diff options
Diffstat (limited to 'drivers/pci/hotplug/s390_pci_hpc.c')
| -rw-r--r-- | drivers/pci/hotplug/s390_pci_hpc.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/s390_pci_hpc.c b/drivers/pci/hotplug/s390_pci_hpc.c new file mode 100644 index 000000000000..dee68e0698e1 --- /dev/null +++ b/drivers/pci/hotplug/s390_pci_hpc.c @@ -0,0 +1,252 @@ +/* + * PCI Hot Plug Controller Driver for System z + * + * Copyright 2012 IBM Corp. + * + * Author(s): + * Jan Glauber <jang@linux.vnet.ibm.com> + */ + +#define COMPONENT "zPCI hpc" +#define pr_fmt(fmt) COMPONENT ": " fmt + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/pci.h> +#include <linux/pci_hotplug.h> +#include <linux/init.h> +#include <asm/sclp.h> + +#define SLOT_NAME_SIZE 10 +static LIST_HEAD(s390_hotplug_slot_list); + +MODULE_AUTHOR("Jan Glauber <jang@linux.vnet.ibm.com"); +MODULE_DESCRIPTION("Hot Plug PCI Controller for System z"); +MODULE_LICENSE("GPL"); + +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 int enable_slot(struct hotplug_slot *hotplug_slot) +{ + struct slot *slot = hotplug_slot->private; + int rc; + + if (slot->zdev->state != ZPCI_FN_STATE_STANDBY) + return -EIO; + + rc = sclp_pci_configure(slot->zdev->fid); + if (!rc) { + slot->zdev->state = ZPCI_FN_STATE_CONFIGURED; + /* automatically scan the device after is was configured */ + zpci_enable_device(slot->zdev); + zpci_scan_device(slot->zdev); + } + return rc; +} + +static int disable_slot(struct hotplug_slot *hotplug_slot) +{ + struct slot *slot = hotplug_slot->private; + int rc; + + if (!zpci_fn_configured(slot->zdev->state)) + return -EIO; + + /* TODO: we rely on the user to unbind/remove the device, is that plausible + * or do we need to trigger that here? + */ + rc = sclp_pci_deconfigure(slot->zdev->fid); + if (!rc) { + /* Fixme: better call List-PCI to find the disabled FH + for the FID since the FH should be opaque... */ + slot->zdev->fh &= 0x7fffffff; + slot->zdev->state = ZPCI_FN_STATE_STANDBY; + } + return rc; +} + +static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value) +{ + struct slot *slot = hotplug_slot->private; + + 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 void release_slot(struct hotplug_slot *hotplug_slot) +{ + struct slot *slot = hotplug_slot->private; + + pr_debug("%s - physical_slot = %s\n", __func__, hotplug_slot_name(hotplug_slot)); + kfree(slot->hotplug_slot->info); + kfree(slot->hotplug_slot); + kfree(slot); +} + +static 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, +}; + +static int init_pci_slot(struct zpci_dev *zdev) +{ + struct hotplug_slot *hotplug_slot; + struct hotplug_slot_info *info; + char name[SLOT_NAME_SIZE]; + struct slot *slot; + int rc; + + if (!zdev) + return 0; + + slot = kzalloc(sizeof(*slot), GFP_KERNEL); + if (!slot) + goto error; + + hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL); + if (!hotplug_slot) + goto error_hp; + hotplug_slot->private = slot; + + slot->hotplug_slot = hotplug_slot; + slot->zdev = zdev; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + goto error_info; + hotplug_slot->info = info; + + hotplug_slot->ops = &s390_hotplug_slot_ops; + hotplug_slot->release = &release_slot; + + get_power_status(hotplug_slot, &info->power_status); + get_adapter_status(hotplug_slot, &info->adapter_status); + + snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid); + rc = pci_hp_register(slot->hotplug_slot, zdev->bus, + ZPCI_DEVFN, name); + if (rc) { + pr_err("pci_hp_register failed with error %d\n", rc); + goto error_reg; + } + list_add(&slot->slot_list, &s390_hotplug_slot_list); + return 0; + +error_reg: + kfree(info); +error_info: + kfree(hotplug_slot); +error_hp: + kfree(slot); +error: + return -ENOMEM; +} + +static int __init init_pci_slots(void) +{ + struct zpci_dev *zdev; + int device = 0; + + /* + * Create a structure for each slot, and register that slot + * with the pci_hotplug subsystem. + */ + mutex_lock(&zpci_list_lock); + list_for_each_entry(zdev, &zpci_list, entry) { + init_pci_slot(zdev); + device++; + } + + mutex_unlock(&zpci_list_lock); + return (device) ? 0 : -ENODEV; +} + +static void exit_pci_slot(struct zpci_dev *zdev) +{ + struct list_head *tmp, *n; + struct slot *slot; + + list_for_each_safe(tmp, n, &s390_hotplug_slot_list) { + slot = list_entry(tmp, struct slot, slot_list); + if (slot->zdev != zdev) + continue; + list_del(&slot->slot_list); + pci_hp_deregister(slot->hotplug_slot); + } +} + +static void __exit exit_pci_slots(void) +{ + struct list_head *tmp, *n; + struct slot *slot; + + /* + * Unregister all of our slots with the pci_hotplug subsystem. + * Memory will be freed in release_slot() callback after slot's + * lifespan is finished. + */ + list_for_each_safe(tmp, n, &s390_hotplug_slot_list) { + slot = list_entry(tmp, struct slot, slot_list); + list_del(&slot->slot_list); + pci_hp_deregister(slot->hotplug_slot); + } +} + +static int __init pci_hotplug_s390_init(void) +{ + /* + * Do specific initialization stuff for your driver here + * like initializing your controller hardware (if any) and + * determining the number of slots you have in the system + * right now. + */ + + if (!pci_probe) + return -EOPNOTSUPP; + + /* register callbacks for slot handling from arch code */ + mutex_lock(&zpci_list_lock); + hotplug_ops.create_slot = init_pci_slot; + hotplug_ops.remove_slot = exit_pci_slot; + mutex_unlock(&zpci_list_lock); + pr_info("registered hotplug slot callbacks\n"); + return init_pci_slots(); +} + +static void __exit pci_hotplug_s390_exit(void) +{ + exit_pci_slots(); +} + +module_init(pci_hotplug_s390_init); +module_exit(pci_hotplug_s390_exit); |