xhci: Refactor interrupter code for initial multi interrupter support.

xHC supports several interrupters, each with its own mmio register set,
event ring and MSI/MSI-X vector. Transfers can be assigned different
interrupters when queued. See xhci 4.17 for details.
Current driver only supports one interrupter.

Create a xhci_interrupter structure containing an event ring, pointer to
mmio registers for this interrupter, variables to store registers over s3
suspend, erst, etc. Add functions to create and free an interrupter, and
pass an interrupter pointer to functions that deal with events.

Secondary interrupters are also useful without having an interrupt vector.
One use case is the xHCI audio sideband offloading where a DSP can take
care of specific audio endpoints.

When all transfer events of an offloaded endpoint can be mapped to a
separate interrupter event ring the DSP can poll this ring, and we can mask
these events preventing waking up the CPU.

Only minor functional changes such as clearing some of the interrupter
registers when freeing the interrupter.

Still create only one primary interrupter.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230202150505.618915-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 37 insertions, 31 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 5f1ecdee2c1c..451d48b87cf7 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1833,7 +1833,8 @@ static void xhci_cavium_reset_phy_quirk(struct xhci_hcd *xhci)
 }
 
 static void handle_port_status(struct xhci_hcd *xhci,
-		union xhci_trb *event)
+			       struct xhci_interrupter *ir,
+			       union xhci_trb *event)
 {
 	struct usb_hcd *hcd;
 	u32 port_id;
@@ -1856,7 +1857,7 @@ static void handle_port_status(struct xhci_hcd *xhci,
 	if ((port_id <= 0) || (port_id > max_ports)) {
 		xhci_warn(xhci, "Port change event with invalid port ID %d\n",
 			  port_id);
-		inc_deq(xhci, xhci->event_ring);
+		inc_deq(xhci, ir->event_ring);
 		return;
 	}
 
@@ -1986,7 +1987,7 @@ static void handle_port_status(struct xhci_hcd *xhci,
 
 cleanup:
 	/* Update event ring dequeue pointer before dropping the lock */
-	inc_deq(xhci, xhci->event_ring);
+	inc_deq(xhci, ir->event_ring);
 
 	/* Don't make the USB core poll the roothub if we got a bad port status
 	 * change event.  Besides, at that point we can't tell which roothub
@@ -2519,7 +2520,8 @@ finish_td:
  * At this point, the host controller is probably hosed and should be reset.
  */
 static int handle_tx_event(struct xhci_hcd *xhci,
-		struct xhci_transfer_event *event)
+			   struct xhci_interrupter *ir,
+			   struct xhci_transfer_event *event)
 {
 	struct xhci_virt_ep *ep;
 	struct xhci_ring *ep_ring;
@@ -2868,7 +2870,7 @@ cleanup:
 		 * processing missed tds.
 		 */
 		if (!handling_skipped_tds)
-			inc_deq(xhci, xhci->event_ring);
+			inc_deq(xhci, ir->event_ring);
 
 	/*
 	 * If ep->skip is set, it means there are missed tds on the
@@ -2883,8 +2885,8 @@ cleanup:
 err_out:
 	xhci_err(xhci, "@%016llx %08x %08x %08x %08x\n",
 		 (unsigned long long) xhci_trb_virt_to_dma(
-			 xhci->event_ring->deq_seg,
-			 xhci->event_ring->dequeue),
+			 ir->event_ring->deq_seg,
+			 ir->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),
@@ -2898,7 +2900,7 @@ err_out:
  * Returns >0 for "possibly more events to process" (caller should call again),
  * otherwise 0 if done.  In future, <0 returns should indicate error code.
  */
-static int xhci_handle_event(struct xhci_hcd *xhci)
+static int xhci_handle_event(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
 {
 	union xhci_trb *event;
 	int update_ptrs = 1;
@@ -2906,18 +2908,18 @@ static int xhci_handle_event(struct xhci_hcd *xhci)
 	int ret;
 
 	/* Event ring hasn't been allocated yet. */
-	if (!xhci->event_ring || !xhci->event_ring->dequeue) {
-		xhci_err(xhci, "ERROR event ring not ready\n");
+	if (!ir || !ir->event_ring || !ir->event_ring->dequeue) {
+		xhci_err(xhci, "ERROR interrupter not ready\n");
 		return -ENOMEM;
 	}
 
-	event = xhci->event_ring->dequeue;
+	event = ir->event_ring->dequeue;
 	/* Does the HC or OS own the TRB? */
 	if ((le32_to_cpu(event->event_cmd.flags) & TRB_CYCLE) !=
-	    xhci->event_ring->cycle_state)
+	    ir->event_ring->cycle_state)
 		return 0;
 
-	trace_xhci_handle_event(xhci->event_ring, &event->generic);
+	trace_xhci_handle_event(ir->event_ring, &event->generic);
 
 	/*
 	 * Barrier between reading the TRB_CYCLE (valid) flag above and any
@@ -2932,11 +2934,11 @@ static int xhci_handle_event(struct xhci_hcd *xhci)
 		handle_cmd_completion(xhci, &event->event_cmd);
 		break;
 	case TRB_PORT_STATUS:
-		handle_port_status(xhci, event);
+		handle_port_status(xhci, ir, event);
 		update_ptrs = 0;
 		break;
 	case TRB_TRANSFER:
-		ret = handle_tx_event(xhci, &event->trans_event);
+		ret = handle_tx_event(xhci, ir, &event->trans_event);
 		if (ret >= 0)
 			update_ptrs = 0;
 		break;
@@ -2960,7 +2962,7 @@ static int xhci_handle_event(struct xhci_hcd *xhci)
 
 	if (update_ptrs)
 		/* Update SW event ring dequeue pointer */
-		inc_deq(xhci, xhci->event_ring);
+		inc_deq(xhci, ir->event_ring);
 
 	/* Are there more items on the event ring?  Caller will call us again to
 	 * check.
@@ -2974,16 +2976,17 @@ static int xhci_handle_event(struct xhci_hcd *xhci)
  * - To avoid "Event Ring Full Error" condition
  */
 static void xhci_update_erst_dequeue(struct xhci_hcd *xhci,
-		union xhci_trb *event_ring_deq)
+				     struct xhci_interrupter *ir,
+				     union xhci_trb *event_ring_deq)
 {
 	u64 temp_64;
 	dma_addr_t deq;
 
-	temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
+	temp_64 = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
 	/* If necessary, update the HW's version of the event ring deq ptr. */
-	if (event_ring_deq != xhci->event_ring->dequeue) {
-		deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg,
-				xhci->event_ring->dequeue);
+	if (event_ring_deq != ir->event_ring->dequeue) {
+		deq = xhci_trb_virt_to_dma(ir->event_ring->deq_seg,
+				ir->event_ring->dequeue);
 		if (deq == 0)
 			xhci_warn(xhci, "WARN something wrong with SW event ring dequeue ptr\n");
 		/*
@@ -3001,7 +3004,7 @@ static void xhci_update_erst_dequeue(struct xhci_hcd *xhci,
 
 	/* Clear the event handler busy flag (RW1C) */
 	temp_64 |= ERST_EHB;
-	xhci_write_64(xhci, temp_64, &xhci->ir_set->erst_dequeue);
+	xhci_write_64(xhci, temp_64, &ir->ir_set->erst_dequeue);
 }
 
 /*
@@ -3013,6 +3016,7 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
 {
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 	union xhci_trb *event_ring_deq;
+	struct xhci_interrupter *ir;
 	irqreturn_t ret = IRQ_NONE;
 	u64 temp_64;
 	u32 status;
@@ -3050,11 +3054,13 @@ 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->interrupter;
 	if (!hcd->msi_enabled) {
 		u32 irq_pending;
-		irq_pending = readl(&xhci->ir_set->irq_pending);
+		irq_pending = readl(&ir->ir_set->irq_pending);
 		irq_pending |= IMAN_IP;
-		writel(irq_pending, &xhci->ir_set->irq_pending);
+		writel(irq_pending, &ir->ir_set->irq_pending);
 	}
 
 	if (xhci->xhc_state & XHCI_STATE_DYING ||
@@ -3064,22 +3070,22 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
 		/* Clear the event handler busy flag (RW1C);
 		 * the event ring should be empty.
 		 */
-		temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
+		temp_64 = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
 		xhci_write_64(xhci, temp_64 | ERST_EHB,
-				&xhci->ir_set->erst_dequeue);
+				&ir->ir_set->erst_dequeue);
 		ret = IRQ_HANDLED;
 		goto out;
 	}
 
-	event_ring_deq = xhci->event_ring->dequeue;
+	event_ring_deq = ir->event_ring->dequeue;
 	/* FIXME this should be a delayed service routine
 	 * that clears the EHB.
 	 */
-	while (xhci_handle_event(xhci) > 0) {
+	while (xhci_handle_event(xhci, ir) > 0) {
 		if (event_loop++ < TRBS_PER_SEGMENT / 2)
 			continue;
-		xhci_update_erst_dequeue(xhci, event_ring_deq);
-		event_ring_deq = xhci->event_ring->dequeue;
+		xhci_update_erst_dequeue(xhci, ir, event_ring_deq);
+		event_ring_deq = ir->event_ring->dequeue;
 
 		/* ring is half-full, force isoc trbs to interrupt more often */
 		if (xhci->isoc_bei_interval > AVOID_BEI_INTERVAL_MIN)
@@ -3088,7 +3094,7 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
 		event_loop = 0;
 	}
 
-	xhci_update_erst_dequeue(xhci, event_ring_deq);
+	xhci_update_erst_dequeue(xhci, ir, event_ring_deq);
 	ret = IRQ_HANDLED;
 
 out: