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 16 struct page; 17 struct scatterlist; 18 struct device; 19 struct sk_buff; 20 21 struct gsi; 22 struct gsi_trans; 23 struct 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 * @links: Links for channel transaction lists by state 33 * @gsi: GSI pointer 34 * @channel_id: Channel number transaction is associated with 35 * @cancelled: If set by the core code, transaction was cancelled 36 * @tre_count: Number of TREs reserved for this transaction 37 * @used: Number of TREs *used* (could be less than tre_count) 38 * @len: Total # of transfer bytes represented in sgl[] (set by core) 39 * @data: Preserved but not touched by the core transaction code 40 * @cmd_opcode: Array of command opcodes (command channel only) 41 * @sgl: An array of scatter/gather entries managed by core code 42 * @direction: DMA transfer direction (DMA_NONE for commands) 43 * @refcount: Reference count used for destruction 44 * @completion: Completed when the transaction completes 45 * @byte_count: TX channel byte count recorded when transaction committed 46 * @trans_count: Channel transaction count when committed (for BQL accounting) 47 * 48 * The size used for some fields in this structure were chosen to ensure 49 * the full structure size is no larger than 128 bytes. 50 */ 51 struct gsi_trans { 52 struct list_head links; /* gsi_channel lists */ 53 54 struct gsi *gsi; 55 u8 channel_id; 56 57 bool cancelled; /* true if transaction was cancelled */ 58 59 u8 tre_count; /* # TREs requested */ 60 u8 used; /* # entries used in sgl[] */ 61 u32 len; /* total # bytes across sgl[] */ 62 63 union { 64 void *data; 65 u8 cmd_opcode[IPA_COMMAND_TRANS_TRE_MAX]; 66 }; 67 struct scatterlist *sgl; 68 enum dma_data_direction direction; 69 70 refcount_t refcount; 71 struct completion completion; 72 73 u64 byte_count; /* channel byte_count when committed */ 74 u64 trans_count; /* channel trans_count when committed */ 75 }; 76 77 /** 78 * gsi_trans_pool_init() - Initialize a pool of structures for transactions 79 * @pool: GSI transaction poll pointer 80 * @size: Size of elements in the pool 81 * @count: Minimum number of elements in the pool 82 * @max_alloc: Maximum number of elements allocated at a time from pool 83 * 84 * Return: 0 if successful, or a negative error code 85 */ 86 int gsi_trans_pool_init(struct gsi_trans_pool *pool, size_t size, u32 count, 87 u32 max_alloc); 88 89 /** 90 * gsi_trans_pool_alloc() - Allocate one or more elements from a pool 91 * @pool: Pool pointer 92 * @count: Number of elements to allocate from the pool 93 * 94 * Return: Virtual address of element(s) allocated from the pool 95 */ 96 void *gsi_trans_pool_alloc(struct gsi_trans_pool *pool, u32 count); 97 98 /** 99 * gsi_trans_pool_exit() - Inverse of gsi_trans_pool_init() 100 * @pool: Pool pointer 101 */ 102 void gsi_trans_pool_exit(struct gsi_trans_pool *pool); 103 104 /** 105 * gsi_trans_pool_init_dma() - Initialize a pool of DMA-able structures 106 * @dev: Device used for DMA 107 * @pool: Pool pointer 108 * @size: Size of elements in the pool 109 * @count: Minimum number of elements in the pool 110 * @max_alloc: Maximum number of elements allocated at a time from pool 111 * 112 * Return: 0 if successful, or a negative error code 113 * 114 * Structures in this pool reside in DMA-coherent memory. 115 */ 116 int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool, 117 size_t size, u32 count, u32 max_alloc); 118 119 /** 120 * gsi_trans_pool_alloc_dma() - Allocate an element from a DMA pool 121 * @pool: DMA pool pointer 122 * @addr: DMA address "handle" associated with the allocation 123 * 124 * Return: Virtual address of element allocated from the pool 125 * 126 * Only one element at a time may be allocated from a DMA pool. 127 */ 128 void *gsi_trans_pool_alloc_dma(struct gsi_trans_pool *pool, dma_addr_t *addr); 129 130 /** 131 * gsi_trans_pool_exit_dma() - Inverse of gsi_trans_pool_init_dma() 132 * @dev: Device used for DMA 133 * @pool: Pool pointer 134 */ 135 void gsi_trans_pool_exit_dma(struct device *dev, struct gsi_trans_pool *pool); 136 137 /** 138 * gsi_channel_trans_idle() - Return whether no transactions are allocated 139 * @gsi: GSI pointer 140 * @channel_id: Channel the transaction is associated with 141 * 142 * Return: True if no transactions are allocated, false otherwise 143 * 144 */ 145 bool gsi_channel_trans_idle(struct gsi *gsi, u32 channel_id); 146 147 /** 148 * gsi_channel_trans_alloc() - Allocate a GSI transaction on a channel 149 * @gsi: GSI pointer 150 * @channel_id: Channel the transaction is associated with 151 * @tre_count: Number of elements in the transaction 152 * @direction: DMA direction for entire SGL (or DMA_NONE) 153 * 154 * Return: A GSI transaction structure, or a null pointer if all 155 * available transactions are in use 156 */ 157 struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id, 158 u32 tre_count, 159 enum dma_data_direction direction); 160 161 /** 162 * gsi_trans_free() - Free a previously-allocated GSI transaction 163 * @trans: Transaction to be freed 164 */ 165 void gsi_trans_free(struct gsi_trans *trans); 166 167 /** 168 * gsi_trans_cmd_add() - Add an immediate command to a transaction 169 * @trans: Transaction 170 * @buf: Buffer pointer for command payload 171 * @size: Number of bytes in buffer 172 * @addr: DMA address for payload 173 * @opcode: IPA immediate command opcode 174 */ 175 void gsi_trans_cmd_add(struct gsi_trans *trans, void *buf, u32 size, 176 dma_addr_t addr, enum ipa_cmd_opcode opcode); 177 178 /** 179 * gsi_trans_page_add() - Add a page transfer to a transaction 180 * @trans: Transaction 181 * @page: Page pointer 182 * @size: Number of bytes (starting at offset) to transfer 183 * @offset: Offset within page for start of transfer 184 */ 185 int gsi_trans_page_add(struct gsi_trans *trans, struct page *page, u32 size, 186 u32 offset); 187 188 /** 189 * gsi_trans_skb_add() - Add a socket transfer to a transaction 190 * @trans: Transaction 191 * @skb: Socket buffer for transfer (outbound) 192 * 193 * Return: 0, or -EMSGSIZE if socket data won't fit in transaction. 194 */ 195 int gsi_trans_skb_add(struct gsi_trans *trans, struct sk_buff *skb); 196 197 /** 198 * gsi_trans_commit() - Commit a GSI transaction 199 * @trans: Transaction to commit 200 * @ring_db: Whether to tell the hardware about these queued transfers 201 */ 202 void gsi_trans_commit(struct gsi_trans *trans, bool ring_db); 203 204 /** 205 * gsi_trans_commit_wait() - Commit a GSI transaction and wait for it 206 * to complete 207 * @trans: Transaction to commit 208 */ 209 void gsi_trans_commit_wait(struct gsi_trans *trans); 210 211 /** 212 * gsi_trans_read_byte() - Issue a single byte read TRE on a channel 213 * @gsi: GSI pointer 214 * @channel_id: Channel on which to read a byte 215 * @addr: DMA address into which to transfer the one byte 216 * 217 * This is not a transaction operation at all. It's defined here because 218 * it needs to be done in coordination with other transaction activity. 219 */ 220 int gsi_trans_read_byte(struct gsi *gsi, u32 channel_id, dma_addr_t addr); 221 222 /** 223 * gsi_trans_read_byte_done() - Clean up after a single byte read TRE 224 * @gsi: GSI pointer 225 * @channel_id: Channel on which byte was read 226 * 227 * This function needs to be called to signal that the work related 228 * to reading a byte initiated by gsi_trans_read_byte() is complete. 229 */ 230 void gsi_trans_read_byte_done(struct gsi *gsi, u32 channel_id); 231 232 #endif /* _GSI_TRANS_H_ */ 233