1 files changed, 0 insertions, 398 deletions
diff --git a/drivers/staging/gasket/gasket_sysfs.c b/drivers/staging/gasket/gasket_sysfs.c
deleted file mode 100644
index af26bc9f184a..000000000000
--- a/drivers/staging/gasket/gasket_sysfs.c
+++ /dev/null
@@ -1,398 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/* Copyright (C) 2018 Google, Inc. */
-#include "gasket_sysfs.h"
-
-#include "gasket_core.h"
-
-#include <linux/device.h>
-#include <linux/printk.h>
-
-/*
- * Pair of kernel device and user-specified pointer. Used in lookups in sysfs
- * "show" functions to return user data.
- */
-
-struct gasket_sysfs_mapping {
-	/*
-	 * The device bound to this mapping. If this is NULL, then this mapping
-	 * is free.
-	 */
-	struct device *device;
-
-	/* The Gasket descriptor for this device. */
-	struct gasket_dev *gasket_dev;
-
-	/* This device's set of sysfs attributes/nodes. */
-	struct gasket_sysfs_attribute *attributes;
-
-	/* The number of live elements in "attributes". */
-	int attribute_count;
-
-	/* Protects structure from simultaneous access. */
-	struct mutex mutex;
-
-	/* Tracks active users of this mapping. */
-	struct kref refcount;
-};
-
-/*
- * Data needed to manage users of this sysfs utility.
- * Currently has a fixed size; if space is a concern, this can be dynamically
- * allocated.
- */
-/*
- * 'Global' (file-scoped) list of mappings between devices and gasket_data
- * pointers. This removes the requirement to have a gasket_sysfs_data
- * handle in all files.
- */
-static struct gasket_sysfs_mapping dev_mappings[GASKET_SYSFS_NUM_MAPPINGS];
-
-/* Callback when a mapping's refcount goes to zero. */
-static void release_entry(struct kref *ref)
-{
-	/* All work is done after the return from kref_put. */
-}
-
-/* Look up mapping information for the given device. */
-static struct gasket_sysfs_mapping *get_mapping(struct device *device)
-{
-	int i;
-
-	for (i = 0; i < GASKET_SYSFS_NUM_MAPPINGS; i++) {
-		mutex_lock(&dev_mappings[i].mutex);
-		if (dev_mappings[i].device == device) {
-			kref_get(&dev_mappings[i].refcount);
-			mutex_unlock(&dev_mappings[i].mutex);
-			return &dev_mappings[i];
-		}
-		mutex_unlock(&dev_mappings[i].mutex);
-	}
-
-	dev_dbg(device, "%s: Mapping to device %s not found\n",
-		__func__, device->kobj.name);
-	return NULL;
-}
-
-/* Put a reference to a mapping. */
-static void put_mapping(struct gasket_sysfs_mapping *mapping)
-{
-	int i;
-	int num_files_to_remove = 0;
-	struct device_attribute *files_to_remove;
-	struct device *device;
-
-	if (!mapping) {
-		pr_debug("%s: Mapping should not be NULL\n", __func__);
-		return;
-	}
-
-	mutex_lock(&mapping->mutex);
-	if (kref_put(&mapping->refcount, release_entry)) {
-		dev_dbg(mapping->device, "Removing Gasket sysfs mapping\n");
-		/*
-		 * We can't remove the sysfs nodes in the kref callback, since
-		 * device_remove_file() blocks until the node is free.
-		 * Readers/writers of sysfs nodes, though, will be blocked on
-		 * the mapping mutex, resulting in deadlock. To fix this, the
-		 * sysfs nodes are removed outside the lock.
-		 */
-		device = mapping->device;
-		num_files_to_remove = mapping->attribute_count;
-		files_to_remove = kcalloc(num_files_to_remove,
-					  sizeof(*files_to_remove),
-					  GFP_KERNEL);
-		if (files_to_remove)
-			for (i = 0; i < num_files_to_remove; i++)
-				files_to_remove[i] =
-				    mapping->attributes[i].attr;
-		else
-			num_files_to_remove = 0;
-
-		kfree(mapping->attributes);
-		mapping->attributes = NULL;
-		mapping->attribute_count = 0;
-		put_device(mapping->device);
-		mapping->device = NULL;
-		mapping->gasket_dev = NULL;
-	}
-	mutex_unlock(&mapping->mutex);
-
-	if (num_files_to_remove != 0) {
-		for (i = 0; i < num_files_to_remove; ++i)
-			device_remove_file(device, &files_to_remove[i]);
-		kfree(files_to_remove);
-	}
-}
-
-/*
- * Put a reference to a mapping N times.
- *
- * In higher-level resource acquire/release function pairs, the release function
- * will need to release a mapping 2x - once for the refcount taken in the
- * release function itself, and once for the count taken in the acquire call.
- */
-static void put_mapping_n(struct gasket_sysfs_mapping *mapping, int times)
-{
-	int i;
-
-	for (i = 0; i < times; i++)
-		put_mapping(mapping);
-}
-
-void gasket_sysfs_init(void)
-{
-	int i;
-
-	for (i = 0; i < GASKET_SYSFS_NUM_MAPPINGS; i++) {
-		dev_mappings[i].device = NULL;
-		mutex_init(&dev_mappings[i].mutex);
-	}
-}
-
-int gasket_sysfs_create_mapping(struct device *device,
-				struct gasket_dev *gasket_dev)
-{
-	struct gasket_sysfs_mapping *mapping;
-	int map_idx = -1;
-
-	/*
-	 * We need a function-level mutex to protect against the same device
-	 * being added [multiple times] simultaneously.
-	 */
-	static DEFINE_MUTEX(function_mutex);
-
-	mutex_lock(&function_mutex);
-	dev_dbg(device, "Creating sysfs entries for device\n");
-
-	/* Check that the device we're adding hasn't already been added. */
-	mapping = get_mapping(device);
-	if (mapping) {
-		dev_err(device,
-			"Attempting to re-initialize sysfs mapping for device\n");
-		put_mapping(mapping);
-		mutex_unlock(&function_mutex);
-		return -EBUSY;
-	}
-
-	/* Find the first empty entry in the array. */
-	for (map_idx = 0; map_idx < GASKET_SYSFS_NUM_MAPPINGS; ++map_idx) {
-		mutex_lock(&dev_mappings[map_idx].mutex);
-		if (!dev_mappings[map_idx].device)
-			/* Break with the mutex held! */
-			break;
-		mutex_unlock(&dev_mappings[map_idx].mutex);
-	}
-
-	if (map_idx == GASKET_SYSFS_NUM_MAPPINGS) {
-		dev_err(device, "All mappings have been exhausted\n");
-		mutex_unlock(&function_mutex);
-		return -ENOMEM;
-	}
-
-	dev_dbg(device, "Creating sysfs mapping for device %s\n",
-		device->kobj.name);
-
-	mapping = &dev_mappings[map_idx];
-	mapping->attributes = kcalloc(GASKET_SYSFS_MAX_NODES,
-				      sizeof(*mapping->attributes),
-				      GFP_KERNEL);
-	if (!mapping->attributes) {
-		dev_dbg(device, "Unable to allocate sysfs attribute array\n");
-		mutex_unlock(&mapping->mutex);
-		mutex_unlock(&function_mutex);
-		return -ENOMEM;
-	}
-
-	kref_init(&mapping->refcount);
-	mapping->device = get_device(device);
-	mapping->gasket_dev = gasket_dev;
-	mapping->attribute_count = 0;
-	mutex_unlock(&mapping->mutex);
-	mutex_unlock(&function_mutex);
-
-	/* Don't decrement the refcount here! One open count keeps it alive! */
-	return 0;
-}
-
-int gasket_sysfs_create_entries(struct device *device,
-				const struct gasket_sysfs_attribute *attrs)
-{
-	int i;
-	int ret;
-	struct gasket_sysfs_mapping *mapping = get_mapping(device);
-
-	if (!mapping) {
-		dev_dbg(device,
-			"Creating entries for device without first initializing mapping\n");
-		return -EINVAL;
-	}
-
-	mutex_lock(&mapping->mutex);
-	for (i = 0; attrs[i].attr.attr.name != NULL; i++) {
-		if (mapping->attribute_count == GASKET_SYSFS_MAX_NODES) {
-			dev_err(device,
-				"Maximum number of sysfs nodes reached for device\n");
-			mutex_unlock(&mapping->mutex);
-			put_mapping(mapping);
-			return -ENOMEM;
-		}
-
-		ret = device_create_file(device, &attrs[i].attr);
-		if (ret) {
-			dev_dbg(device, "Unable to create device entries\n");
-			mutex_unlock(&mapping->mutex);
-			put_mapping(mapping);
-			return ret;
-		}
-
-		mapping->attributes[mapping->attribute_count] = attrs[i];
-		++mapping->attribute_count;
-	}
-
-	mutex_unlock(&mapping->mutex);
-	put_mapping(mapping);
-	return 0;
-}
-EXPORT_SYMBOL(gasket_sysfs_create_entries);
-
-void gasket_sysfs_remove_mapping(struct device *device)
-{
-	struct gasket_sysfs_mapping *mapping = get_mapping(device);
-
-	if (!mapping) {
-		dev_err(device,
-			"Attempted to remove non-existent sysfs mapping to device\n");
-		return;
-	}
-
-	put_mapping_n(mapping, 2);
-}
-
-struct gasket_dev *gasket_sysfs_get_device_data(struct device *device)
-{
-	struct gasket_sysfs_mapping *mapping = get_mapping(device);
-
-	if (!mapping) {
-		dev_err(device, "device not registered\n");
-		return NULL;
-	}
-
-	return mapping->gasket_dev;
-}
-EXPORT_SYMBOL(gasket_sysfs_get_device_data);
-
-void gasket_sysfs_put_device_data(struct device *device, struct gasket_dev *dev)
-{
-	struct gasket_sysfs_mapping *mapping = get_mapping(device);
-
-	if (!mapping)
-		return;
-
-	/* See comment of put_mapping_n() for why the '2' is necessary. */
-	put_mapping_n(mapping, 2);
-}
-EXPORT_SYMBOL(gasket_sysfs_put_device_data);
-
-struct gasket_sysfs_attribute *
-gasket_sysfs_get_attr(struct device *device, struct device_attribute *attr)
-{
-	int i;
-	int num_attrs;
-	struct gasket_sysfs_mapping *mapping = get_mapping(device);
-	struct gasket_sysfs_attribute *attrs = NULL;
-
-	if (!mapping)
-		return NULL;
-
-	attrs = mapping->attributes;
-	num_attrs = mapping->attribute_count;
-	for (i = 0; i < num_attrs; ++i) {
-		if (!strcmp(attrs[i].attr.attr.name, attr->attr.name))
-			return &attrs[i];
-	}
-
-	dev_err(device, "Unable to find match for device_attribute %s\n",
-		attr->attr.name);
-	return NULL;
-}
-EXPORT_SYMBOL(gasket_sysfs_get_attr);
-
-void gasket_sysfs_put_attr(struct device *device,
-			   struct gasket_sysfs_attribute *attr)
-{
-	int i;
-	int num_attrs;
-	struct gasket_sysfs_mapping *mapping = get_mapping(device);
-	struct gasket_sysfs_attribute *attrs = NULL;
-
-	if (!mapping)
-		return;
-
-	attrs = mapping->attributes;
-	num_attrs = mapping->attribute_count;
-	for (i = 0; i < num_attrs; ++i) {
-		if (&attrs[i] == attr) {
-			put_mapping_n(mapping, 2);
-			return;
-		}
-	}
-
-	dev_err(device, "Unable to put unknown attribute: %s\n",
-		attr->attr.attr.name);
-	put_mapping(mapping);
-}
-EXPORT_SYMBOL(gasket_sysfs_put_attr);
-
-ssize_t gasket_sysfs_register_store(struct device *device,
-				    struct device_attribute *attr,
-				    const char *buf, size_t count)
-{
-	ulong parsed_value = 0;
-	struct gasket_sysfs_mapping *mapping;
-	struct gasket_dev *gasket_dev;
-	struct gasket_sysfs_attribute *gasket_attr;
-
-	if (count < 3 || buf[0] != '0' || buf[1] != 'x') {
-		dev_err(device,
-			"sysfs register write format: \"0x<hex value>\"\n");
-		return -EINVAL;
-	}
-
-	if (kstrtoul(buf, 16, &parsed_value) != 0) {
-		dev_err(device,
-			"Unable to parse input as 64-bit hex value: %s\n", buf);
-		return -EINVAL;
-	}
-
-	mapping = get_mapping(device);
-	if (!mapping) {
-		dev_err(device, "Device driver may have been removed\n");
-		return 0;
-	}
-
-	gasket_dev = mapping->gasket_dev;
-	if (!gasket_dev) {
-		dev_err(device, "Device driver may have been removed\n");
-		put_mapping(mapping);
-		return 0;
-	}
-
-	gasket_attr = gasket_sysfs_get_attr(device, attr);
-	if (!gasket_attr) {
-		put_mapping(mapping);
-		return count;
-	}
-
-	gasket_dev_write_64(gasket_dev, parsed_value,
-			    gasket_attr->data.bar_address.bar,
-			    gasket_attr->data.bar_address.offset);
-
-	if (gasket_attr->write_callback)
-		gasket_attr->write_callback(gasket_dev, gasket_attr,
-					    parsed_value);
-
-	gasket_sysfs_put_attr(device, gasket_attr);
-	put_mapping(mapping);
-	return count;
-}
-EXPORT_SYMBOL(gasket_sysfs_register_store);