drivers/pci/hotplug/pciehp_core.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * PCI Express Hot Plug Controller Driver
  *
  * Copyright (C) 1995,2001 Compaq Computer Corporation
  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
  * Copyright (C) 2001 IBM Corp.
  * Copyright (C) 2003-2004 Intel Corporation
  *
  * All rights reserved.
  *
  * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
  *
  * Authors:
  *   Dan Zink <dan.zink@compaq.com>
  *   Greg Kroah-Hartman <greg@kroah.com>
  *   Dely Sy <dely.l.sy@intel.com>"
  */

 #define pr_fmt(fmt) "pciehp: " fmt
 #define dev_fmt pr_fmt

 #include <linux/moduleparam.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/pci.h>
 #include "pciehp.h"

 #include "../pci.h"

 /* Global variables */
 bool pciehp_poll_mode;
 int pciehp_poll_time;

 /*
  * not really modular, but the easiest way to keep compat with existing
  * bootargs behaviour is to continue using module_param here.
  */
 module_param(pciehp_poll_mode, bool, 0644);
 module_param(pciehp_poll_time, int, 0644);
 MODULE_PARM_DESC(pciehp_poll_mode, "Using polling mechanism for hot-plug events or not");
 MODULE_PARM_DESC(pciehp_poll_time, "Polling mechanism frequency, in seconds");

 static int set_attention_status(struct hotplug_slot *slot, u8 value);
 static int get_power_status(struct hotplug_slot *slot, u8 *value);
 static int get_latch_status(struct hotplug_slot *slot, u8 *value);
 static int get_adapter_status(struct hotplug_slot *slot, u8 *value);

 static int init_slot(struct controller *ctrl)
 {
 	struct hotplug_slot_ops *ops;
 	char name[SLOT_NAME_SIZE];
 	int retval;

 	/* Setup hotplug slot ops */
 	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
 	if (!ops)
 		return -ENOMEM;

 	ops->enable_slot = pciehp_sysfs_enable_slot;
 	ops->disable_slot = pciehp_sysfs_disable_slot;
 	ops->get_power_status = get_power_status;
 	ops->get_adapter_status = get_adapter_status;
 	ops->reset_slot = pciehp_reset_slot;
 	if (MRL_SENS(ctrl))
 		ops->get_latch_status = get_latch_status;
 	if (ATTN_LED(ctrl)) {
 		ops->get_attention_status = pciehp_get_attention_status;
 		ops->set_attention_status = set_attention_status;
 	} else if (ctrl->pcie->port->hotplug_user_indicators) {
 		ops->get_attention_status = pciehp_get_raw_indicator_status;
 		ops->set_attention_status = pciehp_set_raw_indicator_status;
 	}

 	/* register this slot with the hotplug pci core */
 	ctrl->hotplug_slot.ops = ops;
 	snprintf(name, SLOT_NAME_SIZE, "%u", PSN(ctrl));

 	retval = pci_hp_initialize(&ctrl->hotplug_slot,
 				   ctrl->pcie->port->subordinate, 0, name);
 	if (retval) {
 		ctrl_err(ctrl, "pci_hp_initialize failed: error %d\n", retval);
 		kfree(ops);
 	}
 	return retval;
 }

 static void cleanup_slot(struct controller *ctrl)
 {
 	struct hotplug_slot *hotplug_slot = &ctrl->hotplug_slot;

 	pci_hp_destroy(hotplug_slot);
 	kfree(hotplug_slot->ops);
 }

 /*
  * set_attention_status - Turns the Attention Indicator on, off or blinking
  */
 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
 {
 	struct controller *ctrl = to_ctrl(hotplug_slot);
 	struct pci_dev *pdev = ctrl->pcie->port;

 	if (status)
 		status <<= PCI_EXP_SLTCTL_ATTN_IND_SHIFT;
 	else
 		status = PCI_EXP_SLTCTL_ATTN_IND_OFF;

 	pci_config_pm_runtime_get(pdev);
 	pciehp_set_indicators(ctrl, INDICATOR_NOOP, status);
 	pci_config_pm_runtime_put(pdev);
 	return 0;
 }

 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 {
 	struct controller *ctrl = to_ctrl(hotplug_slot);
 	struct pci_dev *pdev = ctrl->pcie->port;

 	pci_config_pm_runtime_get(pdev);
 	pciehp_get_power_status(ctrl, value);
 	pci_config_pm_runtime_put(pdev);
 	return 0;
 }

 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
 {
 	struct controller *ctrl = to_ctrl(hotplug_slot);
 	struct pci_dev *pdev = ctrl->pcie->port;

 	pci_config_pm_runtime_get(pdev);
 	pciehp_get_latch_status(ctrl, value);
 	pci_config_pm_runtime_put(pdev);
 	return 0;
 }

 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 {
 	struct controller *ctrl = to_ctrl(hotplug_slot);
 	struct pci_dev *pdev = ctrl->pcie->port;
 	int ret;

 	pci_config_pm_runtime_get(pdev);
 	ret = pciehp_card_present_or_link_active(ctrl);
 	pci_config_pm_runtime_put(pdev);
 	if (ret < 0)
 		return ret;

 	*value = ret;
 	return 0;
 }

 /**
  * pciehp_check_presence() - synthesize event if presence has changed
  *
  * On probe and resume, an explicit presence check is necessary to bring up an
  * occupied slot or bring down an unoccupied slot.  This can't be triggered by
  * events in the Slot Status register, they may be stale and are therefore
  * cleared.  Secondly, sending an interrupt for "events that occur while
  * interrupt generation is disabled [when] interrupt generation is subsequently
  * enabled" is optional per PCIe r4.0, sec 6.7.3.4.
  */
 static void pciehp_check_presence(struct controller *ctrl)
 {
 	int occupied;

 	down_read(&ctrl->reset_lock);
 	mutex_lock(&ctrl->state_lock);

 	occupied = pciehp_card_present_or_link_active(ctrl);
 	if ((occupied > 0 && (ctrl->state == OFF_STATE ||
 			  ctrl->state == BLINKINGON_STATE)) ||
 	    (!occupied && (ctrl->state == ON_STATE ||
 			   ctrl->state == BLINKINGOFF_STATE)))
 		pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);

 	mutex_unlock(&ctrl->state_lock);
 	up_read(&ctrl->reset_lock);
 }

 static int pciehp_probe(struct pcie_device *dev)
 {
 	int rc;
 	struct controller *ctrl;

 	/* If this is not a "hotplug" service, we have no business here. */
 	if (dev->service != PCIE_PORT_SERVICE_HP)
 		return -ENODEV;

 	if (!dev->port->subordinate) {
 		/* Can happen if we run out of bus numbers during probe */
 		pci_err(dev->port,
 			"Hotplug bridge without secondary bus, ignoring\n");
 		return -ENODEV;
 	}

 	ctrl = pcie_init(dev);
 	if (!ctrl) {
 		pci_err(dev->port, "Controller initialization failed\n");
 		return -ENODEV;
 	}
 	set_service_data(dev, ctrl);

 	/* Setup the slot information structures */
 	rc = init_slot(ctrl);
 	if (rc) {
 		if (rc == -EBUSY)
 			ctrl_warn(ctrl, "Slot already registered by another hotplug driver\n");
 		else
 			ctrl_err(ctrl, "Slot initialization failed (%d)\n", rc);
 		goto err_out_release_ctlr;
 	}

 	/* Enable events after we have setup the data structures */
 	rc = pcie_init_notification(ctrl);
 	if (rc) {
 		ctrl_err(ctrl, "Notification initialization failed (%d)\n", rc);
 		goto err_out_free_ctrl_slot;
 	}

 	/* Publish to user space */
 	rc = pci_hp_add(&ctrl->hotplug_slot);
 	if (rc) {
 		ctrl_err(ctrl, "Publication to user space failed (%d)\n", rc);
 		goto err_out_shutdown_notification;
 	}

 	pciehp_check_presence(ctrl);

 	return 0;

 err_out_shutdown_notification:
 	pcie_shutdown_notification(ctrl);
 err_out_free_ctrl_slot:
 	cleanup_slot(ctrl);
 err_out_release_ctlr:
 	pciehp_release_ctrl(ctrl);
 	return -ENODEV;
 }

 static void pciehp_remove(struct pcie_device *dev)
 {
 	struct controller *ctrl = get_service_data(dev);

 	pci_hp_del(&ctrl->hotplug_slot);
 	pcie_shutdown_notification(ctrl);
 	cleanup_slot(ctrl);
 	pciehp_release_ctrl(ctrl);
 }

 #ifdef CONFIG_PM
 static bool pme_is_native(struct pcie_device *dev)
 {
 	const struct pci_host_bridge *host;

 	host = pci_find_host_bridge(dev->port->bus);
 	return pcie_ports_native || host->native_pme;
 }

 static void pciehp_disable_interrupt(struct pcie_device *dev)
 {
 	/*
 	 * Disable hotplug interrupt so that it does not trigger
 	 * immediately when the downstream link goes down.
 	 */
 	if (pme_is_native(dev))
 		pcie_disable_interrupt(get_service_data(dev));
 }

 #ifdef CONFIG_PM_SLEEP
 static int pciehp_suspend(struct pcie_device *dev)
 {
 	/*
 	 * If the port is already runtime suspended we can keep it that
 	 * way.
 	 */
 	if (dev_pm_skip_suspend(&dev->port->dev))
 		return 0;

 	pciehp_disable_interrupt(dev);
 	return 0;
 }

 static int pciehp_resume_noirq(struct pcie_device *dev)
 {
 	struct controller *ctrl = get_service_data(dev);

 	/* pci_restore_state() just wrote to the Slot Control register */
 	ctrl->cmd_started = jiffies;
 	ctrl->cmd_busy = true;

 	/* clear spurious events from rediscovery of inserted card */
 	if (ctrl->state == ON_STATE || ctrl->state == BLINKINGOFF_STATE)
 		pcie_clear_hotplug_events(ctrl);

 	return 0;
 }
 #endif

 static int pciehp_resume(struct pcie_device *dev)
 {
 	struct controller *ctrl = get_service_data(dev);

 	if (pme_is_native(dev))
 		pcie_enable_interrupt(ctrl);

 	pciehp_check_presence(ctrl);

 	return 0;
 }

 static int pciehp_runtime_suspend(struct pcie_device *dev)
 {
 	pciehp_disable_interrupt(dev);
 	return 0;
 }

 static int pciehp_runtime_resume(struct pcie_device *dev)
 {
 	struct controller *ctrl = get_service_data(dev);

 	/* pci_restore_state() just wrote to the Slot Control register */
 	ctrl->cmd_started = jiffies;
 	ctrl->cmd_busy = true;

 	/* clear spurious events from rediscovery of inserted card */
 	if ((ctrl->state == ON_STATE || ctrl->state == BLINKINGOFF_STATE) &&
 	     pme_is_native(dev))
 		pcie_clear_hotplug_events(ctrl);

 	return pciehp_resume(dev);
 }
 #endif /* PM */

 static struct pcie_port_service_driver hpdriver_portdrv = {
 	.name		= "pciehp",
 	.port_type	= PCIE_ANY_PORT,
 	.service	= PCIE_PORT_SERVICE_HP,

 	.probe		= pciehp_probe,
 	.remove		= pciehp_remove,

 #ifdef	CONFIG_PM
 #ifdef	CONFIG_PM_SLEEP
 	.suspend	= pciehp_suspend,
 	.resume_noirq	= pciehp_resume_noirq,
 	.resume		= pciehp_resume,
 #endif
 	.runtime_suspend = pciehp_runtime_suspend,
 	.runtime_resume	= pciehp_runtime_resume,
 #endif	/* PM */
 };

 int __init pcie_hp_init(void)
 {
 	int retval = 0;

 	retval = pcie_port_service_register(&hpdriver_portdrv);
 	pr_debug("pcie_port_service_register = %d\n", retval);
 	if (retval)
 		pr_debug("Failure to register service\n");

 	return retval;
 }
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* PCI Express Hot Plug Controller Driver
	*
	* Copyright (C) 1995,2001 Compaq Computer Corporation
	* Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
	* Copyright (C) 2001 IBM Corp.
	* Copyright (C) 2003-2004 Intel Corporation
	*
	* All rights reserved.
	*
	* Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
	*
	* Authors:
	* Dan Zink <dan.zink@compaq.com>
	* Greg Kroah-Hartman <greg@kroah.com>
	* Dely Sy <dely.l.sy@intel.com>"
	*/

	#define pr_fmt(fmt) "pciehp: " fmt
	#define dev_fmt pr_fmt

	#include <linux/moduleparam.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/types.h>
	#include <linux/pci.h>
	#include "pciehp.h"

	#include "../pci.h"

	/* Global variables */
	bool pciehp_poll_mode;
	int pciehp_poll_time;

	/*
	* not really modular, but the easiest way to keep compat with existing
	* bootargs behaviour is to continue using module_param here.
	*/
	module_param(pciehp_poll_mode, bool, 0644);
	module_param(pciehp_poll_time, int, 0644);
	MODULE_PARM_DESC(pciehp_poll_mode, "Using polling mechanism for hot-plug events or not");
	MODULE_PARM_DESC(pciehp_poll_time, "Polling mechanism frequency, in seconds");

	static int set_attention_status(struct hotplug_slot *slot, u8 value);
	static int get_power_status(struct hotplug_slot slot, u8 value);
	static int get_latch_status(struct hotplug_slot slot, u8 value);
	static int get_adapter_status(struct hotplug_slot slot, u8 value);

	static int init_slot(struct controller *ctrl)
	{
	struct hotplug_slot_ops *ops;
	char name[SLOT_NAME_SIZE];
	int retval;

	/* Setup hotplug slot ops */
	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
	if (!ops)
	return -ENOMEM;

	ops->enable_slot = pciehp_sysfs_enable_slot;
	ops->disable_slot = pciehp_sysfs_disable_slot;
	ops->get_power_status = get_power_status;
	ops->get_adapter_status = get_adapter_status;
	ops->reset_slot = pciehp_reset_slot;
	if (MRL_SENS(ctrl))
	ops->get_latch_status = get_latch_status;
	if (ATTN_LED(ctrl)) {
	ops->get_attention_status = pciehp_get_attention_status;
	ops->set_attention_status = set_attention_status;
	} else if (ctrl->pcie->port->hotplug_user_indicators) {
	ops->get_attention_status = pciehp_get_raw_indicator_status;
	ops->set_attention_status = pciehp_set_raw_indicator_status;
	}

	/* register this slot with the hotplug pci core */
	ctrl->hotplug_slot.ops = ops;
	snprintf(name, SLOT_NAME_SIZE, "%u", PSN(ctrl));

	retval = pci_hp_initialize(&ctrl->hotplug_slot,
	ctrl->pcie->port->subordinate, 0, name);
	if (retval) {
	ctrl_err(ctrl, "pci_hp_initialize failed: error %d\n", retval);
	kfree(ops);
	}
	return retval;
	}

	static void cleanup_slot(struct controller *ctrl)
	{
	struct hotplug_slot *hotplug_slot = &ctrl->hotplug_slot;

	pci_hp_destroy(hotplug_slot);
	kfree(hotplug_slot->ops);
	}

	/*
	* set_attention_status - Turns the Attention Indicator on, off or blinking
	*/
	static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
	{
	struct controller *ctrl = to_ctrl(hotplug_slot);
	struct pci_dev *pdev = ctrl->pcie->port;

	if (status)
	status <<= PCI_EXP_SLTCTL_ATTN_IND_SHIFT;
	else
	status = PCI_EXP_SLTCTL_ATTN_IND_OFF;

	pci_config_pm_runtime_get(pdev);
	pciehp_set_indicators(ctrl, INDICATOR_NOOP, status);
	pci_config_pm_runtime_put(pdev);
	return 0;
	}

	static int get_power_status(struct hotplug_slot hotplug_slot, u8 value)
	{
	struct controller *ctrl = to_ctrl(hotplug_slot);
	struct pci_dev *pdev = ctrl->pcie->port;

	pci_config_pm_runtime_get(pdev);
	pciehp_get_power_status(ctrl, value);
	pci_config_pm_runtime_put(pdev);
	return 0;
	}

	static int get_latch_status(struct hotplug_slot hotplug_slot, u8 value)
	{
	struct controller *ctrl = to_ctrl(hotplug_slot);
	struct pci_dev *pdev = ctrl->pcie->port;

	pci_config_pm_runtime_get(pdev);
	pciehp_get_latch_status(ctrl, value);
	pci_config_pm_runtime_put(pdev);
	return 0;
	}

	static int get_adapter_status(struct hotplug_slot hotplug_slot, u8 value)
	{
	struct controller *ctrl = to_ctrl(hotplug_slot);
	struct pci_dev *pdev = ctrl->pcie->port;
	int ret;

	pci_config_pm_runtime_get(pdev);
	ret = pciehp_card_present_or_link_active(ctrl);
	pci_config_pm_runtime_put(pdev);
	if (ret < 0)
	return ret;

	*value = ret;
	return 0;
	}

	/**
	* pciehp_check_presence() - synthesize event if presence has changed
	*
	* On probe and resume, an explicit presence check is necessary to bring up an
	* occupied slot or bring down an unoccupied slot. This can't be triggered by
	* events in the Slot Status register, they may be stale and are therefore
	* cleared. Secondly, sending an interrupt for "events that occur while
	* interrupt generation is disabled [when] interrupt generation is subsequently
	* enabled" is optional per PCIe r4.0, sec 6.7.3.4.
	*/
	static void pciehp_check_presence(struct controller *ctrl)
	{
	int occupied;

	down_read(&ctrl->reset_lock);
	mutex_lock(&ctrl->state_lock);

	occupied = pciehp_card_present_or_link_active(ctrl);
	if ((occupied > 0 && (ctrl->state == OFF_STATE \|\|
	ctrl->state == BLINKINGON_STATE)) \|\|
	(!occupied && (ctrl->state == ON_STATE \|\|
	ctrl->state == BLINKINGOFF_STATE)))
	pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);

	mutex_unlock(&ctrl->state_lock);
	up_read(&ctrl->reset_lock);
	}

	static int pciehp_probe(struct pcie_device *dev)
	{
	int rc;
	struct controller *ctrl;

	/* If this is not a "hotplug" service, we have no business here. */
	if (dev->service != PCIE_PORT_SERVICE_HP)
	return -ENODEV;

	if (!dev->port->subordinate) {
	/* Can happen if we run out of bus numbers during probe */
	pci_err(dev->port,
	"Hotplug bridge without secondary bus, ignoring\n");
	return -ENODEV;
	}

	ctrl = pcie_init(dev);
	if (!ctrl) {
	pci_err(dev->port, "Controller initialization failed\n");
	return -ENODEV;
	}
	set_service_data(dev, ctrl);

	/* Setup the slot information structures */
	rc = init_slot(ctrl);
	if (rc) {
	if (rc == -EBUSY)
	ctrl_warn(ctrl, "Slot already registered by another hotplug driver\n");
	else
	ctrl_err(ctrl, "Slot initialization failed (%d)\n", rc);
	goto err_out_release_ctlr;
	}

	/* Enable events after we have setup the data structures */
	rc = pcie_init_notification(ctrl);
	if (rc) {
	ctrl_err(ctrl, "Notification initialization failed (%d)\n", rc);
	goto err_out_free_ctrl_slot;
	}

	/* Publish to user space */
	rc = pci_hp_add(&ctrl->hotplug_slot);
	if (rc) {
	ctrl_err(ctrl, "Publication to user space failed (%d)\n", rc);
	goto err_out_shutdown_notification;
	}

	pciehp_check_presence(ctrl);

	return 0;

	err_out_shutdown_notification:
	pcie_shutdown_notification(ctrl);
	err_out_free_ctrl_slot:
	cleanup_slot(ctrl);
	err_out_release_ctlr:
	pciehp_release_ctrl(ctrl);
	return -ENODEV;
	}

	static void pciehp_remove(struct pcie_device *dev)
	{
	struct controller *ctrl = get_service_data(dev);

	pci_hp_del(&ctrl->hotplug_slot);
	pcie_shutdown_notification(ctrl);
	cleanup_slot(ctrl);
	pciehp_release_ctrl(ctrl);
	}

	#ifdef CONFIG_PM
	static bool pme_is_native(struct pcie_device *dev)
	{
	const struct pci_host_bridge *host;

	host = pci_find_host_bridge(dev->port->bus);
	return pcie_ports_native \|\| host->native_pme;
	}

	static void pciehp_disable_interrupt(struct pcie_device *dev)
	{
	/*
	* Disable hotplug interrupt so that it does not trigger
	* immediately when the downstream link goes down.
	*/
	if (pme_is_native(dev))
	pcie_disable_interrupt(get_service_data(dev));
	}

	#ifdef CONFIG_PM_SLEEP
	static int pciehp_suspend(struct pcie_device *dev)
	{
	/*
	* If the port is already runtime suspended we can keep it that
	* way.
	*/
	if (dev_pm_skip_suspend(&dev->port->dev))
	return 0;

	pciehp_disable_interrupt(dev);
	return 0;
	}

	static int pciehp_resume_noirq(struct pcie_device *dev)
	{
	struct controller *ctrl = get_service_data(dev);

	/* pci_restore_state() just wrote to the Slot Control register */
	ctrl->cmd_started = jiffies;
	ctrl->cmd_busy = true;

	/* clear spurious events from rediscovery of inserted card */
	if (ctrl->state == ON_STATE \|\| ctrl->state == BLINKINGOFF_STATE)
	pcie_clear_hotplug_events(ctrl);

	return 0;
	}
	#endif

	static int pciehp_resume(struct pcie_device *dev)
	{
	struct controller *ctrl = get_service_data(dev);

	if (pme_is_native(dev))
	pcie_enable_interrupt(ctrl);

	pciehp_check_presence(ctrl);

	return 0;
	}

	static int pciehp_runtime_suspend(struct pcie_device *dev)
	{
	pciehp_disable_interrupt(dev);
	return 0;
	}

	static int pciehp_runtime_resume(struct pcie_device *dev)
	{
	struct controller *ctrl = get_service_data(dev);

	/* pci_restore_state() just wrote to the Slot Control register */
	ctrl->cmd_started = jiffies;
	ctrl->cmd_busy = true;

	/* clear spurious events from rediscovery of inserted card */
	if ((ctrl->state == ON_STATE \|\| ctrl->state == BLINKINGOFF_STATE) &&
	pme_is_native(dev))
	pcie_clear_hotplug_events(ctrl);

	return pciehp_resume(dev);
	}
	#endif /* PM */

	static struct pcie_port_service_driver hpdriver_portdrv = {
	.name = "pciehp",
	.port_type = PCIE_ANY_PORT,
	.service = PCIE_PORT_SERVICE_HP,

	.probe = pciehp_probe,
	.remove = pciehp_remove,

	#ifdef CONFIG_PM
	#ifdef CONFIG_PM_SLEEP
	.suspend = pciehp_suspend,
	.resume_noirq = pciehp_resume_noirq,
	.resume = pciehp_resume,
	#endif
	.runtime_suspend = pciehp_runtime_suspend,
	.runtime_resume = pciehp_runtime_resume,
	#endif /* PM */
	};

	int __init pcie_hp_init(void)
	{
	int retval = 0;

	retval = pcie_port_service_register(&hpdriver_portdrv);
	pr_debug("pcie_port_service_register = %d\n", retval);
	if (retval)
	pr_debug("Failure to register service\n");

	return retval;
	}