diff options
| -rw-r--r-- | MAINTAINERS | 6 | ||||
| -rw-r--r-- | drivers/pci/hotplug/pciehp_ctrl.c | 5 | ||||
| -rw-r--r-- | drivers/pci/pci.c | 2 | ||||
| -rw-r--r-- | drivers/pci/pci.h | 11 | ||||
| -rw-r--r-- | drivers/pci/pcie/Makefile | 2 | ||||
| -rw-r--r-- | drivers/pci/pcie/bwctrl.c | 186 | ||||
| -rw-r--r-- | drivers/pci/pcie/portdrv.c | 9 | ||||
| -rw-r--r-- | drivers/pci/pcie/portdrv.h | 6 | ||||
| -rw-r--r-- | drivers/pci/quirks.c | 9 | ||||
| -rw-r--r-- | include/linux/pci.h | 2 |
10 files changed, 229 insertions, 9 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index c27f3190737f..8c555b3325d6 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17933,6 +17933,12 @@ F: include/linux/of_pci.h F: include/linux/pci* F: include/uapi/linux/pci* +PCIE BANDWIDTH CONTROLLER +M: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> +L: linux-pci@vger.kernel.org +S: Supported +F: drivers/pci/pcie/bwctrl.c + PCIE DRIVER FOR AMAZON ANNAPURNA LABS M: Jonathan Chocron <jonnyc@amazon.com> L: linux-pci@vger.kernel.org diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index dcdbfcf404dd..d603a7aa7483 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -19,6 +19,8 @@ #include <linux/types.h> #include <linux/pm_runtime.h> #include <linux/pci.h> + +#include "../pci.h" #include "pciehp.h" /* The following routines constitute the bulk of the @@ -127,6 +129,9 @@ static void remove_board(struct controller *ctrl, bool safe_removal) pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF, INDICATOR_NOOP); + + /* Don't carry LBMS indications across */ + pcie_reset_lbms_count(ctrl->pcie->port); } static int pciehp_enable_slot(struct controller *ctrl); diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 3d67e8b50ba2..f85f380cdb9b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4740,7 +4740,7 @@ int pcie_retrain_link(struct pci_dev *pdev, bool use_lt) * to track link speed or width changes made by hardware itself * in attempt to correct unreliable link operation. */ - pcie_capability_write_word(pdev, PCI_EXP_LNKSTA, PCI_EXP_LNKSTA_LBMS); + pcie_reset_lbms_count(pdev); return rc; } diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 8137ad2fead8..8ec189c8f3f5 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -698,6 +698,17 @@ static inline void pcie_set_ecrc_checking(struct pci_dev *dev) { } static inline void pcie_ecrc_get_policy(char *str) { } #endif +#ifdef CONFIG_PCIEPORTBUS +void pcie_reset_lbms_count(struct pci_dev *port); +int pcie_lbms_count(struct pci_dev *port, unsigned long *val); +#else +static inline void pcie_reset_lbms_count(struct pci_dev *port) {} +static inline int pcie_lbms_count(struct pci_dev *port, unsigned long *val) +{ + return -EOPNOTSUPP; +} +#endif + struct pci_dev_reset_methods { u16 vendor; u16 device; diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile index 6461aa93fe76..53ccab62314d 100644 --- a/drivers/pci/pcie/Makefile +++ b/drivers/pci/pcie/Makefile @@ -4,7 +4,7 @@ pcieportdrv-y := portdrv.o rcec.o -obj-$(CONFIG_PCIEPORTBUS) += pcieportdrv.o +obj-$(CONFIG_PCIEPORTBUS) += pcieportdrv.o bwctrl.o obj-y += aspm.o obj-$(CONFIG_PCIEAER) += aer.o err.o diff --git a/drivers/pci/pcie/bwctrl.c b/drivers/pci/pcie/bwctrl.c new file mode 100644 index 000000000000..b3da24900271 --- /dev/null +++ b/drivers/pci/pcie/bwctrl.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * PCIe bandwidth controller + * + * Author: Alexandru Gagniuc <mr.nuke.me@gmail.com> + * + * Copyright (C) 2019 Dell Inc + * Copyright (C) 2023-2024 Intel Corporation + * + * This service port driver hooks into the Bandwidth Notification interrupt + * watching for changes or links becoming degraded in operation. It updates + * the cached Current Link Speed that is exposed to user space through sysfs. + */ + +#define dev_fmt(fmt) "bwctrl: " fmt + +#include <linux/atomic.h> +#include <linux/cleanup.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/pci.h> +#include <linux/rwsem.h> +#include <linux/slab.h> +#include <linux/types.h> + +#include "../pci.h" +#include "portdrv.h" + +/** + * struct pcie_bwctrl_data - PCIe bandwidth controller + * @lbms_count: Count for LBMS (since last reset) + */ +struct pcie_bwctrl_data { + atomic_t lbms_count; +}; + +/* Prevents port removal during LBMS count accessors */ +static DECLARE_RWSEM(pcie_bwctrl_lbms_rwsem); + +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 */ + 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); + + pcie_capability_set_word(port, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_LBMIE | PCI_EXP_LNKCTL_LABIE); + pcie_capability_write_word(port, PCI_EXP_LNKSTA, + PCI_EXP_LNKSTA_LBMS | PCI_EXP_LNKSTA_LABS); + + /* + * Update after enabling notifications & clearing status bits ensures + * link speed is up to date. + */ + pcie_update_link_speed(port->subordinate); +} + +static void pcie_bwnotif_disable(struct pci_dev *port) +{ + pcie_capability_clear_word(port, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_LBMIE | PCI_EXP_LNKCTL_LABIE); +} + +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; + + ret = pcie_capability_read_word(port, PCI_EXP_LNKSTA, &link_status); + if (ret != PCIBIOS_SUCCESSFUL) + return IRQ_NONE; + + events = link_status & (PCI_EXP_LNKSTA_LBMS | PCI_EXP_LNKSTA_LABS); + if (!events) + return IRQ_NONE; + + if (events & PCI_EXP_LNKSTA_LBMS) + atomic_inc(&data->lbms_count); + + pcie_capability_write_word(port, PCI_EXP_LNKSTA, events); + + /* + * Interrupts will not be triggered from any further Link Speed + * change until LBMS is cleared by the write. Therefore, re-read the + * speed (inside pcie_update_link_speed()) after LBMS has been + * cleared to avoid missing link speed changes. + */ + pcie_update_link_speed(port->subordinate); + + return IRQ_HANDLED; +} + +void pcie_reset_lbms_count(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; +} + +static int pcie_bwnotif_probe(struct pcie_device *srv) +{ + struct pci_dev *port = srv->port; + int ret; + + struct pcie_bwctrl_data *data = devm_kzalloc(&srv->device, + sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + ret = devm_request_irq(&srv->device, srv->irq, pcie_bwnotif_irq, + IRQF_SHARED, "PCIe bwctrl", srv); + if (ret) + return ret; + + scoped_guard(rwsem_write, &pcie_bwctrl_lbms_rwsem) { + port->link_bwctrl = no_free_ptr(data); + pcie_bwnotif_enable(srv); + } + + pci_dbg(port, "enabled with IRQ %d\n", srv->irq); + + return 0; +} + +static void pcie_bwnotif_remove(struct pcie_device *srv) +{ + pcie_bwnotif_disable(srv->port); + scoped_guard(rwsem_write, &pcie_bwctrl_lbms_rwsem) + srv->port->link_bwctrl = NULL; +} + +static int pcie_bwnotif_suspend(struct pcie_device *srv) +{ + pcie_bwnotif_disable(srv->port); + return 0; +} + +static int pcie_bwnotif_resume(struct pcie_device *srv) +{ + pcie_bwnotif_enable(srv); + return 0; +} + +static struct pcie_port_service_driver pcie_bwctrl_driver = { + .name = "pcie_bwctrl", + .port_type = PCIE_ANY_PORT, + .service = PCIE_PORT_SERVICE_BWCTRL, + .probe = pcie_bwnotif_probe, + .suspend = pcie_bwnotif_suspend, + .resume = pcie_bwnotif_resume, + .remove = pcie_bwnotif_remove, +}; + +int __init pcie_bwctrl_init(void) +{ + return pcie_port_service_register(&pcie_bwctrl_driver); +} diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c index 6af5e0425872..5e10306b6308 100644 --- a/drivers/pci/pcie/portdrv.c +++ b/drivers/pci/pcie/portdrv.c @@ -68,7 +68,7 @@ static int pcie_message_numbers(struct pci_dev *dev, int mask, */ if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP | - PCIE_PORT_SERVICE_BWNOTIF)) { + PCIE_PORT_SERVICE_BWCTRL)) { pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16); *pme = FIELD_GET(PCI_EXP_FLAGS_IRQ, reg16); nvec = *pme + 1; @@ -150,11 +150,11 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask) /* 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_PORT_SERVICE_BWCTRL)) { 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; + irqs[PCIE_PORT_SERVICE_BWCTRL_SHIFT] = pcie_irq; } if (mask & PCIE_PORT_SERVICE_AER) @@ -271,7 +271,7 @@ static int get_port_device_capability(struct pci_dev *dev) pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &linkcap); if (linkcap & PCI_EXP_LNKCAP_LBNC) - services |= PCIE_PORT_SERVICE_BWNOTIF; + services |= PCIE_PORT_SERVICE_BWCTRL; } return services; @@ -828,6 +828,7 @@ static void __init pcie_init_services(void) pcie_aer_init(); pcie_pme_init(); pcie_dpc_init(); + pcie_bwctrl_init(); pcie_hp_init(); } diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h index 12c89ea0313b..bd29d1cc7b8b 100644 --- a/drivers/pci/pcie/portdrv.h +++ b/drivers/pci/pcie/portdrv.h @@ -20,8 +20,8 @@ #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_SERVICE_BWCTRL_SHIFT 4 /* Bandwidth Controller (notifications) */ +#define PCIE_PORT_SERVICE_BWCTRL (1 << PCIE_PORT_SERVICE_BWCTRL_SHIFT) #define PCIE_PORT_DEVICE_MAXSERVICES 5 @@ -51,6 +51,8 @@ int pcie_dpc_init(void); static inline int pcie_dpc_init(void) { return 0; } #endif +int pcie_bwctrl_init(void); + /* Port Type */ #define PCIE_ANY_PORT (~0) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index a560ea403b8e..e6d502dca939 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -35,7 +35,14 @@ static bool pcie_lbms_seen(struct pci_dev *dev, u16 lnksta) { - return lnksta & PCI_EXP_LNKSTA_LBMS; + unsigned long count; + int ret; + + ret = pcie_lbms_count(dev, &count); + if (ret < 0) + return lnksta & PCI_EXP_LNKSTA_LBMS; + + return count > 0; } /* diff --git a/include/linux/pci.h b/include/linux/pci.h index 99c6fa30d25b..579b28833429 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -313,6 +313,7 @@ struct pci_vpd { }; struct irq_affinity; +struct pcie_bwctrl_data; struct pcie_link_state; struct pci_sriov; struct pci_p2pdma; @@ -502,6 +503,7 @@ struct pci_dev { unsigned int dpc_rp_extensions:1; u8 dpc_rp_log_size; #endif + struct pcie_bwctrl_data *link_bwctrl; #ifdef CONFIG_PCI_ATS union { struct pci_sriov *sriov; /* PF: SR-IOV info */ |