LXR linux/drivers/usb/gadget/u

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * u_f.h
   4 *
   5 * Utility definitions for USB functions
   6 *
   7 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
   8 *              http://www.samsung.com
   9 *
  10 * Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
  11 */
  12
  13#ifndef __U_F_H__
  14#define __U_F_H__
  15
  16#include <linux/usb/gadget.h>
  17
  18/* Variable Length Array Macros **********************************************/
  19#define vla_group(groupname) size_t groupname##__next = 0
  20#define vla_group_size(groupname) groupname##__next
  21
  22#define vla_item(groupname, type, name, n) \
  23        size_t groupname##_##name##__offset = ({                               \
  24                size_t align_mask = __alignof__(type) - 1;                     \
  25                size_t offset = (groupname##__next + align_mask) & ~align_mask;\
  26                size_t size = (n) * sizeof(type);                              \
  27                groupname##__next = offset + size;                             \
  28                offset;                                                        \
  29        })
  30
  31#define vla_item_with_sz(groupname, type, name, n) \
  32        size_t groupname##_##name##__sz = (n) * sizeof(type);                  \
  33        size_t groupname##_##name##__offset = ({                               \
  34                size_t align_mask = __alignof__(type) - 1;                     \
  35                size_t offset = (groupname##__next + align_mask) & ~align_mask;\
  36                size_t size = groupname##_##name##__sz;                        \
  37                groupname##__next = offset + size;                             \
  38                offset;                                                        \
  39        })
  40
  41#define vla_ptr(ptr, groupname, name) \
  42        ((void *) ((char *)ptr + groupname##_##name##__offset))
  43
  44struct usb_ep;
  45struct usb_request;
  46
  47/**
  48 * alloc_ep_req - returns a usb_request allocated by the gadget driver and
  49 * allocates the request's buffer.
  50 *
  51 * @ep: the endpoint to allocate a usb_request
  52 * @len: usb_requests's buffer suggested size
  53 *
  54 * In case @ep direction is OUT, the @len will be aligned to ep's
  55 * wMaxPacketSize. In order to avoid memory leaks or drops, *always* use
  56 * usb_requests's length (req->length) to refer to the allocated buffer size.
  57 * Requests allocated via alloc_ep_req() *must* be freed by free_ep_req().
  58 */
  59struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len);
  60
  61/* Frees a usb_request previously allocated by alloc_ep_req() */
  62static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req)
  63{
  64        WARN_ON(req->buf == NULL);
  65        kfree(req->buf);
  66        req->buf = NULL;
  67        usb_ep_free_request(ep, req);
  68}
  69
  70#endif /* __U_F_H__ */
  71