From c89f7f98c971e0cabc819b6c0fe6bf509287b7e0 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Fri, 15 Feb 2019 13:49:18 -0600 Subject: PCI/portdrv: Use conventional Device ID table formatting The pci_device_id table was technically correct, but unusually formatted, which made adding entries error-prone. Change the format so it's obvious how to add entries. Signed-off-by: Bjorn Helgaas --- drivers/pci/pcie/portdrv_pci.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index 0acca3596807..a289e734b9a4 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -182,10 +182,10 @@ 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) }, + { }, }; static const struct pci_error_handlers pcie_portdrv_err_handler = { -- cgit v1.2.3-59-g8ed1b From f0cfecea8d1e8e0cd5d5053f9452b3a450f49eb5 Mon Sep 17 00:00:00 2001 From: Honghui Zhang Date: Thu, 14 Feb 2019 13:21:17 +0800 Subject: PCI/portdrv: Support PCIe services on subtractive decode bridges The Class Code for subtractive decode PCI-to-PCI bridge is 060401h; add an entry to make portdrv support this type of bridge. This allows use of PCIe services on subtractive decode ports. Signed-off-by: Honghui Zhang [bhelgaas: add braces surrounding entry] Signed-off-by: Bjorn Helgaas --- drivers/pci/pcie/portdrv_pci.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/pci') diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index a289e734b9a4..99d2abe88d0b 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -185,6 +185,8 @@ static void pcie_portdrv_err_resume(struct pci_dev *dev) static const struct pci_device_id port_pci_ids[] = { /* handle any PCI-Express port */ { 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) }, { }, }; -- cgit v1.2.3-59-g8ed1b From e8303bb7a75c113388badcc49b2a84b4121c1b3e Mon Sep 17 00:00:00 2001 From: Alexandru Gagniuc Date: Wed, 27 Feb 2019 14:58:17 -0600 Subject: PCI/LINK: Report degraded links via link bandwidth notification A warning is generated when a PCIe device is probed with a degraded link, but there was no similar mechanism to warn when the link becomes degraded after probing. The Link Bandwidth Notification provides this mechanism. Use the Link Bandwidth Management Interrupt to detect bandwidth changes, and rescan the bandwidth, looking for the weakest point. This is the same logic used in probe(). Signed-off-by: Alexandru Gagniuc Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner --- drivers/pci/pcie/Makefile | 1 + drivers/pci/pcie/bw_notification.c | 110 +++++++++++++++++++++++++++++++++++++ drivers/pci/pcie/portdrv.h | 6 +- drivers/pci/pcie/portdrv_core.c | 17 ++++-- drivers/pci/pcie/portdrv_pci.c | 1 + 5 files changed, 129 insertions(+), 6 deletions(-) create mode 100644 drivers/pci/pcie/bw_notification.c (limited to 'drivers/pci') 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 + * + * 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 99d2abe88d0b..0a87091a0800 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) -- cgit v1.2.3-59-g8ed1b