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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) 2018-2024 Linaro Ltd.5 */6#ifndef _GSI_H_7#define _GSI_H_8 9#include <linux/completion.h>10#include <linux/mutex.h>11#include <linux/netdevice.h>12#include <linux/types.h>13 14#include "ipa_version.h"15 16/* Maximum number of channels and event rings supported by the driver */17#define GSI_CHANNEL_COUNT_MAX 2818#define GSI_EVT_RING_COUNT_MAX 2819 20/* Maximum TLV FIFO size for a channel; 64 here is arbitrary (and high) */21#define GSI_TLV_MAX 6422 23struct device;24struct platform_device;25 26struct gsi;27struct gsi_trans;28struct ipa_gsi_endpoint_data;29 30struct gsi_ring {31 void *virt; /* ring array base address */32 dma_addr_t addr; /* primarily low 32 bits used */33 u32 count; /* number of elements in ring */34 35 /* The ring index value indicates the next "open" entry in the ring.36 *37 * A channel ring consists of TRE entries filled by the AP and passed38 * to the hardware for processing. For a channel ring, the ring index39 * identifies the next unused entry to be filled by the AP. In this40 * case the initial value is assumed by hardware to be 0.41 *42 * An event ring consists of event structures filled by the hardware43 * and passed to the AP. For event rings, the ring index identifies44 * the next ring entry that is not known to have been filled by the45 * hardware. The initial value used is arbitrary (so we use 0).46 */47 u32 index;48};49 50/* Transactions use several resources that can be allocated dynamically51 * but taken from a fixed-size pool. The number of elements required for52 * the pool is limited by the total number of TREs that can be outstanding.53 *54 * If sufficient TREs are available to reserve for a transaction,55 * allocation from these pools is guaranteed to succeed. Furthermore,56 * these resources are implicitly freed whenever the TREs in the57 * transaction they're associated with are released.58 *59 * The result of a pool allocation of multiple elements is always60 * contiguous.61 */62struct gsi_trans_pool {63 void *base; /* base address of element pool */64 u32 count; /* # elements in the pool */65 u32 free; /* next free element in pool (modulo) */66 u32 size; /* size (bytes) of an element */67 u32 max_alloc; /* max allocation request */68 dma_addr_t addr; /* DMA address if DMA pool (or 0) */69};70 71struct gsi_trans_info {72 atomic_t tre_avail; /* TREs available for allocation */73 74 u16 free_id; /* first free trans in array */75 u16 allocated_id; /* first allocated transaction */76 u16 committed_id; /* first committed transaction */77 u16 pending_id; /* first pending transaction */78 u16 completed_id; /* first completed transaction */79 u16 polled_id; /* first polled transaction */80 struct gsi_trans *trans; /* transaction array */81 struct gsi_trans **map; /* TRE -> transaction map */82 83 struct gsi_trans_pool sg_pool; /* scatterlist pool */84 struct gsi_trans_pool cmd_pool; /* command payload DMA pool */85};86 87/* Hardware values signifying the state of a channel */88enum gsi_channel_state {89 GSI_CHANNEL_STATE_NOT_ALLOCATED = 0x0,90 GSI_CHANNEL_STATE_ALLOCATED = 0x1,91 GSI_CHANNEL_STATE_STARTED = 0x2,92 GSI_CHANNEL_STATE_STOPPED = 0x3,93 GSI_CHANNEL_STATE_STOP_IN_PROC = 0x4,94 GSI_CHANNEL_STATE_FLOW_CONTROLLED = 0x5, /* IPA v4.2-v4.9 */95 GSI_CHANNEL_STATE_ERROR = 0xf,96};97 98/* We only care about channels between IPA and AP */99struct gsi_channel {100 struct gsi *gsi;101 bool toward_ipa;102 bool command; /* AP command TX channel or not */103 104 u8 trans_tre_max; /* max TREs in a transaction */105 u16 tre_count;106 u16 event_count;107 108 struct gsi_ring tre_ring;109 u32 evt_ring_id;110 111 /* The following counts are used only for TX endpoints */112 u64 byte_count; /* total # bytes transferred */113 u64 trans_count; /* total # transactions */114 u64 queued_byte_count; /* last reported queued byte count */115 u64 queued_trans_count; /* ...and queued trans count */116 u64 compl_byte_count; /* last reported completed byte count */117 u64 compl_trans_count; /* ...and completed trans count */118 119 struct gsi_trans_info trans_info;120 121 struct napi_struct napi;122};123 124/* Hardware values signifying the state of an event ring */125enum gsi_evt_ring_state {126 GSI_EVT_RING_STATE_NOT_ALLOCATED = 0x0,127 GSI_EVT_RING_STATE_ALLOCATED = 0x1,128 GSI_EVT_RING_STATE_ERROR = 0xf,129};130 131struct gsi_evt_ring {132 struct gsi_channel *channel;133 struct gsi_ring ring;134};135 136struct gsi {137 struct device *dev; /* Same as IPA device */138 enum ipa_version version;139 void __iomem *virt; /* I/O mapped registers */140 const struct regs *regs;141 142 u32 irq;143 u32 channel_count;144 u32 evt_ring_count;145 u32 event_bitmap; /* allocated event rings */146 u32 modem_channel_bitmap; /* modem channels to allocate */147 u32 type_enabled_bitmap; /* GSI IRQ types enabled */148 u32 ieob_enabled_bitmap; /* IEOB IRQ enabled (event rings) */149 int result; /* Negative errno (generic commands) */150 struct completion completion; /* Signals GSI command completion */151 struct mutex mutex; /* protects commands, programming */152 struct gsi_channel channel[GSI_CHANNEL_COUNT_MAX];153 struct gsi_evt_ring evt_ring[GSI_EVT_RING_COUNT_MAX];154 struct net_device *dummy_dev; /* needed for NAPI */155};156 157/**158 * gsi_setup() - Set up the GSI subsystem159 * @gsi: Address of GSI structure embedded in an IPA structure160 *161 * Return: 0 if successful, or a negative error code162 *163 * Performs initialization that must wait until the GSI hardware is164 * ready (including firmware loaded).165 */166int gsi_setup(struct gsi *gsi);167 168/**169 * gsi_teardown() - Tear down GSI subsystem170 * @gsi: GSI address previously passed to a successful gsi_setup() call171 */172void gsi_teardown(struct gsi *gsi);173 174/**175 * gsi_channel_tre_max() - Channel maximum number of in-flight TREs176 * @gsi: GSI pointer177 * @channel_id: Channel whose limit is to be returned178 *179 * Return: The maximum number of TREs outstanding on the channel180 */181u32 gsi_channel_tre_max(struct gsi *gsi, u32 channel_id);182 183/**184 * gsi_channel_start() - Start an allocated GSI channel185 * @gsi: GSI pointer186 * @channel_id: Channel to start187 *188 * Return: 0 if successful, or a negative error code189 */190int gsi_channel_start(struct gsi *gsi, u32 channel_id);191 192/**193 * gsi_channel_stop() - Stop a started GSI channel194 * @gsi: GSI pointer returned by gsi_setup()195 * @channel_id: Channel to stop196 *197 * Return: 0 if successful, or a negative error code198 */199int gsi_channel_stop(struct gsi *gsi, u32 channel_id);200 201/**202 * gsi_modem_channel_flow_control() - Set channel flow control state (IPA v4.2+)203 * @gsi: GSI pointer returned by gsi_setup()204 * @channel_id: Modem TX channel to control205 * @enable: Whether to enable flow control (i.e., prevent flow)206 */207void gsi_modem_channel_flow_control(struct gsi *gsi, u32 channel_id,208 bool enable);209 210/**211 * gsi_channel_reset() - Reset an allocated GSI channel212 * @gsi: GSI pointer213 * @channel_id: Channel to be reset214 * @doorbell: Whether to (possibly) enable the doorbell engine215 *216 * Reset a channel and reconfigure it. The @doorbell flag indicates217 * that the doorbell engine should be enabled if needed.218 *219 * GSI hardware relinquishes ownership of all pending receive buffer220 * transactions and they will complete with their cancelled flag set.221 */222void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool doorbell);223 224/**225 * gsi_suspend() - Prepare the GSI subsystem for suspend226 * @gsi: GSI pointer227 */228void gsi_suspend(struct gsi *gsi);229 230/**231 * gsi_resume() - Resume the GSI subsystem following suspend232 * @gsi: GSI pointer233 */234void gsi_resume(struct gsi *gsi);235 236/**237 * gsi_channel_suspend() - Suspend a GSI channel238 * @gsi: GSI pointer239 * @channel_id: Channel to suspend240 *241 * For IPA v4.0+, suspend is implemented by stopping the channel.242 */243int gsi_channel_suspend(struct gsi *gsi, u32 channel_id);244 245/**246 * gsi_channel_resume() - Resume a suspended GSI channel247 * @gsi: GSI pointer248 * @channel_id: Channel to resume249 *250 * For IPA v4.0+, the stopped channel is started again.251 */252int gsi_channel_resume(struct gsi *gsi, u32 channel_id);253 254/**255 * gsi_init() - Initialize the GSI subsystem256 * @gsi: Address of GSI structure embedded in an IPA structure257 * @pdev: IPA platform device258 * @version: IPA hardware version (implies GSI version)259 * @count: Number of entries in the configuration data array260 * @data: Endpoint and channel configuration data261 *262 * Return: 0 if successful, or a negative error code263 *264 * Early stage initialization of the GSI subsystem, performing tasks265 * that can be done before the GSI hardware is ready to use.266 */267int gsi_init(struct gsi *gsi, struct platform_device *pdev,268 enum ipa_version version, u32 count,269 const struct ipa_gsi_endpoint_data *data);270 271/**272 * gsi_exit() - Exit the GSI subsystem273 * @gsi: GSI address previously passed to a successful gsi_init() call274 */275void gsi_exit(struct gsi *gsi);276 277#endif /* _GSI_H_ */278