1 /* SPDX-License-Identifier: GPL-2.0 */
3 /* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
4 * Copyright (C) 2018-2021 Linaro Ltd.
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>
16 #include "ipa_version.h"
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
22 /* Maximum TLV FIFO size for a channel; 64 here is arbitrary (and high) */
23 #define GSI_TLV_MAX 64
27 struct platform_device;
31 struct gsi_channel_data;
32 struct ipa_gsi_endpoint_data;
34 /* Execution environment IDs */
43 void *virt; /* ring array base address */
44 dma_addr_t addr; /* primarily low 32 bits used */
45 u32 count; /* number of elements in ring */
47 /* The ring index value indicates the next "open" entry in the ring.
49 * A channel ring consists of TRE entries filled by the AP and passed
50 * to the hardware for processing. For a channel ring, the ring index
51 * identifies the next unused entry to be filled by the AP.
53 * An event ring consists of event structures filled by the hardware
54 * and passed to the AP. For event rings, the ring index identifies
55 * the next ring entry that is not known to have been filled by the
61 /* Transactions use several resources that can be allocated dynamically
62 * but taken from a fixed-size pool. The number of elements required for
63 * the pool is limited by the total number of TREs that can be outstanding.
65 * If sufficient TREs are available to reserve for a transaction,
66 * allocation from these pools is guaranteed to succeed. Furthermore,
67 * these resources are implicitly freed whenever the TREs in the
68 * transaction they're associated with are released.
70 * The result of a pool allocation of multiple elements is always
73 struct gsi_trans_pool {
74 void *base; /* base address of element pool */
75 u32 count; /* # elements in the pool */
76 u32 free; /* next free element in pool (modulo) */
77 u32 size; /* size (bytes) of an element */
78 u32 max_alloc; /* max allocation request */
79 dma_addr_t addr; /* DMA address if DMA pool (or 0) */
82 struct gsi_trans_info {
83 atomic_t tre_avail; /* TREs available for allocation */
84 struct gsi_trans_pool pool; /* transaction pool */
85 struct gsi_trans_pool sg_pool; /* scatterlist pool */
86 struct gsi_trans_pool cmd_pool; /* command payload DMA pool */
87 struct gsi_trans_pool info_pool;/* command information pool */
88 struct gsi_trans **map; /* TRE -> transaction map */
90 spinlock_t spinlock; /* protects updates to the lists */
91 struct list_head alloc; /* allocated, not committed */
92 struct list_head pending; /* committed, awaiting completion */
93 struct list_head complete; /* completed, awaiting poll */
94 struct list_head polled; /* returned by gsi_channel_poll_one() */
97 /* Hardware values signifying the state of a channel */
98 enum gsi_channel_state {
99 GSI_CHANNEL_STATE_NOT_ALLOCATED = 0x0,
100 GSI_CHANNEL_STATE_ALLOCATED = 0x1,
101 GSI_CHANNEL_STATE_STARTED = 0x2,
102 GSI_CHANNEL_STATE_STOPPED = 0x3,
103 GSI_CHANNEL_STATE_STOP_IN_PROC = 0x4,
104 GSI_CHANNEL_STATE_FLOW_CONTROLLED = 0x5, /* IPA v4.2+ */
105 GSI_CHANNEL_STATE_ERROR = 0xf,
108 /* We only care about channels between IPA and AP */
112 bool command; /* AP command TX channel or not */
114 u8 tlv_count; /* # entries in TLV FIFO */
118 struct gsi_ring tre_ring;
121 u64 byte_count; /* total # bytes transferred */
122 u64 trans_count; /* total # transactions */
123 /* The following counts are used only for TX endpoints */
124 u64 queued_byte_count; /* last reported queued byte count */
125 u64 queued_trans_count; /* ...and queued trans count */
126 u64 compl_byte_count; /* last reported completed byte count */
127 u64 compl_trans_count; /* ...and completed trans count */
129 struct gsi_trans_info trans_info;
131 struct napi_struct napi;
134 /* Hardware values signifying the state of an event ring */
135 enum gsi_evt_ring_state {
136 GSI_EVT_RING_STATE_NOT_ALLOCATED = 0x0,
137 GSI_EVT_RING_STATE_ALLOCATED = 0x1,
138 GSI_EVT_RING_STATE_ERROR = 0xf,
141 struct gsi_evt_ring {
142 struct gsi_channel *channel;
143 struct gsi_ring ring;
147 struct device *dev; /* Same as IPA device */
148 enum ipa_version version;
149 void __iomem *virt_raw; /* I/O mapped address range */
150 void __iomem *virt; /* Adjusted for most registers */
154 u32 event_bitmap; /* allocated event rings */
155 u32 modem_channel_bitmap; /* modem channels to allocate */
156 u32 type_enabled_bitmap; /* GSI IRQ types enabled */
157 u32 ieob_enabled_bitmap; /* IEOB IRQ enabled (event rings) */
158 int result; /* Negative errno (generic commands) */
159 struct completion completion; /* Signals GSI command completion */
160 struct mutex mutex; /* protects commands, programming */
161 struct gsi_channel channel[GSI_CHANNEL_COUNT_MAX];
162 struct gsi_evt_ring evt_ring[GSI_EVT_RING_COUNT_MAX];
163 struct net_device dummy_dev; /* needed for NAPI */
167 * gsi_setup() - Set up the GSI subsystem
168 * @gsi: Address of GSI structure embedded in an IPA structure
170 * Return: 0 if successful, or a negative error code
172 * Performs initialization that must wait until the GSI hardware is
173 * ready (including firmware loaded).
175 int gsi_setup(struct gsi *gsi);
178 * gsi_teardown() - Tear down GSI subsystem
179 * @gsi: GSI address previously passed to a successful gsi_setup() call
181 void gsi_teardown(struct gsi *gsi);
184 * gsi_channel_tre_max() - Channel maximum number of in-flight TREs
186 * @channel_id: Channel whose limit is to be returned
188 * Return: The maximum number of TREs oustanding on the channel
190 u32 gsi_channel_tre_max(struct gsi *gsi, u32 channel_id);
193 * gsi_channel_trans_tre_max() - Maximum TREs in a single transaction
195 * @channel_id: Channel whose limit is to be returned
197 * Return: The maximum TRE count per transaction on the channel
199 u32 gsi_channel_trans_tre_max(struct gsi *gsi, u32 channel_id);
202 * gsi_channel_start() - Start an allocated GSI channel
204 * @channel_id: Channel to start
206 * Return: 0 if successful, or a negative error code
208 int gsi_channel_start(struct gsi *gsi, u32 channel_id);
211 * gsi_channel_stop() - Stop a started GSI channel
212 * @gsi: GSI pointer returned by gsi_setup()
213 * @channel_id: Channel to stop
215 * Return: 0 if successful, or a negative error code
217 int gsi_channel_stop(struct gsi *gsi, u32 channel_id);
220 * gsi_modem_channel_flow_control() - Set channel flow control state (IPA v4.2+)
221 * @gsi: GSI pointer returned by gsi_setup()
222 * @channel_id: Modem TX channel to control
223 * @enable: Whether to enable flow control (i.e., prevent flow)
225 void gsi_modem_channel_flow_control(struct gsi *gsi, u32 channel_id,
229 * gsi_channel_reset() - Reset an allocated GSI channel
231 * @channel_id: Channel to be reset
232 * @doorbell: Whether to (possibly) enable the doorbell engine
234 * Reset a channel and reconfigure it. The @doorbell flag indicates
235 * that the doorbell engine should be enabled if needed.
237 * GSI hardware relinquishes ownership of all pending receive buffer
238 * transactions and they will complete with their cancelled flag set.
240 void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool doorbell);
243 * gsi_suspend() - Prepare the GSI subsystem for suspend
246 void gsi_suspend(struct gsi *gsi);
249 * gsi_resume() - Resume the GSI subsystem following suspend
252 void gsi_resume(struct gsi *gsi);
255 * gsi_channel_suspend() - Suspend a GSI channel
257 * @channel_id: Channel to suspend
259 * For IPA v4.0+, suspend is implemented by stopping the channel.
261 int gsi_channel_suspend(struct gsi *gsi, u32 channel_id);
264 * gsi_channel_resume() - Resume a suspended GSI channel
266 * @channel_id: Channel to resume
268 * For IPA v4.0+, the stopped channel is started again.
270 int gsi_channel_resume(struct gsi *gsi, u32 channel_id);
273 * gsi_init() - Initialize the GSI subsystem
274 * @gsi: Address of GSI structure embedded in an IPA structure
275 * @pdev: IPA platform device
276 * @version: IPA hardware version (implies GSI version)
277 * @count: Number of entries in the configuration data array
278 * @data: Endpoint and channel configuration data
280 * Return: 0 if successful, or a negative error code
282 * Early stage initialization of the GSI subsystem, performing tasks
283 * that can be done before the GSI hardware is ready to use.
285 int gsi_init(struct gsi *gsi, struct platform_device *pdev,
286 enum ipa_version version, u32 count,
287 const struct ipa_gsi_endpoint_data *data);
290 * gsi_exit() - Exit the GSI subsystem
291 * @gsi: GSI address previously passed to a successful gsi_init() call
293 void gsi_exit(struct gsi *gsi);