Fixed MTP to work with TWRP

drivers/pci/hotplug/s390_pci_hpc.c

@@ -0,0 +1,214 @@
+/*
+ * 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/module.h>
+#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);
+
+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 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 = hotplug_slot->private;
+	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 = hotplug_slot->private;
+	int rc;
+
+	if (!zpci_fn_configured(slot->zdev->state))
+		return -EIO;
+
+	if (slot->zdev->pdev)
+		pci_stop_and_remove_bus_device_locked(slot->zdev->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 = 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;
+
+	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,
+};
+
+int zpci_init_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)
+		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;
+}
+
+void zpci_exit_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);
+	}
+}