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mei: hbm: define dma ring setup protocol

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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: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tomas Winkler
2018-07-31 09:35:34 +03:00
committed by Greg Kroah-Hartman
parent 98e70866aa
commit ee7aba5aba
1 changed files with 49 additions and 0 deletions
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49
drivers/misc/mei/hw.h
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@@ -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