linux/linux-5.4.31/drivers/pci/hotplug/s390_pci_hpc.c

189 lines
3.7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* PCI Hot Plug Controller Driver for System z
*
* Copyright 2012 IBM Corp.
*
* Author(s):
* Jan Glauber <jang@linux.vnet.ibm.com>
*/
#define KMSG_COMPONENT "zpci"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <asm/pci_debug.h>
#include <asm/sclp.h>
#define SLOT_NAME_SIZE 10
static LIST_HEAD(s390_hotplug_slot_list);
static int zpci_fn_configured(enum zpci_state state)
{
return state == ZPCI_FN_STATE_CONFIGURED ||
state == ZPCI_FN_STATE_ONLINE;
}
/*
* struct slot - slot information for each *physical* slot
*/
struct slot {
struct list_head slot_list;
struct hotplug_slot hotplug_slot;
struct zpci_dev *zdev;
};
static inline struct slot *to_slot(struct hotplug_slot *hotplug_slot)
{
return container_of(hotplug_slot, struct slot, hotplug_slot);
}
static inline int slot_configure(struct slot *slot)
{
int ret = sclp_pci_configure(slot->zdev->fid);
zpci_dbg(3, "conf fid:%x, rc:%d\n", slot->zdev->fid, ret);
if (!ret)
slot->zdev->state = ZPCI_FN_STATE_CONFIGURED;
return ret;
}
static inline int slot_deconfigure(struct slot *slot)
{
int ret = sclp_pci_deconfigure(slot->zdev->fid);
zpci_dbg(3, "deconf fid:%x, rc:%d\n", slot->zdev->fid, ret);
if (!ret)
slot->zdev->state = ZPCI_FN_STATE_STANDBY;
return ret;
}
static int enable_slot(struct hotplug_slot *hotplug_slot)
{
struct slot *slot = to_slot(hotplug_slot);
int rc;
if (slot->zdev->state != ZPCI_FN_STATE_STANDBY)
return -EIO;
rc = slot_configure(slot);
if (rc)
return rc;
rc = zpci_enable_device(slot->zdev);
if (rc)
goto out_deconfigure;
pci_scan_slot(slot->zdev->bus, ZPCI_DEVFN);
pci_lock_rescan_remove();
pci_bus_add_devices(slot->zdev->bus);
pci_unlock_rescan_remove();
return rc;
out_deconfigure:
slot_deconfigure(slot);
return rc;
}
static int disable_slot(struct hotplug_slot *hotplug_slot)
{
struct slot *slot = to_slot(hotplug_slot);
struct pci_dev *pdev;
int rc;
if (!zpci_fn_configured(slot->zdev->state))
return -EIO;
pdev = pci_get_slot(slot->zdev->bus, ZPCI_DEVFN);
if (pdev) {
pci_stop_and_remove_bus_device_locked(pdev);
pci_dev_put(pdev);
}
rc = zpci_disable_device(slot->zdev);
if (rc)
return rc;
return slot_deconfigure(slot);
}
static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = to_slot(hotplug_slot);
switch (slot->zdev->state) {
case ZPCI_FN_STATE_STANDBY:
*value = 0;
break;
default:
*value = 1;
break;
}
return 0;
}
static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
/* if the slot exits it always contains a function */
*value = 1;
return 0;
}
static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
.enable_slot = enable_slot,
.disable_slot = disable_slot,
.get_power_status = get_power_status,
.get_adapter_status = get_adapter_status,
};
int zpci_init_slot(struct zpci_dev *zdev)
{
char name[SLOT_NAME_SIZE];
struct slot *slot;
int rc;
if (!zdev)
return 0;
slot = kzalloc(sizeof(*slot), GFP_KERNEL);
if (!slot)
goto error;
slot->zdev = zdev;
slot->hotplug_slot.ops = &s390_hotplug_slot_ops;
snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
rc = pci_hp_register(&slot->hotplug_slot, zdev->bus,
ZPCI_DEVFN, name);
if (rc)
goto error_reg;
list_add(&slot->slot_list, &s390_hotplug_slot_list);
return 0;
error_reg:
kfree(slot);
error:
return -ENOMEM;
}
void zpci_exit_slot(struct zpci_dev *zdev)
{
struct slot *slot, *next;
list_for_each_entry_safe(slot, next, &s390_hotplug_slot_list,
slot_list) {
if (slot->zdev != zdev)
continue;
list_del(&slot->slot_list);
pci_hp_deregister(&slot->hotplug_slot);
kfree(slot);
}
}