Release 4.16 drivers/pci/hotplug/pciehp_ctrl.c

// 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>
 *
 */

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

static void interrupt_event_handler(struct work_struct *work);



void pciehp_queue_interrupt_event(struct slot *p_slot, u32 event_type)
{
	struct event_info *info;

	info = kmalloc(sizeof(*info), GFP_ATOMIC);
	if (!info) {
		ctrl_err(p_slot->ctrl, "dropped event %d (ENOMEM)\n", event_type);
		return;
	}

	INIT_WORK(&info->work, interrupt_event_handler);
	info->event_type = event_type;
	info->p_slot = p_slot;
	queue_work(p_slot->wq, &info->work);
}

Contributors
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Kenji Kaneshige
54
64.29%
2
33.33%
Björn Helgaas
25
29.76%
2
33.33%
Yijing Wang
3
3.57%
1
16.67%
Tejun Heo
2
2.38%
1
16.67%
Total
84
100.00%
6
100.00%

/* The following routines constitute the bulk of the
   hotplug controller logic
 */



static void set_slot_off(struct controller *ctrl, struct slot *pslot)
{
	/* turn off slot, turn on Amber LED, turn off Green LED if supported*/
	if (POWER_CTRL(ctrl)) {
		pciehp_power_off_slot(pslot);

		/*
                 * After turning power off, we must wait for at least 1 second
                 * before taking any action that relies on power having been
                 * removed from the slot/adapter.
                 */
		msleep(1000);
	}

	pciehp_green_led_off(pslot);
	pciehp_set_attention_status(pslot, 1);
}

Contributors
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CommitProp
Rajesh Shah
31
63.27%
2
33.33%
Kenji Kaneshige
10
20.41%
3
50.00%
Dely Sy
8
16.33%
1
16.67%
Total
49
100.00%
6
100.00%

/**
 * board_added - Called after a board has been added to the system.
 * @p_slot: &slot where board is added
 *
 * Turns power on for the board.
 * Configures board.
 */


static int board_added(struct slot *p_slot)
{
	int retval = 0;
	struct controller *ctrl = p_slot->ctrl;
	struct pci_bus *parent = ctrl->pcie->port->subordinate;

	if (POWER_CTRL(ctrl)) {
		/* Power on slot */
		retval = pciehp_power_on_slot(p_slot);
		if (retval)
			return retval;
	}

	pciehp_green_led_blink(p_slot);

	/* Check link training status */
	retval = pciehp_check_link_status(ctrl);
	if (retval) {
		ctrl_err(ctrl, "Failed to check link status\n");
		goto err_exit;
	}

	/* Check for a power fault */
	if (ctrl->power_fault_detected || pciehp_query_power_fault(p_slot)) {
		ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(p_slot));
		retval = -EIO;
		goto err_exit;
	}

	retval = pciehp_configure_device(p_slot);
	if (retval) {
		if (retval != -EEXIST) {
			ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
				 pci_domain_nr(parent), parent->number);
			goto err_exit;
		}
	}

	pciehp_green_led_on(p_slot);
	pciehp_set_attention_status(p_slot, 0);
	return 0;

err_exit:
	set_slot_off(ctrl, p_slot);
	return retval;
}

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CommitProp
Rajesh Shah
62
32.12%
4
22.22%
Dely Sy
52
26.94%
1
5.56%
Kenji Kaneshige
37
19.17%
7
38.89%
Taku Izumi
24
12.44%
2
11.11%
Mika Westerberg
9
4.66%
1
5.56%
Keith Busch
7
3.63%
1
5.56%
Björn Helgaas
1
0.52%
1
5.56%
Rolf Eike Beer
1
0.52%
1
5.56%
Total
193
100.00%
18
100.00%

/**
 * remove_board - Turns off slot and LEDs
 * @p_slot: slot where board is being removed
 */


static int remove_board(struct slot *p_slot)
{
	int retval;
	struct controller *ctrl = p_slot->ctrl;

	retval = pciehp_unconfigure_device(p_slot);
	if (retval)
		return retval;

	if (POWER_CTRL(ctrl)) {
		pciehp_power_off_slot(p_slot);

		/*
                 * After turning power off, we must wait for at least 1 second
                 * before taking any action that relies on power having been
                 * removed from the slot/adapter.
                 */
		msleep(1000);
	}

	/* turn off Green LED */
	pciehp_green_led_off(p_slot);
	return 0;
}

Contributors
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CommitProp
Rajesh Shah
32
48.48%
3
33.33%
Kenji Kaneshige
18
27.27%
4
44.44%
Rolf Eike Beer
11
16.67%
1
11.11%
Dely Sy
5
7.58%
1
11.11%
Total
66
100.00%
9
100.00%


struct power_work_info {
	
struct slot *p_slot;
	
struct work_struct work;
	
unsigned int req;

#define DISABLE_REQ 0

#define ENABLE_REQ  1
};

/**
 * pciehp_power_thread - handle pushbutton events
 * @work: &struct work_struct describing work to be done
 *
 * Scheduled procedure to handle blocking stuff for the pushbuttons.
 * Handles all pending events and exits.
 */


static void pciehp_power_thread(struct work_struct *work)
{
	struct power_work_info *info =
		container_of(work, struct power_work_info, work);
	struct slot *p_slot = info->p_slot;
	int ret;

	switch (info->req) {
	case DISABLE_REQ:
		mutex_lock(&p_slot->hotplug_lock);
		pciehp_disable_slot(p_slot);
		mutex_unlock(&p_slot->hotplug_lock);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		mutex_unlock(&p_slot->lock);
		break;
	case ENABLE_REQ:
		mutex_lock(&p_slot->hotplug_lock);
		ret = pciehp_enable_slot(p_slot);
		mutex_unlock(&p_slot->hotplug_lock);
		if (ret)
			pciehp_green_led_off(p_slot);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		mutex_unlock(&p_slot->lock);
		break;
	default:
		break;
	}

	kfree(info);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Kenji Kaneshige
56
35.44%
2
33.33%
Rajat Jain
52
32.91%
2
33.33%
Rajesh Shah
33
20.89%
1
16.67%
Dely Sy
17
10.76%
1
16.67%
Total
158
100.00%
6
100.00%



static void pciehp_queue_power_work(struct slot *p_slot, int req)
{
	struct power_work_info *info;

	p_slot->state = (req == ENABLE_REQ) ? POWERON_STATE : POWEROFF_STATE;

	info = kmalloc(sizeof(*info), GFP_KERNEL);
	if (!info) {
		ctrl_err(p_slot->ctrl, "no memory to queue %s request\n",
			 (req == ENABLE_REQ) ? "poweron" : "poweroff");
		return;
	}
	info->p_slot = p_slot;
	INIT_WORK(&info->work, pciehp_power_thread);
	info->req = req;
	queue_work(p_slot->wq, &info->work);
}

Contributors
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Guenter Roeck
50
46.73%
1
20.00%
Kenji Kaneshige
24
22.43%
1
20.00%
Rajesh Shah
19
17.76%
1
20.00%
Dely Sy
9
8.41%
1
20.00%
Taku Izumi
5
4.67%
1
20.00%
Total
107
100.00%
5
100.00%



void pciehp_queue_pushbutton_work(struct work_struct *work)
{
	struct slot *p_slot = container_of(work, struct slot, work.work);

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case BLINKINGOFF_STATE:
		pciehp_queue_power_work(p_slot, DISABLE_REQ);
		break;
	case BLINKINGON_STATE:
		pciehp_queue_power_work(p_slot, ENABLE_REQ);
		break;
	default:
		break;
	}
	mutex_unlock(&p_slot->lock);
}

Contributors
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CommitProp
Guenter Roeck
35
46.67%
1
20.00%
Kenji Kaneshige
24
32.00%
1
20.00%
Dely Sy
6
8.00%
1
20.00%
Rajesh Shah
6
8.00%
1
20.00%
Rajat Jain
4
5.33%
1
20.00%
Total
75
100.00%
5
100.00%

/*
 * Note: This function must be called with slot->lock held
 */


static void handle_button_press_event(struct slot *p_slot)
{
	struct controller *ctrl = p_slot->ctrl;
	u8 getstatus;

	switch (p_slot->state) {
	case STATIC_STATE:
		pciehp_get_power_status(p_slot, &getstatus);
		if (getstatus) {
			p_slot->state = BLINKINGOFF_STATE;
			ctrl_info(ctrl, "Slot(%s): Powering off due to button press\n",
				  slot_name(p_slot));
		} else {
			p_slot->state = BLINKINGON_STATE;
			ctrl_info(ctrl, "Slot(%s) Powering on due to button press\n",
				  slot_name(p_slot));
		}
		/* blink green LED and turn off amber */
		pciehp_green_led_blink(p_slot);
		pciehp_set_attention_status(p_slot, 0);
		queue_delayed_work(p_slot->wq, &p_slot->work, 5*HZ);
		break;
	case BLINKINGOFF_STATE:
	case BLINKINGON_STATE:
		/*
                 * Cancel if we are still blinking; this means that we
                 * press the attention again before the 5 sec. limit
                 * expires to cancel hot-add or hot-remove
                 */
		ctrl_info(ctrl, "Slot(%s): Button cancel\n", slot_name(p_slot));
		cancel_delayed_work(&p_slot->work);
		if (p_slot->state == BLINKINGOFF_STATE)
			pciehp_green_led_on(p_slot);
		else
			pciehp_green_led_off(p_slot);
		pciehp_set_attention_status(p_slot, 0);
		ctrl_info(ctrl, "Slot(%s): Action canceled due to button press\n",
			  slot_name(p_slot));
		p_slot->state = STATIC_STATE;
		break;
	case POWEROFF_STATE:
	case POWERON_STATE:
		/*
                 * Ignore if the slot is on power-on or power-off state;
                 * this means that the previous attention button action
                 * to hot-add or hot-remove is undergoing
                 */
		ctrl_info(ctrl, "Slot(%s): Button ignored\n",
			  slot_name(p_slot));
		break;
	default:
		ctrl_err(ctrl, "Slot(%s): Ignoring invalid state %#x\n",
			 slot_name(p_slot), p_slot->state);
		break;
	}
}

Contributors
Person
Tokens
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CommitProp
Kenji Kaneshige
111
48.90%
2
20.00%
Dely Sy
32
14.10%
1
10.00%
Rajesh Shah
31
13.66%
1
10.00%
Taku Izumi
17
7.49%
1
10.00%
Björn Helgaas
16
7.05%
2
20.00%
Alexander Chiang
15
6.61%
1
10.00%
Yijing Wang
3
1.32%
1
10.00%
Tejun Heo
2
0.88%
1
10.00%
Total
227
100.00%
10
100.00%

/*
 * Note: This function must be called with slot->lock held
 */


static void handle_link_event(struct slot *p_slot, u32 event)
{
	struct controller *ctrl = p_slot->ctrl;

	switch (p_slot->state) {
	case BLINKINGON_STATE:
	case BLINKINGOFF_STATE:
		cancel_delayed_work(&p_slot->work);
		/* Fall through */
	case STATIC_STATE:
		pciehp_queue_power_work(p_slot, event == INT_LINK_UP ?
					ENABLE_REQ : DISABLE_REQ);
		break;
	case POWERON_STATE:
		if (event == INT_LINK_UP) {
			ctrl_info(ctrl, "Slot(%s): Link Up event ignored; already powering on\n",
				  slot_name(p_slot));
		} else {
			ctrl_info(ctrl, "Slot(%s): Link Down event queued; currently getting powered on\n",
				  slot_name(p_slot));
			pciehp_queue_power_work(p_slot, DISABLE_REQ);
		}
		break;
	case POWEROFF_STATE:
		if (event == INT_LINK_UP) {
			ctrl_info(ctrl, "Slot(%s): Link Up event queued; currently getting powered off\n",
				  slot_name(p_slot));
			pciehp_queue_power_work(p_slot, ENABLE_REQ);
		} else {
			ctrl_info(ctrl, "Slot(%s): Link Down event ignored; already powering off\n",
				  slot_name(p_slot));
		}
		break;
	default:
		ctrl_err(ctrl, "Slot(%s): Ignoring invalid state %#x\n",
			 slot_name(p_slot), p_slot->state);
		break;
	}
}

Contributors
Person
Tokens
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CommitProp
Rajat Jain
155
89.60%
1
33.33%
Björn Helgaas
9
5.20%
1
33.33%
Guenter Roeck
9
5.20%
1
33.33%
Total
173
100.00%
3
100.00%



static void interrupt_event_handler(struct work_struct *work)
{
	struct event_info *info = container_of(work, struct event_info, work);
	struct slot *p_slot = info->p_slot;
	struct controller *ctrl = p_slot->ctrl;

	mutex_lock(&p_slot->lock);
	switch (info->event_type) {
	case INT_BUTTON_PRESS:
		handle_button_press_event(p_slot);
		break;
	case INT_POWER_FAULT:
		if (!POWER_CTRL(ctrl))
			break;
		pciehp_set_attention_status(p_slot, 1);
		pciehp_green_led_off(p_slot);
		break;
	case INT_PRESENCE_ON:
		pciehp_queue_power_work(p_slot, ENABLE_REQ);
		break;
	case INT_PRESENCE_OFF:
		/*
                 * Regardless of surprise capability, we need to
                 * definitely remove a card that has been pulled out!
                 */
		pciehp_queue_power_work(p_slot, DISABLE_REQ);
		break;
	case INT_LINK_UP:
	case INT_LINK_DOWN:
		handle_link_event(p_slot, info->event_type);
		break;
	default:
		break;
	}
	mutex_unlock(&p_slot->lock);

	kfree(info);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Kenji Kaneshige
70
47.30%
2
28.57%
Rajat Jain
25
16.89%
2
28.57%
Dely Sy
24
16.22%
1
14.29%
Rajesh Shah
23
15.54%
1
14.29%
Mayurkumar Patel
6
4.05%
1
14.29%
Total
148
100.00%
7
100.00%

/*
 * Note: This function must be called with slot->hotplug_lock held
 */


int pciehp_enable_slot(struct slot *p_slot)
{
	u8 getstatus = 0;
	struct controller *ctrl = p_slot->ctrl;

	pciehp_get_adapter_status(p_slot, &getstatus);
	if (!getstatus) {
		ctrl_info(ctrl, "Slot(%s): No adapter\n", slot_name(p_slot));
		return -ENODEV;
	}
	if (MRL_SENS(p_slot->ctrl)) {
		pciehp_get_latch_status(p_slot, &getstatus);
		if (getstatus) {
			ctrl_info(ctrl, "Slot(%s): Latch open\n",
				  slot_name(p_slot));
			return -ENODEV;
		}
	}

	if (POWER_CTRL(p_slot->ctrl)) {
		pciehp_get_power_status(p_slot, &getstatus);
		if (getstatus) {
			ctrl_info(ctrl, "Slot(%s): Already enabled\n",
				  slot_name(p_slot));
			return 0;
		}
	}

	return board_added(p_slot);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Rajesh Shah
70
49.30%
2
18.18%
Dely Sy
30
21.13%
1
9.09%
Taku Izumi
18
12.68%
1
9.09%
Alexander Chiang
9
6.34%
1
9.09%
Kenji Kaneshige
7
4.93%
2
18.18%
Björn Helgaas
4
2.82%
2
18.18%
Rolf Eike Beer
3
2.11%
1
9.09%
Ashok Raj
1
0.70%
1
9.09%
Total
142
100.00%
11
100.00%

/*
 * Note: This function must be called with slot->hotplug_lock held
 */


int pciehp_disable_slot(struct slot *p_slot)
{
	u8 getstatus = 0;
	struct controller *ctrl = p_slot->ctrl;

	if (!p_slot->ctrl)
		return 1;

	if (POWER_CTRL(p_slot->ctrl)) {
		pciehp_get_power_status(p_slot, &getstatus);
		if (!getstatus) {
			ctrl_info(ctrl, "Slot(%s): Already disabled\n",
				  slot_name(p_slot));
			return -EINVAL;
		}
	}

	return remove_board(p_slot);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Rajesh Shah
41
50.00%
1
12.50%
Dely Sy
21
25.61%
1
12.50%
Taku Izumi
12
14.63%
1
12.50%
Kenji Kaneshige
4
4.88%
3
37.50%
Alexander Chiang
3
3.66%
1
12.50%
Björn Helgaas
1
1.22%
1
12.50%
Total
82
100.00%
8
100.00%



int pciehp_sysfs_enable_slot(struct slot *p_slot)
{
	int retval = -ENODEV;
	struct controller *ctrl = p_slot->ctrl;

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case BLINKINGON_STATE:
		cancel_delayed_work(&p_slot->work);
	case STATIC_STATE:
		p_slot->state = POWERON_STATE;
		mutex_unlock(&p_slot->lock);
		mutex_lock(&p_slot->hotplug_lock);
		retval = pciehp_enable_slot(p_slot);
		mutex_unlock(&p_slot->hotplug_lock);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		break;
	case POWERON_STATE:
		ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",
			  slot_name(p_slot));
		break;
	case BLINKINGOFF_STATE:
	case POWEROFF_STATE:
		ctrl_info(ctrl, "Slot(%s): Already enabled\n",
			  slot_name(p_slot));
		break;
	default:
		ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
			 slot_name(p_slot), p_slot->state);
		break;
	}
	mutex_unlock(&p_slot->lock);

	return retval;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Kenji Kaneshige
121
70.76%
1
20.00%
Taku Izumi
18
10.53%
1
20.00%
Rajat Jain
16
9.36%
1
20.00%
Alexander Chiang
9
5.26%
1
20.00%
Björn Helgaas
7
4.09%
1
20.00%
Total
171
100.00%
5
100.00%



int pciehp_sysfs_disable_slot(struct slot *p_slot)
{
	int retval = -ENODEV;
	struct controller *ctrl = p_slot->ctrl;

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case BLINKINGOFF_STATE:
		cancel_delayed_work(&p_slot->work);
	case STATIC_STATE:
		p_slot->state = POWEROFF_STATE;
		mutex_unlock(&p_slot->lock);
		mutex_lock(&p_slot->hotplug_lock);
		retval = pciehp_disable_slot(p_slot);
		mutex_unlock(&p_slot->hotplug_lock);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		break;
	case POWEROFF_STATE:
		ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",
			  slot_name(p_slot));
		break;
	case BLINKINGON_STATE:
	case POWERON_STATE:
		ctrl_info(ctrl, "Slot(%s): Already disabled\n",
			  slot_name(p_slot));
		break;
	default:
		ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
			 slot_name(p_slot), p_slot->state);
		break;
	}
	mutex_unlock(&p_slot->lock);

	return retval;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Kenji Kaneshige
121
70.76%
1
20.00%
Taku Izumi
18
10.53%
1
20.00%
Guenter Roeck
16
9.36%
1
20.00%
Alexander Chiang
9
5.26%
1
20.00%
Björn Helgaas
7
4.09%
1
20.00%
Total
171
100.00%
5
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Kenji Kaneshige
674
35.23%
14
31.11%
Rajesh Shah
350
18.30%
4
8.89%
Rajat Jain
266
13.90%
4
8.89%
Dely Sy
230
12.02%
2
4.44%
Taku Izumi
112
5.85%
2
4.44%
Guenter Roeck
110
5.75%
2
4.44%
Björn Helgaas
72
3.76%
6
13.33%
Alexander Chiang
45
2.35%
1
2.22%
Rolf Eike Beer
15
0.78%
2
4.44%
Mika Westerberg
9
0.47%
1
2.22%
Keith Busch
7
0.37%
1
2.22%
Tejun Heo
7
0.37%
2
4.44%
Mayurkumar Patel
6
0.31%
1
2.22%
Yijing Wang
6
0.31%
1
2.22%
Randy Dunlap
3
0.16%
1
2.22%
Ashok Raj
1
0.05%
1
2.22%
Total
1913
100.00%
45
100.00%
Directory: drivers/pci/hotplug

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