1 files changed, 19 insertions, 67 deletions

diff --git a/drivers/pci/pcie/bwctrl.c b/drivers/pci/pcie/bwctrl.c
index d8d2aa85a229..36f939f23d34 100644
--- a/drivers/pci/pcie/bwctrl.c
+++ b/drivers/pci/pcie/bwctrl.c
@@ -38,24 +38,14 @@
 /**
  * struct pcie_bwctrl_data - PCIe bandwidth controller
  * @set_speed_mutex:	Serializes link speed changes
- * @lbms_count:		Count for LBMS (since last reset)
  * @cdev:		Thermal cooling device associated with the port
  */
 struct pcie_bwctrl_data {
 	struct mutex set_speed_mutex;
-	atomic_t lbms_count;
 	struct thermal_cooling_device *cdev;
 };
 
-/*
- * Prevent port removal during LBMS count accessors and Link Speed changes.
- *
- * These have to be differentiated because pcie_bwctrl_change_speed() calls
- * pcie_retrain_link() which uses LBMS count reset accessor on success
- * (using just one rwsem triggers "possible recursive locking detected"
- * warning).
- */
-static DECLARE_RWSEM(pcie_bwctrl_lbms_rwsem);
+/* Prevent port removal during Link Speed changes. */
 static DECLARE_RWSEM(pcie_bwctrl_setspeed_rwsem);
 
 static bool pcie_valid_speed(enum pci_bus_speed speed)
@@ -127,18 +117,7 @@ static int pcie_bwctrl_change_speed(struct pci_dev *port, u16 target_speed, bool
 	if (ret != PCIBIOS_SUCCESSFUL)
 		return pcibios_err_to_errno(ret);
 
-	ret = pcie_retrain_link(port, use_lt);
-	if (ret < 0)
-		return ret;
-
-	/*
-	 * Ensure link speed updates also with platforms that have problems
-	 * with notifications.
-	 */
-	if (port->subordinate)
-		pcie_update_link_speed(port->subordinate);
-
-	return 0;
+	return pcie_retrain_link(port, use_lt);
 }
 
 /**
@@ -202,15 +181,14 @@ int pcie_set_target_speed(struct pci_dev *port, enum pci_bus_speed speed_req,
 
 static void pcie_bwnotif_enable(struct pcie_device *srv)
 {
-	struct pcie_bwctrl_data *data = srv->port->link_bwctrl;
 	struct pci_dev *port = srv->port;
 	u16 link_status;
 	int ret;
 
-	/* Count LBMS seen so far as one */
+	/* Note if LBMS has been seen so far */
 	ret = pcie_capability_read_word(port, PCI_EXP_LNKSTA, &link_status);
 	if (ret == PCIBIOS_SUCCESSFUL && link_status & PCI_EXP_LNKSTA_LBMS)
-		atomic_inc(&data->lbms_count);
+		set_bit(PCI_LINK_LBMS_SEEN, &port->priv_flags);
 
 	pcie_capability_set_word(port, PCI_EXP_LNKCTL,
 				 PCI_EXP_LNKCTL_LBMIE | PCI_EXP_LNKCTL_LABIE);
@@ -233,7 +211,6 @@ static void pcie_bwnotif_disable(struct pci_dev *port)
 static irqreturn_t pcie_bwnotif_irq(int irq, void *context)
 {
 	struct pcie_device *srv = context;
-	struct pcie_bwctrl_data *data = srv->port->link_bwctrl;
 	struct pci_dev *port = srv->port;
 	u16 link_status, events;
 	int ret;
@@ -247,7 +224,7 @@ static irqreturn_t pcie_bwnotif_irq(int irq, void *context)
 		return IRQ_NONE;
 
 	if (events & PCI_EXP_LNKSTA_LBMS)
-		atomic_inc(&data->lbms_count);
+		set_bit(PCI_LINK_LBMS_SEEN, &port->priv_flags);
 
 	pcie_capability_write_word(port, PCI_EXP_LNKSTA, events);
 
@@ -262,31 +239,10 @@ static irqreturn_t pcie_bwnotif_irq(int irq, void *context)
 	return IRQ_HANDLED;
 }
 
-void pcie_reset_lbms_count(struct pci_dev *port)
+void pcie_reset_lbms(struct pci_dev *port)
 {
-	struct pcie_bwctrl_data *data;
-
-	guard(rwsem_read)(&pcie_bwctrl_lbms_rwsem);
-	data = port->link_bwctrl;
-	if (data)
-		atomic_set(&data->lbms_count, 0);
-	else
-		pcie_capability_write_word(port, PCI_EXP_LNKSTA,
-					   PCI_EXP_LNKSTA_LBMS);
-}
-
-int pcie_lbms_count(struct pci_dev *port, unsigned long *val)
-{
-	struct pcie_bwctrl_data *data;
-
-	guard(rwsem_read)(&pcie_bwctrl_lbms_rwsem);
-	data = port->link_bwctrl;
-	if (!data)
-		return -ENOTTY;
-
-	*val = atomic_read(&data->lbms_count);
-
-	return 0;
+	clear_bit(PCI_LINK_LBMS_SEEN, &port->priv_flags);
+	pcie_capability_write_word(port, PCI_EXP_LNKSTA, PCI_EXP_LNKSTA_LBMS);
 }
 
 static int pcie_bwnotif_probe(struct pcie_device *srv)
@@ -308,18 +264,16 @@ static int pcie_bwnotif_probe(struct pcie_device *srv)
 		return ret;
 
 	scoped_guard(rwsem_write, &pcie_bwctrl_setspeed_rwsem) {
-		scoped_guard(rwsem_write, &pcie_bwctrl_lbms_rwsem) {
-			port->link_bwctrl = data;
-
-			ret = request_irq(srv->irq, pcie_bwnotif_irq,
-					  IRQF_SHARED, "PCIe bwctrl", srv);
-			if (ret) {
-				port->link_bwctrl = NULL;
-				return ret;
-			}
+		port->link_bwctrl = data;
 
-			pcie_bwnotif_enable(srv);
+		ret = request_irq(srv->irq, pcie_bwnotif_irq,
+				  IRQF_SHARED, "PCIe bwctrl", srv);
+		if (ret) {
+			port->link_bwctrl = NULL;
+			return ret;
 		}
+
+		pcie_bwnotif_enable(srv);
 	}
 
 	pci_dbg(port, "enabled with IRQ %d\n", srv->irq);
@@ -339,13 +293,11 @@ static void pcie_bwnotif_remove(struct pcie_device *srv)
 	pcie_cooling_device_unregister(data->cdev);
 
 	scoped_guard(rwsem_write, &pcie_bwctrl_setspeed_rwsem) {
-		scoped_guard(rwsem_write, &pcie_bwctrl_lbms_rwsem) {
-			pcie_bwnotif_disable(srv->port);
+		pcie_bwnotif_disable(srv->port);
 
-			free_irq(srv->irq, srv);
+		free_irq(srv->irq, srv);
 
-			srv->port->link_bwctrl = NULL;
-		}
+		srv->port->link_bwctrl = NULL;
 	}
 }