drivers/net/ipa/gsi.h

   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   28
  18 #define GSI_EVT_RING_COUNT_MAX  28
  19
  20 /* Maximum TLV FIFO size for a channel; 64 here is arbitrary (and high) */
  21 #define GSI_TLV_MAX             64
  22
  23 struct device;
  24 struct platform_device;
  25
  26 struct gsi;
  27 struct gsi_trans;
  28 struct ipa_gsi_endpoint_data;
  29
  30 struct 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 passed
  38          * to the hardware for processing.  For a channel ring, the ring index
  39          * identifies the next unused entry to be filled by the AP.  In this
  40          * case the initial value is assumed by hardware to be 0.
  41          *
  42          * An event ring consists of event structures filled by the hardware
  43          * and passed to the AP.  For event rings, the ring index identifies
  44          * the next ring entry that is not known to have been filled by the
  45          * 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 dynamically
  51  * but taken from a fixed-size pool.  The number of elements required for
  52  * 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 the
  57  * transaction they're associated with are released.
  58  *
  59  * The result of a pool allocation of multiple elements is always
  60  * contiguous.
  61  */
  62 struct 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
  71 struct 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 */
  88 enum 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 */
  99 struct 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 */
 125 enum 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
 131 struct gsi_evt_ring {
 132         struct gsi_channel *channel;
 133         struct gsi_ring ring;
 134 };
 135
 136 struct 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 subsystem
 159  * @gsi:        Address of GSI structure embedded in an IPA structure
 160  *
 161  * Return:      0 if successful, or a negative error code
 162  *
 163  * Performs initialization that must wait until the GSI hardware is
 164  * ready (including firmware loaded).
 165  */
 166 int gsi_setup(struct gsi *gsi);
 167
 168 /**
 169  * gsi_teardown() - Tear down GSI subsystem
 170  * @gsi:        GSI address previously passed to a successful gsi_setup() call
 171  */
 172 void gsi_teardown(struct gsi *gsi);
 173
 174 /**
 175  * gsi_channel_tre_max() - Channel maximum number of in-flight TREs
 176  * @gsi:        GSI pointer
 177  * @channel_id: Channel whose limit is to be returned
 178  *
 179  * Return:       The maximum number of TREs outstanding on the channel
 180  */
 181 u32 gsi_channel_tre_max(struct gsi *gsi, u32 channel_id);
 182
 183 /**
 184  * gsi_channel_start() - Start an allocated GSI channel
 185  * @gsi:        GSI pointer
 186  * @channel_id: Channel to start
 187  *
 188  * Return:      0 if successful, or a negative error code
 189  */
 190 int gsi_channel_start(struct gsi *gsi, u32 channel_id);
 191
 192 /**
 193  * gsi_channel_stop() - Stop a started GSI channel
 194  * @gsi:        GSI pointer returned by gsi_setup()
 195  * @channel_id: Channel to stop
 196  *
 197  * Return:      0 if successful, or a negative error code
 198  */
 199 int 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 control
 205  * @enable:     Whether to enable flow control (i.e., prevent flow)
 206  */
 207 void gsi_modem_channel_flow_control(struct gsi *gsi, u32 channel_id,
 208                                     bool enable);
 209
 210 /**
 211  * gsi_channel_reset() - Reset an allocated GSI channel
 212  * @gsi:        GSI pointer
 213  * @channel_id: Channel to be reset
 214  * @doorbell:   Whether to (possibly) enable the doorbell engine
 215  *
 216  * Reset a channel and reconfigure it.  The @doorbell flag indicates
 217  * that the doorbell engine should be enabled if needed.
 218  *
 219  * GSI hardware relinquishes ownership of all pending receive buffer
 220  * transactions and they will complete with their cancelled flag set.
 221  */
 222 void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool doorbell);
 223
 224 /**
 225  * gsi_suspend() - Prepare the GSI subsystem for suspend
 226  * @gsi:        GSI pointer
 227  */
 228 void gsi_suspend(struct gsi *gsi);
 229
 230 /**
 231  * gsi_resume() - Resume the GSI subsystem following suspend
 232  * @gsi:        GSI pointer
 233  */
 234 void gsi_resume(struct gsi *gsi);
 235
 236 /**
 237  * gsi_channel_suspend() - Suspend a GSI channel
 238  * @gsi:        GSI pointer
 239  * @channel_id: Channel to suspend
 240  *
 241  * For IPA v4.0+, suspend is implemented by stopping the channel.
 242  */
 243 int gsi_channel_suspend(struct gsi *gsi, u32 channel_id);
 244
 245 /**
 246  * gsi_channel_resume() - Resume a suspended GSI channel
 247  * @gsi:        GSI pointer
 248  * @channel_id: Channel to resume
 249  *
 250  * For IPA v4.0+, the stopped channel is started again.
 251  */
 252 int gsi_channel_resume(struct gsi *gsi, u32 channel_id);
 253
 254 /**
 255  * gsi_init() - Initialize the GSI subsystem
 256  * @gsi:        Address of GSI structure embedded in an IPA structure
 257  * @pdev:       IPA platform device
 258  * @version:    IPA hardware version (implies GSI version)
 259  * @count:      Number of entries in the configuration data array
 260  * @data:       Endpoint and channel configuration data
 261  *
 262  * Return:      0 if successful, or a negative error code
 263  *
 264  * Early stage initialization of the GSI subsystem, performing tasks
 265  * that can be done before the GSI hardware is ready to use.
 266  */
 267 int 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 subsystem
 273  * @gsi:        GSI address previously passed to a successful gsi_init() call
 274  */
 275 void gsi_exit(struct gsi *gsi);
 276
 277 #endif /* _GSI_H_ */