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      1 /*
      2  * Copyright (C) 2006 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ANDROID_USB_INL_H__
     18 #define ANDROID_USB_INL_H__
     19 /** \file
     20   This file consists of inline routines for the driver.
     21 */
     22 
     23 /// Gets control code out of the entire IOCTL code packet
     24 __forceinline ULONG GetCtlCode(ULONG ioctl_code) {
     25   return (ioctl_code >> 2) & 0x0FFF;
     26 }
     27 
     28 /** \brief
     29   Converts string length from number of wide characters into number of bytes.
     30 */
     31 __forceinline USHORT ByteLen(USHORT wchar_len) {
     32   return static_cast<USHORT>(wchar_len * sizeof(WCHAR));
     33 }
     34 
     35 /** \brief Gets byte length of a zero-terminated string not including
     36   zero terminator. Must be called at low IRQL.
     37 */
     38 __forceinline USHORT ByteLen(const WCHAR* str) {
     39   ASSERT_IRQL_LOW();
     40   return (NULL != str) ? ByteLen(static_cast<USHORT>(wcslen(str))) : 0;
     41 }
     42 
     43 /** \brief
     44   Converts string length from number of bytes into number of wide characters.
     45   Can be called at any IRQL.
     46 */
     47 __forceinline USHORT WcharLen(USHORT byte_len) {
     48   return byte_len / sizeof(WCHAR);
     49 }
     50 
     51 /** \brief Retrieves pointer out of the WDFMEMORY handle
     52 */
     53 __forceinline void* GetAddress(WDFMEMORY wdf_mem) {
     54   ASSERT(NULL != wdf_mem);
     55   return (NULL != wdf_mem) ? WdfMemoryGetBuffer(wdf_mem, NULL) : NULL;
     56 }
     57 
     58 /** \brief Retrieves output memory address for WDFREQUEST
     59 
     60   @param request[in] A handle to KMDF request object
     61   @param status[out] Receives status of the call. Can be NULL.
     62 */
     63 __forceinline void* OutAddress(WDFREQUEST request, NTSTATUS* status) {
     64   ASSERT(NULL != request);
     65   WDFMEMORY wdf_mem = NULL;
     66   NTSTATUS stat = WdfRequestRetrieveOutputMemory(request, &wdf_mem);
     67   ASSERT((NULL != wdf_mem) || (!NT_SUCCESS(stat)));
     68   if (NULL != status)
     69     *status = stat;
     70   return NT_SUCCESS(stat) ? GetAddress(wdf_mem) : NULL;
     71 }
     72 
     73 /** \brief Retrieves input memory address for WDFREQUEST
     74 
     75   @param request[in] A handle to KMDF request object
     76   @param status[out] Receives status of the call. Can be NULL.
     77 */
     78 __forceinline void* InAddress(WDFREQUEST request, NTSTATUS* status) {
     79   ASSERT(NULL != request);
     80   WDFMEMORY wdf_mem = NULL;
     81   NTSTATUS stat = WdfRequestRetrieveInputMemory(request, &wdf_mem);
     82   ASSERT((NULL != wdf_mem) || (!NT_SUCCESS(stat)));
     83   if (NULL != status)
     84     *status = stat;
     85   return NT_SUCCESS(stat) ? GetAddress(wdf_mem) : NULL;
     86 }
     87 
     88 #endif  // ANDROID_USB_INL_H__
     89