1 /* SPDX-License-Identifier: GPL-2.0+ */
2
3 #ifndef _FDMA_API_H_
4 #define _FDMA_API_H_
5
6 #include <linux/bits.h>
7 #include <linux/etherdevice.h>
8 #include <linux/types.h>
9
10 /* This provides a common set of functions and data structures for interacting
11 * with the Frame DMA engine on multiple Microchip switchcores.
12 *
13 * Frame DMA DCB format:
14 *
15 * +---------------------------+
16 * | Next Ptr |
17 * +---------------------------+
18 * | Reserved | Info |
19 * +---------------------------+
20 * | Data0 Ptr |
21 * +---------------------------+
22 * | Reserved | Status0 |
23 * +---------------------------+
24 * | Data1 Ptr |
25 * +---------------------------+
26 * | Reserved | Status1 |
27 * +---------------------------+
28 * | Data2 Ptr |
29 * +---------------------------+
30 * | Reserved | Status2 |
31 * |-------------|-------------|
32 * | |
33 * | |
34 * | |
35 * | |
36 * | |
37 * |---------------------------|
38 * | Data14 Ptr |
39 * +-------------|-------------+
40 * | Reserved | Status14 |
41 * +-------------|-------------+
42 *
43 * The data pointers points to the actual frame data to be received or sent. The
44 * addresses of the data pointers can, as of writing, be either a: DMA address,
45 * physical address or mapped address.
46 *
47 */
48
49 #define FDMA_DCB_INFO_DATAL(x) ((x) & GENMASK(15, 0))
50 #define FDMA_DCB_INFO_TOKEN BIT(17)
51 #define FDMA_DCB_INFO_INTR BIT(18)
52 #define FDMA_DCB_INFO_SW(x) (((x) << 24) & GENMASK(31, 24))
53
54 #define FDMA_DCB_STATUS_BLOCKL(x) ((x) & GENMASK(15, 0))
55 #define FDMA_DCB_STATUS_SOF BIT(16)
56 #define FDMA_DCB_STATUS_EOF BIT(17)
57 #define FDMA_DCB_STATUS_INTR BIT(18)
58 #define FDMA_DCB_STATUS_DONE BIT(19)
59 #define FDMA_DCB_STATUS_BLOCKO(x) (((x) << 20) & GENMASK(31, 20))
60 #define FDMA_DCB_INVALID_DATA 0x1
61
62 #define FDMA_DB_MAX 15 /* Max number of DB's on Sparx5 */
63
64 struct fdma;
65
66 struct fdma_db {
67 u64 dataptr;
68 u64 status;
69 };
70
71 struct fdma_dcb {
72 u64 nextptr;
73 u64 info;
74 struct fdma_db db[FDMA_DB_MAX];
75 };
76
77 struct fdma_ops {
78 /* User-provided callback to set the dataptr */
79 int (*dataptr_cb)(struct fdma *fdma, int dcb_idx, int db_idx, u64 *ptr);
80 /* User-provided callback to set the nextptr */
81 int (*nextptr_cb)(struct fdma *fdma, int dcb_idx, u64 *ptr);
82 };
83
84 struct fdma {
85 void *priv;
86
87 /* Virtual addresses */
88 struct fdma_dcb *dcbs;
89 struct fdma_dcb *last_dcb;
90
91 /* DMA address */
92 dma_addr_t dma;
93
94 /* Size of DCB + DB memory */
95 int size;
96
97 /* Indexes used to access the next-to-be-used DCB or DB */
98 int db_index;
99 int dcb_index;
100
101 /* Number of DCB's and DB's */
102 u32 n_dcbs;
103 u32 n_dbs;
104
105 /* Size of DB's */
106 u32 db_size;
107
108 /* Channel id this FDMA object operates on */
109 u32 channel_id;
110
111 struct fdma_ops ops;
112 };
113
114 /* Advance the DCB index and wrap if required. */
fdma_dcb_advance(struct fdma * fdma)115 static inline void fdma_dcb_advance(struct fdma *fdma)
116 {
117 fdma->dcb_index++;
118 if (fdma->dcb_index >= fdma->n_dcbs)
119 fdma->dcb_index = 0;
120 }
121
122 /* Advance the DB index. */
fdma_db_advance(struct fdma * fdma)123 static inline void fdma_db_advance(struct fdma *fdma)
124 {
125 fdma->db_index++;
126 }
127
128 /* Reset the db index to zero. */
fdma_db_reset(struct fdma * fdma)129 static inline void fdma_db_reset(struct fdma *fdma)
130 {
131 fdma->db_index = 0;
132 }
133
134 /* Check if a DCB can be reused in case of multiple DB's per DCB. */
fdma_dcb_is_reusable(struct fdma * fdma)135 static inline bool fdma_dcb_is_reusable(struct fdma *fdma)
136 {
137 return fdma->db_index != fdma->n_dbs;
138 }
139
140 /* Check if the FDMA has marked this DB as done. */
fdma_db_is_done(struct fdma_db * db)141 static inline bool fdma_db_is_done(struct fdma_db *db)
142 {
143 return db->status & FDMA_DCB_STATUS_DONE;
144 }
145
146 /* Get the length of a DB. */
fdma_db_len_get(struct fdma_db * db)147 static inline int fdma_db_len_get(struct fdma_db *db)
148 {
149 return FDMA_DCB_STATUS_BLOCKL(db->status);
150 }
151
152 /* Set the length of a DB. */
fdma_dcb_len_set(struct fdma_dcb * dcb,u32 len)153 static inline void fdma_dcb_len_set(struct fdma_dcb *dcb, u32 len)
154 {
155 dcb->info = FDMA_DCB_INFO_DATAL(len);
156 }
157
158 /* Get a DB by index. */
fdma_db_get(struct fdma * fdma,int dcb_idx,int db_idx)159 static inline struct fdma_db *fdma_db_get(struct fdma *fdma, int dcb_idx,
160 int db_idx)
161 {
162 return &fdma->dcbs[dcb_idx].db[db_idx];
163 }
164
165 /* Get the next DB. */
fdma_db_next_get(struct fdma * fdma)166 static inline struct fdma_db *fdma_db_next_get(struct fdma *fdma)
167 {
168 return fdma_db_get(fdma, fdma->dcb_index, fdma->db_index);
169 }
170
171 /* Get a DCB by index. */
fdma_dcb_get(struct fdma * fdma,int dcb_idx)172 static inline struct fdma_dcb *fdma_dcb_get(struct fdma *fdma, int dcb_idx)
173 {
174 return &fdma->dcbs[dcb_idx];
175 }
176
177 /* Get the next DCB. */
fdma_dcb_next_get(struct fdma * fdma)178 static inline struct fdma_dcb *fdma_dcb_next_get(struct fdma *fdma)
179 {
180 return fdma_dcb_get(fdma, fdma->dcb_index);
181 }
182
183 /* Check if the FDMA has frames ready for extraction. */
fdma_has_frames(struct fdma * fdma)184 static inline bool fdma_has_frames(struct fdma *fdma)
185 {
186 return fdma_db_is_done(fdma_db_next_get(fdma));
187 }
188
189 /* Get a nextptr by index */
fdma_nextptr_cb(struct fdma * fdma,int dcb_idx,u64 * nextptr)190 static inline int fdma_nextptr_cb(struct fdma *fdma, int dcb_idx, u64 *nextptr)
191 {
192 *nextptr = fdma->dma + (sizeof(struct fdma_dcb) * dcb_idx);
193 return 0;
194 }
195
196 /* Get the DMA address of a dataptr, by index. This function is only applicable
197 * if the dataptr addresses and DCB's are in contiguous memory and the driver
198 * supports XDP.
199 */
fdma_dataptr_get_contiguous(struct fdma * fdma,int dcb_idx,int db_idx)200 static inline u64 fdma_dataptr_get_contiguous(struct fdma *fdma, int dcb_idx,
201 int db_idx)
202 {
203 return fdma->dma + (sizeof(struct fdma_dcb) * fdma->n_dcbs) +
204 (dcb_idx * fdma->n_dbs + db_idx) * fdma->db_size +
205 XDP_PACKET_HEADROOM;
206 }
207
208 /* Get the virtual address of a dataptr, by index. This function is only
209 * applicable if the dataptr addresses and DCB's are in contiguous memory and
210 * the driver supports XDP.
211 */
fdma_dataptr_virt_get_contiguous(struct fdma * fdma,int dcb_idx,int db_idx)212 static inline void *fdma_dataptr_virt_get_contiguous(struct fdma *fdma,
213 int dcb_idx, int db_idx)
214 {
215 return (u8 *)fdma->dcbs + (sizeof(struct fdma_dcb) * fdma->n_dcbs) +
216 (dcb_idx * fdma->n_dbs + db_idx) * fdma->db_size +
217 XDP_PACKET_HEADROOM;
218 }
219
220 /* Check if this DCB is the last used DCB. */
fdma_is_last(struct fdma * fdma,struct fdma_dcb * dcb)221 static inline bool fdma_is_last(struct fdma *fdma, struct fdma_dcb *dcb)
222 {
223 return dcb == fdma->last_dcb;
224 }
225
226 int fdma_dcbs_init(struct fdma *fdma, u64 info, u64 status);
227 int fdma_db_add(struct fdma *fdma, int dcb_idx, int db_idx, u64 status);
228 int fdma_dcb_add(struct fdma *fdma, int dcb_idx, u64 info, u64 status);
229 int __fdma_dcb_add(struct fdma *fdma, int dcb_idx, u64 info, u64 status,
230 int (*dcb_cb)(struct fdma *fdma, int dcb_idx, u64 *nextptr),
231 int (*db_cb)(struct fdma *fdma, int dcb_idx, int db_idx,
232 u64 *dataptr));
233
234 int fdma_alloc_coherent(struct device *dev, struct fdma *fdma);
235 int fdma_alloc_phys(struct fdma *fdma);
236
237 void fdma_free_coherent(struct device *dev, struct fdma *fdma);
238 void fdma_free_phys(struct fdma *fdma);
239
240 u32 fdma_get_size(struct fdma *fdma);
241 u32 fdma_get_size_contiguous(struct fdma *fdma);
242
243 #endif
244