/* SPDX-License-Identifier: GPL-2.0+ */
#ifndef _FDMA_API_H_
#define _FDMA_API_H_
#include <linux/bits.h>
#include <linux/etherdevice.h>
#include <linux/types.h>
/* This provides a common set of functions and data structures for interacting
* with the Frame DMA engine on multiple Microchip switchcores.
*
* Frame DMA DCB format:
*
* +---------------------------+
* | Next Ptr |
* +---------------------------+
* | Reserved | Info |
* +---------------------------+
* | Data0 Ptr |
* +---------------------------+
* | Reserved | Status0 |
* +---------------------------+
* | Data1 Ptr |
* +---------------------------+
* | Reserved | Status1 |
* +---------------------------+
* | Data2 Ptr |
* +---------------------------+
* | Reserved | Status2 |
* |-------------|-------------|
* | |
* | |
* | |
* | |
* | |
* |---------------------------|
* | Data14 Ptr |
* +-------------|-------------+
* | Reserved | Status14 |
* +-------------|-------------+
*
* The data pointers points to the actual frame data to be received or sent. The
* addresses of the data pointers can, as of writing, be either a: DMA address,
* physical address or mapped address.
*
*/
#define FDMA_DCB_INFO_DATAL(x) ((x) & GENMASK(15, 0))
#define FDMA_DCB_INFO_TOKEN BIT(17)
#define FDMA_DCB_INFO_INTR BIT(18)
#define FDMA_DCB_INFO_SW(x) (((x) << 24) & GENMASK(31, 24))
#define FDMA_DCB_STATUS_BLOCKL(x) ((x) & GENMASK(15, 0))
#define FDMA_DCB_STATUS_SOF BIT(16)
#define FDMA_DCB_STATUS_EOF BIT(17)
#define FDMA_DCB_STATUS_INTR BIT(18)
#define FDMA_DCB_STATUS_DONE BIT(19)
#define FDMA_DCB_STATUS_BLOCKO(x) (((x) << 20) & GENMASK(31, 20))
#define FDMA_DCB_INVALID_DATA 0x1
#define FDMA_DB_MAX 15 /* Max number of DB's on Sparx5 */
struct fdma;
struct fdma_db {
u64 dataptr;
u64 status;
};
struct fdma_dcb {
u64 nextptr;
u64 info;
struct fdma_db db[FDMA_DB_MAX];
};
struct fdma_ops {
/* User-provided callback to set the dataptr */
int (*dataptr_cb)(struct fdma *fdma, int dcb_idx, int db_idx, u64 *ptr);
/* User-provided callback to set the nextptr */
int (*nextptr_cb)(struct fdma *fdma, int dcb_idx, u64 *ptr);
};
struct fdma {
void *priv;
/* Virtual addresses */
struct fdma_dcb *dcbs;
struct fdma_dcb *last_dcb;
/* DMA address */
dma_addr_t dma;
/* Size of DCB + DB memory */
int size;
/* Indexes used to access the next-to-be-used DCB or DB */
int db_index;
int dcb_index;
/* Number of DCB's and DB's */
u32 n_dcbs;
u32 n_dbs;
/* Size of DB's */
u32 db_size;
/* Channel id this FDMA object operates on */
u32 channel_id;
struct fdma_ops ops;
};
/* Advance the DCB index and wrap if required. */
static inline void fdma_dcb_advance(struct fdma *fdma)
{
fdma->dcb_index++;
if (fdma->dcb_index >= fdma->n_dcbs)
fdma->dcb_index = 0;
}
/* Advance the DB index. */
static inline void fdma_db_advance(struct fdma *fdma)
{
fdma->db_index++;
}
/* Reset the db index to zero. */
static inline void fdma_db_reset(struct fdma *fdma)
{
fdma->db_index = 0;
}
/* Check if a DCB can be reused in case of multiple DB's per DCB. */
static inline bool fdma_dcb_is_reusable(struct fdma *fdma)
{
return fdma->db_index != fdma->n_dbs;
}
/* Check if the FDMA has marked this DB as done. */
static inline bool fdma_db_is_done(struct fdma_db *db)
{
return db->status & FDMA_DCB_STATUS_DONE;
}
/* Get the length of a DB. */
static inline int fdma_db_len_get(struct fdma_db *db)
{
return FDMA_DCB_STATUS_BLOCKL(db->status);
}
/* Set the length of a DB. */
static inline void fdma_dcb_len_set(struct fdma_dcb *dcb, u32 len)
{
dcb->info = FDMA_DCB_INFO_DATAL(len);
}
/* Get a DB by index. */
static inline struct fdma_db *fdma_db_get(struct fdma *fdma, int dcb_idx,
int db_idx)
{
return &fdma->dcbs[dcb_idx].db[db_idx];
}
/* Get the next DB. */
static inline struct fdma_db *fdma_db_next_get(struct fdma *fdma)
{
return fdma_db_get(fdma, fdma->dcb_index, fdma->db_index);
}
/* Get a DCB by index. */
static inline struct fdma_dcb *fdma_dcb_get(struct fdma *fdma, int dcb_idx)
{
return &fdma->dcbs[dcb_idx];
}
/* Get the next DCB. */
static inline struct fdma_dcb *fdma_dcb_next_get(struct fdma *fdma)
{
return fdma_dcb_get(fdma, fdma->dcb_index);
}
/* Check if the FDMA has frames ready for extraction. */
static inline bool fdma_has_frames(struct fdma *fdma)
{
return fdma_db_is_done(fdma_db_next_get(fdma));
}
/* Get a nextptr by index */
static inline int fdma_nextptr_cb(struct fdma *fdma, int dcb_idx, u64 *nextptr)
{
*nextptr = fdma->dma + (sizeof(struct fdma_dcb) * dcb_idx);
return 0;
}
/* Get the DMA address of a dataptr, by index. This function is only applicable
* if the dataptr addresses and DCB's are in contiguous memory and the driver
* supports XDP.
*/
static inline u64 fdma_dataptr_get_contiguous(struct fdma *fdma, int dcb_idx,
int db_idx)
{
return fdma->dma + (sizeof(struct fdma_dcb) * fdma->n_dcbs) +
(dcb_idx * fdma->n_dbs + db_idx) * fdma->db_size +
XDP_PACKET_HEADROOM;
}
/* Get the virtual address of a dataptr, by index. This function is only
* applicable if the dataptr addresses and DCB's are in contiguous memory and
* the driver supports XDP.
*/
static inline void *fdma_dataptr_virt_get_contiguous(struct fdma *fdma,
int dcb_idx, int db_idx)
{
return (u8 *)fdma->dcbs + (sizeof(struct fdma_dcb) * fdma->n_dcbs) +
(dcb_idx * fdma->n_dbs + db_idx) * fdma->db_size +
XDP_PACKET_HEADROOM;
}
/* Check if this DCB is the last used DCB. */
static inline bool fdma_is_last(struct fdma *fdma, struct fdma_dcb *dcb)
{
return dcb == fdma->last_dcb;
}
int fdma_dcbs_init(struct fdma *fdma, u64 info, u64 status);
int fdma_db_add(struct fdma *fdma, int dcb_idx, int db_idx, u64 status);
int fdma_dcb_add(struct fdma *fdma, int dcb_idx, u64 info, u64 status);
int __fdma_dcb_add(struct fdma *fdma, int dcb_idx, u64 info, u64 status,
int (*dcb_cb)(struct fdma *fdma, int dcb_idx, u64 *nextptr),
int (*db_cb)(struct fdma *fdma, int dcb_idx, int db_idx,
u64 *dataptr));
int fdma_alloc_coherent(struct device *dev, struct fdma *fdma);
int fdma_alloc_phys(struct fdma *fdma);
void fdma_free_coherent(struct device *dev, struct fdma *fdma);
void fdma_free_phys(struct fdma *fdma);
u32 fdma_get_size(struct fdma *fdma);
u32 fdma_get_size_contiguous(struct fdma *fdma);
#endif
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