linux/drivers/pci/pcie/portdrv.h
Ilpo Järvinen 665745f274 PCI/bwctrl: Re-add BW notification portdrv as PCIe BW controller
This mostly reverts the commit b4c7d2076b4e ("PCI/LINK: Remove bandwidth
notification"). An upcoming commit extends this driver building PCIe
bandwidth controller on top of it.

PCIe bandwidth notifications were first added in the commit e8303bb7a75c
("PCI/LINK: Report degraded links via link bandwidth notification") but
later had to be removed. The significant changes compared with the old
bandwidth notification driver include:

1) Don't print the notifications into kernel log, just keep the Link
   Speed cached in struct pci_bus updated. While somewhat unfortunate,
   the log spam was the source of complaints that eventually lead to
   the removal of the bandwidth notifications driver (see the links
   below for further information).

2) Besides the Link Bandwidth Management Interrupt, also enable Link
   Autonomous Bandwidth Interrupt to cover the other source of bandwidth
   changes.

3) Handle Link Speed updates robustly. Refresh the cached Link Speed
   when enabling Bandwidth Notification Interrupts, and solve the race
   between Link Speed read and LBMS/LABS update in
   pcie_bwnotif_irq_thread().

4) Use concurrency safe LNKCTL RMW operations.

5) The driver is now called PCIe bwctrl (bandwidth controller) instead
   of just bandwidth notifications because of increased scope and
   functionality within the driver.

6) Coexist with the Target Link Speed quirk in pcie_failed_link_retrain().
   Provide LBMS counting API for it.

7) Tweaks to variable/functions names for consistency and length reasons.

Bandwidth Notifications enable the cur_bus_speed in the struct pci_bus to
keep track PCIe Link Speed changes.

[bhelgaas: This is based on previous work by Alexandru Gagniuc
<mr.nuke.me@gmail.com>; see e8303bb7a75c ("PCI/LINK: Report degraded links
via link bandwidth notification")]

Link: https://lore.kernel.org/r/20241018144755.7875-7-ilpo.jarvinen@linux.intel.com
Link: https://lore.kernel.org/all/20190429185611.121751-1-helgaas@kernel.org/
Link: https://lore.kernel.org/linux-pci/20190501142942.26972-1-keith.busch@intel.com/
Link: https://lore.kernel.org/linux-pci/20200115221008.GA191037@google.com/
Suggested-by: Lukas Wunner <lukas@wunner.de> # Building bwctrl on top of bwnotif
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: squash fix to drop IRQF_ONESHOT and convert to hardirq handler:
https://lore.kernel.org/r/20241115165717.15233-1-ilpo.jarvinen@linux.intel.com]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2024-11-16 10:09:04 -06:00

127 lines
3.6 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_BWCTRL_SHIFT 4 /* Bandwidth Controller (notifications) */
#define PCIE_PORT_SERVICE_BWCTRL (1 << PCIE_PORT_SERVICE_BWCTRL_SHIFT)
#define PCIE_PORT_DEVICE_MAXSERVICES 5
extern bool pcie_ports_dpc_native;
#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
int pcie_bwctrl_init(void);
/* 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);
int (*slot_reset)(struct pcie_device *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);
extern const struct bus_type pcie_port_bus_type;
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 */
struct device *pcie_port_find_device(struct pci_dev *dev, u32 service);
#endif /* _PORTDRV_H_ */