[PATCH v13 08/53] xhci: move event processing for one interrupter to a separate function

Wesley Cheng
2024-02-03T02:37:53Z

From: Mathias Nyman <mathias.nyman@linux.intel.com>

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>
---
drivers/usb/host/xhci-ring.c | 87 +++++++++++++++++-------------------
1 file changed, 42 insertions(+), 45 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 0289d77839cf..338b6fddedc3 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3019,6 +3019,46 @@ 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
@@ -3027,11 +3067,8 @@ 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 */
@@ -3064,50 +3101,10 @@ 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);