diff options
| -rw-r--r-- | drivers/pci/pcie/Makefile | 1 | ||||
| -rw-r--r-- | drivers/pci/pcie/bw_notification.c | 110 | ||||
| -rw-r--r-- | drivers/pci/pcie/portdrv.h | 6 | ||||
| -rw-r--r-- | drivers/pci/pcie/portdrv_core.c | 17 | ||||
| -rw-r--r-- | drivers/pci/pcie/portdrv_pci.c | 9 |
5 files changed, 134 insertions, 9 deletions
diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile index ab514083d5d4..f1d7bc1e5efa 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 000000000000..d2eae3b7cc0f --- /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 fbbf00b0992e..1d50dc58ac40 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 f458ac9cb70c..7d04f9d087a6 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 0acca3596807..0a87091a0800 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -182,10 +182,12 @@ static void pcie_portdrv_err_resume(struct pci_dev *dev) /* * LINUX Device Driver Model */ -static const struct pci_device_id port_pci_ids[] = { { +static const struct pci_device_id port_pci_ids[] = { /* handle any PCI-Express port */ - PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0), - }, { /* end: all zeroes */ } + { PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0) }, + /* subtractive decode PCI-to-PCI bridge, class type is 060401h */ + { PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x01), ~0) }, + { }, }; static const struct pci_error_handlers pcie_portdrv_err_handler = { @@ -238,6 +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) |