| 1 | /* Virtual DMA Services (VDS) */
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| 2 |
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| 3 | #define VDS_FLAGS_OFS 0x7B /* Offset of VDS flag byte in BDA. */
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| 4 | #define VDS_PRESENT 0x20 /* The VDS present bit. */
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| 5 |
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| 6 | /* The DMA descriptor data structure. */
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| 7 |
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| 8 | typedef struct {
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| 9 | uint32_t region_size; /* Region size in bytes. */
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| 10 | uint32_t offset; /* Offset. */
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| 11 | uint16_t seg_sel; /* Segment selector. */
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| 12 | uint16_t buf_id; /* Buffer ID. */
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| 13 | uint32_t phys_addr; /* Physical address. */
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| 14 | } vds_dds;
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| 15 |
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| 16 |
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| 17 | /* Scatter/gather descriptor entry. */
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| 18 |
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| 19 | typedef struct {
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| 20 | uint32_t phys_addr; /* Physical address. */
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| 21 | uint32_t size; /* Entry size. */
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| 22 | } vds_sg;
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| 23 |
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| 24 | /* The extended DDS for scatter/gather. Note that the EDDS contains either
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| 25 | * S/G descriptors or x86-style PTEs.
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| 26 | */
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| 27 |
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| 28 | typedef struct {
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| 29 | uint32_t region_size; /* Region size in bytes. */
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| 30 | uint32_t offset; /* Offset. */
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| 31 | uint16_t seg_sel; /* Segment or selector. */
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| 32 | uint16_t resvd; /* Reserved. */
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| 33 | uint16_t num_avail; /* Number of entries available. */
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| 34 | uint16_t num_used; /* Number of entries used. */
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| 35 | union {
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| 36 | vds_sg sg[1]; /* S/G entry array. */
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| 37 | uint32_t pte[1]; /* Page table entry array. */
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| 38 | } u;
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| 39 | } vds_edds;
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| 40 |
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| 41 |
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| 42 | /* VDS services */
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| 43 |
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| 44 | #define VDS_SERVICE 0x81
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| 45 |
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| 46 | #define VDS_GET_VERSION 0x02 /* Get version */
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| 47 | #define VDS_LOCK_BUFFER 0x03 /* Lock DMA buffer region */
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| 48 | #define VDS_UNLOCK_BUFFER 0x04 /* Unlock DMA buffer region */
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| 49 | #define VDS_SG_LOCK 0x05 /* Scatter/gather lock region */
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| 50 | #define VDS_SG_UNLOCK 0x06 /* Scatter/gather unlock region */
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| 51 | #define VDS_REQUEST_BUFFER 0x07 /* Request DMA buffer */
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| 52 | #define VDS_RELEASE_BUFFER 0x08 /* Release DMA buffer */
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| 53 | #define VDS_BUFFER_COPYIN 0x09 /* Copy into DMA buffer */
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| 54 | #define VDS_BUFFER_COPYOUT 0x0A /* Copy out of DMA buffer */
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| 55 | #define VDS_DISABLE_DMA_XLAT 0x0B /* Disable DMA translation */
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| 56 | #define VDS_ENABLE_DMA_XLAT 0x0C /* Enable DMA translation */
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| 57 |
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| 58 | /* VDS error codes */
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| 59 |
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| 60 | #define VDS_SUCCESS 0x00 /* No error */
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| 61 | #define VDS_ERR_NOT_CONTIG 0x01 /* Region not contiguous */
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| 62 | #define VDS_ERR_BOUNDRY_CROSS 0x02 /* Rgn crossed phys align boundary */
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| 63 | #define VDS_ERR_CANT_LOCK 0x03 /* Unable to lock pages */
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| 64 | #define VDS_ERR_NO_BUF 0x04 /* No buffer available */
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| 65 | #define VDS_ERR_RGN_TOO_BIG 0x05 /* Region too large for buffer */
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| 66 | #define VDS_ERR_BUF_IN_USE 0x06 /* Buffer currently in use */
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| 67 | #define VDS_ERR_RGN_INVALID 0x07 /* Invalid memory region */
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| 68 | #define VDS_ERR_RGN_NOT_LOCKED 0x08 /* Region was not locked */
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| 69 | #define VDS_ERR_TOO_MANY_PAGES 0x09 /* Num pages greater than table len */
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| 70 | #define VDS_ERR_INVALID_ID 0x0A /* Invalid buffer ID */
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| 71 | #define VDS_ERR_BNDRY_VIOL 0x0B /* Buffer boundary violated */
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| 72 | #define VDS_ERR_INVAL_DMACHN 0x0C /* Invalid DMA channel number */
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| 73 | #define VDS_ERR_COUNT_OVRFLO 0x0D /* Disable count overflow */
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| 74 | #define VDS_ERR_COUNT_UNDRFLO 0x0E /* Disable count underflow */
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| 75 | #define VDS_ERR_UNSUPP_FUNC 0x0F /* Function not supported */
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| 76 | #define VDS_ERR_BAD_FLAG 0x10 /* Reserved flag bits set in DX */
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| 77 |
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| 78 | /* VDS option flags */
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| 79 |
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| 80 | #define VDSF_AUTOCOPY 0x02 /* Automatic copy to/from buffer */
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| 81 | #define VDSF_NOALLOC 0x04 /* Disable auto buffer allocation */
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| 82 | #define VDSF_NOREMAP 0x08 /* Disable auto remap feature */
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| 83 | #define VDSF_NO64K 0x10 /* Region can't cross 64K boundary */
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| 84 | #define VDSF_NO128K 0x20 /* Region can't cross 128K boundary */
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| 85 | #define VDSF_COPYTBL 0x40 /* Copy page table for S/G remap */
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| 86 | #define VDSF_NPOK 0x80 /* Allow non-present pages for S/G */
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| 87 |
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| 88 | /* Higher level routines for utilizing VDS. */
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| 89 |
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| 90 | int vds_build_sg_list( vds_edds __far *edds, void __far *buf, uint32_t len );
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| 91 | int vds_free_sg_list( vds_edds __far *edds );
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| 92 |
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| 93 | /* Helper for translating 16:16 real mode addresses to 32-bit linear. */
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| 94 |
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| 95 | uint32_t vds_real_to_lin( void __far *ptr );
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