Merge branch 'pci/portdrv'

- Allow portdrv to claim subtractive decode Ports so PCIe services will
    work for them (Honghui Zhang)

  - Report PCIe links that become degraded at run-time (Alexandru Gagniuc)

* pci/portdrv:
  PCI/LINK: Report degraded links via link bandwidth notification
  PCI/portdrv: Support PCIe services on subtractive decode bridges
  PCI/portdrv: Use conventional Device ID table formatting
This commit is contained in:
Bjorn Helgaas 2019-03-06 15:30:14 -06:00
commit 9c926ec785
5 changed files with 134 additions and 9 deletions

View file

@ -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

View file

@ -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);
}

View file

@ -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)

View file

@ -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;
}

View file

@ -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)