vds.h revision f428e0958e4b4a8c3c0fcd30b0a7bb2751f9b05d
/* Virtual DMA Services (VDS) */
#define VDS_FLAGS_OFS 0x7B /* Offset of VDS flag byte in BDA. */
#define VDS_PRESENT 0x20 /* The VDS present bit. */
/* The DMA descriptor data structure. */
typedef struct {
uint32_t region_size; /* Region size in bytes. */
uint32_t offset; /* Offset. */
uint16_t seg_sel; /* Segment selector. */
uint16_t buf_id; /* Buffer ID. */
uint32_t phys_addr; /* Physical address. */
} vds_dds;
/* Scatter/gather descriptor entry. */
typedef struct {
uint32_t phys_addr; /* Physical address. */
uint32_t size; /* Entry size. */
} vds_sg;
/* The extended DDS for scatter/gather. Note that the EDDS contains either
* S/G descriptors or x86-style PTEs.
*/
typedef struct {
uint32_t region_size; /* Region size in bytes. */
uint32_t offset; /* Offset. */
uint16_t seg_sel; /* Segment or selector. */
uint16_t resvd; /* Reserved. */
uint16_t num_avail; /* Number of entries available. */
uint16_t num_used; /* Number of entries used. */
union {
vds_sg sg[1]; /* S/G entry array. */
uint32_t pte[1]; /* Page table entry array. */
} u;
} vds_edds;
/* VDS services */
#define VDS_SERVICE 0x81
#define VDS_GET_VERSION 0x02 /* Get version */
#define VDS_LOCK_BUFFER 0x03 /* Lock DMA buffer region */
#define VDS_UNLOCK_BUFFER 0x04 /* Unlock DMA buffer region */
#define VDS_SG_LOCK 0x05 /* Scatter/gather lock region */
#define VDS_SG_UNLOCK 0x06 /* Scatter/gather unlock region */
#define VDS_REQUEST_BUFFER 0x07 /* Request DMA buffer */
#define VDS_RELEASE_BUFFER 0x08 /* Release DMA buffer */
#define VDS_BUFFER_COPYIN 0x09 /* Copy into DMA buffer */
#define VDS_BUFFER_COPYOUT 0x0A /* Copy out of DMA buffer */
#define VDS_DISABLE_DMA_XLAT 0x0B /* Disable DMA translation */
#define VDS_ENABLE_DMA_XLAT 0x0C /* Enable DMA translation */
/* VDS error codes */
#define VDS_SUCCESS 0x00 /* No error */
#define VDS_ERR_NOT_CONTIG 0x01 /* Region not contiguous */
#define VDS_ERR_BOUNDRY_CROSS 0x02 /* Rgn crossed phys align boundary */
#define VDS_ERR_CANT_LOCK 0x03 /* Unable to lock pages */
#define VDS_ERR_NO_BUF 0x04 /* No buffer available */
#define VDS_ERR_RGN_TOO_BIG 0x05 /* Region too large for buffer */
#define VDS_ERR_BUF_IN_USE 0x06 /* Buffer currently in use */
#define VDS_ERR_RGN_INVALID 0x07 /* Invalid memory region */
#define VDS_ERR_RGN_NOT_LOCKED 0x08 /* Region was not locked */
#define VDS_ERR_TOO_MANY_PAGES 0x09 /* Num pages greater than table len */
#define VDS_ERR_INVALID_ID 0x0A /* Invalid buffer ID */
#define VDS_ERR_BNDRY_VIOL 0x0B /* Buffer boundary violated */
#define VDS_ERR_INVAL_DMACHN 0x0C /* Invalid DMA channel number */
#define VDS_ERR_COUNT_OVRFLO 0x0D /* Disable count overflow */
#define VDS_ERR_COUNT_UNDRFLO 0x0E /* Disable count underflow */
#define VDS_ERR_UNSUPP_FUNC 0x0F /* Function not supported */
#define VDS_ERR_BAD_FLAG 0x10 /* Reserved flag bits set in DX */
/* VDS option flags */
#define VDSF_AUTOCOPY 0x02 /* Automatic copy to/from buffer */
#define VDSF_NOALLOC 0x04 /* Disable auto buffer allocation */
#define VDSF_NOREMAP 0x08 /* Disable auto remap feature */
#define VDSF_NO64K 0x10 /* Region can't cross 64K boundary */
#define VDSF_NO128K 0x20 /* Region can't cross 128K boundary */
#define VDSF_COPYTBL 0x40 /* Copy page table for S/G remap */
#define VDSF_NPOK 0x80 /* Allow non-present pages for S/G */
/* Higher level routines for utilizing VDS. */
int vds_build_sg_list( vds_edds __far *edds, void __far *buf, uint32_t len );
int vds_free_sg_list( vds_edds __far *edds );
/* Helper for translating 16:16 real mode addresses to 32-bit linear. */
uint32_t vds_real_to_lin( void __far *ptr );