1/* SPDX-License-Identifier: GPL-2.0 */
2
3/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
4 * Copyright (C) 2019-2020 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 scatterlist;
17struct device;
18struct sk_buff;
19
20struct gsi;
21struct gsi_trans;
22struct gsi_trans_pool;
23
24/**
25 * struct gsi_trans - a GSI transaction
26 *
27 * Most fields in this structure for internal use by the transaction core code:
28 * @links:	Links for channel transaction lists by state
29 * @gsi:	GSI pointer
30 * @channel_id: Channel number transaction is associated with
31 * @cancelled:	If set by the core code, transaction was cancelled
32 * @tre_count:	Number of TREs reserved for this transaction
33 * @used:	Number of TREs *used* (could be less than tre_count)
34 * @len:	Total # of transfer bytes represented in sgl[] (set by core)
35 * @data:	Preserved but not touched by the core transaction code
36 * @sgl:	An array of scatter/gather entries managed by core code
37 * @info:	Array of command information structures (command channel)
38 * @direction:	DMA transfer direction (DMA_NONE for commands)
39 * @refcount:	Reference count used for destruction
40 * @completion:	Completed when the transaction completes
41 * @byte_count:	TX channel byte count recorded when transaction committed
42 * @trans_count: Channel transaction count when committed (for BQL accounting)
43 *
44 * The size used for some fields in this structure were chosen to ensure
45 * the full structure size is no larger than 128 bytes.
46 */
47struct gsi_trans {
48	struct list_head links;		/* gsi_channel lists */
49
50	struct gsi *gsi;
51	u8 channel_id;
52
53	bool cancelled;			/* true if transaction was cancelled */
54
55	u8 tre_count;			/* # TREs requested */
56	u8 used;			/* # entries used in sgl[] */
57	u32 len;			/* total # bytes across sgl[] */
58
59	void *data;
60	struct scatterlist *sgl;
61	struct ipa_cmd_info *info;	/* array of entries, or null */
62	enum dma_data_direction direction;
63
64	refcount_t refcount;
65	struct completion completion;
66
67	u64 byte_count;			/* channel byte_count when committed */
68	u64 trans_count;		/* channel trans_count when committed */
69};
70
71/**
72 * gsi_trans_pool_init() - Initialize a pool of structures for transactions
73 * @gsi:	GSI pointer
74 * @size:	Size of elements in the pool
75 * @count:	Minimum number of elements in the pool
76 * @max_alloc:	Maximum number of elements allocated at a time from pool
77 *
78 * Return:	0 if successful, or a negative error code
79 */
80int gsi_trans_pool_init(struct gsi_trans_pool *pool, size_t size, u32 count,
81			u32 max_alloc);
82
83/**
84 * gsi_trans_pool_alloc() - Allocate one or more elements from a pool
85 * @pool:	Pool pointer
86 * @count:	Number of elements to allocate from the pool
87 *
88 * Return:	Virtual address of element(s) allocated from the pool
89 */
90void *gsi_trans_pool_alloc(struct gsi_trans_pool *pool, u32 count);
91
92/**
93 * gsi_trans_pool_exit() - Inverse of gsi_trans_pool_init()
94 * @pool:	Pool pointer
95 */
96void gsi_trans_pool_exit(struct gsi_trans_pool *pool);
97
98/**
99 * gsi_trans_pool_init_dma() - Initialize a pool of DMA-able structures
100 * @dev:	Device used for DMA
101 * @pool:	Pool pointer
102 * @size:	Size of elements in the pool
103 * @count:	Minimum number of elements in the pool
104 * @max_alloc:	Maximum number of elements allocated at a time from pool
105 *
106 * Return:	0 if successful, or a negative error code
107 *
108 * Structures in this pool reside in DMA-coherent memory.
109 */
110int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool,
111			    size_t size, u32 count, u32 max_alloc);
112
113/**
114 * gsi_trans_pool_alloc_dma() - Allocate an element from a DMA pool
115 * @pool:	DMA pool pointer
116 * @addr:	DMA address "handle" associated with the allocation
117 *
118 * Return:	Virtual address of element allocated from the pool
119 *
120 * Only one element at a time may be allocated from a DMA pool.
121 */
122void *gsi_trans_pool_alloc_dma(struct gsi_trans_pool *pool, dma_addr_t *addr);
123
124/**
125 * gsi_trans_pool_exit() - Inverse of gsi_trans_pool_init()
126 * @pool:	Pool pointer
127 */
128void gsi_trans_pool_exit_dma(struct device *dev, struct gsi_trans_pool *pool);
129
130/**
131 * gsi_channel_trans_alloc() - Allocate a GSI transaction on a channel
132 * @gsi:	GSI pointer
133 * @channel_id:	Channel the transaction is associated with
134 * @tre_count:	Number of elements in the transaction
135 * @direction:	DMA direction for entire SGL (or DMA_NONE)
136 *
137 * Return:	A GSI transaction structure, or a null pointer if all
138 *		available transactions are in use
139 */
140struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id,
141					  u32 tre_count,
142					  enum dma_data_direction direction);
143
144/**
145 * gsi_trans_free() - Free a previously-allocated GSI transaction
146 * @trans:	Transaction to be freed
147 */
148void gsi_trans_free(struct gsi_trans *trans);
149
150/**
151 * gsi_trans_cmd_add() - Add an immediate command to a transaction
152 * @trans:	Transaction
153 * @buf:	Buffer pointer for command payload
154 * @size:	Number of bytes in buffer
155 * @addr:	DMA address for payload
156 * @direction:	Direction of DMA transfer (or DMA_NONE if none required)
157 * @opcode:	IPA immediate command opcode
158 */
159void gsi_trans_cmd_add(struct gsi_trans *trans, void *buf, u32 size,
160		       dma_addr_t addr, enum dma_data_direction direction,
161		       enum ipa_cmd_opcode opcode);
162
163/**
164 * gsi_trans_page_add() - Add a page transfer to a transaction
165 * @trans:	Transaction
166 * @page:	Page pointer
167 * @size:	Number of bytes (starting at offset) to transfer
168 * @offset:	Offset within page for start of transfer
169 */
170int gsi_trans_page_add(struct gsi_trans *trans, struct page *page, u32 size,
171		       u32 offset);
172
173/**
174 * gsi_trans_skb_add() - Add a socket transfer to a transaction
175 * @trans:	Transaction
176 * @skb:	Socket buffer for transfer (outbound)
177 *
178 * Return:	0, or -EMSGSIZE if socket data won't fit in transaction.
179 */
180int gsi_trans_skb_add(struct gsi_trans *trans, struct sk_buff *skb);
181
182/**
183 * gsi_trans_commit() - Commit a GSI transaction
184 * @trans:	Transaction to commit
185 * @ring_db:	Whether to tell the hardware about these queued transfers
186 */
187void gsi_trans_commit(struct gsi_trans *trans, bool ring_db);
188
189/**
190 * gsi_trans_commit_wait() - Commit a GSI transaction and wait for it
191 *			     to complete
192 * @trans:	Transaction to commit
193 */
194void gsi_trans_commit_wait(struct gsi_trans *trans);
195
196/**
197 * gsi_trans_commit_wait_timeout() - Commit a GSI transaction and wait for
198 *				     it to complete, with timeout
199 * @trans:	Transaction to commit
200 * @timeout:	Timeout period (in milliseconds)
201 */
202int gsi_trans_commit_wait_timeout(struct gsi_trans *trans,
203				  unsigned long timeout);
204
205/**
206 * gsi_trans_read_byte() - Issue a single byte read TRE on a channel
207 * @gsi:	GSI pointer
208 * @channel_id:	Channel on which to read a byte
209 * @addr:	DMA address into which to transfer the one byte
210 *
211 * This is not a transaction operation at all.  It's defined here because
212 * it needs to be done in coordination with other transaction activity.
213 */
214int gsi_trans_read_byte(struct gsi *gsi, u32 channel_id, dma_addr_t addr);
215
216/**
217 * gsi_trans_read_byte_done() - Clean up after a single byte read TRE
218 * @gsi:	GSI pointer
219 * @channel_id:	Channel on which byte was read
220 *
221 * This function needs to be called to signal that the work related
222 * to reading a byte initiated by gsi_trans_read_byte() is complete.
223 */
224void gsi_trans_read_byte_done(struct gsi *gsi, u32 channel_id);
225
226#endif /* _GSI_TRANS_H_ */
227