linux_dsm_epyc7002/drivers/pci/hotplug/pciehp_ctrl.c
Bjorn Helgaas d98e092907 Revert "PCI: pciehp: Add runtime PM support for PCIe hotplug ports"
This reverts commit 68db9bc814.

Yinghai reported that the following manual hotplug sequence:

  # echo 0 > /sys/bus/pci/slots/8/power
  # echo 1 > /sys/bus/pci/slots/8/power

worked in v4.9, but fails in v4.10-rc1, and that reverting 68db9bc814
("PCI: pciehp: Add runtime PM support for PCIe hotplug ports") makes it
work again.

Fixes: 68db9bc814 ("PCI: pciehp: Add runtime PM support for PCIe hotplug ports")
Link: https://lkml.kernel.org/r/CAE9FiQVCMCa7iVyuwp9z6VrY0cE7V_xghuXip28Ft52=8QmTWw@mail.gmail.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=193951
Reported-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-02-03 08:53:51 -06:00

516 lines
13 KiB
C

/*
* 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.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* 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);
}
/* 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);
}
/**
* 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) {
ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
pci_domain_nr(parent), parent->number);
if (retval != -EEXIST)
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;
}
/**
* 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;
}
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);
}
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);
}
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);
}
/*
* 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;
}
}
/*
* 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;
}
}
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);
}
/*
* 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);
}
/*
* 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);
}
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;
}
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;
}