_remove_dbc_dev(struct xhci_hcd *xhci)
+{
+ unsigned long flags;
+
+ if (!xhci->dbc)
+ return;
+
+ xhci_dbc_tty_remove(xhci->dbc);
+ spin_lock_irqsave(&xhci->lock, flags);
+ xhci->dbc = NULL;
+ spin_unlock_irqrestore(&xhci->lock, flags);
+}
+
+#ifdef CONFIG_PM
+int xhci_dbc_suspend(struct xhci_hcd *xhci)
+{
+ struct xhci_dbc *dbc = xhci->dbc;
+
+ if (!dbc)
+ return 0;
+
+ if (dbc->state == DS_CONFIGURED)
+ dbc->resume_required = 1;
+
+ xhci_dbc_stop(dbc);
+
+ return 0;
+}
+
+int xhci_dbc_resume(struct xhci_hcd *xhci)
+{
+ int ret = 0;
+ struct xhci_dbc *dbc = xhci->dbc;
+
+ if (!dbc)
+ return 0;
+
+ if (dbc->resume_required) {
+ dbc->resume_required = 0;
+ xhci_dbc_start(dbc);
+ }
+
+ return ret;
+}
+#endif /* CONFIG_PM */
+
+int xhci_dbc_init(void)
+{
+ return dbc_tty_init();
+}
+
+void xhci_dbc_exit(void)
+{
+ dbc_tty_exit();
+}