pci/hotplug/shpchp_ctrl.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Standard 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 "shpchp.h"

static void interrupt_event_handler(struct work_struct *work);
static int shpchp_enable_slot(struct slot *p_slot);
static int shpchp_disable_slot(struct slot *p_slot);

static int queue_interrupt_event(struct slot *p_slot, u32 event_type)
{
	struct event_info *info;

	info = kmalloc(sizeof(*info), GFP_ATOMIC);
	if (!info)
		return -ENOMEM;

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

	queue_work(p_slot->wq, &info->work);

	return 0;
}

u8 shpchp_handle_attention_button(u8 hp_slot, struct controller *ctrl)
{
	struct slot *p_slot;
	u32 event_type;

	/* Attention Button Change */
	ctrl_dbg(ctrl, "Attention button interrupt received\n");

	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
	shpchp_get_adapter_status(p_slot, &p_slot->presence_save);

	/*
	 *  Button pressed - See if need to TAKE ACTION!!!
	 */
	ctrl_info(ctrl, "Button pressed on Slot(%s)\n", slot_name(p_slot));
	event_type = INT_BUTTON_PRESS;

	queue_interrupt_event(p_slot, event_type);

	return 0;

}

u8 shpchp_handle_switch_change(u8 hp_slot, struct controller *ctrl)
{
	struct slot *p_slot;
	u8 getstatus;
	u32 event_type;

	/* Switch Change */
	ctrl_dbg(ctrl, "Switch interrupt received\n");

	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
	shpchp_get_adapter_status(p_slot, &p_slot->presence_save);
	shpchp_get_latch_status(p_slot, &getstatus);
	ctrl_dbg(ctrl, "Card present %x Power status %x\n",
		 p_slot->presence_save, p_slot->pwr_save);

	if (getstatus) {
		/*
		 * Switch opened
		 */
		ctrl_info(ctrl, "Latch open on Slot(%s)\n", slot_name(p_slot));
		event_type = INT_SWITCH_OPEN;
		if (p_slot->pwr_save && p_slot->presence_save) {
			event_type = INT_POWER_FAULT;
			ctrl_err(ctrl, "Surprise Removal of card\n");
		}
	} else {
		/*
		 *  Switch closed
		 */
		ctrl_info(ctrl, "Latch close on Slot(%s)\n", slot_name(p_slot));
		event_type = INT_SWITCH_CLOSE;
	}

	queue_interrupt_event(p_slot, event_type);

	return 1;
}

u8 shpchp_handle_presence_change(u8 hp_slot, struct controller *ctrl)
{
	struct slot *p_slot;
	u32 event_type;

	/* Presence Change */
	ctrl_dbg(ctrl, "Presence/Notify input change\n");

	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

	/*
	 * Save the presence state
	 */
	shpchp_get_adapter_status(p_slot, &p_slot->presence_save);
	if (p_slot->presence_save) {
		/*
		 * Card Present
		 */
		ctrl_info(ctrl, "Card present on Slot(%s)\n",
			  slot_name(p_slot));
		event_type = INT_PRESENCE_ON;
	} else {
		/*
		 * Not Present
		 */
		ctrl_info(ctrl, "Card not present on Slot(%s)\n",
			  slot_name(p_slot));
		event_type = INT_PRESENCE_OFF;
	}

	queue_interrupt_event(p_slot, event_type);

	return 1;
}

u8 shpchp_handle_power_fault(u8 hp_slot, struct controller *ctrl)
{
	struct slot *p_slot;
	u32 event_type;

	/* Power fault */
	ctrl_dbg(ctrl, "Power fault interrupt received\n");

	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

	if (!(shpchp_query_power_fault(p_slot))) {
		/*
		 * Power fault Cleared
		 */
		ctrl_info(ctrl, "Power fault cleared on Slot(%s)\n",
			  slot_name(p_slot));
		p_slot->status = 0x00;
		event_type = INT_POWER_FAULT_CLEAR;
	} else {
		/*
		 *   Power fault
		 */
		ctrl_info(ctrl, "Power fault on Slot(%s)\n", slot_name(p_slot));
		event_type = INT_POWER_FAULT;
		/* set power fault status for this board */
		p_slot->status = 0xFF;
		ctrl_info(ctrl, "Power fault bit %x set\n", hp_slot);
	}

	queue_interrupt_event(p_slot, event_type);

	return 1;
}

/* The following routines constitute the bulk of the
   hotplug controller logic
 */
static int change_bus_speed(struct controller *ctrl, struct slot *p_slot,
		enum pci_bus_speed speed)
{
	int rc = 0;

	ctrl_dbg(ctrl, "Change speed to %d\n", speed);
	rc = shpchp_set_bus_speed_mode(p_slot, speed);
	if (rc) {
		ctrl_err(ctrl, "%s: Issue of set bus speed mode command failed\n",
			 __func__);
		return WRONG_BUS_FREQUENCY;
	}
	return rc;
}

static int fix_bus_speed(struct controller *ctrl, struct slot *pslot,
		u8 flag, enum pci_bus_speed asp, enum pci_bus_speed bsp,
		enum pci_bus_speed msp)
{
	int rc = 0;

	/*
	 * If other slots on the same bus are occupied, we cannot
	 * change the bus speed.
	 */
	if (flag) {
		if (asp < bsp) {
			ctrl_err(ctrl, "Speed of bus %x and adapter %x mismatch\n",
				 bsp, asp);
			rc = WRONG_BUS_FREQUENCY;
		}
		return rc;
	}

	if (asp < msp) {
		if (bsp != asp)
			rc = change_bus_speed(ctrl, pslot, asp);
	} else {
		if (bsp != msp)
			rc = change_bus_speed(ctrl, pslot, msp);
	}
	return rc;
}

/**
 * board_added - Called after a board has been added to the system.
 * @p_slot: target &slot
 *
 * Turns power on for the board.
 * Configures board.
 */
static int board_added(struct slot *p_slot)
{
	u8 hp_slot;
	u8 slots_not_empty = 0;
	int rc = 0;
	enum pci_bus_speed asp, bsp, msp;
	struct controller *ctrl = p_slot->ctrl;
	struct pci_bus *parent = ctrl->pci_dev->subordinate;

	hp_slot = p_slot->device - ctrl->slot_device_offset;

	ctrl_dbg(ctrl, "%s: p_slot->device, slot_offset, hp_slot = %d, %d ,%d\n",
		 __func__, p_slot->device, ctrl->slot_device_offset, hp_slot);

	/* Power on slot without connecting to bus */
	rc = shpchp_power_on_slot(p_slot);
	if (rc) {
		ctrl_err(ctrl, "Failed to power on slot\n");
		return -1;
	}

	if ((ctrl->pci_dev->vendor == 0x8086) && (ctrl->pci_dev->device == 0x0332)) {
		rc = shpchp_set_bus_speed_mode(p_slot, PCI_SPEED_33MHz);
		if (rc) {
			ctrl_err(ctrl, "%s: Issue of set bus speed mode command failed\n",
				 __func__);
			return WRONG_BUS_FREQUENCY;
		}

		/* turn on board, blink green LED, turn off Amber LED */
		rc = shpchp_slot_enable(p_slot);
		if (rc) {
			ctrl_err(ctrl, "Issue of Slot Enable command failed\n");
			return rc;
		}
	}

	rc = shpchp_get_adapter_speed(p_slot, &asp);
	if (rc) {
		ctrl_err(ctrl, "Can't get adapter speed or bus mode mismatch\n");
		return WRONG_BUS_FREQUENCY;
	}

	bsp = ctrl->pci_dev->subordinate->cur_bus_speed;
	msp = ctrl->pci_dev->subordinate->max_bus_speed;

	/* Check if there are other slots or devices on the same bus */
	if (!list_empty(&ctrl->pci_dev->subordinate->devices))
		slots_not_empty = 1;

	ctrl_dbg(ctrl, "%s: slots_not_empty %d, adapter_speed %d, bus_speed %d, max_bus_speed %d\n",
		 __func__, slots_not_empty, asp,
		 bsp, msp);

	rc = fix_bus_speed(ctrl, p_slot, slots_not_empty, asp, bsp, msp);
	if (rc)
		return rc;

	/* turn on board, blink green LED, turn off Amber LED */
	rc = shpchp_slot_enable(p_slot);
	if (rc) {
		ctrl_err(ctrl, "Issue of Slot Enable command failed\n");
		return rc;
	}

	/* Wait for ~1 second */
	msleep(1000);

	ctrl_dbg(ctrl, "%s: slot status = %x\n", __func__, p_slot->status);
	/* Check for a power fault */
	if (p_slot->status == 0xFF) {
		/* power fault occurred, but it was benign */
		ctrl_dbg(ctrl, "%s: Power fault\n", __func__);
		p_slot->status = 0;
		goto err_exit;
	}

	if (shpchp_configure_device(p_slot)) {
		ctrl_err(ctrl, "Cannot add device at %04x:%02x:%02x\n",
			 pci_domain_nr(parent), p_slot->bus, p_slot->device);
		goto err_exit;
	}

	p_slot->status = 0;
	p_slot->is_a_board = 0x01;
	p_slot->pwr_save = 1;

	shpchp_green_led_on(p_slot);

	return 0;

err_exit:
	/* turn off slot, turn on Amber LED, turn off Green LED */
	rc = shpchp_slot_disable(p_slot);
	if (rc) {
		ctrl_err(ctrl, "%s: Issue of Slot Disable command failed\n",
			 __func__);
		return rc;
	}

	return(rc);
}


/**
 * remove_board - Turns off slot and LEDs
 * @p_slot: target &slot
 */
static int remove_board(struct slot *p_slot)
{
	struct controller *ctrl = p_slot->ctrl;
	u8 hp_slot;
	int rc;

	shpchp_unconfigure_device(p_slot);

	hp_slot = p_slot->device - ctrl->slot_device_offset;
	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

	ctrl_dbg(ctrl, "%s: hp_slot = %d\n", __func__, hp_slot);

	/* Change status to shutdown */
	if (p_slot->is_a_board)
		p_slot->status = 0x01;

	/* turn off slot, turn on Amber LED, turn off Green LED */
	rc = shpchp_slot_disable(p_slot);
	if (rc) {
		ctrl_err(ctrl, "%s: Issue of Slot Disable command failed\n",
			 __func__);
		return rc;
	}

	rc = shpchp_set_attention_status(p_slot, 0);
	if (rc) {
		ctrl_err(ctrl, "Issue of Set Attention command failed\n");
		return rc;
	}

	p_slot->pwr_save = 0;
	p_slot->is_a_board = 0;

	return 0;
}


struct pushbutton_work_info {
	struct slot *p_slot;
	struct work_struct work;
};

/**
 * shpchp_pushbutton_thread - handle pushbutton events
 * @work: &struct work_struct to be handled
 *
 * Scheduled procedure to handle blocking stuff for the pushbuttons.
 * Handles all pending events and exits.
 */
static void shpchp_pushbutton_thread(struct work_struct *work)
{
	struct pushbutton_work_info *info =
		container_of(work, struct pushbutton_work_info, work);
	struct slot *p_slot = info->p_slot;

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case POWEROFF_STATE:
		mutex_unlock(&p_slot->lock);
		shpchp_disable_slot(p_slot);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		break;
	case POWERON_STATE:
		mutex_unlock(&p_slot->lock);
		if (shpchp_enable_slot(p_slot))
			shpchp_green_led_off(p_slot);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		break;
	default:
		break;
	}
	mutex_unlock(&p_slot->lock);

	kfree(info);
}

void shpchp_queue_pushbutton_work(struct work_struct *work)
{
	struct slot *p_slot = container_of(work, struct slot, work.work);
	struct pushbutton_work_info *info;

	info = kmalloc(sizeof(*info), GFP_KERNEL);
	if (!info) {
		ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
			 __func__);
		return;
	}
	info->p_slot = p_slot;
	INIT_WORK(&info->work, shpchp_pushbutton_thread);

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case BLINKINGOFF_STATE:
		p_slot->state = POWEROFF_STATE;
		break;
	case BLINKINGON_STATE:
		p_slot->state = POWERON_STATE;
		break;
	default:
		kfree(info);
		goto out;
	}
	queue_work(p_slot->wq, &info->work);
 out:
	mutex_unlock(&p_slot->lock);
}

static void update_slot_info(struct slot *slot)
{
	shpchp_get_power_status(slot, &slot->pwr_save);
	shpchp_get_attention_status(slot, &slot->attention_save);
	shpchp_get_latch_status(slot, &slot->latch_save);
	shpchp_get_adapter_status(slot, &slot->presence_save);
}

/*
 * Note: This function must be called with slot->lock held
 */
static void handle_button_press_event(struct slot *p_slot)
{
	u8 getstatus;
	struct controller *ctrl = p_slot->ctrl;

	switch (p_slot->state) {
	case STATIC_STATE:
		shpchp_get_power_status(p_slot, &getstatus);
		if (getstatus) {
			p_slot->state = BLINKINGOFF_STATE;
			ctrl_info(ctrl, "PCI slot #%s - powering off due to button press\n",
				  slot_name(p_slot));
		} else {
			p_slot->state = BLINKINGON_STATE;
			ctrl_info(ctrl, "PCI slot #%s - powering on due to button press\n",
				  slot_name(p_slot));
		}
		/* blink green LED and turn off amber */
		shpchp_green_led_blink(p_slot);
		shpchp_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, "Button cancel on Slot(%s)\n",
			  slot_name(p_slot));
		cancel_delayed_work(&p_slot->work);
		if (p_slot->state == BLINKINGOFF_STATE)
			shpchp_green_led_on(p_slot);
		else
			shpchp_green_led_off(p_slot);
		shpchp_set_attention_status(p_slot, 0);
		ctrl_info(ctrl, "PCI 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, "Button ignore on Slot(%s)\n",
			  slot_name(p_slot));
		update_slot_info(p_slot);
		break;
	default:
		ctrl_warn(ctrl, "Not a valid state\n");
		break;
	}
}

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;

	mutex_lock(&p_slot->lock);
	switch (info->event_type) {
	case INT_BUTTON_PRESS:
		handle_button_press_event(p_slot);
		break;
	case INT_POWER_FAULT:
		ctrl_dbg(p_slot->ctrl, "%s: Power fault\n", __func__);
		shpchp_set_attention_status(p_slot, 1);
		shpchp_green_led_off(p_slot);
		break;
	default:
		update_slot_info(p_slot);
		break;
	}
	mutex_unlock(&p_slot->lock);

	kfree(info);
}


static int shpchp_enable_slot (struct slot *p_slot)
{
	u8 getstatus = 0;
	int rc, retval = -ENODEV;
	struct controller *ctrl = p_slot->ctrl;

	/* Check to see if (latch closed, card present, power off) */
	mutex_lock(&p_slot->ctrl->crit_sect);
	rc = shpchp_get_adapter_status(p_slot, &getstatus);
	if (rc || !getstatus) {
		ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
		goto out;
	}
	rc = shpchp_get_latch_status(p_slot, &getstatus);
	if (rc || getstatus) {
		ctrl_info(ctrl, "Latch open on slot(%s)\n", slot_name(p_slot));
		goto out;
	}
	rc = shpchp_get_power_status(p_slot, &getstatus);
	if (rc || getstatus) {
		ctrl_info(ctrl, "Already enabled on slot(%s)\n",
			  slot_name(p_slot));
		goto out;
	}

	p_slot->is_a_board = 1;

	/* We have to save the presence info for these slots */
	shpchp_get_adapter_status(p_slot, &p_slot->presence_save);
	shpchp_get_power_status(p_slot, &p_slot->pwr_save);
	ctrl_dbg(ctrl, "%s: p_slot->pwr_save %x\n", __func__, p_slot->pwr_save);
	shpchp_get_latch_status(p_slot, &getstatus);

	if ((p_slot->ctrl->pci_dev->vendor == PCI_VENDOR_ID_AMD &&
	     p_slot->ctrl->pci_dev->device == PCI_DEVICE_ID_AMD_POGO_7458)
	     && p_slot->ctrl->num_slots == 1) {
		/* handle AMD POGO errata; this must be done before enable  */
		amd_pogo_errata_save_misc_reg(p_slot);
		retval = board_added(p_slot);
		/* handle AMD POGO errata; this must be done after enable  */
		amd_pogo_errata_restore_misc_reg(p_slot);
	} else
		retval = board_added(p_slot);

	if (retval) {
		shpchp_get_adapter_status(p_slot, &p_slot->presence_save);
		shpchp_get_latch_status(p_slot, &getstatus);
	}

	update_slot_info(p_slot);
 out:
	mutex_unlock(&p_slot->ctrl->crit_sect);
	return retval;
}


static int shpchp_disable_slot (struct slot *p_slot)
{
	u8 getstatus = 0;
	int rc, retval = -ENODEV;
	struct controller *ctrl = p_slot->ctrl;

	if (!p_slot->ctrl)
		return -ENODEV;

	/* Check to see if (latch closed, card present, power on) */
	mutex_lock(&p_slot->ctrl->crit_sect);

	rc = shpchp_get_adapter_status(p_slot, &getstatus);
	if (rc || !getstatus) {
		ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
		goto out;
	}
	rc = shpchp_get_latch_status(p_slot, &getstatus);
	if (rc || getstatus) {
		ctrl_info(ctrl, "Latch open on slot(%s)\n", slot_name(p_slot));
		goto out;
	}
	rc = shpchp_get_power_status(p_slot, &getstatus);
	if (rc || !getstatus) {
		ctrl_info(ctrl, "Already disabled on slot(%s)\n",
			  slot_name(p_slot));
		goto out;
	}

	retval = remove_board(p_slot);
	update_slot_info(p_slot);
 out:
	mutex_unlock(&p_slot->ctrl->crit_sect);
	return retval;
}

int shpchp_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);
		fallthrough;
	case STATIC_STATE:
		p_slot->state = POWERON_STATE;
		mutex_unlock(&p_slot->lock);
		retval = shpchp_enable_slot(p_slot);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		break;
	case POWERON_STATE:
		ctrl_info(ctrl, "Slot %s is already in powering on state\n",
			  slot_name(p_slot));
		break;
	case BLINKINGOFF_STATE:
	case POWEROFF_STATE:
		ctrl_info(ctrl, "Already enabled on slot %s\n",
			  slot_name(p_slot));
		break;
	default:
		ctrl_err(ctrl, "Not a valid state on slot %s\n",
			 slot_name(p_slot));
		break;
	}
	mutex_unlock(&p_slot->lock);

	return retval;
}

int shpchp_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);
		fallthrough;
	case STATIC_STATE:
		p_slot->state = POWEROFF_STATE;
		mutex_unlock(&p_slot->lock);
		retval = shpchp_disable_slot(p_slot);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		break;
	case POWEROFF_STATE:
		ctrl_info(ctrl, "Slot %s is already in powering off state\n",
			  slot_name(p_slot));
		break;
	case BLINKINGON_STATE:
	case POWERON_STATE:
		ctrl_info(ctrl, "Already disabled on slot %s\n",
			  slot_name(p_slot));
		break;
	default:
		ctrl_err(ctrl, "Not a valid state on slot %s\n",
			 slot_name(p_slot));
		break;
	}
	mutex_unlock(&p_slot->lock);

	return retval;
}