xhci: move event processing for one interrupter to a separate function

Split the main XHCI interrupt handler into a different API, so that other
potential interrupters can utilize similar event ring handling.  A scenario
would be if a secondary interrupter required to skip pending events in the
event ring, which would warrant a similar set of operations.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/20240217001017.29969-7-quic_wcheng@quicinc.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 62bde16f435ec88fdfa38b5df2666bff9e13b3a4..ad008a5abc811498f2bac7b3682da8a012ac0fde 100644 (file)
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3069,6 +3069,46 @@ static void xhci_clear_interrupt_pending(struct xhci_hcd *xhci,
        }
 }
 
+static int xhci_handle_events(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
+{
+       int event_loop = 0;
+       u64 temp;
+
+       xhci_clear_interrupt_pending(xhci, ir);
+
+       if (xhci->xhc_state & XHCI_STATE_DYING ||
+           xhci->xhc_state & XHCI_STATE_HALTED) {
+               xhci_dbg(xhci, "xHCI dying, ignoring interrupt. Shouldn't IRQs be disabled?\n");
+
+               /* Clear the event handler busy flag (RW1C) */
+               temp = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
+               xhci_write_64(xhci, temp | ERST_EHB, &ir->ir_set->erst_dequeue);
+               return -ENODEV;
+       }
+
+       while (xhci_handle_event(xhci, ir) > 0) {
+               /*
+                * If half a segment of events have been handled in one go then
+                * update ERDP, and force isoc trbs to interrupt more often
+                */
+               if (event_loop++ > TRBS_PER_SEGMENT / 2) {
+                       xhci_update_erst_dequeue(xhci, ir, false);
+
+                       if (ir->isoc_bei_interval > AVOID_BEI_INTERVAL_MIN)
+                               ir->isoc_bei_interval = ir->isoc_bei_interval / 2;
+
+                       event_loop = 0;
+               }
+
+               /* Update SW event ring dequeue pointer */
+               inc_deq(xhci, ir->event_ring);
+       }
+
+       xhci_update_erst_dequeue(xhci, ir, true);
+
+       return 0;
+}
+
 /*
  * xHCI spec says we can get an interrupt, and if the HC has an error condition,
  * we might get bad data out of the event ring.  Section 4.10.2.7 has a list of
@@ -3077,11 +3117,8 @@ static void xhci_clear_interrupt_pending(struct xhci_hcd *xhci,
 irqreturn_t xhci_irq(struct usb_hcd *hcd)
 {
        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
-       struct xhci_interrupter *ir;
        irqreturn_t ret = IRQ_NONE;
-       u64 temp_64;
        u32 status;
-       int event_loop = 0;
 
        spin_lock(&xhci->lock);
        /* Check if the xHC generated the interrupt, or the irq is shared */
@@ -3114,50 +3151,10 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
         */
        status |= STS_EINT;
        writel(status, &xhci->op_regs->status);
-
-       /* This is the handler of the primary interrupter */
-       ir = xhci->interrupters[0];
-
-       xhci_clear_interrupt_pending(xhci, ir);
-
-       if (xhci->xhc_state & XHCI_STATE_DYING ||
-           xhci->xhc_state & XHCI_STATE_HALTED) {
-               xhci_dbg(xhci, "xHCI dying, ignoring interrupt. "
-                               "Shouldn't IRQs be disabled?\n");
-               /* Clear the event handler busy flag (RW1C);
-                * the event ring should be empty.
-                */
-               temp_64 = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
-               xhci_write_64(xhci, temp_64 | ERST_EHB,
-                               &ir->ir_set->erst_dequeue);
-               ret = IRQ_HANDLED;
-               goto out;
-       }
-
-       /* FIXME this should be a delayed service routine
-        * that clears the EHB.
-        */
-       while (xhci_handle_event(xhci, ir) > 0) {
-               /*
-                * If half a segment of events have been handled in one go then
-                * update ERDP, and force isoc trbs to interrupt more often
-                */
-               if (event_loop++ > TRBS_PER_SEGMENT / 2) {
-                       xhci_update_erst_dequeue(xhci, ir, false);
-
-                       if (ir->isoc_bei_interval > AVOID_BEI_INTERVAL_MIN)
-                               ir->isoc_bei_interval = ir->isoc_bei_interval / 2;
-
-                       event_loop = 0;
-               }
-
-               /* Update SW event ring dequeue pointer */
-               inc_deq(xhci, ir->event_ring);
-       }
-
-       xhci_update_erst_dequeue(xhci, ir, true);
        ret = IRQ_HANDLED;
 
+       /* This is the handler of the primary interrupter */
+       xhci_handle_events(xhci, xhci->interrupters[0]);
 out:
        spin_unlock(&xhci->lock);