linux/drivers/pci/hotplug/pciehp.h

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/*
* 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>
*
*/
#ifndef _PCIEHP_H
#define _PCIEHP_H
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/delay.h>
#include <linux/sched/signal.h> /* signal_pending() */
#include <linux/pcieport_if.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#define MY_NAME "pciehp"
extern bool pciehp_poll_mode;
extern int pciehp_poll_time;
extern bool pciehp_debug;
#define dbg(format, arg...) \
do { \
if (pciehp_debug) \
printk(KERN_DEBUG "%s: " format, MY_NAME, ## arg); \
} while (0)
#define err(format, arg...) \
printk(KERN_ERR "%s: " format, MY_NAME, ## arg)
#define info(format, arg...) \
printk(KERN_INFO "%s: " format, MY_NAME, ## arg)
#define warn(format, arg...) \
printk(KERN_WARNING "%s: " format, MY_NAME, ## arg)
#define ctrl_dbg(ctrl, format, arg...) \
do { \
if (pciehp_debug) \
dev_printk(KERN_DEBUG, &ctrl->pcie->device, \
format, ## arg); \
} while (0)
#define ctrl_err(ctrl, format, arg...) \
dev_err(&ctrl->pcie->device, format, ## arg)
#define ctrl_info(ctrl, format, arg...) \
dev_info(&ctrl->pcie->device, format, ## arg)
#define ctrl_warn(ctrl, format, arg...) \
dev_warn(&ctrl->pcie->device, format, ## arg)
#define SLOT_NAME_SIZE 10
struct slot {
u8 state;
struct controller *ctrl;
struct hotplug_slot *hotplug_slot;
struct delayed_work work; /* work for button event */
struct mutex lock;
struct mutex hotplug_lock;
PCI: pciehp: Use per-slot workqueues to avoid deadlock When we have a hotplug-capable PCIe port with a second hotplug-capable PCIe port below it, removing the device below the upstream port causes a deadlock. The deadlock happens because we use the pciehp_wq workqueue to run pciehp_power_thread(), which uses pciehp_disable_slot() to remove devices below the upstream port. When we remove the downstream PCIe port, we call pciehp_remove(), the pciehp driver's .remove() method. That calls flush_workqueue(pciehp_wq), which deadlocks because the pciehp_power_thread() work item is still running. This patch avoids the deadlock by creating a workqueue for every PCIe port and removing the single shared workqueue. Here's the call path that leads to the deadlock: pciehp_queue_pushbutton_work queue_work(pciehp_wq) # queue pciehp_power_thread ... pciehp_power_thread pciehp_disable_slot remove_board pciehp_unconfigure_device pci_stop_and_remove_bus_device ... pciehp_remove # pciehp driver .remove method pciehp_release_ctrl pcie_cleanup_slot flush_workqueue(pciehp_wq) This is fairly urgent because it can be caused by simply unplugging a Thunderbolt adapter, as reported by Daniel below. [bhelgaas: changelog] Reference: http://lkml.kernel.org/r/CAMVG2ssiRgcTD1bej2tkUUfsWmpL5eNtPcNif9va2-Gzb2u8nQ@mail.gmail.com Reported-and-tested-by: Daniel J Blueman <daniel@quora.org> Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org
2013-01-11 10:15:54 +08:00
struct workqueue_struct *wq;
};
struct event_info {
u32 event_type;
struct slot *p_slot;
struct work_struct work;
};
struct controller {
struct mutex ctrl_lock; /* controller lock */
struct pcie_device *pcie; /* PCI Express port service */
struct slot *slot;
wait_queue_head_t queue; /* sleep & wake process */
u32 slot_cap;
u16 slot_ctrl;
struct timer_list poll_timer;
unsigned long cmd_started; /* jiffies */
unsigned int cmd_busy:1;
unsigned int link_active_reporting:1;
unsigned int notification_enabled:1;
unsigned int power_fault_detected;
};
#define INT_PRESENCE_ON 1
#define INT_PRESENCE_OFF 2
#define INT_POWER_FAULT 3
#define INT_BUTTON_PRESS 4
#define INT_LINK_UP 5
#define INT_LINK_DOWN 6
#define STATIC_STATE 0
#define BLINKINGON_STATE 1
#define BLINKINGOFF_STATE 2
#define POWERON_STATE 3
#define POWEROFF_STATE 4
#define ATTN_BUTTN(ctrl) ((ctrl)->slot_cap & PCI_EXP_SLTCAP_ABP)
#define POWER_CTRL(ctrl) ((ctrl)->slot_cap & PCI_EXP_SLTCAP_PCP)
#define MRL_SENS(ctrl) ((ctrl)->slot_cap & PCI_EXP_SLTCAP_MRLSP)
#define ATTN_LED(ctrl) ((ctrl)->slot_cap & PCI_EXP_SLTCAP_AIP)
#define PWR_LED(ctrl) ((ctrl)->slot_cap & PCI_EXP_SLTCAP_PIP)
#define HP_SUPR_RM(ctrl) ((ctrl)->slot_cap & PCI_EXP_SLTCAP_HPS)
#define EMI(ctrl) ((ctrl)->slot_cap & PCI_EXP_SLTCAP_EIP)
#define NO_CMD_CMPL(ctrl) ((ctrl)->slot_cap & PCI_EXP_SLTCAP_NCCS)
#define PSN(ctrl) (((ctrl)->slot_cap & PCI_EXP_SLTCAP_PSN) >> 19)
int pciehp_sysfs_enable_slot(struct slot *slot);
int pciehp_sysfs_disable_slot(struct slot *slot);
void pciehp_queue_interrupt_event(struct slot *slot, u32 event_type);
int pciehp_configure_device(struct slot *p_slot);
int pciehp_unconfigure_device(struct slot *p_slot);
void pciehp_queue_pushbutton_work(struct work_struct *work);
struct controller *pcie_init(struct pcie_device *dev);
int pcie_init_notification(struct controller *ctrl);
int pciehp_enable_slot(struct slot *p_slot);
int pciehp_disable_slot(struct slot *p_slot);
void pcie_enable_notification(struct controller *ctrl);
int pciehp_power_on_slot(struct slot *slot);
void pciehp_power_off_slot(struct slot *slot);
void pciehp_get_power_status(struct slot *slot, u8 *status);
void pciehp_get_attention_status(struct slot *slot, u8 *status);
void pciehp_set_attention_status(struct slot *slot, u8 status);
void pciehp_get_latch_status(struct slot *slot, u8 *status);
void pciehp_get_adapter_status(struct slot *slot, u8 *status);
int pciehp_query_power_fault(struct slot *slot);
void pciehp_green_led_on(struct slot *slot);
void pciehp_green_led_off(struct slot *slot);
void pciehp_green_led_blink(struct slot *slot);
int pciehp_check_link_status(struct controller *ctrl);
bool pciehp_check_link_active(struct controller *ctrl);
void pciehp_release_ctrl(struct controller *ctrl);
int pciehp_reset_slot(struct slot *slot, int probe);
int pciehp_set_raw_indicator_status(struct hotplug_slot *h_slot, u8 status);
int pciehp_get_raw_indicator_status(struct hotplug_slot *h_slot, u8 *status);
static inline const char *slot_name(struct slot *slot)
{
return hotplug_slot_name(slot->hotplug_slot);
}
#endif /* _PCIEHP_H */