ArmPkg/Include/Library/ArmMtlLib.h

   1 /** @file
   2
   3   Copyright (c) 2017-2018, Arm Limited. All rights reserved.
   4
   5   This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13   System Control and Management Interface V1.0
  14     http://infocenter.arm.com/help/topic/com.arm.doc.den0056a/
  15     DEN0056A_System_Control_and_Management_Interface.pdf
  16 **/
  17
  18 #ifndef ARM_MTL_LIB_H_
  19 #define ARM_MTL_LIB_H_
  20
  21 #include <Uefi/UefiBaseType.h>
  22
  23 // Ideally we don't need packed struct. However we can't rely on compilers.
  24 #pragma pack(1)
  25
  26 typedef struct {
  27   UINT32 Reserved1;
  28   UINT32 ChannelStatus;
  29   UINT64 Reserved2;
  30   UINT32 Flags;
  31   UINT32 Length;
  32   UINT32 MessageHeader;
  33
  34   // NOTE: Since EDK2 does not allow flexible array member [] we declare
  35   // here array of 1 element length. However below is used as a variable
  36   // length array.
  37   UINT32 Payload[1];    // size less object gives offset to payload.
  38 } MTL_MAILBOX;
  39
  40 #pragma pack()
  41
  42 // Channel Type, Low-priority, and High-priority
  43 typedef enum {
  44   MTL_CHANNEL_TYPE_LOW = 0,
  45   MTL_CHANNEL_TYPE_HIGH = 1
  46 } MTL_CHANNEL_TYPE;
  47
  48 typedef struct {
  49   UINT64 PhysicalAddress;
  50   UINT32 ModifyMask;
  51   UINT32 PreserveMask;
  52 } MTL_DOORBELL;
  53
  54 typedef struct {
  55   MTL_CHANNEL_TYPE ChannelType;
  56   MTL_MAILBOX      * CONST MailBox;
  57   MTL_DOORBELL     DoorBell;
  58 } MTL_CHANNEL;
  59
  60 /** Wait until channel is free.
  61
  62   @param[in] Channel                Pointer to a channel.
  63   @param[in] TimeOutInMicroSeconds  Time out in micro seconds.
  64
  65   @retval EFI_SUCCESS               Channel is free.
  66   @retval EFI_TIMEOUT               Time out error.
  67 **/
  68 EFI_STATUS
  69 MtlWaitUntilChannelFree (
  70   IN MTL_CHANNEL  *Channel,
  71   IN UINT64       TimeOutInMicroSeconds
  72   );
  73
  74 /** Return the address of the message payload.
  75
  76   @param[in] Channel   Pointer to a channel.
  77
  78   @retval UINT32*      Pointer to the payload.
  79 **/
  80 UINT32*
  81 MtlGetChannelPayload (
  82   IN MTL_CHANNEL  *Channel
  83   );
  84
  85 /** Return pointer to a channel for the requested channel type.
  86
  87   @param[in] ChannelType        ChannelType, Low or High priority channel.
  88                                 MTL_CHANNEL_TYPE_LOW or
  89                                 MTL_CHANNEL_TYPE_HIGH
  90
  91   @param[out] Channel           Holds pointer to the channel.
  92
  93   @retval EFI_SUCCESS           Pointer to channel is returned.
  94   @retval EFI_UNSUPPORTED       Requested channel type not supported.
  95 **/
  96 EFI_STATUS
  97 MtlGetChannel (
  98   IN  MTL_CHANNEL_TYPE  ChannelType,
  99   OUT MTL_CHANNEL       **Channel
 100   );
 101
 102 /** Mark the channel busy and ring the doorbell.
 103
 104   @param[in] Channel               Pointer to a channel.
 105   @param[in] MessageHeader         Message header.
 106
 107   @param[out] PayloadLength        Message length.
 108
 109   @retval EFI_SUCCESS              Message sent successfully.
 110   @retval EFI_DEVICE_ERROR         Channel is busy.
 111 **/
 112 EFI_STATUS
 113 MtlSendMessage (
 114   IN  MTL_CHANNEL  *Channel,
 115   IN  UINT32       MessageHeader,
 116   OUT UINT32       PayloadLength
 117   );
 118
 119 /** Wait for a response on a channel.
 120
 121   If channel is free after sending message, it implies SCP responded
 122   with a response on the channel.
 123
 124   @param[in] Channel               Pointer to a channel.
 125
 126   @retval EFI_SUCCESS              Message received successfully.
 127   @retval EFI_TIMEOUT              Time out error.
 128 **/
 129 EFI_STATUS
 130 MtlReceiveMessage (
 131   IN  MTL_CHANNEL  *Channel,
 132   OUT UINT32       *MessageHeader,
 133   OUT UINT32       *PayloadLength
 134   );
 135
 136 #endif  /* ARM_MTL_LIB_H_ */
 137