[PATCH 03/17][SRU][OEM-OSP1-B] thunderbolt: Cache adapter specific capability offset into struct port

[You-Sheng Yang]

From: Mika Westerberg <mika.westerberg at linux.intel.com>

BugLink: https://bugs.launchpad.net/bugs/1844680

The adapter specific capability either is there or not if the port does
not hold an adapter. Instead of always finding it on-demand we read the
offset just once when the port is initialized.

While there we update the struct port documentation to follow kernel-doc
format.

Signed-off-by: Mika Westerberg <mika.westerberg at linux.intel.com>
(cherry picked from commit 56183c88f368eef7134c32df826792ee140f2864)
Signed-off-by: You-Sheng Yang <vicamo.yang at canonical.com>
---
 drivers/thunderbolt/switch.c     | 4 ++++
 drivers/thunderbolt/tb.c         | 8 ++++----
 drivers/thunderbolt/tb.h         | 2 ++
 drivers/thunderbolt/tunnel_pci.c | 9 +++------
 4 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 33488b2c4155..e460099799df 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -586,6 +586,10 @@ static int tb_init_port(struct tb_port *port)
 			port->cap_phy = cap;
 		else
 			tb_port_WARN(port, "non switch port without a PHY\n");
+	} else if (port->port != 0) {
+		cap = tb_port_find_cap(port, TB_PORT_CAP_ADAP);
+		if (cap > 0)
+			port->cap_adap = cap;
 	}
 
 	tb_dump_port(port->sw->tb, &port->config);
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index d8f4ed0f2ef8..e71530d0af65 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -151,8 +151,8 @@ static struct tb_port *tb_find_unused_down_port(struct tb_switch *sw)
 			continue;
 		if (sw->ports[i].config.type != TB_TYPE_PCIE_DOWN)
 			continue;
-		cap = tb_port_find_cap(&sw->ports[i], TB_PORT_CAP_ADAP);
-		if (cap < 0)
+		cap = sw->ports[i].cap_adap;
+		if (!cap)
 			continue;
 		res = tb_port_read(&sw->ports[i], &data, TB_CFG_PORT, cap, 1);
 		if (res < 0)
@@ -197,8 +197,8 @@ static void tb_activate_pcie_devices(struct tb *tb)
 		}
 
 		/* check whether port is already activated */
-		cap = tb_port_find_cap(up_port, TB_PORT_CAP_ADAP);
-		if (cap < 0)
+		cap = up_port->cap_adap;
+		if (!cap)
 			continue;
 		if (tb_port_read(up_port, &data, TB_CFG_PORT, cap, 1))
 			continue;
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 95775d41af07..7f0814470165 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -122,6 +122,7 @@ struct tb_switch {
  * @remote: Remote port (%NULL if not connected)
  * @xdomain: Remote host (%NULL if not connected)
  * @cap_phy: Offset, zero if not found
+ * @cap_adap: Offset of the adapter specific capability (%0 if not present)
  * @port: Port number on switch
  * @disabled: Disabled by eeprom
  * @dual_link_port: If the switch is connected using two ports, points
@@ -134,6 +135,7 @@ struct tb_port {
 	struct tb_port *remote;
 	struct tb_xdomain *xdomain;
 	int cap_phy;
+	int cap_adap;
 	u8 port;
 	bool disabled;
 	struct tb_port *dual_link_port;
diff --git a/drivers/thunderbolt/tunnel_pci.c b/drivers/thunderbolt/tunnel_pci.c
index 0637537ea53f..2de4edccbd6d 100644
--- a/drivers/thunderbolt/tunnel_pci.c
+++ b/drivers/thunderbolt/tunnel_pci.c
@@ -148,12 +148,9 @@ bool tb_pci_is_invalid(struct tb_pci_tunnel *tunnel)
 static int tb_pci_port_active(struct tb_port *port, bool active)
 {
 	u32 word = active ? 0x80000000 : 0x0;
-	int cap = tb_port_find_cap(port, TB_PORT_CAP_ADAP);
-	if (cap < 0) {
-		tb_port_warn(port, "TB_PORT_CAP_ADAP not found: %d\n", cap);
-		return cap;
-	}
-	return tb_port_write(port, &word, TB_CFG_PORT, cap, 1);
+	if (!port->cap_adap)
+		return -ENXIO;
+	return tb_port_write(port, &word, TB_CFG_PORT, port->cap_adap, 1);
 }
 
 /**
-- 
2.20.1