cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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guc_communication_mmio_abi.h (2027B)

      1/* SPDX-License-Identifier: MIT */
      2/*
      3 * Copyright © 2014-2021 Intel Corporation
      4 */
      5
      6#ifndef _ABI_GUC_COMMUNICATION_MMIO_ABI_H
      7#define _ABI_GUC_COMMUNICATION_MMIO_ABI_H
      8
      9/**
     10 * DOC: GuC MMIO based communication
     11 *
     12 * The MMIO based communication between Host and GuC relies on special
     13 * hardware registers which format could be defined by the software
     14 * (so called scratch registers).
     15 *
     16 * Each MMIO based message, both Host to GuC (H2G) and GuC to Host (G2H)
     17 * messages, which maximum length depends on number of available scratch
     18 * registers, is directly written into those scratch registers.
     19 *
     20 * For Gen9+, there are 16 software scratch registers 0xC180-0xC1B8,
     21 * but no H2G command takes more than 4 parameters and the GuC firmware
     22 * itself uses an 4-element array to store the H2G message.
     23 *
     24 * For Gen11+, there are additional 4 registers 0x190240-0x19024C, which
     25 * are, regardless on lower count, preferred over legacy ones.
     26 *
     27 * The MMIO based communication is mainly used during driver initialization
     28 * phase to setup the `CTB based communication`_ that will be used afterwards.
     29 */
     30
     31#define GUC_MAX_MMIO_MSG_LEN		4
     32
     33/**
     34 * DOC: MMIO HXG Message
     35 *
     36 * Format of the MMIO messages follows definitions of `HXG Message`_.
     37 *
     38 *  +---+-------+--------------------------------------------------------------+
     39 *  |   | Bits  | Description                                                  |
     40 *  +===+=======+==============================================================+
     41 *  | 0 |  31:0 |                                                              |
     42 *  +---+-------+                                                              |
     43 *  |...|       | [Embedded `HXG Message`_]                                    |
     44 *  +---+-------+                                                              |
     45 *  | n |  31:0 |                                                              |
     46 *  +---+-------+--------------------------------------------------------------+
     47 */
     48
     49#endif /* _ABI_GUC_COMMUNICATION_MMIO_ABI_H */