1 /* SPDX-License-Identifier: GPL-2.0 */ 2 3 /* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved. 4 * Copyright (C) 2018-2023 Linaro Ltd. 5 */ 6 #ifndef _GSI_H_ 7 #define _GSI_H_ 8 9 #include <linux/types.h> 10 #include <linux/spinlock.h> 11 #include <linux/mutex.h> 12 #include <linux/completion.h> 13 #include <linux/platform_device.h> 14 #include <linux/netdevice.h> 15 16 #include "ipa_version.h" 17 18 /* Maximum number of channels and event rings supported by the driver */ 19 #define GSI_CHANNEL_COUNT_MAX 23 20 #define GSI_EVT_RING_COUNT_MAX 24 21 22 /* Maximum TLV FIFO size for a channel; 64 here is arbitrary (and high) */ 23 #define GSI_TLV_MAX 64 24 25 struct device; 26 struct scatterlist; 27 struct platform_device; 28 29 struct gsi; 30 struct gsi_trans; 31 struct gsi_channel_data; 32 struct ipa_gsi_endpoint_data; 33 34 struct gsi_ring { 35 void *virt; /* ring array base address */ 36 dma_addr_t addr; /* primarily low 32 bits used */ 37 u32 count; /* number of elements in ring */ 38 39 /* The ring index value indicates the next "open" entry in the ring. 40 * 41 * A channel ring consists of TRE entries filled by the AP and passed 42 * to the hardware for processing. For a channel ring, the ring index 43 * identifies the next unused entry to be filled by the AP. In this 44 * case the initial value is assumed by hardware to be 0. 45 * 46 * An event ring consists of event structures filled by the hardware 47 * and passed to the AP. For event rings, the ring index identifies 48 * the next ring entry that is not known to have been filled by the 49 * hardware. The initial value used is arbitrary (so we use 0). 50 */ 51 u32 index; 52 }; 53 54 /* Transactions use several resources that can be allocated dynamically 55 * but taken from a fixed-size pool. The number of elements required for 56 * the pool is limited by the total number of TREs that can be outstanding. 57 * 58 * If sufficient TREs are available to reserve for a transaction, 59 * allocation from these pools is guaranteed to succeed. Furthermore, 60 * these resources are implicitly freed whenever the TREs in the 61 * transaction they're associated with are released. 62 * 63 * The result of a pool allocation of multiple elements is always 64 * contiguous. 65 */ 66 struct gsi_trans_pool { 67 void *base; /* base address of element pool */ 68 u32 count; /* # elements in the pool */ 69 u32 free; /* next free element in pool (modulo) */ 70 u32 size; /* size (bytes) of an element */ 71 u32 max_alloc; /* max allocation request */ 72 dma_addr_t addr; /* DMA address if DMA pool (or 0) */ 73 }; 74 75 struct gsi_trans_info { 76 atomic_t tre_avail; /* TREs available for allocation */ 77 78 u16 free_id; /* first free trans in array */ 79 u16 allocated_id; /* first allocated transaction */ 80 u16 committed_id; /* first committed transaction */ 81 u16 pending_id; /* first pending transaction */ 82 u16 completed_id; /* first completed transaction */ 83 u16 polled_id; /* first polled transaction */ 84 struct gsi_trans *trans; /* transaction array */ 85 struct gsi_trans **map; /* TRE -> transaction map */ 86 87 struct gsi_trans_pool sg_pool; /* scatterlist pool */ 88 struct gsi_trans_pool cmd_pool; /* command payload DMA pool */ 89 }; 90 91 /* Hardware values signifying the state of a channel */ 92 enum gsi_channel_state { 93 GSI_CHANNEL_STATE_NOT_ALLOCATED = 0x0, 94 GSI_CHANNEL_STATE_ALLOCATED = 0x1, 95 GSI_CHANNEL_STATE_STARTED = 0x2, 96 GSI_CHANNEL_STATE_STOPPED = 0x3, 97 GSI_CHANNEL_STATE_STOP_IN_PROC = 0x4, 98 GSI_CHANNEL_STATE_FLOW_CONTROLLED = 0x5, /* IPA v4.2-v4.9 */ 99 GSI_CHANNEL_STATE_ERROR = 0xf, 100 }; 101 102 /* We only care about channels between IPA and AP */ 103 struct gsi_channel { 104 struct gsi *gsi; 105 bool toward_ipa; 106 bool command; /* AP command TX channel or not */ 107 108 u8 trans_tre_max; /* max TREs in a transaction */ 109 u16 tre_count; 110 u16 event_count; 111 112 struct gsi_ring tre_ring; 113 u32 evt_ring_id; 114 115 /* The following counts are used only for TX endpoints */ 116 u64 byte_count; /* total # bytes transferred */ 117 u64 trans_count; /* total # transactions */ 118 u64 queued_byte_count; /* last reported queued byte count */ 119 u64 queued_trans_count; /* ...and queued trans count */ 120 u64 compl_byte_count; /* last reported completed byte count */ 121 u64 compl_trans_count; /* ...and completed trans count */ 122 123 struct gsi_trans_info trans_info; 124 125 struct napi_struct napi; 126 }; 127 128 /* Hardware values signifying the state of an event ring */ 129 enum gsi_evt_ring_state { 130 GSI_EVT_RING_STATE_NOT_ALLOCATED = 0x0, 131 GSI_EVT_RING_STATE_ALLOCATED = 0x1, 132 GSI_EVT_RING_STATE_ERROR = 0xf, 133 }; 134 135 struct gsi_evt_ring { 136 struct gsi_channel *channel; 137 struct gsi_ring ring; 138 }; 139 140 struct gsi { 141 struct device *dev; /* Same as IPA device */ 142 enum ipa_version version; 143 void __iomem *virt; /* I/O mapped registers */ 144 const struct regs *regs; 145 146 u32 irq; 147 u32 channel_count; 148 u32 evt_ring_count; 149 u32 event_bitmap; /* allocated event rings */ 150 u32 modem_channel_bitmap; /* modem channels to allocate */ 151 u32 type_enabled_bitmap; /* GSI IRQ types enabled */ 152 u32 ieob_enabled_bitmap; /* IEOB IRQ enabled (event rings) */ 153 int result; /* Negative errno (generic commands) */ 154 struct completion completion; /* Signals GSI command completion */ 155 struct mutex mutex; /* protects commands, programming */ 156 struct gsi_channel channel[GSI_CHANNEL_COUNT_MAX]; 157 struct gsi_evt_ring evt_ring[GSI_EVT_RING_COUNT_MAX]; 158 struct net_device dummy_dev; /* needed for NAPI */ 159 }; 160 161 /** 162 * gsi_setup() - Set up the GSI subsystem 163 * @gsi: Address of GSI structure embedded in an IPA structure 164 * 165 * Return: 0 if successful, or a negative error code 166 * 167 * Performs initialization that must wait until the GSI hardware is 168 * ready (including firmware loaded). 169 */ 170 int gsi_setup(struct gsi *gsi); 171 172 /** 173 * gsi_teardown() - Tear down GSI subsystem 174 * @gsi: GSI address previously passed to a successful gsi_setup() call 175 */ 176 void gsi_teardown(struct gsi *gsi); 177 178 /** 179 * gsi_channel_tre_max() - Channel maximum number of in-flight TREs 180 * @gsi: GSI pointer 181 * @channel_id: Channel whose limit is to be returned 182 * 183 * Return: The maximum number of TREs outstanding on the channel 184 */ 185 u32 gsi_channel_tre_max(struct gsi *gsi, u32 channel_id); 186 187 /** 188 * gsi_channel_start() - Start an allocated GSI channel 189 * @gsi: GSI pointer 190 * @channel_id: Channel to start 191 * 192 * Return: 0 if successful, or a negative error code 193 */ 194 int gsi_channel_start(struct gsi *gsi, u32 channel_id); 195 196 /** 197 * gsi_channel_stop() - Stop a started GSI channel 198 * @gsi: GSI pointer returned by gsi_setup() 199 * @channel_id: Channel to stop 200 * 201 * Return: 0 if successful, or a negative error code 202 */ 203 int gsi_channel_stop(struct gsi *gsi, u32 channel_id); 204 205 /** 206 * gsi_modem_channel_flow_control() - Set channel flow control state (IPA v4.2+) 207 * @gsi: GSI pointer returned by gsi_setup() 208 * @channel_id: Modem TX channel to control 209 * @enable: Whether to enable flow control (i.e., prevent flow) 210 */ 211 void gsi_modem_channel_flow_control(struct gsi *gsi, u32 channel_id, 212 bool enable); 213 214 /** 215 * gsi_channel_reset() - Reset an allocated GSI channel 216 * @gsi: GSI pointer 217 * @channel_id: Channel to be reset 218 * @doorbell: Whether to (possibly) enable the doorbell engine 219 * 220 * Reset a channel and reconfigure it. The @doorbell flag indicates 221 * that the doorbell engine should be enabled if needed. 222 * 223 * GSI hardware relinquishes ownership of all pending receive buffer 224 * transactions and they will complete with their cancelled flag set. 225 */ 226 void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool doorbell); 227 228 /** 229 * gsi_suspend() - Prepare the GSI subsystem for suspend 230 * @gsi: GSI pointer 231 */ 232 void gsi_suspend(struct gsi *gsi); 233 234 /** 235 * gsi_resume() - Resume the GSI subsystem following suspend 236 * @gsi: GSI pointer 237 */ 238 void gsi_resume(struct gsi *gsi); 239 240 /** 241 * gsi_channel_suspend() - Suspend a GSI channel 242 * @gsi: GSI pointer 243 * @channel_id: Channel to suspend 244 * 245 * For IPA v4.0+, suspend is implemented by stopping the channel. 246 */ 247 int gsi_channel_suspend(struct gsi *gsi, u32 channel_id); 248 249 /** 250 * gsi_channel_resume() - Resume a suspended GSI channel 251 * @gsi: GSI pointer 252 * @channel_id: Channel to resume 253 * 254 * For IPA v4.0+, the stopped channel is started again. 255 */ 256 int gsi_channel_resume(struct gsi *gsi, u32 channel_id); 257 258 /** 259 * gsi_init() - Initialize the GSI subsystem 260 * @gsi: Address of GSI structure embedded in an IPA structure 261 * @pdev: IPA platform device 262 * @version: IPA hardware version (implies GSI version) 263 * @count: Number of entries in the configuration data array 264 * @data: Endpoint and channel configuration data 265 * 266 * Return: 0 if successful, or a negative error code 267 * 268 * Early stage initialization of the GSI subsystem, performing tasks 269 * that can be done before the GSI hardware is ready to use. 270 */ 271 int gsi_init(struct gsi *gsi, struct platform_device *pdev, 272 enum ipa_version version, u32 count, 273 const struct ipa_gsi_endpoint_data *data); 274 275 /** 276 * gsi_exit() - Exit the GSI subsystem 277 * @gsi: GSI address previously passed to a successful gsi_init() call 278 */ 279 void gsi_exit(struct gsi *gsi); 280 281 #endif /* _GSI_H_ */ 282