1/* SPDX-License-Identifier: GPL-2.0 */
2
3/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
4 * Copyright (C) 2019-2022 Linaro Ltd.
5 */
6#ifndef _GSI_TRANS_H_
7#define _GSI_TRANS_H_
8
9#include <linux/types.h>
10#include <linux/refcount.h>
11#include <linux/completion.h>
12#include <linux/dma-direction.h>
13
14#include "ipa_cmd.h"
15
16struct page;
17struct scatterlist;
18struct device;
19struct sk_buff;
20
21struct gsi;
22struct gsi_trans;
23struct gsi_trans_pool;
24
25/* Maximum number of TREs in an IPA immediate command transaction */
26#define IPA_COMMAND_TRANS_TRE_MAX	8
27
28/**
29 * struct gsi_trans - a GSI transaction
30 *
31 * Most fields in this structure for internal use by the transaction core code:
32 * @gsi:	GSI pointer
33 * @channel_id: Channel number transaction is associated with
34 * @cancelled:	If set by the core code, transaction was cancelled
35 * @rsvd_count:	Number of TREs reserved for this transaction
36 * @used_count:	Number of TREs *used* (could be less than rsvd_count)
37 * @len:	Number of bytes sent or received by the transaction
38 * @data:	Preserved but not touched by the core transaction code
39 * @cmd_opcode:	Array of command opcodes (command channel only)
40 * @sgl:	An array of scatter/gather entries managed by core code
41 * @direction:	DMA transfer direction (DMA_NONE for commands)
42 * @refcount:	Reference count used for destruction
43 * @completion:	Completed when the transaction completes
44 * @byte_count:	TX channel byte count recorded when transaction committed
45 * @trans_count: Channel transaction count when committed (for BQL accounting)
46 *
47 * The @len field is set when the transaction is committed.  For RX
48 * transactions it is updated later to reflect the actual number of bytes
49 * received.
50 */
51struct gsi_trans {
52	struct gsi *gsi;
53	u8 channel_id;
54
55	bool cancelled;			/* true if transaction was cancelled */
56
57	u8 rsvd_count;			/* # TREs requested */
58	u8 used_count;			/* # entries used in sgl[] */
59	u32 len;			/* total # bytes across sgl[] */
60
61	union {
62		void *data;
63		u8 cmd_opcode[IPA_COMMAND_TRANS_TRE_MAX];
64	};
65	struct scatterlist *sgl;
66	enum dma_data_direction direction;
67
68	refcount_t refcount;
69	struct completion completion;
70
71	u64 byte_count;			/* channel byte_count when committed */
72	u64 trans_count;		/* channel trans_count when committed */
73};
74
75/**
76 * gsi_trans_pool_init() - Initialize a pool of structures for transactions
77 * @pool:	GSI transaction pool pointer
78 * @size:	Size of elements in the pool
79 * @count:	Minimum number of elements in the pool
80 * @max_alloc:	Maximum number of elements allocated at a time from pool
81 *
82 * Return:	0 if successful, or a negative error code
83 */
84int gsi_trans_pool_init(struct gsi_trans_pool *pool, size_t size, u32 count,
85			u32 max_alloc);
86
87/**
88 * gsi_trans_pool_alloc() - Allocate one or more elements from a pool
89 * @pool:	Pool pointer
90 * @count:	Number of elements to allocate from the pool
91 *
92 * Return:	Virtual address of element(s) allocated from the pool
93 */
94void *gsi_trans_pool_alloc(struct gsi_trans_pool *pool, u32 count);
95
96/**
97 * gsi_trans_pool_exit() - Inverse of gsi_trans_pool_init()
98 * @pool:	Pool pointer
99 */
100void gsi_trans_pool_exit(struct gsi_trans_pool *pool);
101
102/**
103 * gsi_trans_pool_init_dma() - Initialize a pool of DMA-able structures
104 * @dev:	Device used for DMA
105 * @pool:	Pool pointer
106 * @size:	Size of elements in the pool
107 * @count:	Minimum number of elements in the pool
108 * @max_alloc:	Maximum number of elements allocated at a time from pool
109 *
110 * Return:	0 if successful, or a negative error code
111 *
112 * Structures in this pool reside in DMA-coherent memory.
113 */
114int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool,
115			    size_t size, u32 count, u32 max_alloc);
116
117/**
118 * gsi_trans_pool_alloc_dma() - Allocate an element from a DMA pool
119 * @pool:	DMA pool pointer
120 * @addr:	DMA address "handle" associated with the allocation
121 *
122 * Return:	Virtual address of element allocated from the pool
123 *
124 * Only one element at a time may be allocated from a DMA pool.
125 */
126void *gsi_trans_pool_alloc_dma(struct gsi_trans_pool *pool, dma_addr_t *addr);
127
128/**
129 * gsi_trans_pool_exit_dma() - Inverse of gsi_trans_pool_init_dma()
130 * @dev:	Device used for DMA
131 * @pool:	Pool pointer
132 */
133void gsi_trans_pool_exit_dma(struct device *dev, struct gsi_trans_pool *pool);
134
135/**
136 * gsi_channel_trans_idle() - Return whether no transactions are allocated
137 * @gsi:	GSI pointer
138 * @channel_id:	Channel the transaction is associated with
139 *
140 * Return:	True if no transactions are allocated, false otherwise
141 *
142 */
143bool gsi_channel_trans_idle(struct gsi *gsi, u32 channel_id);
144
145/**
146 * gsi_channel_trans_alloc() - Allocate a GSI transaction on a channel
147 * @gsi:	GSI pointer
148 * @channel_id:	Channel the transaction is associated with
149 * @tre_count:	Number of elements in the transaction
150 * @direction:	DMA direction for entire SGL (or DMA_NONE)
151 *
152 * Return:	A GSI transaction structure, or a null pointer if all
153 *		available transactions are in use
154 */
155struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id,
156					  u32 tre_count,
157					  enum dma_data_direction direction);
158
159/**
160 * gsi_trans_free() - Free a previously-allocated GSI transaction
161 * @trans:	Transaction to be freed
162 */
163void gsi_trans_free(struct gsi_trans *trans);
164
165/**
166 * gsi_trans_cmd_add() - Add an immediate command to a transaction
167 * @trans:	Transaction
168 * @buf:	Buffer pointer for command payload
169 * @size:	Number of bytes in buffer
170 * @addr:	DMA address for payload
171 * @opcode:	IPA immediate command opcode
172 */
173void gsi_trans_cmd_add(struct gsi_trans *trans, void *buf, u32 size,
174		       dma_addr_t addr, enum ipa_cmd_opcode opcode);
175
176/**
177 * gsi_trans_page_add() - Add a page transfer to a transaction
178 * @trans:	Transaction
179 * @page:	Page pointer
180 * @size:	Number of bytes (starting at offset) to transfer
181 * @offset:	Offset within page for start of transfer
182 */
183int gsi_trans_page_add(struct gsi_trans *trans, struct page *page, u32 size,
184		       u32 offset);
185
186/**
187 * gsi_trans_skb_add() - Add a socket transfer to a transaction
188 * @trans:	Transaction
189 * @skb:	Socket buffer for transfer (outbound)
190 *
191 * Return:	0, or -EMSGSIZE if socket data won't fit in transaction.
192 */
193int gsi_trans_skb_add(struct gsi_trans *trans, struct sk_buff *skb);
194
195/**
196 * gsi_trans_commit() - Commit a GSI transaction
197 * @trans:	Transaction to commit
198 * @ring_db:	Whether to tell the hardware about these queued transfers
199 */
200void gsi_trans_commit(struct gsi_trans *trans, bool ring_db);
201
202/**
203 * gsi_trans_commit_wait() - Commit a GSI transaction and wait for it
204 *			     to complete
205 * @trans:	Transaction to commit
206 */
207void gsi_trans_commit_wait(struct gsi_trans *trans);
208
209/**
210 * gsi_trans_read_byte() - Issue a single byte read TRE on a channel
211 * @gsi:	GSI pointer
212 * @channel_id:	Channel on which to read a byte
213 * @addr:	DMA address into which to transfer the one byte
214 *
215 * This is not a transaction operation at all.  It's defined here because
216 * it needs to be done in coordination with other transaction activity.
217 */
218int gsi_trans_read_byte(struct gsi *gsi, u32 channel_id, dma_addr_t addr);
219
220/**
221 * gsi_trans_read_byte_done() - Clean up after a single byte read TRE
222 * @gsi:	GSI pointer
223 * @channel_id:	Channel on which byte was read
224 *
225 * This function needs to be called to signal that the work related
226 * to reading a byte initiated by gsi_trans_read_byte() is complete.
227 */
228void gsi_trans_read_byte_done(struct gsi *gsi, u32 channel_id);
229
230#endif /* _GSI_TRANS_H_ */
231