![Greg Kroah-Hartman](/assets/img/avatar_default.png)
Now that the SPDX tag is in all greybus files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Vaibhav Hiremath <hvaibhav.linux@gmail.com> Reviewed-by: Alex Elder <elder@linaro.org> Acked-by: Vaibhav Agarwal <vaibhav.sr@gmail.com> Acked-by: David Lin <dtwlin@gmail.com> Acked-by: Johan Hovold <johan@kernel.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Mark Greer <mgreer@animalcreek.com> Acked-by: Rui Miguel Silva <rmfrfs@gmail.com> Acked-by: "Bryan O'Donoghue" <pure.logic@nexus-software.ie> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
381 lines
8.3 KiB
C
381 lines
8.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Greybus driver for the Raw protocol
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*
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* Copyright 2015 Google Inc.
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* Copyright 2015 Linaro Ltd.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/sizes.h>
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#include <linux/cdev.h>
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#include <linux/fs.h>
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#include <linux/idr.h>
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#include <linux/uaccess.h>
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#include "greybus.h"
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struct gb_raw {
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struct gb_connection *connection;
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struct list_head list;
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int list_data;
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struct mutex list_lock;
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dev_t dev;
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struct cdev cdev;
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struct device *device;
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};
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struct raw_data {
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struct list_head entry;
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u32 len;
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u8 data[0];
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};
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static struct class *raw_class;
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static int raw_major;
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static const struct file_operations raw_fops;
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static DEFINE_IDA(minors);
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/* Number of minor devices this driver supports */
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#define NUM_MINORS 256
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/* Maximum size of any one send data buffer we support */
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#define MAX_PACKET_SIZE (PAGE_SIZE * 2)
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/*
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* Maximum size of the data in the receive buffer we allow before we start to
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* drop messages on the floor
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*/
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#define MAX_DATA_SIZE (MAX_PACKET_SIZE * 8)
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/*
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* Add the raw data message to the list of received messages.
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*/
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static int receive_data(struct gb_raw *raw, u32 len, u8 *data)
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{
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struct raw_data *raw_data;
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struct device *dev = &raw->connection->bundle->dev;
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int retval = 0;
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if (len > MAX_PACKET_SIZE) {
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dev_err(dev, "Too big of a data packet, rejected\n");
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return -EINVAL;
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}
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mutex_lock(&raw->list_lock);
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if ((raw->list_data + len) > MAX_DATA_SIZE) {
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dev_err(dev, "Too much data in receive buffer, now dropping packets\n");
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retval = -EINVAL;
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goto exit;
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}
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raw_data = kmalloc(sizeof(*raw_data) + len, GFP_KERNEL);
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if (!raw_data) {
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retval = -ENOMEM;
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goto exit;
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}
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raw->list_data += len;
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raw_data->len = len;
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memcpy(&raw_data->data[0], data, len);
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list_add_tail(&raw_data->entry, &raw->list);
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exit:
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mutex_unlock(&raw->list_lock);
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return retval;
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}
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static int gb_raw_request_handler(struct gb_operation *op)
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{
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struct gb_connection *connection = op->connection;
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struct device *dev = &connection->bundle->dev;
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struct gb_raw *raw = greybus_get_drvdata(connection->bundle);
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struct gb_raw_send_request *receive;
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u32 len;
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if (op->type != GB_RAW_TYPE_SEND) {
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dev_err(dev, "unknown request type 0x%02x\n", op->type);
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return -EINVAL;
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}
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/* Verify size of payload */
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if (op->request->payload_size < sizeof(*receive)) {
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dev_err(dev, "raw receive request too small (%zu < %zu)\n",
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op->request->payload_size, sizeof(*receive));
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return -EINVAL;
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}
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receive = op->request->payload;
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len = le32_to_cpu(receive->len);
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if (len != (int)(op->request->payload_size - sizeof(__le32))) {
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dev_err(dev, "raw receive request wrong size %d vs %d\n", len,
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(int)(op->request->payload_size - sizeof(__le32)));
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return -EINVAL;
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}
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if (len == 0) {
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dev_err(dev, "raw receive request of 0 bytes?\n");
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return -EINVAL;
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}
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return receive_data(raw, len, receive->data);
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}
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static int gb_raw_send(struct gb_raw *raw, u32 len, const char __user *data)
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{
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struct gb_connection *connection = raw->connection;
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struct gb_raw_send_request *request;
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int retval;
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request = kmalloc(len + sizeof(*request), GFP_KERNEL);
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if (!request)
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return -ENOMEM;
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if (copy_from_user(&request->data[0], data, len)) {
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kfree(request);
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return -EFAULT;
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}
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request->len = cpu_to_le32(len);
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retval = gb_operation_sync(connection, GB_RAW_TYPE_SEND,
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request, len + sizeof(*request),
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NULL, 0);
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kfree(request);
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return retval;
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}
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static int gb_raw_probe(struct gb_bundle *bundle,
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const struct greybus_bundle_id *id)
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{
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struct greybus_descriptor_cport *cport_desc;
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struct gb_connection *connection;
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struct gb_raw *raw;
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int retval;
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int minor;
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if (bundle->num_cports != 1)
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return -ENODEV;
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cport_desc = &bundle->cport_desc[0];
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if (cport_desc->protocol_id != GREYBUS_PROTOCOL_RAW)
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return -ENODEV;
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raw = kzalloc(sizeof(*raw), GFP_KERNEL);
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if (!raw)
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return -ENOMEM;
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connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id),
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gb_raw_request_handler);
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if (IS_ERR(connection)) {
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retval = PTR_ERR(connection);
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goto error_free;
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}
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INIT_LIST_HEAD(&raw->list);
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mutex_init(&raw->list_lock);
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raw->connection = connection;
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greybus_set_drvdata(bundle, raw);
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minor = ida_simple_get(&minors, 0, 0, GFP_KERNEL);
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if (minor < 0) {
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retval = minor;
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goto error_connection_destroy;
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}
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raw->dev = MKDEV(raw_major, minor);
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cdev_init(&raw->cdev, &raw_fops);
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retval = gb_connection_enable(connection);
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if (retval)
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goto error_remove_ida;
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retval = cdev_add(&raw->cdev, raw->dev, 1);
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if (retval)
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goto error_connection_disable;
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raw->device = device_create(raw_class, &connection->bundle->dev,
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raw->dev, raw, "gb!raw%d", minor);
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if (IS_ERR(raw->device)) {
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retval = PTR_ERR(raw->device);
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goto error_del_cdev;
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}
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return 0;
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error_del_cdev:
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cdev_del(&raw->cdev);
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error_connection_disable:
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gb_connection_disable(connection);
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error_remove_ida:
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ida_simple_remove(&minors, minor);
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error_connection_destroy:
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gb_connection_destroy(connection);
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error_free:
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kfree(raw);
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return retval;
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}
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static void gb_raw_disconnect(struct gb_bundle *bundle)
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{
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struct gb_raw *raw = greybus_get_drvdata(bundle);
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struct gb_connection *connection = raw->connection;
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struct raw_data *raw_data;
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struct raw_data *temp;
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// FIXME - handle removing a connection when the char device node is open.
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device_destroy(raw_class, raw->dev);
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cdev_del(&raw->cdev);
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gb_connection_disable(connection);
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ida_simple_remove(&minors, MINOR(raw->dev));
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gb_connection_destroy(connection);
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mutex_lock(&raw->list_lock);
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list_for_each_entry_safe(raw_data, temp, &raw->list, entry) {
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list_del(&raw_data->entry);
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kfree(raw_data);
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}
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mutex_unlock(&raw->list_lock);
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kfree(raw);
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}
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/*
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* Character device node interfaces.
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*
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* Note, we are using read/write to only allow a single read/write per message.
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* This means for read(), you have to provide a big enough buffer for the full
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* message to be copied into. If the buffer isn't big enough, the read() will
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* fail with -ENOSPC.
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*/
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static int raw_open(struct inode *inode, struct file *file)
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{
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struct cdev *cdev = inode->i_cdev;
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struct gb_raw *raw = container_of(cdev, struct gb_raw, cdev);
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file->private_data = raw;
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return 0;
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}
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static ssize_t raw_write(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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struct gb_raw *raw = file->private_data;
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int retval;
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if (!count)
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return 0;
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if (count > MAX_PACKET_SIZE)
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return -E2BIG;
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retval = gb_raw_send(raw, count, buf);
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if (retval)
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return retval;
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return count;
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}
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static ssize_t raw_read(struct file *file, char __user *buf, size_t count,
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loff_t *ppos)
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{
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struct gb_raw *raw = file->private_data;
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int retval = 0;
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struct raw_data *raw_data;
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mutex_lock(&raw->list_lock);
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if (list_empty(&raw->list))
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goto exit;
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raw_data = list_first_entry(&raw->list, struct raw_data, entry);
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if (raw_data->len > count) {
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retval = -ENOSPC;
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goto exit;
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}
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if (copy_to_user(buf, &raw_data->data[0], raw_data->len)) {
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retval = -EFAULT;
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goto exit;
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}
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list_del(&raw_data->entry);
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raw->list_data -= raw_data->len;
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retval = raw_data->len;
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kfree(raw_data);
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exit:
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mutex_unlock(&raw->list_lock);
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return retval;
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}
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static const struct file_operations raw_fops = {
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.owner = THIS_MODULE,
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.write = raw_write,
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.read = raw_read,
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.open = raw_open,
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.llseek = noop_llseek,
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};
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static const struct greybus_bundle_id gb_raw_id_table[] = {
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{ GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_RAW) },
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{ }
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};
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MODULE_DEVICE_TABLE(greybus, gb_raw_id_table);
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static struct greybus_driver gb_raw_driver = {
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.name = "raw",
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.probe = gb_raw_probe,
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.disconnect = gb_raw_disconnect,
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.id_table = gb_raw_id_table,
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};
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static int raw_init(void)
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{
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dev_t dev;
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int retval;
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raw_class = class_create(THIS_MODULE, "gb_raw");
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if (IS_ERR(raw_class)) {
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retval = PTR_ERR(raw_class);
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goto error_class;
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}
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retval = alloc_chrdev_region(&dev, 0, NUM_MINORS, "gb_raw");
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if (retval < 0)
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goto error_chrdev;
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raw_major = MAJOR(dev);
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retval = greybus_register(&gb_raw_driver);
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if (retval)
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goto error_gb;
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return 0;
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error_gb:
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unregister_chrdev_region(dev, NUM_MINORS);
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error_chrdev:
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class_destroy(raw_class);
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error_class:
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return retval;
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}
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module_init(raw_init);
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static void __exit raw_exit(void)
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{
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greybus_deregister(&gb_raw_driver);
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unregister_chrdev_region(MKDEV(raw_major, 0), NUM_MINORS);
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class_destroy(raw_class);
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ida_destroy(&minors);
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}
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module_exit(raw_exit);
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MODULE_LICENSE("GPL v2");
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