[PATCH v8 06/34] usb: host: xhci-mem: Allow for interrupter clients to choose specific index

[Wesley Cheng]

Some clients may operate only on a specific XHCI interrupter instance.
Allow for the associated class driver to request for the interrupter that
it requires.

Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
---
 drivers/usb/host/xhci-mem.c       | 30 ++++++++++++++++--------------
 drivers/usb/host/xhci-sideband.c  |  5 +++--
 drivers/usb/host/xhci.h           |  3 ++-
 include/linux/usb/xhci-sideband.h |  3 ++-
 4 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index e6df1cb15e5b..cdfa70275dec 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2343,7 +2343,7 @@ xhci_add_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir,
 }
 
 struct xhci_interrupter *
-xhci_create_secondary_interrupter(struct usb_hcd *hcd)
+xhci_create_secondary_interrupter(struct usb_hcd *hcd, int intr_num)
 {
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 	struct xhci_interrupter *ir;
@@ -2358,28 +2358,30 @@ xhci_create_secondary_interrupter(struct usb_hcd *hcd)
 		return NULL;
 
 	spin_lock_irq(&xhci->lock);
-
-	/* Find available secondary interrupter, interrupter 0 is reserved for primary */
+	/* Find available secondary interrupter, interrupter 0 is reserverd for primary */
 	for (i = 1; i < xhci->max_interrupters; i++) {
-		if (xhci->interrupters[i] == NULL) {
-			err = xhci_add_interrupter(xhci, ir, i);
-			break;
+		if ((intr_num > 0 && i == intr_num) || intr_num <= 0) {
+			if (xhci->interrupters[i] == NULL) {
+				err = xhci_add_interrupter(xhci, ir, i);
+				if (err) {
+					spin_unlock_irq(&xhci->lock);
+					goto free_ir;
+				}
+				break;
+			}
 		}
 	}
-
 	spin_unlock_irq(&xhci->lock);
 
-	if (err) {
-		xhci_warn(xhci, "Failed to add secondary interrupter, max interrupters %d\n",
-			  xhci->max_interrupters);
-		xhci_free_interrupter(xhci, ir);
-		return NULL;
-	}
-
 	xhci_dbg(xhci, "Add secondary interrupter %d, max interrupters %d\n",
 		 i, xhci->max_interrupters);
 
 	return ir;
+
+free_ir:
+	xhci_free_interrupter(xhci, ir);
+
+	return NULL;
 }
 EXPORT_SYMBOL_GPL(xhci_create_secondary_interrupter);
 
diff --git a/drivers/usb/host/xhci-sideband.c b/drivers/usb/host/xhci-sideband.c
index cc4f90375e00..13a8a260b024 100644
--- a/drivers/usb/host/xhci-sideband.c
+++ b/drivers/usb/host/xhci-sideband.c
@@ -242,12 +242,13 @@ EXPORT_SYMBOL_GPL(xhci_sideband_get_event_buffer);
  * Returns 0 on success, negative error otherwise
  */
 int
-xhci_sideband_create_interrupter(struct xhci_sideband *sb)
+xhci_sideband_create_interrupter(struct xhci_sideband *sb, int intr_num)
 {
 	if (sb->ir)
 		return -EBUSY;
 
-	sb->ir = xhci_create_secondary_interrupter(xhci_to_hcd(sb->xhci));
+	sb->ir = xhci_create_secondary_interrupter(xhci_to_hcd(sb->xhci),
+			intr_num);
 	if (!sb->ir)
 		return -ENOMEM;
 
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 9ef375e5c27e..298bcef81918 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -2092,7 +2092,8 @@ struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
 		int type, gfp_t flags);
 void xhci_free_container_ctx(struct xhci_hcd *xhci,
 		struct xhci_container_ctx *ctx);
-struct xhci_interrupter *xhci_create_secondary_interrupter(struct usb_hcd *hcd);
+struct xhci_interrupter *xhci_create_secondary_interrupter(struct usb_hcd *hcd,
+		int intr_num);
 void xhci_remove_secondary_interrupter(struct usb_hcd
 				       *hcd, struct xhci_interrupter *ir);
 void xhci_skip_sec_intr_events(struct xhci_hcd *xhci,
diff --git a/include/linux/usb/xhci-sideband.h b/include/linux/usb/xhci-sideband.h
index c1457d1800f4..7f4080f530d3 100644
--- a/include/linux/usb/xhci-sideband.h
+++ b/include/linux/usb/xhci-sideband.h
@@ -54,7 +54,8 @@ struct sg_table *
 xhci_sideband_get_event_buffer(struct xhci_sideband *sb);
 
 int
-xhci_sideband_create_interrupter(struct xhci_sideband *sb);
+xhci_sideband_create_interrupter(struct xhci_sideband *sb,
+				 int intr_num);
 
 void
 xhci_sideband_remove_interrupter(struct xhci_sideband *sb);