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Commit 34d03419 authored by Kristen Carlson Accardi's avatar Kristen Carlson Accardi Committed by Greg Kroah-Hartman
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PCIEHP: Add Electro Mechanical Interlock (EMI) support to the PCIE hotplug driver. 



Signed-off-by: default avatarKristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 262303fe

drivers/pci/hotplug/pciehp.h

+5 −0
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ struct slot { 
	struct hotplug_slot *hotplug_slot;

	struct list_head	slot_list;

	char name[SLOT_NAME_SIZE];

	unsigned long last_emi_toggle;

};



struct event_info {
@@ -138,6 +139,7 @@ struct controller { 
#define ATTN_LED_PRSN	0x00000008

#define PWR_LED_PRSN	0x00000010

#define HP_SUPR_RM_SUP	0x00000020

#define EMI_PRSN	0x00020000



#define ATTN_BUTTN(cap)		(cap & ATTN_BUTTN_PRSN)

#define POWER_CTRL(cap)		(cap & PWR_CTRL_PRSN)
@@ -145,6 +147,7 @@ struct controller { 
#define ATTN_LED(cap)		(cap & ATTN_LED_PRSN)

#define PWR_LED(cap)		(cap & PWR_LED_PRSN) 

#define HP_SUPR_RM(cap)		(cap & HP_SUPR_RM_SUP)

#define EMI(cap)		(cap & EMI_PRSN)



extern int pciehp_event_start_thread(void);

extern void pciehp_event_stop_thread(void);
@@ -182,6 +185,8 @@ struct hpc_ops { 
	int (*set_attention_status)(struct slot *slot, u8 status);

	int (*get_latch_status)(struct slot *slot, u8 *status);

	int (*get_adapter_status)(struct slot *slot, u8 *status);

	int (*get_emi_status)(struct slot *slot, u8 *status);

	int (*toggle_emi)(struct slot *slot);

	int (*get_max_bus_speed)(struct slot *slot, enum pci_bus_speed *speed);

	int (*get_cur_bus_speed)(struct slot *slot, enum pci_bus_speed *speed);

	int (*get_max_lnk_width)(struct slot *slot, enum pcie_link_width *val);

drivers/pci/hotplug/pciehp_core.c

+103 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include <linux/pci.h>

#include "pciehp.h"

#include <linux/interrupt.h>

#include <linux/time.h>



/* Global variables */

int pciehp_debug;
@@ -87,6 +88,95 @@ static struct hotplug_slot_ops pciehp_hotplug_slot_ops = { 
  	.get_cur_bus_speed =	get_cur_bus_speed,

};



/*

 * Check the status of the Electro Mechanical Interlock (EMI)

 */

static int get_lock_status(struct hotplug_slot *hotplug_slot, u8 *value)

{

	struct slot *slot = hotplug_slot->private;

	return (slot->hpc_ops->get_emi_status(slot, value));

}



/*

 * sysfs interface for the Electro Mechanical Interlock (EMI)

 * 1 == locked, 0 == unlocked

 */

static ssize_t lock_read_file(struct hotplug_slot *slot, char *buf)

{

	int retval;

	u8 value;



	retval = get_lock_status(slot, &value);

	if (retval)

		goto lock_read_exit;

	retval = sprintf (buf, "%d\n", value);



lock_read_exit:

	return retval;

}



/*

 * Change the status of the Electro Mechanical Interlock (EMI)

 * This is a toggle - in addition there must be at least 1 second

 * in between toggles.

 */

static int set_lock_status(struct hotplug_slot *hotplug_slot, u8 status)

{

	struct slot *slot = hotplug_slot->private;

	int retval;

	u8 value;



	mutex_lock(&slot->ctrl->crit_sect);



	/* has it been >1 sec since our last toggle? */

	if ((get_seconds() - slot->last_emi_toggle) < 1)

		return -EINVAL;



	/* see what our current state is */

	retval = get_lock_status(hotplug_slot, &value);

	if (retval || (value == status))

		goto set_lock_exit;



	slot->hpc_ops->toggle_emi(slot);

set_lock_exit:

	mutex_unlock(&slot->ctrl->crit_sect);

	return 0;

}



/*

 * sysfs interface which allows the user to toggle the Electro Mechanical

 * Interlock.  Valid values are either 0 or 1.  0 == unlock, 1 == lock

 */

static ssize_t lock_write_file(struct hotplug_slot *slot, const char *buf,

		size_t count)

{

	unsigned long llock;

	u8 lock;

	int retval = 0;



	llock = simple_strtoul(buf, NULL, 10);

	lock = (u8)(llock & 0xff);



	switch (lock) {

		case 0:

		case 1:

			retval = set_lock_status(slot, lock);

			break;

		default:

			err ("%d is an invalid lock value\n", lock);

			retval = -EINVAL;

	}

	if (retval)

		return retval;

	return count;

}



static struct hotplug_slot_attribute hotplug_slot_attr_lock = {

	.attr = {.name = "lock", .mode = S_IFREG | S_IRUGO | S_IWUSR},

	.show = lock_read_file,

	.store = lock_write_file

};



/**

 * release_slot - free up the memory used by a slot

 * @hotplug_slot: slot to free
@@ -159,6 +249,16 @@ static int init_slots(struct controller *ctrl) 
			err ("pci_hp_register failed with error %d\n", retval);

			goto error_info;

		}

		/* create additional sysfs entries */

		if (EMI(ctrl->ctrlcap)) {

			retval = sysfs_create_file(&hotplug_slot->kobj,

				&hotplug_slot_attr_lock.attr);

			if (retval) {

				pci_hp_deregister(hotplug_slot);

				err("cannot create additional sysfs entries\n");

				goto error_info;

			}

		}



		list_add(&slot->slot_list, &ctrl->slot_list);

	}
@@ -183,6 +283,9 @@ static void cleanup_slots(struct controller *ctrl) 
	list_for_each_safe(tmp, next, &ctrl->slot_list) {

		slot = list_entry(tmp, struct slot, slot_list);

		list_del(&slot->slot_list);

		if (EMI(ctrl->ctrlcap))

			sysfs_remove_file(&slot->hotplug_slot->kobj,

				&hotplug_slot_attr_lock.attr);

		pci_hp_deregister(slot->hotplug_slot);

	}

}

drivers/pci/hotplug/pciehp_hpc.c

+55 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 
#include <linux/timer.h>

#include <linux/pci.h>

#include <linux/interrupt.h>

#include <linux/time.h>



#include "../pci.h"

#include "pciehp.h"
@@ -192,6 +193,7 @@ static inline int pciehp_writel(struct controller *ctrl, int reg, u32 value) 
#define ATTN_LED_CTRL			0x00C0

#define PWR_LED_CTRL			0x0300

#define PWR_CTRL			0x0400

#define EMI_CTRL			0x0800



/* Attention indicator and Power indicator states */

#define LED_ON		0x01
@@ -202,6 +204,10 @@ static inline int pciehp_writel(struct controller *ctrl, int reg, u32 value) 
#define POWER_ON	0

#define POWER_OFF	0x0400



/* EMI Status defines */

#define EMI_DISENGAGED	0

#define EMI_ENGAGED	1



/* Field definitions in Slot Status Register */

#define ATTN_BUTTN_PRESSED	0x0001

#define PWR_FAULT_DETECTED	0x0002
@@ -210,6 +216,8 @@ static inline int pciehp_writel(struct controller *ctrl, int reg, u32 value) 
#define CMD_COMPLETED		0x0010

#define MRL_STATE		0x0020

#define PRSN_STATE		0x0040

#define EMI_STATE		0x0080

#define EMI_STATUS_BIT		7



static spinlock_t hpc_event_lock;
@@ -474,6 +482,51 @@ static int hpc_query_power_fault(struct slot *slot) 
	return pwr_fault;

}



static int hpc_get_emi_status(struct slot *slot, u8 *status)

{

	struct controller *ctrl = slot->ctrl;

	u16 slot_status;

	int retval = 0;



	DBG_ENTER_ROUTINE



	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);

	if (retval) {

		err("%s : Cannot check EMI status\n", __FUNCTION__);

		return retval;

	}

	*status = (slot_status & EMI_STATE) >> EMI_STATUS_BIT;



	DBG_LEAVE_ROUTINE

	return retval;

}



static int hpc_toggle_emi(struct slot *slot)

{

	struct controller *ctrl = slot->ctrl;

	u16 slot_cmd = 0;

	u16 slot_ctrl;

	int rc = 0;



	DBG_ENTER_ROUTINE



	rc = pciehp_readw(ctrl, SLOTCTRL, &slot_ctrl);

	if (rc) {

		err("%s : hp_register_read_word SLOT_CTRL failed\n",

			__FUNCTION__);

		return rc;

	}



	slot_cmd = (slot_ctrl | EMI_CTRL);

	if (!pciehp_poll_mode)

		slot_cmd = slot_cmd | HP_INTR_ENABLE;



	pcie_write_cmd(slot, slot_cmd);

	slot->last_emi_toggle = get_seconds();

	DBG_LEAVE_ROUTINE

	return rc;

}



static int hpc_set_attention_status(struct slot *slot, u8 value)

{

	struct controller *ctrl = slot->ctrl;
@@ -1009,6 +1062,8 @@ static struct hpc_ops pciehp_hpc_ops = { 
	.get_attention_status		= hpc_get_attention_status,

	.get_latch_status		= hpc_get_latch_status,

	.get_adapter_status		= hpc_get_adapter_status,

	.get_emi_status			= hpc_get_emi_status,

	.toggle_emi			= hpc_toggle_emi,



	.get_max_bus_speed		= hpc_get_max_lnk_speed,

	.get_cur_bus_speed		= hpc_get_cur_lnk_speed,