--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+
+#include "fdma_api.h"
+
+#include <linux/bits.h>
+#include <linux/etherdevice.h>
+#include <linux/types.h>
+
+/* Add a DB to a DCB, providing a callback for getting the DB dataptr. */
+static int __fdma_db_add(struct fdma *fdma, int dcb_idx, int db_idx, u64 status,
+ int (*cb)(struct fdma *fdma, int dcb_idx,
+ int db_idx, u64 *dataptr))
+{
+ struct fdma_db *db = fdma_db_get(fdma, dcb_idx, db_idx);
+
+ db->status = status;
+
+ return cb(fdma, dcb_idx, db_idx, &db->dataptr);
+}
+
+/* Add a DB to a DCB, using the callback set in the fdma_ops struct. */
+int fdma_db_add(struct fdma *fdma, int dcb_idx, int db_idx, u64 status)
+{
+ return __fdma_db_add(fdma,
+ dcb_idx,
+ db_idx,
+ status,
+ fdma->ops.dataptr_cb);
+}
+
+/* Add a DCB with callbacks for getting the DB dataptr and the DCB nextptr. */
+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))
+{
+ struct fdma_dcb *dcb = fdma_dcb_get(fdma, dcb_idx);
+ int i, err;
+
+ for (i = 0; i < fdma->n_dbs; i++) {
+ err = __fdma_db_add(fdma, dcb_idx, i, status, db_cb);
+ if (unlikely(err))
+ return err;
+ }
+
+ err = dcb_cb(fdma, dcb_idx, &fdma->last_dcb->nextptr);
+ if (unlikely(err))
+ return err;
+
+ fdma->last_dcb = dcb;
+
+ dcb->nextptr = FDMA_DCB_INVALID_DATA;
+ dcb->info = info;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__fdma_dcb_add);
+
+/* Add a DCB, using the preset callbacks in the fdma_ops struct. */
+int fdma_dcb_add(struct fdma *fdma, int dcb_idx, u64 info, u64 status)
+{
+ return __fdma_dcb_add(fdma,
+ dcb_idx,
+ info, status,
+ fdma->ops.nextptr_cb,
+ fdma->ops.dataptr_cb);
+}
+EXPORT_SYMBOL_GPL(fdma_dcb_add);
+
+/* Initialize the DCB's and DB's. */
+int fdma_dcbs_init(struct fdma *fdma, u64 info, u64 status)
+{
+ int i, err;
+
+ fdma->last_dcb = fdma->dcbs;
+ fdma->db_index = 0;
+ fdma->dcb_index = 0;
+
+ for (i = 0; i < fdma->n_dcbs; i++) {
+ err = fdma_dcb_add(fdma, i, info, status);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fdma_dcbs_init);
+
+/* Allocate coherent DMA memory for FDMA. */
+int fdma_alloc_coherent(struct device *dev, struct fdma *fdma)
+{
+ fdma->dcbs = dma_alloc_coherent(dev,
+ fdma->size,
+ &fdma->dma,
+ GFP_KERNEL);
+ if (!fdma->dcbs)
+ return -ENOMEM;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fdma_alloc_coherent);
+
+/* Allocate physical memory for FDMA. */
+int fdma_alloc_phys(struct fdma *fdma)
+{
+ fdma->dcbs = kzalloc(fdma->size, GFP_KERNEL);
+ if (!fdma->dcbs)
+ return -ENOMEM;
+
+ fdma->dma = virt_to_phys(fdma->dcbs);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fdma_alloc_phys);
+
+/* Free coherent DMA memory. */
+void fdma_free_coherent(struct device *dev, struct fdma *fdma)
+{
+ dma_free_coherent(dev, fdma->size, fdma->dcbs, fdma->dma);
+}
+EXPORT_SYMBOL_GPL(fdma_free_coherent);
+
+/* Free virtual memory. */
+void fdma_free_phys(struct fdma *fdma)
+{
+ kfree(fdma->dcbs);
+}
+EXPORT_SYMBOL_GPL(fdma_free_phys);
+
+/* Get the size of the FDMA memory */
+u32 fdma_get_size(struct fdma *fdma)
+{
+ return ALIGN(sizeof(struct fdma_dcb) * fdma->n_dcbs, PAGE_SIZE);
+}
+EXPORT_SYMBOL_GPL(fdma_get_size);
+
+/* Get the size of the FDMA memory. This function is only applicable if the
+ * dataptr addresses and DCB's are in contiguous memory.
+ */
+u32 fdma_get_size_contiguous(struct fdma *fdma)
+{
+ return ALIGN(fdma->n_dcbs * sizeof(struct fdma_dcb) +
+ fdma->n_dcbs * fdma->n_dbs * fdma->db_size,
+ PAGE_SIZE);
+}
+EXPORT_SYMBOL_GPL(fdma_get_size_contiguous);
--- /dev/null
+/* 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
projects / users / jedix / linux-maple.git / commitdiff