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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Cadence CDNSP DRD Driver.
  *
  * Copyright (C) 2020 Cadence.
  *
  * Author: Pawel Laszczak <pawell@cadence.com>
  *
  * Code based on Linux XHCI driver.
  * Origin: Copyright (C) 2008 Intel Corp
  */
 
 /*
  * Ring initialization rules:
  * 1. Each segment is initialized to zero, except for link TRBs.
  * 2. Ring cycle state = 0. This represents Producer Cycle State (PCS) or
  *    Consumer Cycle State (CCS), depending on ring function.
  * 3. Enqueue pointer = dequeue pointer = address of first TRB in the segment.
  *
  * Ring behavior rules:
  * 1. A ring is empty if enqueue == dequeue. This means there will always be at
  *    least one free TRB in the ring. This is useful if you want to turn that
  *    into a link TRB and expand the ring.
  * 2. When incrementing an enqueue or dequeue pointer, if the next TRB is a
  *    link TRB, then load the pointer with the address in the link TRB. If the
  *    link TRB had its toggle bit set, you may need to update the ring cycle
  *    state (see cycle bit rules). You may have to do this multiple times
  *    until you reach a non-link TRB.
  * 3. A ring is full if enqueue++ (for the definition of increment above)
  *    equals the dequeue pointer.
  *
  * Cycle bit rules:
  * 1. When a consumer increments a dequeue pointer and encounters a toggle bit
  *    in a link TRB, it must toggle the ring cycle state.
  * 2. When a producer increments an enqueue pointer and encounters a toggle bit
  *    in a link TRB, it must toggle the ring cycle state.
  *
  * Producer rules:
  * 1. Check if ring is full before you enqueue.
  * 2. Write the ring cycle state to the cycle bit in the TRB you're enqueuing.
  *    Update enqueue pointer between each write (which may update the ring
  *    cycle state).
  * 3. Notify consumer. If SW is producer, it rings the doorbell for command
  *    and endpoint rings. If controller is the producer for the event ring,
  *    and it generates an interrupt according to interrupt modulation rules.
  *
  * Consumer rules:
  * 1. Check if TRB belongs to you. If the cycle bit == your ring cycle state,
  *    the TRB is owned by the consumer.
  * 2. Update dequeue pointer (which may update the ring cycle state) and
  *    continue processing TRBs until you reach a TRB which is not owned by you.
  * 3. Notify the producer. SW is the consumer for the event ring, and it
  *    updates event ring dequeue pointer. Controller is the consumer for the
  *    command and endpoint rings; it generates events on the event ring
  *    for these.
  */
 
 #include <linux/scatterlist.h>
 #include <linux/dma-mapping.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/irq.h>
 
 #include "cdnsp-trace.h"
 #include "cdnsp-gadget.h"
 
 /*
  * Returns zero if the TRB isn't in this segment, otherwise it returns the DMA
  * address of the TRB.
  */
 dma_addr_t cdnsp_trb_virt_to_dma(struct cdnsp_segment *seg,
                  union cdnsp_trb *trb)
 {
     unsigned long segment_offset = trb - seg->trbs;
 
     if (trb < seg->trbs || segment_offset >= TRBS_PER_SEGMENT)
         return 0;
 
     return seg->dma + (segment_offset * sizeof(*trb));
 }
 
 static bool cdnsp_trb_is_noop(union cdnsp_trb *trb)
 {
     return TRB_TYPE_NOOP_LE32(trb->generic.field[3]);
 }
 
 static bool cdnsp_trb_is_link(union cdnsp_trb *trb)
 {
     return TRB_TYPE_LINK_LE32(trb->link.control);
 }
 
 bool cdnsp_last_trb_on_seg(struct cdnsp_segment *seg, union cdnsp_trb *trb)
 {
     return trb == &seg->trbs[TRBS_PER_SEGMENT - 1];
 }
 
 bool cdnsp_last_trb_on_ring(struct cdnsp_ring *ring,
                 struct cdnsp_segment *seg,
                 union cdnsp_trb *trb)
 {
     return cdnsp_last_trb_on_seg(seg, trb) && (seg->next == ring->first_seg);
 }
 
 static bool cdnsp_link_trb_toggles_cycle(union cdnsp_trb *trb)
 {
     return le32_to_cpu(trb->link.control) & LINK_TOGGLE;
 }
 
 static void cdnsp_trb_to_noop(union cdnsp_trb *trb, u32 noop_type)
 {
     if (cdnsp_trb_is_link(trb)) {
         /* Unchain chained link TRBs. */
         trb->link.control &= cpu_to_le32(~TRB_CHAIN);
     } else {
         trb->generic.field[0] = 0;
         trb->generic.field[1] = 0;
         trb->generic.field[2] = 0;
         /* Preserve only the cycle bit of this TRB. */
         trb->generic.field[3] &= cpu_to_le32(TRB_CYCLE);
         trb->generic.field[3] |= cpu_to_le32(TRB_TYPE(noop_type));
     }
 }
 
 /*
  * Updates trb to point to the next TRB in the ring, and updates seg if the next
  * TRB is in a new segment. This does not skip over link TRBs, and it does not
  * effect the ring dequeue or enqueue pointers.
  */
 static void cdnsp_next_trb(struct cdnsp_device *pdev,
                struct cdnsp_ring *ring,
                struct cdnsp_segment **seg,
                union cdnsp_trb **trb)
 {
     if (cdnsp_trb_is_link(*trb)) {
         *seg = (*seg)->next;
         *trb = ((*seg)->trbs);
     } else {
         (*trb)++;
     }
 }
 
 /*
  * See Cycle bit rules. SW is the consumer for the event ring only.
  * Don't make a ring full of link TRBs. That would be dumb and this would loop.
  */
 void cdnsp_inc_deq(struct cdnsp_device *pdev, struct cdnsp_ring *ring)
 {
     /* event ring doesn't have link trbs, check for last trb. */
     if (ring->type == TYPE_EVENT) {
         if (!cdnsp_last_trb_on_seg(ring->deq_seg, ring->dequeue)) {
             ring->dequeue++;
             goto out;
         }
 
         if (cdnsp_last_trb_on_ring(ring, ring->deq_seg, ring->dequeue))
             ring->cycle_state ^= 1;
 
         ring->deq_seg = ring->deq_seg->next;
         ring->dequeue = ring->deq_seg->trbs;
         goto out;
     }
 
     /* All other rings have link trbs. */
     if (!cdnsp_trb_is_link(ring->dequeue)) {
         ring->dequeue++;
         ring->num_trbs_free++;
     }
     while (cdnsp_trb_is_link(ring->dequeue)) {
         ring->deq_seg = ring->deq_seg->next;
         ring->dequeue = ring->deq_seg->trbs;
     }
 out:
     trace_cdnsp_inc_deq(ring);
 }
 
 /*
  * See Cycle bit rules. SW is the consumer for the event ring only.
  * Don't make a ring full of link TRBs. That would be dumb and this would loop.
  *
  * If we've just enqueued a TRB that is in the middle of a TD (meaning the
  * chain bit is set), then set the chain bit in all the following link TRBs.
  * If we've enqueued the last TRB in a TD, make sure the following link TRBs
  * have their chain bit cleared (so that each Link TRB is a separate TD).
  *
  * @more_trbs_coming:   Will you enqueue more TRBs before ringing the doorbell.
  */
 static void cdnsp_inc_enq(struct cdnsp_device *pdev,
               struct cdnsp_ring *ring,
               bool more_trbs_coming)
 {
     union cdnsp_trb *next;
     u32 chain;
 
     chain = le32_to_cpu(ring->enqueue->generic.field[3]) & TRB_CHAIN;
 
     /* If this is not event ring, there is one less usable TRB. */
     if (!cdnsp_trb_is_link(ring->enqueue))
         ring->num_trbs_free--;
     next = ++(ring->enqueue);
 
     /* Update the dequeue pointer further if that was a link TRB */
     while (cdnsp_trb_is_link(next)) {
         /*
          * If the caller doesn't plan on enqueuing more TDs before
          * ringing the doorbell, then we don't want to give the link TRB
          * to the hardware just yet. We'll give the link TRB back in
          * cdnsp_prepare_ring() just before we enqueue the TD at the
          * top of the ring.
          */
         if (!chain && !more_trbs_coming)
             break;
 
         next->link.control &= cpu_to_le32(~TRB_CHAIN);
         next->link.control |= cpu_to_le32(chain);
 
         /* Give this link TRB to the hardware */
         wmb();
         next->link.control ^= cpu_to_le32(TRB_CYCLE);
 
         /* Toggle the cycle bit after the last ring segment. */
         if (cdnsp_link_trb_toggles_cycle(next))
             ring->cycle_state ^= 1;
 
         ring->enq_seg = ring->enq_seg->next;
         ring->enqueue = ring->enq_seg->trbs;
         next = ring->enqueue;
     }
 
     trace_cdnsp_inc_enq(ring);
 }
 
 /*
  * Check to see if there's room to enqueue num_trbs on the ring and make sure
  * enqueue pointer will not advance into dequeue segment.
  */
 static bool cdnsp_room_on_ring(struct cdnsp_device *pdev,
                    struct cdnsp_ring *ring,
                    unsigned int num_trbs)
 {
     int num_trbs_in_deq_seg;
 
     if (ring->num_trbs_free < num_trbs)
         return false;
 
     if (ring->type != TYPE_COMMAND && ring->type != TYPE_EVENT) {
         num_trbs_in_deq_seg = ring->dequeue - ring->deq_seg->trbs;
 
         if (ring->num_trbs_free < num_trbs + num_trbs_in_deq_seg)
             return false;
     }
 
     return true;
 }
 
 /*
  * Workaround for L1: controller has issue with resuming from L1 after
  * setting doorbell for endpoint during L1 state. This function forces
  * resume signal in such case.
  */
 static void cdnsp_force_l0_go(struct cdnsp_device *pdev)
 {
     if (pdev->active_port == &pdev->usb2_port && pdev->gadget.lpm_capable)
         cdnsp_set_link_state(pdev, &pdev->active_port->regs->portsc, XDEV_U0);
 }
 
 /* Ring the doorbell after placing a command on the ring. */
 void cdnsp_ring_cmd_db(struct cdnsp_device *pdev)
 {
     writel(DB_VALUE_CMD, &pdev->dba->cmd_db);
 }
 
 /*
  * Ring the doorbell after placing a transfer on the ring.
  * Returns true if doorbell was set, otherwise false.
  */
 static bool cdnsp_ring_ep_doorbell(struct cdnsp_device *pdev,
                    struct cdnsp_ep *pep,
                    unsigned int stream_id)
 {
     __le32 __iomem *reg_addr = &pdev->dba->ep_db;
     unsigned int ep_state = pep->ep_state;
     unsigned int db_value;
 
     /*
      * Don't ring the doorbell for this endpoint if endpoint is halted or
      * disabled.
      */
     if (ep_state & EP_HALTED || !(ep_state & EP_ENABLED))
         return false;
 
     /* For stream capable endpoints driver can ring doorbell only twice. */
     if (pep->ep_state & EP_HAS_STREAMS) {
         if (pep->stream_info.drbls_count >= 2)
             return false;
 
         pep->stream_info.drbls_count++;
     }
 
     pep->ep_state &= ~EP_STOPPED;
 
     if (pep->idx == 0 && pdev->ep0_stage == CDNSP_DATA_STAGE &&
         !pdev->ep0_expect_in)
         db_value = DB_VALUE_EP0_OUT(pep->idx, stream_id);
     else
         db_value = DB_VALUE(pep->idx, stream_id);
 
     trace_cdnsp_tr_drbl(pep, stream_id);
 
     writel(db_value, reg_addr);
 
     cdnsp_force_l0_go(pdev);
 
     /* Doorbell was set. */
     return true;
 }
 
 /*
  * Get the right ring for the given pep and stream_id.
  * If the endpoint supports streams, boundary check the USB request's stream ID.
  * If the endpoint doesn't support streams, return the singular endpoint ring.
  */
 static struct cdnsp_ring *cdnsp_get_transfer_ring(struct cdnsp_device *pdev,
                           struct cdnsp_ep *pep,
                           unsigned int stream_id)
 {
     if (!(pep->ep_state & EP_HAS_STREAMS))
         return pep->ring;
 
     if (stream_id == 0 || stream_id >= pep->stream_info.num_streams) {
         dev_err(pdev->dev, "ERR: %s ring doesn't exist for SID: %d.\n",
             pep->name, stream_id);
         return NULL;
     }
 
     return pep->stream_info.stream_rings[stream_id];
 }
 
 static struct cdnsp_ring *
     cdnsp_request_to_transfer_ring(struct cdnsp_device *pdev,
                        struct cdnsp_request *preq)
 {
     return cdnsp_get_transfer_ring(pdev, preq->pep,
                        preq->request.stream_id);
 }
 
 /* Ring the doorbell for any rings with pending requests. */
 void cdnsp_ring_doorbell_for_active_rings(struct cdnsp_device *pdev,
                       struct cdnsp_ep *pep)
 {
     struct cdnsp_stream_info *stream_info;
     unsigned int stream_id;
     int ret;
 
     if (pep->ep_state & EP_DIS_IN_RROGRESS)
         return;
 
     /* A ring has pending Request if its TD list is not empty. */
     if (!(pep->ep_state & EP_HAS_STREAMS) && pep->number) {
         if (pep->ring && !list_empty(&pep->ring->td_list))
             cdnsp_ring_ep_doorbell(pdev, pep, 0);
         return;
     }
 
     stream_info = &pep->stream_info;
 
     for (stream_id = 1; stream_id < stream_info->num_streams; stream_id++) {
         struct cdnsp_td *td, *td_temp;
         struct cdnsp_ring *ep_ring;
 
         if (stream_info->drbls_count >= 2)
             return;
 
         ep_ring = cdnsp_get_transfer_ring(pdev, pep, stream_id);
         if (!ep_ring)
             continue;
 
         if (!ep_ring->stream_active || ep_ring->stream_rejected)
             continue;
 
         list_for_each_entry_safe(td, td_temp, &ep_ring->td_list,
                      td_list) {
             if (td->drbl)
                 continue;
 
             ret = cdnsp_ring_ep_doorbell(pdev, pep, stream_id);
             if (ret)
                 td->drbl = 1;
         }
     }
 }
 
 /*
  * Get the hw dequeue pointer controller stopped on, either directly from the
  * endpoint context, or if streams are in use from the stream context.
  * The returned hw_dequeue contains the lowest four bits with cycle state
  * and possible stream context type.
  */
 static u64 cdnsp_get_hw_deq(struct cdnsp_device *pdev,
                 unsigned int ep_index,
                 unsigned int stream_id)
 {
     struct cdnsp_stream_ctx *st_ctx;
     struct cdnsp_ep *pep;
 
     pep = &pdev->eps[stream_id];
 
     if (pep->ep_state & EP_HAS_STREAMS) {
         st_ctx = &pep->stream_info.stream_ctx_array[stream_id];
         return le64_to_cpu(st_ctx->stream_ring);
     }
 
     return le64_to_cpu(pep->out_ctx->deq);
 }
 
 /*
  * Move the controller endpoint ring dequeue pointer past cur_td.
  * Record the new state of the controller endpoint ring dequeue segment,
  * dequeue pointer, and new consumer cycle state in state.
  * Update internal representation of the ring's dequeue pointer.
  *
  * We do this in three jumps:
  *  - First we update our new ring state to be the same as when the
  *    controller stopped.
  *  - Then we traverse the ring to find the segment that contains
  *    the last TRB in the TD. We toggle the controller new cycle state
  *    when we pass any link TRBs with the toggle cycle bit set.
  *  - Finally we move the dequeue state one TRB further, toggling the cycle bit
  *    if we've moved it past a link TRB with the toggle cycle bit set.
  */
 static void cdnsp_find_new_dequeue_state(struct cdnsp_device *pdev,
                      struct cdnsp_ep *pep,
                      unsigned int stream_id,
                      struct cdnsp_td *cur_td,
                      struct cdnsp_dequeue_state *state)
 {
     bool td_last_trb_found = false;
     struct cdnsp_segment *new_seg;
     struct cdnsp_ring *ep_ring;
     union cdnsp_trb *new_deq;
     bool cycle_found = false;
     u64 hw_dequeue;
 
     ep_ring = cdnsp_get_transfer_ring(pdev, pep, stream_id);
     if (!ep_ring)
         return;
 
     /*
      * Dig out the cycle state saved by the controller during the
      * stop endpoint command.
      */
     hw_dequeue = cdnsp_get_hw_deq(pdev, pep->idx, stream_id);
     new_seg = ep_ring->deq_seg;
     new_deq = ep_ring->dequeue;
     state->new_cycle_state = hw_dequeue & 0x1;
     state->stream_id = stream_id;
 
     /*
      * We want to find the pointer, segment and cycle state of the new trb
      * (the one after current TD's last_trb). We know the cycle state at
      * hw_dequeue, so walk the ring until both hw_dequeue and last_trb are
      * found.
      */
     do {
         if (!cycle_found && cdnsp_trb_virt_to_dma(new_seg, new_deq)
             == (dma_addr_t)(hw_dequeue & ~0xf)) {
             cycle_found = true;
 
             if (td_last_trb_found)
                 break;
         }
 
         if (new_deq == cur_td->last_trb)
             td_last_trb_found = true;
 
         if (cycle_found && cdnsp_trb_is_link(new_deq) &&
             cdnsp_link_trb_toggles_cycle(new_deq))
             state->new_cycle_state ^= 0x1;
 
         cdnsp_next_trb(pdev, ep_ring, &new_seg, &new_deq);
 
         /* Search wrapped around, bail out. */
         if (new_deq == pep->ring->dequeue) {
             dev_err(pdev->dev,
                 "Error: Failed finding new dequeue state\n");
             state->new_deq_seg = NULL;
             state->new_deq_ptr = NULL;
             return;
         }
 
     } while (!cycle_found || !td_last_trb_found);
 
     state->new_deq_seg = new_seg;
     state->new_deq_ptr = new_deq;
 
     trace_cdnsp_new_deq_state(state);
 }
 
 /*
  * flip_cycle means flip the cycle bit of all but the first and last TRB.
  * (The last TRB actually points to the ring enqueue pointer, which is not part
  * of this TD.) This is used to remove partially enqueued isoc TDs from a ring.
  */
 static void cdnsp_td_to_noop(struct cdnsp_device *pdev,
                  struct cdnsp_ring *ep_ring,
                  struct cdnsp_td *td,
                  bool flip_cycle)
 {
     struct cdnsp_segment *seg = td->start_seg;
     union cdnsp_trb *trb = td->first_trb;
 
     while (1) {
         cdnsp_trb_to_noop(trb, TRB_TR_NOOP);
 
         /* flip cycle if asked to */
         if (flip_cycle && trb != td->first_trb && trb != td->last_trb)
             trb->generic.field[3] ^= cpu_to_le32(TRB_CYCLE);
 
         if (trb == td->last_trb)
             break;
 
         cdnsp_next_trb(pdev, ep_ring, &seg, &trb);
     }
 }
 
 /*
  * This TD is defined by the TRBs starting at start_trb in start_seg and ending
  * at end_trb, which may be in another segment. If the suspect DMA address is a
  * TRB in this TD, this function returns that TRB's segment. Otherwise it
  * returns 0.
  */
 static struct cdnsp_segment *cdnsp_trb_in_td(struct cdnsp_device *pdev,
                          struct cdnsp_segment *start_seg,
                          union cdnsp_trb *start_trb,
                          union cdnsp_trb *end_trb,
                          dma_addr_t suspect_dma)
 {
     struct cdnsp_segment *cur_seg;
     union cdnsp_trb *temp_trb;
     dma_addr_t end_seg_dma;
     dma_addr_t end_trb_dma;
     dma_addr_t start_dma;
 
     start_dma = cdnsp_trb_virt_to_dma(start_seg, start_trb);
     cur_seg = start_seg;
 
     do {
         if (start_dma == 0)
             return NULL;
 
         temp_trb = &cur_seg->trbs[TRBS_PER_SEGMENT - 1];
         /* We may get an event for a Link TRB in the middle of a TD */
         end_seg_dma = cdnsp_trb_virt_to_dma(cur_seg, temp_trb);
         /* If the end TRB isn't in this segment, this is set to 0 */
         end_trb_dma = cdnsp_trb_virt_to_dma(cur_seg, end_trb);
 
         trace_cdnsp_looking_trb_in_td(suspect_dma, start_dma,
                           end_trb_dma, cur_seg->dma,
                           end_seg_dma);
 
         if (end_trb_dma > 0) {
             /*
              * The end TRB is in this segment, so suspect should
              * be here
              */
             if (start_dma <= end_trb_dma) {
                 if (suspect_dma >= start_dma &&
                     suspect_dma <= end_trb_dma) {
                     return cur_seg;
                 }
             } else {
                 /*
                  * Case for one segment with a
                  * TD wrapped around to the top
                  */
                 if ((suspect_dma >= start_dma &&
                      suspect_dma <= end_seg_dma) ||
                     (suspect_dma >= cur_seg->dma &&
                      suspect_dma <= end_trb_dma)) {
                     return cur_seg;
                 }
             }
 
             return NULL;
         }
 
         /* Might still be somewhere in this segment */
         if (suspect_dma >= start_dma && suspect_dma <= end_seg_dma)
             return cur_seg;
 
         cur_seg = cur_seg->next;
         start_dma = cdnsp_trb_virt_to_dma(cur_seg, &cur_seg->trbs[0]);
     } while (cur_seg != start_seg);
 
     return NULL;
 }
 
 static void cdnsp_unmap_td_bounce_buffer(struct cdnsp_device *pdev,
                      struct cdnsp_ring *ring,
                      struct cdnsp_td *td)
 {
     struct cdnsp_segment *seg = td->bounce_seg;
     struct cdnsp_request *preq;
     size_t len;
 
     if (!seg)
         return;
 
     preq = td->preq;
 
     trace_cdnsp_bounce_unmap(td->preq, seg->bounce_len, seg->bounce_offs,
                  seg->bounce_dma, 0);
 
     if (!preq->direction) {
         dma_unmap_single(pdev->dev, seg->bounce_dma,
                  ring->bounce_buf_len,  DMA_TO_DEVICE);
         return;
     }
 
     dma_unmap_single(pdev->dev, seg->bounce_dma, ring->bounce_buf_len,
              DMA_FROM_DEVICE);
 
     /* For in transfers we need to copy the data from bounce to sg */
     len = sg_pcopy_from_buffer(preq->request.sg, preq->request.num_sgs,
                    seg->bounce_buf, seg->bounce_len,
                    seg->bounce_offs);
     if (len != seg->bounce_len)
         dev_warn(pdev->dev, "WARN Wrong bounce buffer read length: %zu != %d\n",
              len, seg->bounce_len);
 
     seg->bounce_len = 0;
     seg->bounce_offs = 0;
 }
 
 static int cdnsp_cmd_set_deq(struct cdnsp_device *pdev,
                  struct cdnsp_ep *pep,
                  struct cdnsp_dequeue_state *deq_state)
 {
     struct cdnsp_ring *ep_ring;
     int ret;
 
     if (!deq_state->new_deq_ptr || !deq_state->new_deq_seg) {
         cdnsp_ring_doorbell_for_active_rings(pdev, pep);
         return 0;
     }
 
     cdnsp_queue_new_dequeue_state(pdev, pep, deq_state);
     cdnsp_ring_cmd_db(pdev);
     ret = cdnsp_wait_for_cmd_compl(pdev);
 
     trace_cdnsp_handle_cmd_set_deq(cdnsp_get_slot_ctx(&pdev->out_ctx));
     trace_cdnsp_handle_cmd_set_deq_ep(pep->out_ctx);
 
     /*
      * Update the ring's dequeue segment and dequeue pointer
      * to reflect the new position.
      */
     ep_ring = cdnsp_get_transfer_ring(pdev, pep, deq_state->stream_id);
 
     if (cdnsp_trb_is_link(ep_ring->dequeue)) {
         ep_ring->deq_seg = ep_ring->deq_seg->next;
         ep_ring->dequeue = ep_ring->deq_seg->trbs;
     }
 
     while (ep_ring->dequeue != deq_state->new_deq_ptr) {
         ep_ring->num_trbs_free++;
         ep_ring->dequeue++;
 
         if (cdnsp_trb_is_link(ep_ring->dequeue)) {
             if (ep_ring->dequeue == deq_state->new_deq_ptr)
                 break;
 
             ep_ring->deq_seg = ep_ring->deq_seg->next;
             ep_ring->dequeue = ep_ring->deq_seg->trbs;
         }
     }
 
     /*
      * Probably there was TIMEOUT during handling Set Dequeue Pointer
      * command. It's critical error and controller will be stopped.
      */
     if (ret)
         return -ESHUTDOWN;
 
     /* Restart any rings with pending requests */
     cdnsp_ring_doorbell_for_active_rings(pdev, pep);
 
     return 0;
 }
 
 int cdnsp_remove_request(struct cdnsp_device *pdev,
              struct cdnsp_request *preq,
              struct cdnsp_ep *pep)
 {
     struct cdnsp_dequeue_state deq_state;
     struct cdnsp_td *cur_td = NULL;
     struct cdnsp_ring *ep_ring;
     struct cdnsp_segment *seg;
     int status = -ECONNRESET;
     int ret = 0;
     u64 hw_deq;
 
     memset(&deq_state, 0, sizeof(deq_state));
 
     trace_cdnsp_remove_request(pep->out_ctx);
     trace_cdnsp_remove_request_td(preq);
 
     cur_td = &preq->td;
     ep_ring = cdnsp_request_to_transfer_ring(pdev, preq);
 
     /*
      * If we stopped on the TD we need to cancel, then we have to
      * move the controller endpoint ring dequeue pointer past
      * this TD.
      */
     hw_deq = cdnsp_get_hw_deq(pdev, pep->idx, preq->request.stream_id);
     hw_deq &= ~0xf;
 
     seg = cdnsp_trb_in_td(pdev, cur_td->start_seg, cur_td->first_trb,
                   cur_td->last_trb, hw_deq);
 
     if (seg && (pep->ep_state & EP_ENABLED))
         cdnsp_find_new_dequeue_state(pdev, pep, preq->request.stream_id,
                          cur_td, &deq_state);
     else
         cdnsp_td_to_noop(pdev, ep_ring, cur_td, false);
 
     /*
      * The event handler won't see a completion for this TD anymore,
      * so remove it from the endpoint ring's TD list.
      */
     list_del_init(&cur_td->td_list);
     ep_ring->num_tds--;
     pep->stream_info.td_count--;
 
     /*
      * During disconnecting all endpoint will be disabled so we don't
      * have to worry about updating dequeue pointer.
      */
     if (pdev->cdnsp_state & CDNSP_STATE_DISCONNECT_PENDING) {
         status = -ESHUTDOWN;
         ret = cdnsp_cmd_set_deq(pdev, pep, &deq_state);
     }
 
     cdnsp_unmap_td_bounce_buffer(pdev, ep_ring, cur_td);
     cdnsp_gadget_giveback(pep, cur_td->preq, status);
 
     return ret;
 }
 
 static int cdnsp_update_port_id(struct cdnsp_device *pdev, u32 port_id)
 {
     struct cdnsp_port *port = pdev->active_port;
     u8 old_port = 0;
 
     if (port && port->port_num == port_id)
         return 0;
 
     if (port)
         old_port = port->port_num;
 
     if (port_id == pdev->usb2_port.port_num) {
         port = &pdev->usb2_port;
     } else if (port_id == pdev->usb3_port.port_num) {
         port  = &pdev->usb3_port;
     } else {
         dev_err(pdev->dev, "Port event with invalid port ID %d\n",
             port_id);
         return -EINVAL;
     }
 
     if (port_id != old_port) {
         cdnsp_disable_slot(pdev);
         pdev->active_port = port;
         cdnsp_enable_slot(pdev);
     }
 
     if (port_id == pdev->usb2_port.port_num)
         cdnsp_set_usb2_hardware_lpm(pdev, NULL, 1);
     else
         writel(PORT_U1_TIMEOUT(1) | PORT_U2_TIMEOUT(1),
                &pdev->usb3_port.regs->portpmsc);
 
     return 0;
 }
 
 static void cdnsp_handle_port_status(struct cdnsp_device *pdev,
                      union cdnsp_trb *event)
 {
     struct cdnsp_port_regs __iomem *port_regs;
     u32 portsc, cmd_regs;
     bool port2 = false;
     u32 link_state;
     u32 port_id;
 
     /* Port status change events always have a successful completion code */
     if (GET_COMP_CODE(le32_to_cpu(event->generic.field[2])) != COMP_SUCCESS)
         dev_err(pdev->dev, "ERR: incorrect PSC event\n");
 
     port_id = GET_PORT_ID(le32_to_cpu(event->generic.field[0]));
 
     if (cdnsp_update_port_id(pdev, port_id))
         goto cleanup;
 
     port_regs = pdev->active_port->regs;
 
     if (port_id == pdev->usb2_port.port_num)
         port2 = true;
 
 new_event:
     portsc = readl(&port_regs->portsc);
     writel(cdnsp_port_state_to_neutral(portsc) |
            (portsc & PORT_CHANGE_BITS), &port_regs->portsc);
 
     trace_cdnsp_handle_port_status(pdev->active_port->port_num, portsc);
 
     pdev->gadget.speed = cdnsp_port_speed(portsc);
     link_state = portsc & PORT_PLS_MASK;
 
     /* Port Link State change detected. */
     if ((portsc & PORT_PLC)) {
         if (!(pdev->cdnsp_state & CDNSP_WAKEUP_PENDING)  &&
             link_state == XDEV_RESUME) {
             cmd_regs = readl(&pdev->op_regs->command);
             if (!(cmd_regs & CMD_R_S))
                 goto cleanup;
 
             if (DEV_SUPERSPEED_ANY(portsc)) {
                 cdnsp_set_link_state(pdev, &port_regs->portsc,
                              XDEV_U0);
 
                 cdnsp_resume_gadget(pdev);
             }
         }
 
         if ((pdev->cdnsp_state & CDNSP_WAKEUP_PENDING) &&
             link_state == XDEV_U0) {
             pdev->cdnsp_state &= ~CDNSP_WAKEUP_PENDING;
 
             cdnsp_force_header_wakeup(pdev, 1);
             cdnsp_ring_cmd_db(pdev);
             cdnsp_wait_for_cmd_compl(pdev);
         }
 
         if (link_state == XDEV_U0 && pdev->link_state == XDEV_U3 &&
             !DEV_SUPERSPEED_ANY(portsc))
             cdnsp_resume_gadget(pdev);
 
         if (link_state == XDEV_U3 &&  pdev->link_state != XDEV_U3)
             cdnsp_suspend_gadget(pdev);
 
         pdev->link_state = link_state;
     }
 
     if (portsc & PORT_CSC) {
         /* Detach device. */
         if (pdev->gadget.connected && !(portsc & PORT_CONNECT))
             cdnsp_disconnect_gadget(pdev);
 
         /* Attach device. */
         if (portsc & PORT_CONNECT) {
             if (!port2)
                 cdnsp_irq_reset(pdev);
 
             usb_gadget_set_state(&pdev->gadget, USB_STATE_ATTACHED);
         }
     }
 
     /* Port reset. */
     if ((portsc & (PORT_RC | PORT_WRC)) && (portsc & PORT_CONNECT)) {
         cdnsp_irq_reset(pdev);
         pdev->u1_allowed = 0;
         pdev->u2_allowed = 0;
         pdev->may_wakeup = 0;
     }
 
     if (portsc & PORT_CEC)
         dev_err(pdev->dev, "Port Over Current detected\n");
 
     if (portsc & PORT_CEC)
         dev_err(pdev->dev, "Port Configure Error detected\n");
 
     if (readl(&port_regs->portsc) & PORT_CHANGE_BITS)
         goto new_event;
 
 cleanup:
     cdnsp_inc_deq(pdev, pdev->event_ring);
 }
 
 static void cdnsp_td_cleanup(struct cdnsp_device *pdev,
                  struct cdnsp_td *td,
                  struct cdnsp_ring *ep_ring,
                  int *status)
 {
     struct cdnsp_request *preq = td->preq;
 
     /* if a bounce buffer was used to align this td then unmap it */
     cdnsp_unmap_td_bounce_buffer(pdev, ep_ring, td);
 
     /*
      * If the controller said we transferred more data than the buffer
      * length, Play it safe and say we didn't transfer anything.
      */
     if (preq->request.actual > preq->request.length) {
         preq->request.actual = 0;
         *status = 0;
     }
 
     list_del_init(&td->td_list);
     ep_ring->num_tds--;
     preq->pep->stream_info.td_count--;
 
     cdnsp_gadget_giveback(preq->pep, preq, *status);
 }
 
 static void cdnsp_finish_td(struct cdnsp_device *pdev,
                 struct cdnsp_td *td,
                 struct cdnsp_transfer_event *event,
                 struct cdnsp_ep *ep,
                 int *status)
 {
     struct cdnsp_ring *ep_ring;
     u32 trb_comp_code;
 
     ep_ring = cdnsp_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
     trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
 
     if (trb_comp_code == COMP_STOPPED_LENGTH_INVALID ||
         trb_comp_code == COMP_STOPPED ||
         trb_comp_code == COMP_STOPPED_SHORT_PACKET) {
         /*
          * The Endpoint Stop Command completion will take care of any
          * stopped TDs. A stopped TD may be restarted, so don't update
          * the ring dequeue pointer or take this TD off any lists yet.
          */
         return;
     }
 
     /* Update ring dequeue pointer */
     while (ep_ring->dequeue != td->last_trb)
         cdnsp_inc_deq(pdev, ep_ring);
 
     cdnsp_inc_deq(pdev, ep_ring);
 
     cdnsp_td_cleanup(pdev, td, ep_ring, status);
 }
 
 /* sum trb lengths from ring dequeue up to stop_trb, _excluding_ stop_trb */
 static int cdnsp_sum_trb_lengths(struct cdnsp_device *pdev,
                  struct cdnsp_ring *ring,
                  union cdnsp_trb *stop_trb)
 {
     struct cdnsp_segment *seg = ring->deq_seg;
     union cdnsp_trb *trb = ring->dequeue;
     u32 sum;
 
     for (sum = 0; trb != stop_trb; cdnsp_next_trb(pdev, ring, &seg, &trb)) {
         if (!cdnsp_trb_is_noop(trb) && !cdnsp_trb_is_link(trb))
             sum += TRB_LEN(le32_to_cpu(trb->generic.field[2]));
     }
     return sum;
 }
 
 static int cdnsp_giveback_first_trb(struct cdnsp_device *pdev,
                     struct cdnsp_ep *pep,
                     unsigned int stream_id,
                     int start_cycle,
                     struct cdnsp_generic_trb *start_trb)
 {
     /*
      * Pass all the TRBs to the hardware at once and make sure this write
      * isn't reordered.
      */
     wmb();
 
     if (start_cycle)
         start_trb->field[3] |= cpu_to_le32(start_cycle);
     else
         start_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
 
     if ((pep->ep_state & EP_HAS_STREAMS) &&
         !pep->stream_info.first_prime_det) {
         trace_cdnsp_wait_for_prime(pep, stream_id);
         return 0;
     }
 
     return cdnsp_ring_ep_doorbell(pdev, pep, stream_id);
 }
 
 /*
  * Process control tds, update USB request status and actual_length.
  */
 static void cdnsp_process_ctrl_td(struct cdnsp_device *pdev,
                   struct cdnsp_td *td,
                   union cdnsp_trb *event_trb,
                   struct cdnsp_transfer_event *event,
                   struct cdnsp_ep *pep,
                   int *status)
 {
     struct cdnsp_ring *ep_ring;
     u32 remaining;
     u32 trb_type;
 
     trb_type = TRB_FIELD_TO_TYPE(le32_to_cpu(event_trb->generic.field[3]));
     ep_ring = cdnsp_dma_to_transfer_ring(pep, le64_to_cpu(event->buffer));
     remaining = EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
 
     /*
      * if on data stage then update the actual_length of the USB
      * request and flag it as set, so it won't be overwritten in the event
      * for the last TRB.
      */
     if (trb_type == TRB_DATA) {
         td->request_length_set = true;
         td->preq->request.actual = td->preq->request.length - remaining;
     }
 
     /* at status stage */
     if (!td->request_length_set)
         td->preq->request.actual = td->preq->request.length;
 
     if (pdev->ep0_stage == CDNSP_DATA_STAGE && pep->number == 0 &&
         pdev->three_stage_setup) {
         td = list_entry(ep_ring->td_list.next, struct cdnsp_td,
                 td_list);
         pdev->ep0_stage = CDNSP_STATUS_STAGE;
 
         cdnsp_giveback_first_trb(pdev, pep, 0, ep_ring->cycle_state,
                      &td->last_trb->generic);
         return;
     }
 
     *status = 0;
 
     cdnsp_finish_td(pdev, td, event, pep, status);
 }
 
 /*
  * Process isochronous tds, update usb request status and actual_length.
  */
 static void cdnsp_process_isoc_td(struct cdnsp_device *pdev,
                   struct cdnsp_td *td,
                   union cdnsp_trb *ep_trb,
                   struct cdnsp_transfer_event *event,
                   struct cdnsp_ep *pep,
                   int status)
 {
     struct cdnsp_request *preq = td->preq;
     u32 remaining, requested, ep_trb_len;
     bool sum_trbs_for_length = false;
     struct cdnsp_ring *ep_ring;
     u32 trb_comp_code;
     u32 td_length;
 
     ep_ring = cdnsp_dma_to_transfer_ring(pep, le64_to_cpu(event->buffer));
     trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
     remaining = EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
     ep_trb_len = TRB_LEN(le32_to_cpu(ep_trb->generic.field[2]));
 
     requested = preq->request.length;
 
     /* handle completion code */
     switch (trb_comp_code) {
     case COMP_SUCCESS:
         preq->request.status = 0;
         break;
     case COMP_SHORT_PACKET:
         preq->request.status = 0;
         sum_trbs_for_length = true;
         break;
     case COMP_ISOCH_BUFFER_OVERRUN:
     case COMP_BABBLE_DETECTED_ERROR:
         preq->request.status = -EOVERFLOW;
         break;
     case COMP_STOPPED:
         sum_trbs_for_length = true;
         break;
     case COMP_STOPPED_SHORT_PACKET:
         /* field normally containing residue now contains transferred */
         preq->request.status  = 0;
         requested = remaining;
         break;
     case COMP_STOPPED_LENGTH_INVALID:
         requested = 0;
         remaining = 0;
         break;
     default:
         sum_trbs_for_length = true;
         preq->request.status = -1;
         break;
     }
 
     if (sum_trbs_for_length) {
         td_length = cdnsp_sum_trb_lengths(pdev, ep_ring, ep_trb);
         td_length += ep_trb_len - remaining;
     } else {
         td_length = requested;
     }
 
     td->preq->request.actual += td_length;
 
     cdnsp_finish_td(pdev, td, event, pep, &status);
 }
 
 static void cdnsp_skip_isoc_td(struct cdnsp_device *pdev,
                    struct cdnsp_td *td,
                    struct cdnsp_transfer_event *event,
                    struct cdnsp_ep *pep,
                    int status)
 {
     struct cdnsp_ring *ep_ring;
 
     ep_ring = cdnsp_dma_to_transfer_ring(pep, le64_to_cpu(event->buffer));
     td->preq->request.status = -EXDEV;
     td->preq->request.actual = 0;
 
     /* Update ring dequeue pointer */
     while (ep_ring->dequeue != td->last_trb)
         cdnsp_inc_deq(pdev, ep_ring);
 
     cdnsp_inc_deq(pdev, ep_ring);
 
     cdnsp_td_cleanup(pdev, td, ep_ring, &status);
 }
 
 /*
  * Process bulk and interrupt tds, update usb request status and actual_length.
  */
 static void cdnsp_process_bulk_intr_td(struct cdnsp_device *pdev,
                        struct cdnsp_td *td,
                        union cdnsp_trb *ep_trb,
                        struct cdnsp_transfer_event *event,
                        struct cdnsp_ep *ep,
                        int *status)
 {
     u32 remaining, requested, ep_trb_len;
     struct cdnsp_ring *ep_ring;
     u32 trb_comp_code;
 
     ep_ring = cdnsp_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
     trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
     remaining = EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
     ep_trb_len = TRB_LEN(le32_to_cpu(ep_trb->generic.field[2]));
     requested = td->preq->request.length;
 
     switch (trb_comp_code) {
     case COMP_SUCCESS:
     case COMP_SHORT_PACKET:
         *status = 0;
         break;
     case COMP_STOPPED_SHORT_PACKET:
         td->preq->request.actual = remaining;
         goto finish_td;
     case COMP_STOPPED_LENGTH_INVALID:
         /* Stopped on ep trb with invalid length, exclude it. */
         ep_trb_len = 0;
         remaining = 0;
         break;
     }
 
     if (ep_trb == td->last_trb)
         ep_trb_len = requested - remaining;
     else
         ep_trb_len = cdnsp_sum_trb_lengths(pdev, ep_ring, ep_trb) +
                            ep_trb_len - remaining;
     td->preq->request.actual = ep_trb_len;
 
 finish_td:
     ep->stream_info.drbls_count--;
 
     cdnsp_finish_td(pdev, td, event, ep, status);
 }
 
 static void cdnsp_handle_tx_nrdy(struct cdnsp_device *pdev,
                  struct cdnsp_transfer_event *event)
 {
     struct cdnsp_generic_trb *generic;
     struct cdnsp_ring *ep_ring;
     struct cdnsp_ep *pep;
     int cur_stream;
     int ep_index;
     int host_sid;
     int dev_sid;
 
     generic = (struct cdnsp_generic_trb *)event;
     ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
     dev_sid = TRB_TO_DEV_STREAM(le32_to_cpu(generic->field[0]));
     host_sid = TRB_TO_HOST_STREAM(le32_to_cpu(generic->field[2]));
 
     pep = &pdev->eps[ep_index];
 
     if (!(pep->ep_state & EP_HAS_STREAMS))
         return;
 
     if (host_sid == STREAM_PRIME_ACK) {
         pep->stream_info.first_prime_det = 1;
         for (cur_stream = 1; cur_stream < pep->stream_info.num_streams;
             cur_stream++) {
             ep_ring = pep->stream_info.stream_rings[cur_stream];
             ep_ring->stream_active = 1;
             ep_ring->stream_rejected = 0;
         }
     }
 
     if (host_sid == STREAM_REJECTED) {
         struct cdnsp_td *td, *td_temp;
 
         pep->stream_info.drbls_count--;
         ep_ring = pep->stream_info.stream_rings[dev_sid];
         ep_ring->stream_active = 0;
         ep_ring->stream_rejected = 1;
 
         list_for_each_entry_safe(td, td_temp, &ep_ring->td_list,
                      td_list) {
             td->drbl = 0;
         }
     }
 
     cdnsp_ring_doorbell_for_active_rings(pdev, pep);
 }
 
 /*
  * If this function returns an error condition, it means it got a Transfer
  * event with a corrupted TRB DMA address or endpoint is disabled.
  */
 static int cdnsp_handle_tx_event(struct cdnsp_device *pdev,
                  struct cdnsp_transfer_event *event)
 {
     const struct usb_endpoint_descriptor *desc;
     bool handling_skipped_tds = false;
     struct cdnsp_segment *ep_seg;
     struct cdnsp_ring *ep_ring;
     int status = -EINPROGRESS;
     union cdnsp_trb *ep_trb;
     dma_addr_t ep_trb_dma;
     struct cdnsp_ep *pep;
     struct cdnsp_td *td;
     u32 trb_comp_code;
     int invalidate;
     int ep_index;
 
     invalidate = le32_to_cpu(event->flags) & TRB_EVENT_INVALIDATE;
     ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
     trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
     ep_trb_dma = le64_to_cpu(event->buffer);
 
     pep = &pdev->eps[ep_index];
     ep_ring = cdnsp_dma_to_transfer_ring(pep, le64_to_cpu(event->buffer));
 
     /*
      * If device is disconnect then all requests will be dequeued
      * by upper layers as part of disconnect sequence.
      * We don't want handle such event to avoid racing.
      */
     if (invalidate || !pdev->gadget.connected)
         goto cleanup;
 
     if (GET_EP_CTX_STATE(pep->out_ctx) == EP_STATE_DISABLED) {
         trace_cdnsp_ep_disabled(pep->out_ctx);
         goto err_out;
     }
 
     /* Some transfer events don't always point to a trb*/
     if (!ep_ring) {
         switch (trb_comp_code) {
         case COMP_INVALID_STREAM_TYPE_ERROR:
         case COMP_INVALID_STREAM_ID_ERROR:
         case COMP_RING_UNDERRUN:
         case COMP_RING_OVERRUN:
             goto cleanup;
         default:
             dev_err(pdev->dev, "ERROR: %s event for unknown ring\n",
                 pep->name);
             goto err_out;
         }
     }
 
     /* Look for some error cases that need special treatment. */
     switch (trb_comp_code) {
     case COMP_BABBLE_DETECTED_ERROR:
         status = -EOVERFLOW;
         break;
     case COMP_RING_UNDERRUN:
     case COMP_RING_OVERRUN:
         /*
          * When the Isoch ring is empty, the controller will generate
          * a Ring Overrun Event for IN Isoch endpoint or Ring
          * Underrun Event for OUT Isoch endpoint.
          */
         goto cleanup;
     case COMP_MISSED_SERVICE_ERROR:
         /*
          * When encounter missed service error, one or more isoc tds
          * may be missed by controller.
          * Set skip flag of the ep_ring; Complete the missed tds as
          * short transfer when process the ep_ring next time.
          */
         pep->skip = true;
         break;
     }
 
     do {
         /*
          * This TRB should be in the TD at the head of this ring's TD
          * list.
          */
         if (list_empty(&ep_ring->td_list)) {
             /*
              * Don't print warnings if it's due to a stopped
              * endpoint generating an extra completion event, or
              * a event for the last TRB of a short TD we already
              * got a short event for.
              * The short TD is already removed from the TD list.
              */
             if (!(trb_comp_code == COMP_STOPPED ||
                   trb_comp_code == COMP_STOPPED_LENGTH_INVALID ||
                   ep_ring->last_td_was_short))
                 trace_cdnsp_trb_without_td(ep_ring,
                     (struct cdnsp_generic_trb *)event);
 
             if (pep->skip) {
                 pep->skip = false;
                 trace_cdnsp_ep_list_empty_with_skip(pep, 0);
             }
 
             goto cleanup;
         }
 
         td = list_entry(ep_ring->td_list.next, struct cdnsp_td,
                 td_list);
 
         /* Is this a TRB in the currently executing TD? */
         ep_seg = cdnsp_trb_in_td(pdev, ep_ring->deq_seg,
                      ep_ring->dequeue, td->last_trb,
                      ep_trb_dma);
 
         /*
          * Skip the Force Stopped Event. The event_trb(ep_trb_dma)
          * of FSE is not in the current TD pointed by ep_ring->dequeue
          * because that the hardware dequeue pointer still at the
          * previous TRB of the current TD. The previous TRB maybe a
          * Link TD or the last TRB of the previous TD. The command
          * completion handle will take care the rest.
          */
         if (!ep_seg && (trb_comp_code == COMP_STOPPED ||
                 trb_comp_code == COMP_STOPPED_LENGTH_INVALID)) {
             pep->skip = false;
             goto cleanup;
         }
 
         desc = td->preq->pep->endpoint.desc;
         if (!ep_seg) {
             if (!pep->skip || !usb_endpoint_xfer_isoc(desc)) {
                 /* Something is busted, give up! */
                 dev_err(pdev->dev,
                     "ERROR Transfer event TRB DMA ptr not "
                     "part of current TD ep_index %d "
                     "comp_code %u\n", ep_index,
                     trb_comp_code);
                 return -EINVAL;
             }
 
             cdnsp_skip_isoc_td(pdev, td, event, pep, status);
             goto cleanup;
         }
 
         if (trb_comp_code == COMP_SHORT_PACKET)
             ep_ring->last_td_was_short = true;
         else
             ep_ring->last_td_was_short = false;
 
         if (pep->skip) {
             pep->skip = false;
             cdnsp_skip_isoc_td(pdev, td, event, pep, status);
             goto cleanup;
         }
 
         ep_trb = &ep_seg->trbs[(ep_trb_dma - ep_seg->dma)
                        / sizeof(*ep_trb)];
 
         trace_cdnsp_handle_transfer(ep_ring,
                         (struct cdnsp_generic_trb *)ep_trb);
 
         if (cdnsp_trb_is_noop(ep_trb))
             goto cleanup;
 
         if (usb_endpoint_xfer_control(desc))
             cdnsp_process_ctrl_td(pdev, td, ep_trb, event, pep,
                           &status);
         else if (usb_endpoint_xfer_isoc(desc))
             cdnsp_process_isoc_td(pdev, td, ep_trb, event, pep,
                           status);
         else
             cdnsp_process_bulk_intr_td(pdev, td, ep_trb, event, pep,
                            &status);
 cleanup:
         handling_skipped_tds = pep->skip;
 
         /*
          * Do not update event ring dequeue pointer if we're in a loop
          * processing missed tds.
          */
         if (!handling_skipped_tds)
             cdnsp_inc_deq(pdev, pdev->event_ring);
 
     /*
      * If ep->skip is set, it means there are missed tds on the
      * endpoint ring need to take care of.
      * Process them as short transfer until reach the td pointed by
      * the event.
      */
     } while (handling_skipped_tds);
     return 0;
 
 err_out:
     dev_err(pdev->dev, "@%016llx %08x %08x %08x %08x\n",
         (unsigned long long)
         cdnsp_trb_virt_to_dma(pdev->event_ring->deq_seg,
                       pdev->event_ring->dequeue),
          lower_32_bits(le64_to_cpu(event->buffer)),
          upper_32_bits(le64_to_cpu(event->buffer)),
          le32_to_cpu(event->transfer_len),
          le32_to_cpu(event->flags));
     return -EINVAL;
 }
 
 /*
  * This function handles all events on the event ring.
  * Returns true for "possibly more events to process" (caller should call
  * again), otherwise false if done.
  */
 static bool cdnsp_handle_event(struct cdnsp_device *pdev)
 {
     unsigned int comp_code;
     union cdnsp_trb *event;
     bool update_ptrs = true;
     u32 cycle_bit;
     int ret = 0;
     u32 flags;
 
     event = pdev->event_ring->dequeue;
     flags = le32_to_cpu(event->event_cmd.flags);
     cycle_bit = (flags & TRB_CYCLE);
 
     /* Does the controller or driver own the TRB? */
     if (cycle_bit != pdev->event_ring->cycle_state)
         return false;
 
     trace_cdnsp_handle_event(pdev->event_ring, &event->generic);
 
     /*
      * Barrier between reading the TRB_CYCLE (valid) flag above and any
      * reads of the event's flags/data below.
      */
     rmb();
 
     switch (flags & TRB_TYPE_BITMASK) {
     case TRB_TYPE(TRB_COMPLETION):
         /*
          * Command can't be handled in interrupt context so just
          * increment command ring dequeue pointer.
          */
         cdnsp_inc_deq(pdev, pdev->cmd_ring);
         break;
     case TRB_TYPE(TRB_PORT_STATUS):
         cdnsp_handle_port_status(pdev, event);
         update_ptrs = false;
         break;
     case TRB_TYPE(TRB_TRANSFER):
         ret = cdnsp_handle_tx_event(pdev, &event->trans_event);
         if (ret >= 0)
             update_ptrs = false;
         break;
     case TRB_TYPE(TRB_SETUP):
         pdev->ep0_stage = CDNSP_SETUP_STAGE;
         pdev->setup_id = TRB_SETUPID_TO_TYPE(flags);
         pdev->setup_speed = TRB_SETUP_SPEEDID(flags);
         pdev->setup = *((struct usb_ctrlrequest *)
                 &event->trans_event.buffer);
 
         cdnsp_setup_analyze(pdev);
         break;
     case TRB_TYPE(TRB_ENDPOINT_NRDY):
         cdnsp_handle_tx_nrdy(pdev, &event->trans_event);
         break;
     case TRB_TYPE(TRB_HC_EVENT): {
         comp_code = GET_COMP_CODE(le32_to_cpu(event->generic.field[2]));
 
         switch (comp_code) {
         case COMP_EVENT_RING_FULL_ERROR:
             dev_err(pdev->dev, "Event Ring Full\n");
             break;
         default:
             dev_err(pdev->dev, "Controller error code 0x%02x\n",
                 comp_code);
         }
 
         break;
     }
     case TRB_TYPE(TRB_MFINDEX_WRAP):
     case TRB_TYPE(TRB_DRB_OVERFLOW):
         break;
     default:
         dev_warn(pdev->dev, "ERROR unknown event type %ld\n",
              TRB_FIELD_TO_TYPE(flags));
     }
 
     if (update_ptrs)
         /* Update SW event ring dequeue pointer. */
         cdnsp_inc_deq(pdev, pdev->event_ring);
 
     /*
      * Caller will call us again to check if there are more items
      * on the event ring.
      */
     return true;
 }
 
 irqreturn_t cdnsp_thread_irq_handler(int irq, void *data)
 {
     struct cdnsp_device *pdev = (struct cdnsp_device *)data;
     union cdnsp_trb *event_ring_deq;
     unsigned long flags;
     int counter = 0;
 
     spin_lock_irqsave(&pdev->lock, flags);
 
     if (pdev->cdnsp_state & (CDNSP_STATE_HALTED | CDNSP_STATE_DYING)) {
         /*
          * While removing or stopping driver there may still be deferred
          * not handled interrupt which should not be treated as error.
          * Driver should simply ignore it.
          */
         if (pdev->gadget_driver)
             cdnsp_died(pdev);
 
         spin_unlock_irqrestore(&pdev->lock, flags);
         return IRQ_HANDLED;
     }
 
     event_ring_deq = pdev->event_ring->dequeue;
 
     while (cdnsp_handle_event(pdev)) {
         if (++counter >= TRBS_PER_EV_DEQ_UPDATE) {
             cdnsp_update_erst_dequeue(pdev, event_ring_deq, 0);
             event_ring_deq = pdev->event_ring->dequeue;
             counter = 0;
         }
     }
 
     cdnsp_update_erst_dequeue(pdev, event_ring_deq, 1);
 
     spin_unlock_irqrestore(&pdev->lock, flags);
 
     return IRQ_HANDLED;
 }
 
 irqreturn_t cdnsp_irq_handler(int irq, void *priv)
 {
     struct cdnsp_device *pdev = (struct cdnsp_device *)priv;
     u32 irq_pending;
     u32 status;
 
     status = readl(&pdev->op_regs->status);
 
     if (status == ~(u32)0) {
         cdnsp_died(pdev);
         return IRQ_HANDLED;
     }
 
     if (!(status & STS_EINT))
         return IRQ_NONE;
 
     writel(status | STS_EINT, &pdev->op_regs->status);
     irq_pending = readl(&pdev->ir_set->irq_pending);
     irq_pending |= IMAN_IP;
     writel(irq_pending, &pdev->ir_set->irq_pending);
 
     if (status & STS_FATAL) {
         cdnsp_died(pdev);
         return IRQ_HANDLED;
     }
 
     return IRQ_WAKE_THREAD;
 }
 
 /*
  * Generic function for queuing a TRB on a ring.
  * The caller must have checked to make sure there's room on the ring.
  *
  * @more_trbs_coming:   Will you enqueue more TRBs before setting doorbell?
  */
 static void cdnsp_queue_trb(struct cdnsp_device *pdev, struct cdnsp_ring *ring,
                 bool more_trbs_coming, u32 field1, u32 field2,
                 u32 field3, u32 field4)
 {
     struct cdnsp_generic_trb *trb;
 
     trb = &ring->enqueue->generic;
 
     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);
 
     trace_cdnsp_queue_trb(ring, trb);
     cdnsp_inc_enq(pdev, ring, more_trbs_coming);
 }
 
 /*
  * Does various checks on the endpoint ring, and makes it ready to
  * queue num_trbs.
  */
 static int cdnsp_prepare_ring(struct cdnsp_device *pdev,
                   struct cdnsp_ring *ep_ring,
                   u32 ep_state, unsigned
                   int num_trbs,
                   gfp_t mem_flags)
 {
     unsigned int num_trbs_needed;
 
     /* Make sure the endpoint has been added to controller schedule. */
     switch (ep_state) {
     case EP_STATE_STOPPED:
     case EP_STATE_RUNNING:
     case EP_STATE_HALTED:
         break;
     default:
         dev_err(pdev->dev, "ERROR: incorrect endpoint state\n");
         return -EINVAL;
     }
 
     while (1) {
         if (cdnsp_room_on_ring(pdev, ep_ring, num_trbs))
             break;
 
         trace_cdnsp_no_room_on_ring("try ring expansion");
 
         num_trbs_needed = num_trbs - ep_ring->num_trbs_free;
         if (cdnsp_ring_expansion(pdev, ep_ring, num_trbs_needed,
                      mem_flags)) {
             dev_err(pdev->dev, "Ring expansion failed\n");
             return -ENOMEM;
         }
     }
 
     while (cdnsp_trb_is_link(ep_ring->enqueue)) {
         ep_ring->enqueue->link.control |= cpu_to_le32(TRB_CHAIN);
         /* The cycle bit must be set as the last operation. */
         wmb();
         ep_ring->enqueue->link.control ^= cpu_to_le32(TRB_CYCLE);
 
         /* Toggle the cycle bit after the last ring segment. */
         if (cdnsp_link_trb_toggles_cycle(ep_ring->enqueue))
             ep_ring->cycle_state ^= 1;
         ep_ring->enq_seg = ep_ring->enq_seg->next;
         ep_ring->enqueue = ep_ring->enq_seg->trbs;
     }
     return 0;
 }
 
 static int cdnsp_prepare_transfer(struct cdnsp_device *pdev,
                   struct cdnsp_request *preq,
                   unsigned int num_trbs)
 {
     struct cdnsp_ring *ep_ring;
     int ret;
 
     ep_ring = cdnsp_get_transfer_ring(pdev, preq->pep,
                       preq->request.stream_id);
     if (!ep_ring)
         return -EINVAL;
 
     ret = cdnsp_prepare_ring(pdev, ep_ring,
                  GET_EP_CTX_STATE(preq->pep->out_ctx),
                  num_trbs, GFP_ATOMIC);
     if (ret)
         return ret;
 
     INIT_LIST_HEAD(&preq->td.td_list);
     preq->td.preq = preq;
 
     /* Add this TD to the tail of the endpoint ring's TD list. */
     list_add_tail(&preq->td.td_list, &ep_ring->td_list);
     ep_ring->num_tds++;
     preq->pep->stream_info.td_count++;
 
     preq->td.start_seg = ep_ring->enq_seg;
     preq->td.first_trb = ep_ring->enqueue;
 
     return 0;
 }
 
 static unsigned int cdnsp_count_trbs(u64 addr, u64 len)
 {
     unsigned int num_trbs;
 
     num_trbs = DIV_ROUND_UP(len + (addr & (TRB_MAX_BUFF_SIZE - 1)),
                 TRB_MAX_BUFF_SIZE);
     if (num_trbs == 0)
         num_trbs++;
 
     return num_trbs;
 }
 
 static unsigned int count_trbs_needed(struct cdnsp_request *preq)
 {
     return cdnsp_count_trbs(preq->request.dma, preq->request.length);
 }
 
 static unsigned int count_sg_trbs_needed(struct cdnsp_request *preq)
 {
     unsigned int i, len, full_len, num_trbs = 0;
     struct scatterlist *sg;
 
     full_len = preq->request.length;
 
     for_each_sg(preq->request.sg, sg, preq->request.num_sgs, i) {
         len = sg_dma_len(sg);
         num_trbs += cdnsp_count_trbs(sg_dma_address(sg), len);
         len = min(len, full_len);
         full_len -= len;
         if (full_len == 0)
             break;
     }
 
     return num_trbs;
 }
 
 static unsigned int count_isoc_trbs_needed(struct cdnsp_request *preq)
 {
     return cdnsp_count_trbs(preq->request.dma, preq->request.length);
 }
 
 static void cdnsp_check_trb_math(struct cdnsp_request *preq, int running_total)
 {
     if (running_total != preq->request.length)
         dev_err(preq->pep->pdev->dev,
             "%s - Miscalculated tx length, "
             "queued %#x, asked for %#x (%d)\n",
             preq->pep->name, running_total,
             preq->request.length, preq->request.actual);
 }
 
 /*
  * TD size is the number of max packet sized packets remaining in the TD
  * (*not* including this TRB).
  *
  * Total TD packet count = total_packet_count =
  *     DIV_ROUND_UP(TD size in bytes / wMaxPacketSize)
  *
  * Packets transferred up to and including this TRB = packets_transferred =
  *     rounddown(total bytes transferred including this TRB / wMaxPacketSize)
  *
  * TD size = total_packet_count - packets_transferred
  *
  * It must fit in bits 21:17, so it can't be bigger than 31.
  * This is taken care of in the TRB_TD_SIZE() macro
  *
  * The last TRB in a TD must have the TD size set to zero.
  */
 static u32 cdnsp_td_remainder(struct cdnsp_device *pdev,
                   int transferred,
                   int trb_buff_len,
                   unsigned int td_total_len,
                   struct cdnsp_request *preq,
                   bool more_trbs_coming)
 {
     u32 maxp, total_packet_count;
 
     /* One TRB with a zero-length data packet. */
     if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
         trb_buff_len == td_total_len)
         return 0;
 
     maxp = usb_endpoint_maxp(preq->pep->endpoint.desc);
     total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
 
     /* Queuing functions don't count the current TRB into transferred. */
     return (total_packet_count - ((transferred + trb_buff_len) / maxp));
 }
 
 static int cdnsp_align_td(struct cdnsp_device *pdev,
               struct cdnsp_request *preq, u32 enqd_len,
               u32 *trb_buff_len, struct cdnsp_segment *seg)
 {
     struct device *dev = pdev->dev;
     unsigned int unalign;
     unsigned int max_pkt;
     u32 new_buff_len;
 
     max_pkt = usb_endpoint_maxp(preq->pep->endpoint.desc);
     unalign = (enqd_len + *trb_buff_len) % max_pkt;
 
     /* We got lucky, last normal TRB data on segment is packet aligned. */
     if (unalign == 0)
         return 0;
 
     /* Is the last nornal TRB alignable by splitting it. */
     if (*trb_buff_len > unalign) {
         *trb_buff_len -= unalign;
         trace_cdnsp_bounce_align_td_split(preq, *trb_buff_len,
                           enqd_len, 0, unalign);
         return 0;
     }
 
     /*
      * We want enqd_len + trb_buff_len to sum up to a number aligned to
      * number which is divisible by the endpoint's wMaxPacketSize. IOW:
      * (size of currently enqueued TRBs + remainder) % wMaxPacketSize == 0.
      */
     new_buff_len = max_pkt - (enqd_len % max_pkt);
 
     if (new_buff_len > (preq->request.length - enqd_len))
         new_buff_len = (preq->request.length - enqd_len);
 
     /* Create a max max_pkt sized bounce buffer pointed to by last trb. */
     if (preq->direction) {
         sg_pcopy_to_buffer(preq->request.sg,
                    preq->request.num_mapped_sgs,
                    seg->bounce_buf, new_buff_len, enqd_len);
         seg->bounce_dma = dma_map_single(dev, seg->bounce_buf,
                          max_pkt, DMA_TO_DEVICE);
     } else {
         seg->bounce_dma = dma_map_single(dev, seg->bounce_buf,
                          max_pkt, DMA_FROM_DEVICE);
     }
 
     if (dma_mapping_error(dev, seg->bounce_dma)) {
         /* Try without aligning.*/
         dev_warn(pdev->dev,
              "Failed mapping bounce buffer, not aligning\n");
         return 0;
     }
 
     *trb_buff_len = new_buff_len;
     seg->bounce_len = new_buff_len;
     seg->bounce_offs = enqd_len;
 
     trace_cdnsp_bounce_map(preq, new_buff_len, enqd_len, seg->bounce_dma,
                    unalign);
 
     /*
      * Bounce buffer successful aligned and seg->bounce_dma will be used
      * in transfer TRB as new transfer buffer address.
      */
     return 1;
 }
 
 int cdnsp_queue_bulk_tx(struct cdnsp_device *pdev, struct cdnsp_request *preq)
 {
     unsigned int enqd_len, block_len, trb_buff_len, full_len;
     unsigned int start_cycle, num_sgs = 0;
     struct cdnsp_generic_trb *start_trb;
     u32 field, length_field, remainder;
     struct scatterlist *sg = NULL;
     bool more_trbs_coming = true;
     bool need_zero_pkt = false;
     bool zero_len_trb = false;
     struct cdnsp_ring *ring;
     bool first_trb = true;
     unsigned int num_trbs;
     struct cdnsp_ep *pep;
     u64 addr, send_addr;
     int sent_len, ret;
 
     ring = cdnsp_request_to_transfer_ring(pdev, preq);
     if (!ring)
         return -EINVAL;
 
     full_len = preq->request.length;
 
     if (preq->request.num_sgs) {
         num_sgs = preq->request.num_sgs;
         sg = preq->request.sg;
         addr = (u64)sg_dma_address(sg);
         block_len = sg_dma_len(sg);
         num_trbs = count_sg_trbs_needed(preq);
     } else {
         num_trbs = count_trbs_needed(preq);
         addr = (u64)preq->request.dma;
         block_len = full_len;
     }
 
     pep = preq->pep;
 
     /* Deal with request.zero - need one more td/trb. */
     if (preq->request.zero && preq->request.length &&
         IS_ALIGNED(full_len, usb_endpoint_maxp(pep->endpoint.desc))) {
         need_zero_pkt = true;
         num_trbs++;
     }
 
     ret = cdnsp_prepare_transfer(pdev, preq, num_trbs);
     if (ret)
         return ret;
 
     /*
      * Don't give the first TRB to the hardware (by toggling the cycle bit)
      * until we've finished creating all the other TRBs. The ring's cycle
      * state may change as we enqueue the other TRBs, so save it too.
      */
     start_trb = &ring->enqueue->generic;
     start_cycle = ring->cycle_state;
     send_addr = addr;
 
     /* Queue the TRBs, even if they are zero-length */
     for (enqd_len = 0; zero_len_trb || first_trb || enqd_len < full_len;
          enqd_len += trb_buff_len) {
         field = TRB_TYPE(TRB_NORMAL);
 
         /* TRB buffer should not cross 64KB boundaries */
         trb_buff_len = TRB_BUFF_LEN_UP_TO_BOUNDARY(addr);
         trb_buff_len = min(trb_buff_len, block_len);
         if (enqd_len + trb_buff_len > full_len)
             trb_buff_len = full_len - enqd_len;
 
         /* Don't change the cycle bit of the first TRB until later */
         if (first_trb) {
             first_trb = false;
             if (start_cycle == 0)
                 field |= TRB_CYCLE;
         } else {
             field |= ring->cycle_state;
         }
 
         /*
          * Chain all the TRBs together; clear the chain bit in the last
          * TRB to indicate it's the last TRB in the chain.
          */
         if (enqd_len + trb_buff_len < full_len || need_zero_pkt) {
             field |= TRB_CHAIN;
             if (cdnsp_trb_is_link(ring->enqueue + 1)) {
                 if (cdnsp_align_td(pdev, preq, enqd_len,
                            &trb_buff_len,
                            ring->enq_seg)) {
                     send_addr = ring->enq_seg->bounce_dma;
                     /* Assuming TD won't span 2 segs */
                     preq->td.bounce_seg = ring->enq_seg;
                 }
             }
         }
 
         if (enqd_len + trb_buff_len >= full_len) {
             if (need_zero_pkt && !zero_len_trb) {
                 zero_len_trb = true;
             } else {
                 zero_len_trb = false;
                 field &= ~TRB_CHAIN;
                 field |= TRB_IOC;
                 more_trbs_coming = false;
                 need_zero_pkt = false;
                 preq->td.last_trb = ring->enqueue;
             }
         }
 
         /* Only set interrupt on short packet for OUT endpoints. */
         if (!preq->direction)
             field |= TRB_ISP;
 
         /* Set the TRB length, TD size, and interrupter fields. */
         remainder = cdnsp_td_remainder(pdev, enqd_len, trb_buff_len,
                            full_len, preq,
                            more_trbs_coming);
 
         length_field = TRB_LEN(trb_buff_len) | TRB_TD_SIZE(remainder) |
             TRB_INTR_TARGET(0);
 
         cdnsp_queue_trb(pdev, ring, more_trbs_coming,
                 lower_32_bits(send_addr),
                 upper_32_bits(send_addr),
                 length_field,
                 field);
 
         addr += trb_buff_len;
         sent_len = trb_buff_len;
         while (sg && sent_len >= block_len) {
             /* New sg entry */
             --num_sgs;
             sent_len -= block_len;
             if (num_sgs != 0) {
                 sg = sg_next(sg);
                 block_len = sg_dma_len(sg);
                 addr = (u64)sg_dma_address(sg);
                 addr += sent_len;
             }
         }
         block_len -= sent_len;
         send_addr = addr;
     }
 
     cdnsp_check_trb_math(preq, enqd_len);
     ret = cdnsp_giveback_first_trb(pdev, pep, preq->request.stream_id,
                        start_cycle, start_trb);
 
     if (ret)
         preq->td.drbl = 1;
 
     return 0;
 }
 
 int cdnsp_queue_ctrl_tx(struct cdnsp_device *pdev, struct cdnsp_request *preq)
 {
     u32 field, length_field, remainder;
     struct cdnsp_ep *pep = preq->pep;
     struct cdnsp_ring *ep_ring;
     int num_trbs;
     int ret;
 
     ep_ring = cdnsp_request_to_transfer_ring(pdev, preq);
     if (!ep_ring)
         return -EINVAL;
 
     /* 1 TRB for data, 1 for status */
     num_trbs = (pdev->three_stage_setup) ? 2 : 1;
 
     ret = cdnsp_prepare_transfer(pdev, preq, num_trbs);
     if (ret)
         return ret;
 
     /* If there's data, queue data TRBs */
     if (pdev->ep0_expect_in)
         field = TRB_TYPE(TRB_DATA) | TRB_IOC;
     else
         field = TRB_ISP | TRB_TYPE(TRB_DATA) | TRB_IOC;
 
     if (preq->request.length > 0) {
         remainder = cdnsp_td_remainder(pdev, 0, preq->request.length,
                            preq->request.length, preq, 1);
 
         length_field = TRB_LEN(preq->request.length) |
                 TRB_TD_SIZE(remainder) | TRB_INTR_TARGET(0);
 
         if (pdev->ep0_expect_in)
             field |= TRB_DIR_IN;
 
         cdnsp_queue_trb(pdev, ep_ring, true,
                 lower_32_bits(preq->request.dma),
                 upper_32_bits(preq->request.dma), length_field,
                 field | ep_ring->cycle_state |
                 TRB_SETUPID(pdev->setup_id) |
                 pdev->setup_speed);
 
         pdev->ep0_stage = CDNSP_DATA_STAGE;
     }
 
     /* Save the DMA address of the last TRB in the TD. */
     preq->td.last_trb = ep_ring->enqueue;
 
     /* Queue status TRB. */
     if (preq->request.length == 0)
         field = ep_ring->cycle_state;
     else
         field = (ep_ring->cycle_state ^ 1);
 
     if (preq->request.length > 0 && pdev->ep0_expect_in)
         field |= TRB_DIR_IN;
 
     if (pep->ep_state & EP0_HALTED_STATUS) {
         pep->ep_state &= ~EP0_HALTED_STATUS;
         field |= TRB_SETUPSTAT(TRB_SETUPSTAT_STALL);
     } else {
         field |= TRB_SETUPSTAT(TRB_SETUPSTAT_ACK);
     }
 
     cdnsp_queue_trb(pdev, ep_ring, false, 0, 0, TRB_INTR_TARGET(0),
             field | TRB_IOC | TRB_SETUPID(pdev->setup_id) |
             TRB_TYPE(TRB_STATUS) | pdev->setup_speed);
 
     cdnsp_ring_ep_doorbell(pdev, pep, preq->request.stream_id);
 
     return 0;
 }
 
 int cdnsp_cmd_stop_ep(struct cdnsp_device *pdev, struct cdnsp_ep *pep)
 {
     u32 ep_state = GET_EP_CTX_STATE(pep->out_ctx);
     int ret = 0;
 
     if (ep_state == EP_STATE_STOPPED || ep_state == EP_STATE_DISABLED) {
         trace_cdnsp_ep_stopped_or_disabled(pep->out_ctx);
         goto ep_stopped;
     }
 
     cdnsp_queue_stop_endpoint(pdev, pep->idx);
     cdnsp_ring_cmd_db(pdev);
     ret = cdnsp_wait_for_cmd_compl(pdev);
 
     trace_cdnsp_handle_cmd_stop_ep(pep->out_ctx);
 
 ep_stopped:
     pep->ep_state |= EP_STOPPED;
     return ret;
 }
 
 int cdnsp_cmd_flush_ep(struct cdnsp_device *pdev, struct cdnsp_ep *pep)
 {
     int ret;
 
     cdnsp_queue_flush_endpoint(pdev, pep->idx);
     cdnsp_ring_cmd_db(pdev);
     ret = cdnsp_wait_for_cmd_compl(pdev);
 
     trace_cdnsp_handle_cmd_flush_ep(pep->out_ctx);
 
     return ret;
 }
 
 /*
  * The transfer burst count field of the isochronous TRB defines the number of
  * bursts that are required to move all packets in this TD. Only SuperSpeed
  * devices can burst up to bMaxBurst number of packets per service interval.
  * This field is zero based, meaning a value of zero in the field means one
  * burst. Basically, for everything but SuperSpeed devices, this field will be
  * zero.
  */
 static unsigned int cdnsp_get_burst_count(struct cdnsp_device *pdev,
                       struct cdnsp_request *preq,
                       unsigned int total_packet_count)
 {
     unsigned int max_burst;
 
     if (pdev->gadget.speed < USB_SPEED_SUPER)
         return 0;
 
     max_burst = preq->pep->endpoint.comp_desc->bMaxBurst;
     return DIV_ROUND_UP(total_packet_count, max_burst + 1) - 1;
 }
 
 /*
  * Returns the number of packets in the last "burst" of packets. This field is
  * valid for all speeds of devices. USB 2.0 devices can only do one "burst", so
  * the last burst packet count is equal to the total number of packets in the
  * TD. SuperSpeed endpoints can have up to 3 bursts. All but the last burst
  * must contain (bMaxBurst + 1) number of packets, but the last burst can
  * contain 1 to (bMaxBurst + 1) packets.
  */
 static unsigned int
     cdnsp_get_last_burst_packet_count(struct cdnsp_device *pdev,
                       struct cdnsp_request *preq,
                       unsigned int total_packet_count)
 {
     unsigned int max_burst;
     unsigned int residue;
 
     if (pdev->gadget.speed >= USB_SPEED_SUPER) {
         /* bMaxBurst is zero based: 0 means 1 packet per burst. */
         max_burst = preq->pep->endpoint.comp_desc->bMaxBurst;
         residue = total_packet_count % (max_burst + 1);
 
         /*
          * If residue is zero, the last burst contains (max_burst + 1)
          * number of packets, but the TLBPC field is zero-based.
          */
         if (residue == 0)
             return max_burst;
 
         return residue - 1;
     }
     if (total_packet_count == 0)
         return 0;
 
     return total_packet_count - 1;
 }
 
 /* Queue function isoc transfer */
 static int cdnsp_queue_isoc_tx(struct cdnsp_device *pdev,
                    struct cdnsp_request *preq)
 {
     int trb_buff_len, td_len, td_remain_len, ret;
     unsigned int burst_count, last_burst_pkt;
     unsigned int total_pkt_count, max_pkt;
     struct cdnsp_generic_trb *start_trb;
     bool more_trbs_coming = true;
     struct cdnsp_ring *ep_ring;
     int running_total = 0;
     u32 field, length_field;
     int start_cycle;
     int trbs_per_td;
     u64 addr;
     int i;
 
     ep_ring = preq->pep->ring;
     start_trb = &ep_ring->enqueue->generic;
     start_cycle = ep_ring->cycle_state;
     td_len = preq->request.length;
     addr = (u64)preq->request.dma;
     td_remain_len = td_len;
 
     max_pkt = usb_endpoint_maxp(preq->pep->endpoint.desc);
     total_pkt_count = DIV_ROUND_UP(td_len, max_pkt);
 
     /* A zero-length transfer still involves at least one packet. */
     if (total_pkt_count == 0)
         total_pkt_count++;
 
     burst_count = cdnsp_get_burst_count(pdev, preq, total_pkt_count);
     last_burst_pkt = cdnsp_get_last_burst_packet_count(pdev, preq,
                                total_pkt_count);
     trbs_per_td = count_isoc_trbs_needed(preq);
 
     ret = cdnsp_prepare_transfer(pdev, preq, trbs_per_td);
     if (ret)
         goto cleanup;
 
     /*
      * Set isoc specific data for the first TRB in a TD.
      * Prevent HW from getting the TRBs by keeping the cycle state
      * inverted in the first TDs isoc TRB.
      */
     field = TRB_TYPE(TRB_ISOC) | TRB_TLBPC(last_burst_pkt) |
         TRB_SIA | TRB_TBC(burst_count);
 
     if (!start_cycle)
         field |= TRB_CYCLE;
 
     /* Fill the rest of the TRB fields, and remaining normal TRBs. */
     for (i = 0; i < trbs_per_td; i++) {
         u32 remainder;
 
         /* Calculate TRB length. */
         trb_buff_len = TRB_BUFF_LEN_UP_TO_BOUNDARY(addr);
         if (trb_buff_len > td_remain_len)
             trb_buff_len = td_remain_len;
 
         /* Set the TRB length, TD size, & interrupter fields. */
         remainder = cdnsp_td_remainder(pdev, running_total,
                            trb_buff_len, td_len, preq,
                            more_trbs_coming);
 
         length_field = TRB_LEN(trb_buff_len) | TRB_INTR_TARGET(0);
 
         /* Only first TRB is isoc, overwrite otherwise. */
         if (i) {
             field = TRB_TYPE(TRB_NORMAL) | ep_ring->cycle_state;
             length_field |= TRB_TD_SIZE(remainder);
         } else {
             length_field |= TRB_TD_SIZE_TBC(burst_count);
         }
 
         /* Only set interrupt on short packet for OUT EPs. */
         if (usb_endpoint_dir_out(preq->pep->endpoint.desc))
             field |= TRB_ISP;
 
         /* Set the chain bit for all except the last TRB. */
         if (i < trbs_per_td - 1) {
             more_trbs_coming = true;
             field |= TRB_CHAIN;
         } else {
             more_trbs_coming = false;
             preq->td.last_trb = ep_ring->enqueue;
             field |= TRB_IOC;
         }
 
         cdnsp_queue_trb(pdev, ep_ring, more_trbs_coming,
                 lower_32_bits(addr), upper_32_bits(addr),
                 length_field, field);
 
         running_total += trb_buff_len;
         addr += trb_buff_len;
         td_remain_len -= trb_buff_len;
     }
 
     /* Check TD length */
     if (running_total != td_len) {
         dev_err(pdev->dev, "ISOC TD length unmatch\n");
         ret = -EINVAL;
         goto cleanup;
     }
 
     cdnsp_giveback_first_trb(pdev, preq->pep, preq->request.stream_id,
                  start_cycle, start_trb);
 
     return 0;
 
 cleanup:
     /* Clean up a partially enqueued isoc transfer. */
     list_del_init(&preq->td.td_list);
     ep_ring->num_tds--;
 
     /*
      * Use the first TD as a temporary variable to turn the TDs we've
      * queued into No-ops with a software-owned cycle bit.
      * That way the hardware won't accidentally start executing bogus TDs
      * when we partially overwrite them.
      * td->first_trb and td->start_seg are already set.
      */
     preq->td.last_trb = ep_ring->enqueue;
     /* Every TRB except the first & last will have its cycle bit flipped. */
     cdnsp_td_to_noop(pdev, ep_ring, &preq->td, true);
 
     /* Reset the ring enqueue back to the first TRB and its cycle bit. */
     ep_ring->enqueue = preq->td.first_trb;
     ep_ring->enq_seg = preq->td.start_seg;
     ep_ring->cycle_state = start_cycle;
     return ret;
 }
 
 int cdnsp_queue_isoc_tx_prepare(struct cdnsp_device *pdev,
                 struct cdnsp_request *preq)
 {
     struct cdnsp_ring *ep_ring;
     u32 ep_state;
     int num_trbs;
     int ret;
 
     ep_ring = preq->pep->ring;
     ep_state = GET_EP_CTX_STATE(preq->pep->out_ctx);
     num_trbs = count_isoc_trbs_needed(preq);
 
     /*
      * Check the ring to guarantee there is enough room for the whole
      * request. Do not insert any td of the USB Request to the ring if the
      * check failed.
      */
     ret = cdnsp_prepare_ring(pdev, ep_ring, ep_state, num_trbs, GFP_ATOMIC);
     if (ret)
         return ret;
 
     return cdnsp_queue_isoc_tx(pdev, preq);
 }
 
 /****       Command Ring Operations     ****/
 /*
  * Generic function for queuing a command TRB on the command ring.
  * Driver queue only one command to ring in the moment.
  */
 static void cdnsp_queue_command(struct cdnsp_device *pdev,
                 u32 field1,
                 u32 field2,
                 u32 field3,
                 u32 field4)
 {
     cdnsp_prepare_ring(pdev, pdev->cmd_ring, EP_STATE_RUNNING, 1,
                GFP_ATOMIC);
 
     pdev->cmd.command_trb = pdev->cmd_ring->enqueue;
 
     cdnsp_queue_trb(pdev, pdev->cmd_ring, false, field1, field2,
             field3, field4 | pdev->cmd_ring->cycle_state);
 }
 
 /* Queue a slot enable or disable request on the command ring */
 void cdnsp_queue_slot_control(struct cdnsp_device *pdev, u32 trb_type)
 {
     cdnsp_queue_command(pdev, 0, 0, 0, TRB_TYPE(trb_type) |
                 SLOT_ID_FOR_TRB(pdev->slot_id));
 }
 
 /* Queue an address device command TRB */
 void cdnsp_queue_address_device(struct cdnsp_device *pdev,
                 dma_addr_t in_ctx_ptr,
                 enum cdnsp_setup_dev setup)
 {
     cdnsp_queue_command(pdev, lower_32_bits(in_ctx_ptr),
                 upper_32_bits(in_ctx_ptr), 0,
                 TRB_TYPE(TRB_ADDR_DEV) |
                 SLOT_ID_FOR_TRB(pdev->slot_id) |
                 (setup == SETUP_CONTEXT_ONLY ? TRB_BSR : 0));
 }
 
 /* Queue a reset device command TRB */
 void cdnsp_queue_reset_device(struct cdnsp_device *pdev)
 {
     cdnsp_queue_command(pdev, 0, 0, 0, TRB_TYPE(TRB_RESET_DEV) |
                 SLOT_ID_FOR_TRB(pdev->slot_id));
 }
 
 /* Queue a configure endpoint command TRB */
 void cdnsp_queue_configure_endpoint(struct cdnsp_device *pdev,
                     dma_addr_t in_ctx_ptr)
 {
     cdnsp_queue_command(pdev, lower_32_bits(in_ctx_ptr),
                 upper_32_bits(in_ctx_ptr), 0,
                 TRB_TYPE(TRB_CONFIG_EP) |
                 SLOT_ID_FOR_TRB(pdev->slot_id));
 }
 
 /*
  * Suspend is set to indicate "Stop Endpoint Command" is being issued to stop
  * activity on an endpoint that is about to be suspended.
  */
 void cdnsp_queue_stop_endpoint(struct cdnsp_device *pdev, unsigned int ep_index)
 {
     cdnsp_queue_command(pdev, 0, 0, 0, SLOT_ID_FOR_TRB(pdev->slot_id) |
                 EP_ID_FOR_TRB(ep_index) | TRB_TYPE(TRB_STOP_RING));
 }
 
 /* Set Transfer Ring Dequeue Pointer command. */
 void cdnsp_queue_new_dequeue_state(struct cdnsp_device *pdev,
                    struct cdnsp_ep *pep,
                    struct cdnsp_dequeue_state *deq_state)
 {
     u32 trb_stream_id = STREAM_ID_FOR_TRB(deq_state->stream_id);
     u32 trb_slot_id = SLOT_ID_FOR_TRB(pdev->slot_id);
     u32 type = TRB_TYPE(TRB_SET_DEQ);
     u32 trb_sct = 0;
     dma_addr_t addr;
 
     addr = cdnsp_trb_virt_to_dma(deq_state->new_deq_seg,
                      deq_state->new_deq_ptr);
 
     if (deq_state->stream_id)
         trb_sct = SCT_FOR_TRB(SCT_PRI_TR);
 
     cdnsp_queue_command(pdev, lower_32_bits(addr) | trb_sct |
                 deq_state->new_cycle_state, upper_32_bits(addr),
                 trb_stream_id, trb_slot_id |
                 EP_ID_FOR_TRB(pep->idx) | type);
 }
 
 void cdnsp_queue_reset_ep(struct cdnsp_device *pdev, unsigned int ep_index)
 {
     return cdnsp_queue_command(pdev, 0, 0, 0,
                    SLOT_ID_FOR_TRB(pdev->slot_id) |
                    EP_ID_FOR_TRB(ep_index) |
                    TRB_TYPE(TRB_RESET_EP));
 }
 
 /*
  * Queue a halt endpoint request on the command ring.
  */
 void cdnsp_queue_halt_endpoint(struct cdnsp_device *pdev, unsigned int ep_index)
 {
     cdnsp_queue_command(pdev, 0, 0, 0, TRB_TYPE(TRB_HALT_ENDPOINT) |
                 SLOT_ID_FOR_TRB(pdev->slot_id) |
                 EP_ID_FOR_TRB(ep_index));
 }
 
 /*
  * Queue a flush endpoint request on the command ring.
  */
 void  cdnsp_queue_flush_endpoint(struct cdnsp_device *pdev,
                  unsigned int ep_index)
 {
     cdnsp_queue_command(pdev, 0, 0, 0, TRB_TYPE(TRB_FLUSH_ENDPOINT) |
                 SLOT_ID_FOR_TRB(pdev->slot_id) |
                 EP_ID_FOR_TRB(ep_index));
 }
 
 void cdnsp_force_header_wakeup(struct cdnsp_device *pdev, int intf_num)
 {
     u32 lo, mid;
 
     lo = TRB_FH_TO_PACKET_TYPE(TRB_FH_TR_PACKET) |
          TRB_FH_TO_DEVICE_ADDRESS(pdev->device_address);
     mid = TRB_FH_TR_PACKET_DEV_NOT |
           TRB_FH_TO_NOT_TYPE(TRB_FH_TR_PACKET_FUNCTION_WAKE) |
           TRB_FH_TO_INTERFACE(intf_num);
 
     cdnsp_queue_command(pdev, lo, mid, 0,
                 TRB_TYPE(TRB_FORCE_HEADER) | SET_PORT_ID(2));
 }

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