fdma_api.c

  1// SPDX-License-Identifier: GPL-2.0+
  2
  3#include "fdma_api.h"
  4
  5#include <linux/bits.h>
  6#include <linux/etherdevice.h>
  7#include <linux/types.h>
  8
  9/* Add a DB to a DCB, providing a callback for getting the DB dataptr. */
 10static int __fdma_db_add(struct fdma *fdma, int dcb_idx, int db_idx, u64 status,
 11			 int (*cb)(struct fdma *fdma, int dcb_idx,
 12				   int db_idx, u64 *dataptr))
 13{
 14	struct fdma_db *db = fdma_db_get(fdma, dcb_idx, db_idx);
 15
 16	db->status = status;
 17
 18	return cb(fdma, dcb_idx, db_idx, &db->dataptr);
 19}
 20
 21/* Add a DB to a DCB, using the callback set in the fdma_ops struct. */
 22int fdma_db_add(struct fdma *fdma, int dcb_idx, int db_idx, u64 status)
 23{
 24	return __fdma_db_add(fdma,
 25			     dcb_idx,
 26			     db_idx,
 27			     status,
 28			     fdma->ops.dataptr_cb);
 29}
 30
 31/* Add a DCB with callbacks for getting the DB dataptr and the DCB nextptr. */
 32int __fdma_dcb_add(struct fdma *fdma, int dcb_idx, u64 info, u64 status,
 33		   int (*dcb_cb)(struct fdma *fdma, int dcb_idx, u64 *nextptr),
 34		   int (*db_cb)(struct fdma *fdma, int dcb_idx, int db_idx,
 35				u64 *dataptr))
 36{
 37	struct fdma_dcb *dcb = fdma_dcb_get(fdma, dcb_idx);
 38	int i, err;
 39
 40	for (i = 0; i < fdma->n_dbs; i++) {
 41		err = __fdma_db_add(fdma, dcb_idx, i, status, db_cb);
 42		if (unlikely(err))
 43			return err;
 44	}
 45
 46	err = dcb_cb(fdma, dcb_idx, &fdma->last_dcb->nextptr);
 47	if (unlikely(err))
 48		return err;
 49
 50	fdma->last_dcb = dcb;
 51
 52	dcb->nextptr = FDMA_DCB_INVALID_DATA;
 53	dcb->info = info;
 54
 55	return 0;
 56}
 57EXPORT_SYMBOL_GPL(__fdma_dcb_add);
 58
 59/* Add a DCB, using the preset callbacks in the fdma_ops struct. */
 60int fdma_dcb_add(struct fdma *fdma, int dcb_idx, u64 info, u64 status)
 61{
 62	return __fdma_dcb_add(fdma,
 63			      dcb_idx,
 64			      info, status,
 65			      fdma->ops.nextptr_cb,
 66			      fdma->ops.dataptr_cb);
 67}
 68EXPORT_SYMBOL_GPL(fdma_dcb_add);
 69
 70/* Initialize the DCB's and DB's. */
 71int fdma_dcbs_init(struct fdma *fdma, u64 info, u64 status)
 72{
 73	int i, err;
 74
 75	fdma->last_dcb = fdma->dcbs;
 76	fdma->db_index = 0;
 77	fdma->dcb_index = 0;
 78
 79	for (i = 0; i < fdma->n_dcbs; i++) {
 80		err = fdma_dcb_add(fdma, i, info, status);
 81		if (err)
 82			return err;
 83	}
 84
 85	return 0;
 86}
 87EXPORT_SYMBOL_GPL(fdma_dcbs_init);
 88
 89/* Allocate coherent DMA memory for FDMA. */
 90int fdma_alloc_coherent(struct device *dev, struct fdma *fdma)
 91{
 92	fdma->dcbs = dma_alloc_coherent(dev,
 93					fdma->size,
 94					&fdma->dma,
 95					GFP_KERNEL);
 96	if (!fdma->dcbs)
 97		return -ENOMEM;
 98
 99	return 0;
100}
101EXPORT_SYMBOL_GPL(fdma_alloc_coherent);
102
103/* Allocate physical memory for FDMA. */
104int fdma_alloc_phys(struct fdma *fdma)
105{
106	fdma->dcbs = kzalloc(fdma->size, GFP_KERNEL);
107	if (!fdma->dcbs)
108		return -ENOMEM;
109
110	fdma->dma = virt_to_phys(fdma->dcbs);
111
112	return 0;
113}
114EXPORT_SYMBOL_GPL(fdma_alloc_phys);
115
116/* Free coherent DMA memory. */
117void fdma_free_coherent(struct device *dev, struct fdma *fdma)
118{
119	dma_free_coherent(dev, fdma->size, fdma->dcbs, fdma->dma);
120}
121EXPORT_SYMBOL_GPL(fdma_free_coherent);
122
123/* Free virtual memory. */
124void fdma_free_phys(struct fdma *fdma)
125{
126	kfree(fdma->dcbs);
127}
128EXPORT_SYMBOL_GPL(fdma_free_phys);
129
130/* Get the size of the FDMA memory */
131u32 fdma_get_size(struct fdma *fdma)
132{
133	return ALIGN(sizeof(struct fdma_dcb) * fdma->n_dcbs, PAGE_SIZE);
134}
135EXPORT_SYMBOL_GPL(fdma_get_size);
136
137/* Get the size of the FDMA memory. This function is only applicable if the
138 * dataptr addresses and DCB's are in contiguous memory.
139 */
140u32 fdma_get_size_contiguous(struct fdma *fdma)
141{
142	return ALIGN(fdma->n_dcbs * sizeof(struct fdma_dcb) +
143		     fdma->n_dcbs * fdma->n_dbs * fdma->db_size,
144		     PAGE_SIZE);
145}
146EXPORT_SYMBOL_GPL(fdma_get_size_contiguous);