diff options
Diffstat (limited to 'drivers/gpu/drm/i915/gt/uc/abi/guc_communication_mmio_abi.h')
-rw-r--r-- | drivers/gpu/drm/i915/gt/uc/abi/guc_communication_mmio_abi.h | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_mmio_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_mmio_abi.h new file mode 100644 index 000000000000..be066a62e9e0 --- /dev/null +++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_mmio_abi.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright © 2014-2021 Intel Corporation + */ + +#ifndef _ABI_GUC_COMMUNICATION_MMIO_ABI_H +#define _ABI_GUC_COMMUNICATION_MMIO_ABI_H + +/** + * DOC: MMIO based communication + * + * The MMIO based communication between Host and GuC uses software scratch + * registers, where first register holds data treated as message header, + * and other registers are used to hold message payload. + * + * For Gen9+, GuC uses software scratch registers 0xC180-0xC1B8, + * but no H2G command takes more than 8 parameters and the GuC FW + * itself uses an 8-element array to store the H2G message. + * + * +-----------+---------+---------+---------+ + * | MMIO[0] | MMIO[1] | ... | MMIO[n] | + * +-----------+---------+---------+---------+ + * | header | optional payload | + * +======+====+=========+=========+=========+ + * | 31:28|type| | | | + * +------+----+ | | | + * | 27:16|data| | | | + * +------+----+ | | | + * | 15:0|code| | | | + * +------+----+---------+---------+---------+ + * + * The message header consists of: + * + * - **type**, indicates message type + * - **code**, indicates message code, is specific for **type** + * - **data**, indicates message data, optional, depends on **code** + * + * The following message **types** are supported: + * + * - **REQUEST**, indicates Host-to-GuC request, requested GuC action code + * must be priovided in **code** field. Optional action specific parameters + * can be provided in remaining payload registers or **data** field. + * + * - **RESPONSE**, indicates GuC-to-Host response from earlier GuC request, + * action response status will be provided in **code** field. Optional + * response data can be returned in remaining payload registers or **data** + * field. + */ + +#define GUC_MAX_MMIO_MSG_LEN 8 + +#endif /* _ABI_GUC_COMMUNICATION_MMIO_ABI_H */ |