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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2
3/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
4 * Copyright (C) 2018-2020 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/* Maximum number of channels and event rings supported by the driver */
17#define GSI_CHANNEL_COUNT_MAX 17
18#define GSI_EVT_RING_COUNT_MAX 13
19
20/* Maximum TLV FIFO size for a channel; 64 here is arbitrary (and high) */
21#define GSI_TLV_MAX 64
22
23struct device;
24struct scatterlist;
25struct platform_device;
26
27struct gsi;
28struct gsi_trans;
29struct gsi_channel_data;
30struct ipa_gsi_endpoint_data;
31
32/* Execution environment IDs */
33enum gsi_ee_id {
34 GSI_EE_AP = 0,
35 GSI_EE_MODEM = 1,
36 GSI_EE_UC = 2,
37 GSI_EE_TZ = 3,
38};
39
40struct gsi_ring {
41 void *virt; /* ring array base address */
42 dma_addr_t addr; /* primarily low 32 bits used */
43 u32 count; /* number of elements in ring */
44
45 /* The ring index value indicates the next "open" entry in the ring.
46 *
47 * A channel ring consists of TRE entries filled by the AP and passed
48 * to the hardware for processing. For a channel ring, the ring index
49 * identifies the next unused entry to be filled by the AP.
50 *
51 * An event ring consists of event structures filled by the hardware
52 * and passed to the AP. For event rings, the ring index identifies
53 * the next ring entry that is not known to have been filled by the
54 * hardware.
55 */
56 u32 index;
57};
58
59/* Transactions use several resources that can be allocated dynamically
60 * but taken from a fixed-size pool. The number of elements required for
61 * the pool is limited by the total number of TREs that can be outstanding.
62 *
63 * If sufficient TREs are available to reserve for a transaction,
64 * allocation from these pools is guaranteed to succeed. Furthermore,
65 * these resources are implicitly freed whenever the TREs in the
66 * transaction they're associated with are released.
67 *
68 * The result of a pool allocation of multiple elements is always
69 * contiguous.
70 */
71struct gsi_trans_pool {
72 void *base; /* base address of element pool */
73 u32 count; /* # elements in the pool */
74 u32 free; /* next free element in pool (modulo) */
75 u32 size; /* size (bytes) of an element */
76 u32 max_alloc; /* max allocation request */
77 dma_addr_t addr; /* DMA address if DMA pool (or 0) */
78};
79
80struct gsi_trans_info {
81 atomic_t tre_avail; /* TREs available for allocation */
82 struct gsi_trans_pool pool; /* transaction pool */
83 struct gsi_trans_pool sg_pool; /* scatterlist pool */
84 struct gsi_trans_pool cmd_pool; /* command payload DMA pool */
85 struct gsi_trans_pool info_pool;/* command information pool */
86 struct gsi_trans **map; /* TRE -> transaction map */
87
88 spinlock_t spinlock; /* protects updates to the lists */
89 struct list_head alloc; /* allocated, not committed */
90 struct list_head pending; /* committed, awaiting completion */
91 struct list_head complete; /* completed, awaiting poll */
92 struct list_head polled; /* returned by gsi_channel_poll_one() */
93};
94
95/* Hardware values signifying the state of a channel */
96enum gsi_channel_state {
97 GSI_CHANNEL_STATE_NOT_ALLOCATED = 0x0,
98 GSI_CHANNEL_STATE_ALLOCATED = 0x1,
99 GSI_CHANNEL_STATE_STARTED = 0x2,
100 GSI_CHANNEL_STATE_STOPPED = 0x3,
101 GSI_CHANNEL_STATE_STOP_IN_PROC = 0x4,
102 GSI_CHANNEL_STATE_ERROR = 0xf,
103};
104
105/* We only care about channels between IPA and AP */
106struct gsi_channel {
107 struct gsi *gsi;
108 bool toward_ipa;
109 bool command; /* AP command TX channel or not */
110 bool use_prefetch; /* use prefetch (else escape buf) */
111
112 u8 tlv_count; /* # entries in TLV FIFO */
113 u16 tre_count;
114 u16 event_count;
115
116 struct completion completion; /* signals channel state changes */
117 enum gsi_channel_state state;
118
119 struct gsi_ring tre_ring;
120 u32 evt_ring_id;
121
122 u64 byte_count; /* total # bytes transferred */
123 u64 trans_count; /* total # transactions */
124 /* The following counts are used only for TX endpoints */
125 u64 queued_byte_count; /* last reported queued byte count */
126 u64 queued_trans_count; /* ...and queued trans count */
127 u64 compl_byte_count; /* last reported completed byte count */
128 u64 compl_trans_count; /* ...and completed trans count */
129
130 struct gsi_trans_info trans_info;
131
132 struct napi_struct napi;
133};
134
135/* Hardware values signifying the state of an event ring */
136enum gsi_evt_ring_state {
137 GSI_EVT_RING_STATE_NOT_ALLOCATED = 0x0,
138 GSI_EVT_RING_STATE_ALLOCATED = 0x1,
139 GSI_EVT_RING_STATE_ERROR = 0xf,
140};
141
142struct gsi_evt_ring {
143 struct gsi_channel *channel;
144 struct completion completion; /* signals event ring state changes */
145 enum gsi_evt_ring_state state;
146 struct gsi_ring ring;
147};
148
149struct gsi {
150 struct device *dev; /* Same as IPA device */
151 struct net_device dummy_dev; /* needed for NAPI */
152 void __iomem *virt;
153 u32 irq;
154 bool irq_wake_enabled;
155 u32 channel_count;
156 u32 evt_ring_count;
157 struct gsi_channel channel[GSI_CHANNEL_COUNT_MAX];
158 struct gsi_evt_ring evt_ring[GSI_EVT_RING_COUNT_MAX];
159 u32 event_bitmap;
160 u32 event_enable_bitmap;
161 u32 modem_channel_bitmap;
162 struct completion completion; /* for global EE commands */
163 struct mutex mutex; /* protects commands, programming */
164};
165
166/**
167 * gsi_setup() - Set up the GSI subsystem
168 * @gsi: Address of GSI structure embedded in an IPA structure
169 * @db_enable: Whether to use the GSI doorbell engine
170 *
171 * @Return: 0 if successful, or a negative error code
172 *
173 * Performs initialization that must wait until the GSI hardware is
174 * ready (including firmware loaded).
175 */
176int gsi_setup(struct gsi *gsi, bool db_enable);
177
178/**
179 * gsi_teardown() - Tear down GSI subsystem
180 * @gsi: GSI address previously passed to a successful gsi_setup() call
181 */
182void gsi_teardown(struct gsi *gsi);
183
184/**
185 * gsi_channel_tre_max() - Channel maximum number of in-flight TREs
186 * @gsi: GSI pointer
187 * @channel_id: Channel whose limit is to be returned
188 *
189 * @Return: The maximum number of TREs oustanding on the channel
190 */
191u32 gsi_channel_tre_max(struct gsi *gsi, u32 channel_id);
192
193/**
194 * gsi_channel_trans_tre_max() - Maximum TREs in a single transaction
195 * @gsi: GSI pointer
196 * @channel_id: Channel whose limit is to be returned
197 *
198 * @Return: The maximum TRE count per transaction on the channel
199 */
200u32 gsi_channel_trans_tre_max(struct gsi *gsi, u32 channel_id);
201
202/**
203 * gsi_channel_start() - Start an allocated GSI channel
204 * @gsi: GSI pointer
205 * @channel_id: Channel to start
206 *
207 * @Return: 0 if successful, or a negative error code
208 */
209int gsi_channel_start(struct gsi *gsi, u32 channel_id);
210
211/**
212 * gsi_channel_stop() - Stop a started GSI channel
213 * @gsi: GSI pointer returned by gsi_setup()
214 * @channel_id: Channel to stop
215 *
216 * @Return: 0 if successful, or a negative error code
217 */
218int gsi_channel_stop(struct gsi *gsi, u32 channel_id);
219
220/**
221 * gsi_channel_reset() - Reset an allocated GSI channel
222 * @gsi: GSI pointer
223 * @channel_id: Channel to be reset
224 * @db_enable: Whether doorbell engine should be enabled
225 *
226 * Reset a channel and reconfigure it. The @db_enable flag indicates
227 * whether the doorbell engine will be enabled following reconfiguration.
228 *
229 * GSI hardware relinquishes ownership of all pending receive buffer
230 * transactions and they will complete with their cancelled flag set.
231 */
232void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool db_enable);
233
234int gsi_channel_suspend(struct gsi *gsi, u32 channel_id, bool stop);
235int gsi_channel_resume(struct gsi *gsi, u32 channel_id, bool start);
236
237/**
238 * gsi_init() - Initialize the GSI subsystem
239 * @gsi: Address of GSI structure embedded in an IPA structure
240 * @pdev: IPA platform device
241 *
242 * @Return: 0 if successful, or a negative error code
243 *
244 * Early stage initialization of the GSI subsystem, performing tasks
245 * that can be done before the GSI hardware is ready to use.
246 */
247int gsi_init(struct gsi *gsi, struct platform_device *pdev, bool prefetch,
248 u32 count, const struct ipa_gsi_endpoint_data *data,
249 bool modem_alloc);
250
251/**
252 * gsi_exit() - Exit the GSI subsystem
253 * @gsi: GSI address previously passed to a successful gsi_init() call
254 */
255void gsi_exit(struct gsi *gsi);
256
257#endif /* _GSI_H_ */