Commit ee7aba5a authored by Tomas Winkler's avatar Tomas Winkler Committed by Greg Kroah-Hartman
Browse files

mei: hbm: define dma ring setup protocol 



The protocol defines how to setup an I/O ring on top of host
memory to utilize the device DMA engine for faster transport.

Three memory buffers are allocated.
A Host circular buffer for from the Host to Device communication.
A Device circular buffer for from Device to the Host communication.
And finally a Control block where the pointers for the both
circular buffers are managed.

Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: default avatarAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 98e70866

drivers/misc/mei/hw.h

+49 −0
Original line number Diff line number Diff line
@@ -122,6 +122,9 @@ 
#define MEI_HBM_NOTIFY_RES_CMD              0x90

#define MEI_HBM_NOTIFICATION_CMD            0x11



#define MEI_HBM_DMA_SETUP_REQ_CMD           0x12

#define MEI_HBM_DMA_SETUP_RES_CMD           0x92



/*

 * MEI Stop Reason

 * used by hbm_host_stop_request.reason
@@ -449,4 +452,50 @@ struct hbm_notification { 
	u8 reserved[1];

} __packed;



/**

 * struct hbm_dma_mem_dscr - dma ring

 *

 * @addr_hi: the high 32bits of 64 bit address

 * @addr_lo: the low  32bits of 64 bit address

 * @size   : size in bytes (must be power of 2)

 */

struct hbm_dma_mem_dscr {

	u32 addr_hi;

	u32 addr_lo;

	u32 size;

} __packed;



enum {

	DMA_DSCR_HOST = 0,

	DMA_DSCR_DEVICE = 1,

	DMA_DSCR_CTRL = 2,

	DMA_DSCR_NUM,

};



/**

 * struct hbm_dma_setup_request - dma setup request

 *

 * @hbm_cmd: bus message command header

 * @reserved: reserved for alignment

 * @dma_dscr: dma descriptor for HOST, DEVICE, and CTRL

 */

struct hbm_dma_setup_request {

	u8 hbm_cmd;

	u8 reserved[3];

	struct hbm_dma_mem_dscr dma_dscr[DMA_DSCR_NUM];

} __packed;



/**

 * struct hbm_dma_setup_response - dma setup response

 *

 * @hbm_cmd: bus message command header

 * @status: 0 on success; otherwise DMA setup failed.

 * @reserved: reserved for alignment

 */

struct hbm_dma_setup_response {

	u8 hbm_cmd;

	u8 status;

	u8 reserved[2];

} __packed;



#endif

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