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 | 65 |
1 files changed, 31 insertions, 34 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 index be066a62e9e0..bbf1ddb77434 100644 --- 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 @@ -7,46 +7,43 @@ #define _ABI_GUC_COMMUNICATION_MMIO_ABI_H /** - * DOC: MMIO based communication + * DOC: GuC 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. + * The MMIO based communication between Host and GuC relies on special + * hardware registers which format could be defined by the software + * (so called scratch registers). * - * 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. + * Each MMIO based message, both Host to GuC (H2G) and GuC to Host (G2H) + * messages, which maximum length depends on number of available scratch + * registers, is directly written into those scratch registers. * - * +-----------+---------+---------+---------+ - * | MMIO[0] | MMIO[1] | ... | MMIO[n] | - * +-----------+---------+---------+---------+ - * | header | optional payload | - * +======+====+=========+=========+=========+ - * | 31:28|type| | | | - * +------+----+ | | | - * | 27:16|data| | | | - * +------+----+ | | | - * | 15:0|code| | | | - * +------+----+---------+---------+---------+ + * For Gen9+, there are 16 software scratch registers 0xC180-0xC1B8, + * but no H2G command takes more than 4 parameters and the GuC firmware + * itself uses an 4-element array to store the H2G message. * - * The message header consists of: + * For Gen11+, there are additional 4 registers 0x190240-0x19024C, which + * are, regardless on lower count, preferred over legacy ones. * - * - **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. + * The MMIO based communication is mainly used during driver initialization + * phase to setup the `CTB based communication`_ that will be used afterwards. */ -#define GUC_MAX_MMIO_MSG_LEN 8 +#define GUC_MAX_MMIO_MSG_LEN 4 + +/** + * DOC: MMIO HXG Message + * + * Format of the MMIO messages follows definitions of `HXG Message`_. + * + * +---+-------+--------------------------------------------------------------+ + * | | Bits | Description | + * +===+=======+==============================================================+ + * | 0 | 31:0 | +--------------------------------------------------------+ | + * +---+-------+ | | | + * |...| | | Embedded `HXG Message`_ | | + * +---+-------+ | | | + * | n | 31:0 | +--------------------------------------------------------+ | + * +---+-------+--------------------------------------------------------------+ + */ #endif /* _ABI_GUC_COMMUNICATION_MMIO_ABI_H */ |