xhci: add xhci_get_virt_ep() helper

In several event handlers we need to find the right endpoint
structure from slot_id and ep_index in the event.

Add a helper for this, check that slot_id and ep_index are valid.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-6-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 28f5245..c9c4c55 100644 (file)
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -446,6 +446,26 @@ void xhci_ring_doorbell_for_active_rings(struct xhci_hcd *xhci,
        ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
 }
 
+static struct xhci_virt_ep *xhci_get_virt_ep(struct xhci_hcd *xhci,
+                                            unsigned int slot_id,
+                                            unsigned int ep_index)
+{
+       if (slot_id == 0 || slot_id >= MAX_HC_SLOTS) {
+               xhci_warn(xhci, "Invalid slot_id %u\n", slot_id);
+               return NULL;
+       }
+       if (ep_index >= EP_CTX_PER_DEV) {
+               xhci_warn(xhci, "Invalid endpoint index %u\n", ep_index);
+               return NULL;
+       }
+       if (!xhci->devs[slot_id]) {
+               xhci_warn(xhci, "No xhci virt device for slot_id %u\n", slot_id);
+               return NULL;
+       }
+
+       return &xhci->devs[slot_id]->eps[ep_index];
+}
+
 /* Get the right ring for the given slot_id, ep_index and stream_id.
  * If the endpoint supports streams, boundary check the URB's stream ID.
  * If the endpoint doesn't support streams, return the singular endpoint ring.
@@ -456,7 +476,10 @@ struct xhci_ring *xhci_triad_to_transfer_ring(struct xhci_hcd *xhci,
 {
        struct xhci_virt_ep *ep;
 
-       ep = &xhci->devs[slot_id]->eps[ep_index];
+       ep = xhci_get_virt_ep(xhci, slot_id, ep_index);
+       if (!ep)
+               return NULL;
+
        /* Common case: no streams */
        if (!(ep->ep_state & EP_HAS_STREAMS))
                return ep->ring;
@@ -742,11 +765,14 @@ static void xhci_handle_cmd_stop_ep(struct xhci_hcd *xhci, int slot_id,
        memset(&deq_state, 0, sizeof(deq_state));
        ep_index = TRB_TO_EP_INDEX(le32_to_cpu(trb->generic.field[3]));
 
-       vdev = xhci->devs[slot_id];
+       ep = xhci_get_virt_ep(xhci, slot_id, ep_index);
+       if (!ep)
+               return;
+
+       vdev = ep->vdev;
        ep_ctx = xhci_get_ep_ctx(xhci, vdev->out_ctx, ep_index);
        trace_xhci_handle_cmd_stop_ep(ep_ctx);
 
-       ep = &xhci->devs[slot_id]->eps[ep_index];
        last_unlinked_td = list_last_entry(&ep->cancelled_td_list,
                        struct xhci_td, cancelled_td_list);
 
@@ -1064,17 +1090,17 @@ static void xhci_handle_cmd_set_deq(struct xhci_hcd *xhci, int slot_id,
        unsigned int ep_index;
        unsigned int stream_id;
        struct xhci_ring *ep_ring;
-       struct xhci_virt_device *dev;
        struct xhci_virt_ep *ep;
        struct xhci_ep_ctx *ep_ctx;
        struct xhci_slot_ctx *slot_ctx;
 
        ep_index = TRB_TO_EP_INDEX(le32_to_cpu(trb->generic.field[3]));
        stream_id = TRB_TO_STREAM_ID(le32_to_cpu(trb->generic.field[2]));
-       dev = xhci->devs[slot_id];
-       ep = &dev->eps[ep_index];
+       ep = xhci_get_virt_ep(xhci, slot_id, ep_index);
+       if (!ep)
+               return;
 
-       ep_ring = xhci_stream_id_to_ring(dev, ep_index, stream_id);
+       ep_ring = xhci_stream_id_to_ring(ep->vdev, ep_index, stream_id);
        if (!ep_ring) {
                xhci_warn(xhci, "WARN Set TR deq ptr command for freed stream ID %u\n",
                                stream_id);
@@ -1082,8 +1108,8 @@ static void xhci_handle_cmd_set_deq(struct xhci_hcd *xhci, int slot_id,
                goto cleanup;
        }
 
-       ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
-       slot_ctx = xhci_get_slot_ctx(xhci, dev->out_ctx);
+       ep_ctx = xhci_get_ep_ctx(xhci, ep->vdev->out_ctx, ep_index);
+       slot_ctx = xhci_get_slot_ctx(xhci, ep->vdev->out_ctx);
        trace_xhci_handle_cmd_set_deq(slot_ctx);
        trace_xhci_handle_cmd_set_deq_ep(ep_ctx);
 
@@ -1136,7 +1162,7 @@ static void xhci_handle_cmd_set_deq(struct xhci_hcd *xhci, int slot_id,
                        /* Update the ring's dequeue segment and dequeue pointer
                         * to reflect the new position.
                         */
-                       update_ring_for_set_deq_completion(xhci, dev,
+                       update_ring_for_set_deq_completion(xhci, ep->vdev,
                                ep_ring, ep_index);
                } else {
                        xhci_warn(xhci, "Mismatch between completed Set TR Deq Ptr command & xHCI internal state.\n");
@@ -1146,9 +1172,9 @@ static void xhci_handle_cmd_set_deq(struct xhci_hcd *xhci, int slot_id,
        }
 
 cleanup:
-       dev->eps[ep_index].ep_state &= ~SET_DEQ_PENDING;
-       dev->eps[ep_index].queued_deq_seg = NULL;
-       dev->eps[ep_index].queued_deq_ptr = NULL;
+       ep->ep_state &= ~SET_DEQ_PENDING;
+       ep->queued_deq_seg = NULL;
+       ep->queued_deq_ptr = NULL;
        /* Restart any rings with pending URBs */
        ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
 }
@@ -1156,13 +1182,16 @@ cleanup:
 static void xhci_handle_cmd_reset_ep(struct xhci_hcd *xhci, int slot_id,
                union xhci_trb *trb, u32 cmd_comp_code)
 {
-       struct xhci_virt_device *vdev;
+       struct xhci_virt_ep *ep;
        struct xhci_ep_ctx *ep_ctx;
        unsigned int ep_index;
 
        ep_index = TRB_TO_EP_INDEX(le32_to_cpu(trb->generic.field[3]));
-       vdev = xhci->devs[slot_id];
-       ep_ctx = xhci_get_ep_ctx(xhci, vdev->out_ctx, ep_index);
+       ep = xhci_get_virt_ep(xhci, slot_id, ep_index);
+       if (!ep)
+               return;
+
+       ep_ctx = xhci_get_ep_ctx(xhci, ep->vdev->out_ctx, ep_index);
        trace_xhci_handle_cmd_reset_ep(ep_ctx);
 
        /* This command will only fail if the endpoint wasn't halted,
@@ -1190,7 +1219,7 @@ static void xhci_handle_cmd_reset_ep(struct xhci_hcd *xhci, int slot_id,
                xhci_ring_cmd_db(xhci);
        } else {
                /* Clear our internal halted state */
-               xhci->devs[slot_id]->eps[ep_index].ep_state &= ~EP_HALTED;
+               ep->ep_state &= ~EP_HALTED;
        }
 
        /* if this was a soft reset, then restart */
@@ -2313,7 +2342,6 @@ finish_td:
 static int handle_tx_event(struct xhci_hcd *xhci,
                struct xhci_transfer_event *event)
 {
-       struct xhci_virt_device *xdev;
        struct xhci_virt_ep *ep;
        struct xhci_ring *ep_ring;
        unsigned int slot_id;
@@ -2334,16 +2362,14 @@ static int handle_tx_event(struct xhci_hcd *xhci,
        trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
        ep_trb_dma = le64_to_cpu(event->buffer);
 
-       xdev = xhci->devs[slot_id];
-       if (!xdev) {
-               xhci_err(xhci, "ERROR Transfer event pointed to bad slot %u\n",
-                        slot_id);
+       ep = xhci_get_virt_ep(xhci, slot_id, ep_index);
+       if (!ep) {
+               xhci_err(xhci, "ERROR Invalid Transfer event\n");
                goto err_out;
        }
 
-       ep = &xdev->eps[ep_index];
        ep_ring = xhci_dma_to_transfer_ring(ep, ep_trb_dma);
-       ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
+       ep_ctx = xhci_get_ep_ctx(xhci, ep->vdev->out_ctx, ep_index);
 
        if (GET_EP_CTX_STATE(ep_ctx) == EP_STATE_DISABLED) {
                xhci_err(xhci,

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 123ccdd..a9862f1 100644 (file)
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -995,6 +995,7 @@ struct xhci_interval_bw_table {
        unsigned int            ss_bw_out;
 };
 
+#define EP_CTX_PER_DEV         31
 
 struct xhci_virt_device {
        int                             slot_id;
@@ -1010,7 +1011,7 @@ struct xhci_virt_device {
        struct xhci_container_ctx       *out_ctx;
        /* Used for addressing devices and configuration changes */
        struct xhci_container_ctx       *in_ctx;
-       struct xhci_virt_ep             eps[31];
+       struct xhci_virt_ep             eps[EP_CTX_PER_DEV];
        u8                              fake_port;
        u8                              real_port;
        struct xhci_interval_bw_table   *bw_table;