mirror of
				https://github.com/torvalds/linux.git
				synced 2025-11-04 02:30:34 +02:00 
			
		
		
		
	e8303bb7a7("PCI/LINK: Report degraded links via link bandwidth notification") added dmesg logging whenever a link changes speed or width to a state that is considered degraded. Unfortunately, it cannot differentiate signal integrity-related link changes from those intentionally initiated by an endpoint driver, including drivers that may live in userspace or VMs when making use of vfio-pci. Some GPU drivers actively manage the link state to save power, which generates a stream of messages like this: vfio-pci 0000:07:00.0: 32.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s x16 link at 0000:00:02.0 (capable of 64.000 Gb/s with 5 GT/s x16 link) Since we can't distinguish the intentional changes from the signal integrity issues, leave the reporting turned off by default. Add a Kconfig option to turn it on if desired. Fixes:e8303bb7a7("PCI/LINK: Report degraded links via link bandwidth notification") Link: https://lore.kernel.org/linux-pci/20190501142942.26972-1-keith.busch@intel.com Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
		
			
				
	
	
		
			165 lines
		
	
	
	
		
			4.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			165 lines
		
	
	
	
		
			4.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
 | 
						|
/*
 | 
						|
 * Purpose:	PCI Express Port Bus Driver's Internal Data Structures
 | 
						|
 *
 | 
						|
 * Copyright (C) 2004 Intel
 | 
						|
 * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
 | 
						|
 */
 | 
						|
 | 
						|
#ifndef _PORTDRV_H_
 | 
						|
#define _PORTDRV_H_
 | 
						|
 | 
						|
#include <linux/compiler.h>
 | 
						|
 | 
						|
/* Service Type */
 | 
						|
#define PCIE_PORT_SERVICE_PME_SHIFT	0	/* Power Management Event */
 | 
						|
#define PCIE_PORT_SERVICE_PME		(1 << PCIE_PORT_SERVICE_PME_SHIFT)
 | 
						|
#define PCIE_PORT_SERVICE_AER_SHIFT	1	/* Advanced Error Reporting */
 | 
						|
#define PCIE_PORT_SERVICE_AER		(1 << PCIE_PORT_SERVICE_AER_SHIFT)
 | 
						|
#define PCIE_PORT_SERVICE_HP_SHIFT	2	/* Native Hotplug */
 | 
						|
#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   5
 | 
						|
 | 
						|
#ifdef CONFIG_PCIEAER
 | 
						|
int pcie_aer_init(void);
 | 
						|
#else
 | 
						|
static inline int pcie_aer_init(void) { return 0; }
 | 
						|
#endif
 | 
						|
 | 
						|
#ifdef CONFIG_HOTPLUG_PCI_PCIE
 | 
						|
int pcie_hp_init(void);
 | 
						|
#else
 | 
						|
static inline int pcie_hp_init(void) { return 0; }
 | 
						|
#endif
 | 
						|
 | 
						|
#ifdef CONFIG_PCIE_PME
 | 
						|
int pcie_pme_init(void);
 | 
						|
#else
 | 
						|
static inline int pcie_pme_init(void) { return 0; }
 | 
						|
#endif
 | 
						|
 | 
						|
#ifdef CONFIG_PCIE_DPC
 | 
						|
int pcie_dpc_init(void);
 | 
						|
#else
 | 
						|
static inline int pcie_dpc_init(void) { return 0; }
 | 
						|
#endif
 | 
						|
 | 
						|
#ifdef CONFIG_PCIE_BW
 | 
						|
int pcie_bandwidth_notification_init(void);
 | 
						|
#else
 | 
						|
static inline int pcie_bandwidth_notification_init(void) { return 0; }
 | 
						|
#endif
 | 
						|
 | 
						|
/* Port Type */
 | 
						|
#define PCIE_ANY_PORT			(~0)
 | 
						|
 | 
						|
struct pcie_device {
 | 
						|
	int		irq;	    /* Service IRQ/MSI/MSI-X Vector */
 | 
						|
	struct pci_dev *port;	    /* Root/Upstream/Downstream Port */
 | 
						|
	u32		service;    /* Port service this device represents */
 | 
						|
	void		*priv_data; /* Service Private Data */
 | 
						|
	struct device	device;     /* Generic Device Interface */
 | 
						|
};
 | 
						|
#define to_pcie_device(d) container_of(d, struct pcie_device, device)
 | 
						|
 | 
						|
static inline void set_service_data(struct pcie_device *dev, void *data)
 | 
						|
{
 | 
						|
	dev->priv_data = data;
 | 
						|
}
 | 
						|
 | 
						|
static inline void *get_service_data(struct pcie_device *dev)
 | 
						|
{
 | 
						|
	return dev->priv_data;
 | 
						|
}
 | 
						|
 | 
						|
struct pcie_port_service_driver {
 | 
						|
	const char *name;
 | 
						|
	int (*probe)(struct pcie_device *dev);
 | 
						|
	void (*remove)(struct pcie_device *dev);
 | 
						|
	int (*suspend)(struct pcie_device *dev);
 | 
						|
	int (*resume_noirq)(struct pcie_device *dev);
 | 
						|
	int (*resume)(struct pcie_device *dev);
 | 
						|
	int (*runtime_suspend)(struct pcie_device *dev);
 | 
						|
	int (*runtime_resume)(struct pcie_device *dev);
 | 
						|
 | 
						|
	/* Device driver may resume normal operations */
 | 
						|
	void (*error_resume)(struct pci_dev *dev);
 | 
						|
 | 
						|
	/* Link Reset Capability - AER service driver specific */
 | 
						|
	pci_ers_result_t (*reset_link)(struct pci_dev *dev);
 | 
						|
 | 
						|
	int port_type;  /* Type of the port this driver can handle */
 | 
						|
	u32 service;    /* Port service this device represents */
 | 
						|
 | 
						|
	struct device_driver driver;
 | 
						|
};
 | 
						|
#define to_service_driver(d) \
 | 
						|
	container_of(d, struct pcie_port_service_driver, driver)
 | 
						|
 | 
						|
int pcie_port_service_register(struct pcie_port_service_driver *new);
 | 
						|
void pcie_port_service_unregister(struct pcie_port_service_driver *new);
 | 
						|
 | 
						|
/*
 | 
						|
 * The PCIe Capability Interrupt Message Number (PCIe r3.1, sec 7.8.2) must
 | 
						|
 * be one of the first 32 MSI-X entries.  Per PCI r3.0, sec 6.8.3.1, MSI
 | 
						|
 * supports a maximum of 32 vectors per function.
 | 
						|
 */
 | 
						|
#define PCIE_PORT_MAX_MSI_ENTRIES	32
 | 
						|
 | 
						|
#define get_descriptor_id(type, service) (((type - 4) << 8) | service)
 | 
						|
 | 
						|
extern struct bus_type pcie_port_bus_type;
 | 
						|
int pcie_port_device_register(struct pci_dev *dev);
 | 
						|
#ifdef CONFIG_PM
 | 
						|
int pcie_port_device_suspend(struct device *dev);
 | 
						|
int pcie_port_device_resume_noirq(struct device *dev);
 | 
						|
int pcie_port_device_resume(struct device *dev);
 | 
						|
int pcie_port_device_runtime_suspend(struct device *dev);
 | 
						|
int pcie_port_device_runtime_resume(struct device *dev);
 | 
						|
#endif
 | 
						|
void pcie_port_device_remove(struct pci_dev *dev);
 | 
						|
int __must_check pcie_port_bus_register(void);
 | 
						|
void pcie_port_bus_unregister(void);
 | 
						|
 | 
						|
struct pci_dev;
 | 
						|
 | 
						|
#ifdef CONFIG_PCIE_PME
 | 
						|
extern bool pcie_pme_msi_disabled;
 | 
						|
 | 
						|
static inline void pcie_pme_disable_msi(void)
 | 
						|
{
 | 
						|
	pcie_pme_msi_disabled = true;
 | 
						|
}
 | 
						|
 | 
						|
static inline bool pcie_pme_no_msi(void)
 | 
						|
{
 | 
						|
	return pcie_pme_msi_disabled;
 | 
						|
}
 | 
						|
 | 
						|
void pcie_pme_interrupt_enable(struct pci_dev *dev, bool enable);
 | 
						|
#else /* !CONFIG_PCIE_PME */
 | 
						|
static inline void pcie_pme_disable_msi(void) {}
 | 
						|
static inline bool pcie_pme_no_msi(void) { return false; }
 | 
						|
static inline void pcie_pme_interrupt_enable(struct pci_dev *dev, bool en) {}
 | 
						|
#endif /* !CONFIG_PCIE_PME */
 | 
						|
 | 
						|
#ifdef CONFIG_ACPI_APEI
 | 
						|
int pcie_aer_get_firmware_first(struct pci_dev *pci_dev);
 | 
						|
#else
 | 
						|
static inline int pcie_aer_get_firmware_first(struct pci_dev *pci_dev)
 | 
						|
{
 | 
						|
	if (pci_dev->__aer_firmware_first_valid)
 | 
						|
		return pci_dev->__aer_firmware_first;
 | 
						|
	return 0;
 | 
						|
}
 | 
						|
#endif
 | 
						|
 | 
						|
struct pcie_port_service_driver *pcie_port_find_service(struct pci_dev *dev,
 | 
						|
							u32 service);
 | 
						|
struct device *pcie_port_find_device(struct pci_dev *dev, u32 service);
 | 
						|
#endif /* _PORTDRV_H_ */
 |