diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile
index ab514083d5d4246ec3b56de9d578e7c2716359c1..f1d7bc1e5efae2561fecba886b15a17a17ee5c4b 100644
--- a/drivers/pci/pcie/Makefile
+++ b/drivers/pci/pcie/Makefile
@@ -3,6 +3,7 @@
# Makefile for PCI Express features and port driver
pcieportdrv-y := portdrv_core.o portdrv_pci.o err.o
+pcieportdrv-y += bw_notification.o
obj-$(CONFIG_PCIEPORTBUS) += pcieportdrv.o
diff --git a/drivers/pci/pcie/bw_notification.c b/drivers/pci/pcie/bw_notification.c
new file mode 100644
index 0000000000000000000000000000000000000000..d2eae3b7cc0f74d5c8fdec80fa6ffffd68dd8501
--- /dev/null
+++ b/drivers/pci/pcie/bw_notification.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCI Express Link Bandwidth Notification services driver
+ * Author: Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ *
+ * Copyright (C) 2019, Dell Inc
+ *
+ * The PCIe Link Bandwidth Notification provides a way to notify the
+ * operating system when the link width or data rate changes. This
+ * capability is required for all root ports and downstream ports
+ * supporting links wider than x1 and/or multiple link speeds.
+ *
+ * This service port driver hooks into the bandwidth notification interrupt
+ * and warns when links become degraded in operation.
+ */
+
+#include "../pci.h"
+#include "portdrv.h"
+
+static bool pcie_link_bandwidth_notification_supported(struct pci_dev *dev)
+{
+ int ret;
+ u32 lnk_cap;
+
+ ret = pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnk_cap);
+ return (ret == PCIBIOS_SUCCESSFUL) && (lnk_cap & PCI_EXP_LNKCAP_LBNC);
+}
+
+static void pcie_enable_link_bandwidth_notification(struct pci_dev *dev)
+{
+ u16 lnk_ctl;
+
+ pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &lnk_ctl);
+ lnk_ctl |= PCI_EXP_LNKCTL_LBMIE;
+ pcie_capability_write_word(dev, PCI_EXP_LNKCTL, lnk_ctl);
+}
+
+static void pcie_disable_link_bandwidth_notification(struct pci_dev *dev)
+{
+ u16 lnk_ctl;
+
+ pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &lnk_ctl);
+ lnk_ctl &= ~PCI_EXP_LNKCTL_LBMIE;
+ pcie_capability_write_word(dev, PCI_EXP_LNKCTL, lnk_ctl);
+}
+
+static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
+{
+ struct pcie_device *srv = context;
+ struct pci_dev *port = srv->port;
+ struct pci_dev *dev;
+ u16 link_status, events;
+ int ret;
+
+ ret = pcie_capability_read_word(port, PCI_EXP_LNKSTA, &link_status);
+ events = link_status & PCI_EXP_LNKSTA_LBMS;
+
+ if (ret != PCIBIOS_SUCCESSFUL || !events)
+ return IRQ_NONE;
+
+ /*
+ * Print status from downstream devices, not this root port or
+ * downstream switch port.
+ */
+ down_read(&pci_bus_sem);
+ list_for_each_entry(dev, &port->subordinate->devices, bus_list)
+ __pcie_print_link_status(dev, false);
+ up_read(&pci_bus_sem);
+
+ pcie_update_link_speed(port->subordinate, link_status);
+ pcie_capability_write_word(port, PCI_EXP_LNKSTA, events);
+ return IRQ_HANDLED;
+}
+
+static int pcie_bandwidth_notification_probe(struct pcie_device *srv)
+{
+ int ret;
+
+ /* Single-width or single-speed ports do not have to support this. */
+ if (!pcie_link_bandwidth_notification_supported(srv->port))
+ return -ENODEV;
+
+ ret = request_threaded_irq(srv->irq, NULL, pcie_bw_notification_handler,
+ IRQF_SHARED, "PCIe BW notif", srv);
+ if (ret)
+ return ret;
+
+ pcie_enable_link_bandwidth_notification(srv->port);
+
+ return 0;
+}
+
+static void pcie_bandwidth_notification_remove(struct pcie_device *srv)
+{
+ pcie_disable_link_bandwidth_notification(srv->port);
+ free_irq(srv->irq, srv);
+}
+
+static struct pcie_port_service_driver pcie_bandwidth_notification_driver = {
+ .name = "pcie_bw_notification",
+ .port_type = PCIE_ANY_PORT,
+ .service = PCIE_PORT_SERVICE_BWNOTIF,
+ .probe = pcie_bandwidth_notification_probe,
+ .remove = pcie_bandwidth_notification_remove,
+};
+
+int __init pcie_bandwidth_notification_init(void)
+{
+ return pcie_port_service_register(&pcie_bandwidth_notification_driver);
+}
diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
index fbbf00b0992e50e946f7a5ebd465324bf8c8f2de..1d50dc58ac400ae1a325f788ee33352aebf58c09 100644
--- a/drivers/pci/pcie/portdrv.h
+++ b/drivers/pci/pcie/portdrv.h
@@ -20,8 +20,10 @@
#define PCIE_PORT_SERVICE_HP (1 << PCIE_PORT_SERVICE_HP_SHIFT)
#define PCIE_PORT_SERVICE_DPC_SHIFT 3 /* Downstream Port Containment */
#define PCIE_PORT_SERVICE_DPC (1 << PCIE_PORT_SERVICE_DPC_SHIFT)
+#define PCIE_PORT_SERVICE_BWNOTIF_SHIFT 4 /* Bandwidth notification */
+#define PCIE_PORT_SERVICE_BWNOTIF (1 << PCIE_PORT_SERVICE_BWNOTIF_SHIFT)
-#define PCIE_PORT_DEVICE_MAXSERVICES 4
+#define PCIE_PORT_DEVICE_MAXSERVICES 5
#ifdef CONFIG_PCIEAER
int pcie_aer_init(void);
@@ -47,6 +49,8 @@ int pcie_dpc_init(void);
static inline int pcie_dpc_init(void) { return 0; }
#endif
+int pcie_bandwidth_notification_init(void);
+
/* Port Type */
#define PCIE_ANY_PORT (~0)
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index f458ac9cb70c397868a17fa48027ccb21f80e762..7d04f9d087a62a94cf4edd5fdab4749d752f2c4e 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -99,7 +99,7 @@ static int pcie_message_numbers(struct pci_dev *dev, int mask,
*/
static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
{
- int nr_entries, nvec;
+ int nr_entries, nvec, pcie_irq;
u32 pme = 0, aer = 0, dpc = 0;
/* Allocate the maximum possible number of MSI/MSI-X vectors */
@@ -135,10 +135,13 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
return nr_entries;
}
- /* PME and hotplug share an MSI/MSI-X vector */
- if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
- irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, pme);
- irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, pme);
+ /* PME, hotplug and bandwidth notification share an MSI/MSI-X vector */
+ if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP |
+ PCIE_PORT_SERVICE_BWNOTIF)) {
+ pcie_irq = pci_irq_vector(dev, pme);
+ irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pcie_irq;
+ irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pcie_irq;
+ irqs[PCIE_PORT_SERVICE_BWNOTIF_SHIFT] = pcie_irq;
}
if (mask & PCIE_PORT_SERVICE_AER)
@@ -250,6 +253,10 @@ static int get_port_device_capability(struct pci_dev *dev)
pci_aer_available() && services & PCIE_PORT_SERVICE_AER)
services |= PCIE_PORT_SERVICE_DPC;
+ if (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM ||
+ pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
+ services |= PCIE_PORT_SERVICE_BWNOTIF;
+
return services;
}
diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
index 99d2abe88d0b53b4b25bfc1ce35126689ad3dbb2..0a87091a0800e8316a9d05a9bea7268528ff687c 100644
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -240,6 +240,7 @@ static void __init pcie_init_services(void)
pcie_pme_init();
pcie_dpc_init();
pcie_hp_init();
+ pcie_bandwidth_notification_init();
}
static int __init pcie_portdrv_init(void)