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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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4a90f09b20
Use kref in the USB serial drivers so that we don't free tty structures from under the URB receive handlers as has historically been the case if you were unlucky. This also gives us a framework for general tty drivers to use tty_port objects and refcount. Contains two err->dev_err changes merged together to fix clashes in the -next tree. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
440 lines
11 KiB
C
440 lines
11 KiB
C
/*
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* USB Serial Converter Generic functions
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*
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* Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version
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* 2 as published by the Free Software Foundation.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/tty.h>
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#include <linux/tty_flip.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/usb.h>
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#include <linux/usb/serial.h>
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#include <linux/uaccess.h>
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static int debug;
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#ifdef CONFIG_USB_SERIAL_GENERIC
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static int generic_probe(struct usb_interface *interface,
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const struct usb_device_id *id);
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static __u16 vendor = 0x05f9;
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static __u16 product = 0xffff;
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module_param(vendor, ushort, 0);
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MODULE_PARM_DESC(vendor, "User specified USB idVendor");
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module_param(product, ushort, 0);
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MODULE_PARM_DESC(product, "User specified USB idProduct");
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static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
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/* we want to look at all devices, as the vendor/product id can change
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* depending on the command line argument */
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static struct usb_device_id generic_serial_ids[] = {
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{.driver_info = 42},
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{}
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};
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static struct usb_driver generic_driver = {
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.name = "usbserial_generic",
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.probe = generic_probe,
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.disconnect = usb_serial_disconnect,
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.id_table = generic_serial_ids,
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.no_dynamic_id = 1,
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};
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/* All of the device info needed for the Generic Serial Converter */
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struct usb_serial_driver usb_serial_generic_device = {
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.driver = {
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.owner = THIS_MODULE,
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.name = "generic",
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},
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.id_table = generic_device_ids,
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.usb_driver = &generic_driver,
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.num_ports = 1,
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.shutdown = usb_serial_generic_shutdown,
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.throttle = usb_serial_generic_throttle,
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.unthrottle = usb_serial_generic_unthrottle,
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.resume = usb_serial_generic_resume,
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};
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static int generic_probe(struct usb_interface *interface,
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const struct usb_device_id *id)
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{
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const struct usb_device_id *id_pattern;
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id_pattern = usb_match_id(interface, generic_device_ids);
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if (id_pattern != NULL)
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return usb_serial_probe(interface, id);
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return -ENODEV;
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}
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#endif
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int usb_serial_generic_register(int _debug)
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{
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int retval = 0;
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debug = _debug;
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#ifdef CONFIG_USB_SERIAL_GENERIC
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generic_device_ids[0].idVendor = vendor;
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generic_device_ids[0].idProduct = product;
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generic_device_ids[0].match_flags =
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USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
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/* register our generic driver with ourselves */
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retval = usb_serial_register(&usb_serial_generic_device);
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if (retval)
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goto exit;
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retval = usb_register(&generic_driver);
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if (retval)
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usb_serial_deregister(&usb_serial_generic_device);
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exit:
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#endif
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return retval;
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}
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void usb_serial_generic_deregister(void)
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{
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#ifdef CONFIG_USB_SERIAL_GENERIC
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/* remove our generic driver */
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usb_deregister(&generic_driver);
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usb_serial_deregister(&usb_serial_generic_device);
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#endif
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}
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int usb_serial_generic_open(struct tty_struct *tty,
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struct usb_serial_port *port, struct file *filp)
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{
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struct usb_serial *serial = port->serial;
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int result = 0;
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unsigned long flags;
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dbg("%s - port %d", __func__, port->number);
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/* force low_latency on so that our tty_push actually forces the data
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through, otherwise it is scheduled, and with high data rates (like
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with OHCI) data can get lost. */
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if (tty)
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tty->low_latency = 1;
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/* clear the throttle flags */
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spin_lock_irqsave(&port->lock, flags);
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port->throttled = 0;
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port->throttle_req = 0;
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spin_unlock_irqrestore(&port->lock, flags);
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/* if we have a bulk endpoint, start reading from it */
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if (serial->num_bulk_in) {
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/* Start reading from the device */
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usb_fill_bulk_urb(port->read_urb, serial->dev,
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usb_rcvbulkpipe(serial->dev,
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port->bulk_in_endpointAddress),
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port->read_urb->transfer_buffer,
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port->read_urb->transfer_buffer_length,
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((serial->type->read_bulk_callback) ?
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serial->type->read_bulk_callback :
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usb_serial_generic_read_bulk_callback),
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port);
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result = usb_submit_urb(port->read_urb, GFP_KERNEL);
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if (result)
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dev_err(&port->dev,
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"%s - failed resubmitting read urb, error %d\n",
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__func__, result);
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}
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return result;
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}
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EXPORT_SYMBOL_GPL(usb_serial_generic_open);
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static void generic_cleanup(struct usb_serial_port *port)
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{
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struct usb_serial *serial = port->serial;
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dbg("%s - port %d", __func__, port->number);
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if (serial->dev) {
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/* shutdown any bulk reads that might be going on */
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if (serial->num_bulk_out)
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usb_kill_urb(port->write_urb);
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if (serial->num_bulk_in)
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usb_kill_urb(port->read_urb);
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}
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}
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int usb_serial_generic_resume(struct usb_serial *serial)
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{
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struct usb_serial_port *port;
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int i, c = 0, r;
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#ifdef CONFIG_PM
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/*
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* If this is an autoresume, don't submit URBs.
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* They will be submitted in the open function instead.
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*/
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if (serial->dev->auto_pm)
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return 0;
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#endif
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for (i = 0; i < serial->num_ports; i++) {
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port = serial->port[i];
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if (port->port.count && port->read_urb) {
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r = usb_submit_urb(port->read_urb, GFP_NOIO);
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if (r < 0)
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c++;
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}
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}
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return c ? -EIO : 0;
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}
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void usb_serial_generic_close(struct tty_struct *tty,
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struct usb_serial_port *port, struct file *filp)
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{
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dbg("%s - port %d", __func__, port->number);
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generic_cleanup(port);
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}
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int usb_serial_generic_write(struct tty_struct *tty,
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struct usb_serial_port *port, const unsigned char *buf, int count)
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{
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struct usb_serial *serial = port->serial;
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int result;
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unsigned char *data;
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dbg("%s - port %d", __func__, port->number);
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if (count == 0) {
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dbg("%s - write request of 0 bytes", __func__);
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return 0;
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}
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/* only do something if we have a bulk out endpoint */
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if (serial->num_bulk_out) {
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unsigned long flags;
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spin_lock_irqsave(&port->lock, flags);
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if (port->write_urb_busy) {
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spin_unlock_irqrestore(&port->lock, flags);
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dbg("%s - already writing", __func__);
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return 0;
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}
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port->write_urb_busy = 1;
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spin_unlock_irqrestore(&port->lock, flags);
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count = (count > port->bulk_out_size) ?
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port->bulk_out_size : count;
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memcpy(port->write_urb->transfer_buffer, buf, count);
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data = port->write_urb->transfer_buffer;
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usb_serial_debug_data(debug, &port->dev, __func__, count, data);
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/* set up our urb */
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usb_fill_bulk_urb(port->write_urb, serial->dev,
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usb_sndbulkpipe(serial->dev,
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port->bulk_out_endpointAddress),
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port->write_urb->transfer_buffer, count,
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((serial->type->write_bulk_callback) ?
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serial->type->write_bulk_callback :
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usb_serial_generic_write_bulk_callback),
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port);
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/* send the data out the bulk port */
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port->write_urb_busy = 1;
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result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
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if (result) {
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dev_err(&port->dev,
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"%s - failed submitting write urb, error %d\n",
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__func__, result);
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/* don't have to grab the lock here, as we will
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retry if != 0 */
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port->write_urb_busy = 0;
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} else
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result = count;
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return result;
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}
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/* no bulk out, so return 0 bytes written */
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return 0;
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}
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int usb_serial_generic_write_room(struct tty_struct *tty)
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{
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struct usb_serial_port *port = tty->driver_data;
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struct usb_serial *serial = port->serial;
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int room = 0;
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dbg("%s - port %d", __func__, port->number);
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/* FIXME: Locking */
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if (serial->num_bulk_out) {
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if (!(port->write_urb_busy))
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room = port->bulk_out_size;
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}
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dbg("%s - returns %d", __func__, room);
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return room;
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}
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int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
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{
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struct usb_serial_port *port = tty->driver_data;
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struct usb_serial *serial = port->serial;
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int chars = 0;
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dbg("%s - port %d", __func__, port->number);
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/* FIXME: Locking */
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if (serial->num_bulk_out) {
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if (port->write_urb_busy)
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chars = port->write_urb->transfer_buffer_length;
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}
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dbg("%s - returns %d", __func__, chars);
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return chars;
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}
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static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
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{
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struct urb *urb = port->read_urb;
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struct usb_serial *serial = port->serial;
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int result;
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/* Continue reading from device */
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usb_fill_bulk_urb(urb, serial->dev,
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usb_rcvbulkpipe(serial->dev,
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port->bulk_in_endpointAddress),
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urb->transfer_buffer,
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urb->transfer_buffer_length,
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((serial->type->read_bulk_callback) ?
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serial->type->read_bulk_callback :
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usb_serial_generic_read_bulk_callback), port);
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result = usb_submit_urb(urb, mem_flags);
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if (result)
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dev_err(&port->dev,
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"%s - failed resubmitting read urb, error %d\n",
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__func__, result);
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}
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/* Push data to tty layer and resubmit the bulk read URB */
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static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
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{
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struct urb *urb = port->read_urb;
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struct tty_struct *tty = tty_port_tty_get(&port->port);
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int room;
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/* Push data to tty */
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if (tty && urb->actual_length) {
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room = tty_buffer_request_room(tty, urb->actual_length);
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if (room) {
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tty_insert_flip_string(tty, urb->transfer_buffer, room);
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tty_flip_buffer_push(tty);
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}
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}
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tty_kref_put(tty);
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resubmit_read_urb(port, GFP_ATOMIC);
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}
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void usb_serial_generic_read_bulk_callback(struct urb *urb)
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{
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struct usb_serial_port *port = urb->context;
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unsigned char *data = urb->transfer_buffer;
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int status = urb->status;
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unsigned long flags;
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dbg("%s - port %d", __func__, port->number);
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if (unlikely(status != 0)) {
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dbg("%s - nonzero read bulk status received: %d",
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__func__, status);
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return;
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}
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usb_serial_debug_data(debug, &port->dev, __func__,
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urb->actual_length, data);
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/* Throttle the device if requested by tty */
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spin_lock_irqsave(&port->lock, flags);
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port->throttled = port->throttle_req;
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if (!port->throttled) {
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spin_unlock_irqrestore(&port->lock, flags);
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flush_and_resubmit_read_urb(port);
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} else
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spin_unlock_irqrestore(&port->lock, flags);
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}
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EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
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void usb_serial_generic_write_bulk_callback(struct urb *urb)
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{
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struct usb_serial_port *port = urb->context;
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int status = urb->status;
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dbg("%s - port %d", __func__, port->number);
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port->write_urb_busy = 0;
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if (status) {
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dbg("%s - nonzero write bulk status received: %d",
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__func__, status);
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return;
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}
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usb_serial_port_softint(port);
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}
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EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
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void usb_serial_generic_throttle(struct tty_struct *tty)
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{
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struct usb_serial_port *port = tty->driver_data;
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unsigned long flags;
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dbg("%s - port %d", __func__, port->number);
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/* Set the throttle request flag. It will be picked up
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* by usb_serial_generic_read_bulk_callback(). */
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spin_lock_irqsave(&port->lock, flags);
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port->throttle_req = 1;
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spin_unlock_irqrestore(&port->lock, flags);
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}
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void usb_serial_generic_unthrottle(struct tty_struct *tty)
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{
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struct usb_serial_port *port = tty->driver_data;
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int was_throttled;
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unsigned long flags;
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dbg("%s - port %d", __func__, port->number);
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/* Clear the throttle flags */
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spin_lock_irqsave(&port->lock, flags);
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was_throttled = port->throttled;
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port->throttled = port->throttle_req = 0;
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spin_unlock_irqrestore(&port->lock, flags);
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if (was_throttled) {
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/* Resume reading from device */
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resubmit_read_urb(port, GFP_KERNEL);
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}
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}
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void usb_serial_generic_shutdown(struct usb_serial *serial)
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{
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int i;
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dbg("%s", __func__);
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/* stop reads and writes on all ports */
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for (i = 0; i < serial->num_ports; ++i)
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generic_cleanup(serial->port[i]);
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}
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