Commit 9c926ec7 authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

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
parents 6d940a71 e8303bb7

drivers/pci/pcie/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/pci/pcie/bw_notification.c

0 → 100644
+110 −0
Original line number Diff line number Diff line 
// 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);

}

drivers/pci/pcie/portdrv.h

+5 −1
Original line number Diff line number Diff line
@@ -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)

drivers/pci/pcie/portdrv_core.c

+12 −5
Original line number Diff line number Diff line
@@ -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;

}

drivers/pci/pcie/portdrv_pci.c

+6 −3
Original line number Diff line number Diff line
@@ -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)

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