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/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
* Copyright (C) 2018-2023 Linaro Ltd.
*/
#ifndef _GSI_H_
#define _GSI_H_
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/completion.h>
#include <linux/platform_device.h>
#include <linux/netdevice.h>
#include "ipa_version.h"
/* Maximum number of channels and event rings supported by the driver */
#define GSI_CHANNEL_COUNT_MAX 28
#define GSI_EVT_RING_COUNT_MAX 28
/* Maximum TLV FIFO size for a channel; 64 here is arbitrary (and high) */
#define GSI_TLV_MAX 64
struct device;
struct scatterlist;
struct platform_device;
struct gsi;
struct gsi_trans;
struct gsi_channel_data;
struct ipa_gsi_endpoint_data;
struct gsi_ring {
void *virt; /* ring array base address */
dma_addr_t addr; /* primarily low 32 bits used */
u32 count; /* number of elements in ring */
/* The ring index value indicates the next "open" entry in the ring.
*
* A channel ring consists of TRE entries filled by the AP and passed
* to the hardware for processing. For a channel ring, the ring index
* identifies the next unused entry to be filled by the AP. In this
* case the initial value is assumed by hardware to be 0.
*
* An event ring consists of event structures filled by the hardware
* and passed to the AP. For event rings, the ring index identifies
* the next ring entry that is not known to have been filled by the
* hardware. The initial value used is arbitrary (so we use 0).
*/
u32 index;
};
/* Transactions use several resources that can be allocated dynamically
* but taken from a fixed-size pool. The number of elements required for
* the pool is limited by the total number of TREs that can be outstanding.
*
* If sufficient TREs are available to reserve for a transaction,
* allocation from these pools is guaranteed to succeed. Furthermore,
* these resources are implicitly freed whenever the TREs in the
* transaction they're associated with are released.
*
* The result of a pool allocation of multiple elements is always
* contiguous.
*/
struct gsi_trans_pool {
void *base; /* base address of element pool */
u32 count; /* # elements in the pool */
u32 free; /* next free element in pool (modulo) */
u32 size; /* size (bytes) of an element */
u32 max_alloc; /* max allocation request */
dma_addr_t addr; /* DMA address if DMA pool (or 0) */
};
struct gsi_trans_info {
atomic_t tre_avail; /* TREs available for allocation */
u16 free_id; /* first free trans in array */
u16 allocated_id; /* first allocated transaction */
u16 committed_id; /* first committed transaction */
u16 pending_id; /* first pending transaction */
u16 completed_id; /* first completed transaction */
u16 polled_id; /* first polled transaction */
struct gsi_trans *trans; /* transaction array */
struct gsi_trans **map; /* TRE -> transaction map */
struct gsi_trans_pool sg_pool; /* scatterlist pool */
struct gsi_trans_pool cmd_pool; /* command payload DMA pool */
};
/* Hardware values signifying the state of a channel */
enum gsi_channel_state {
GSI_CHANNEL_STATE_NOT_ALLOCATED = 0x0,
GSI_CHANNEL_STATE_ALLOCATED = 0x1,
GSI_CHANNEL_STATE_STARTED = 0x2,
GSI_CHANNEL_STATE_STOPPED = 0x3,
GSI_CHANNEL_STATE_STOP_IN_PROC = 0x4,
GSI_CHANNEL_STATE_FLOW_CONTROLLED = 0x5, /* IPA v4.2-v4.9 */
GSI_CHANNEL_STATE_ERROR = 0xf,
};
/* We only care about channels between IPA and AP */
struct gsi_channel {
struct gsi *gsi;
bool toward_ipa;
bool command; /* AP command TX channel or not */
u8 trans_tre_max; /* max TREs in a transaction */
u16 tre_count;
u16 event_count;
struct gsi_ring tre_ring;
u32 evt_ring_id;
/* The following counts are used only for TX endpoints */
u64 byte_count; /* total # bytes transferred */
u64 trans_count; /* total # transactions */
u64 queued_byte_count; /* last reported queued byte count */
u64 queued_trans_count; /* ...and queued trans count */
u64 compl_byte_count; /* last reported completed byte count */
u64 compl_trans_count; /* ...and completed trans count */
struct gsi_trans_info trans_info;
struct napi_struct napi;
};
/* Hardware values signifying the state of an event ring */
enum gsi_evt_ring_state {
GSI_EVT_RING_STATE_NOT_ALLOCATED = 0x0,
GSI_EVT_RING_STATE_ALLOCATED = 0x1,
GSI_EVT_RING_STATE_ERROR = 0xf,
};
struct gsi_evt_ring {
struct gsi_channel *channel;
struct gsi_ring ring;
};
struct gsi {
struct device *dev; /* Same as IPA device */
enum ipa_version version;
void __iomem *virt; /* I/O mapped registers */
const struct regs *regs;
u32 irq;
u32 channel_count;
u32 evt_ring_count;
u32 event_bitmap; /* allocated event rings */
u32 modem_channel_bitmap; /* modem channels to allocate */
u32 type_enabled_bitmap; /* GSI IRQ types enabled */
u32 ieob_enabled_bitmap; /* IEOB IRQ enabled (event rings) */
int result; /* Negative errno (generic commands) */
struct completion completion; /* Signals GSI command completion */
struct mutex mutex; /* protects commands, programming */
struct gsi_channel channel[GSI_CHANNEL_COUNT_MAX];
struct gsi_evt_ring evt_ring[GSI_EVT_RING_COUNT_MAX];
struct net_device dummy_dev; /* needed for NAPI */
};
/**
* gsi_setup() - Set up the GSI subsystem
* @gsi: Address of GSI structure embedded in an IPA structure
*
* Return: 0 if successful, or a negative error code
*
* Performs initialization that must wait until the GSI hardware is
* ready (including firmware loaded).
*/
int gsi_setup(struct gsi *gsi);
/**
* gsi_teardown() - Tear down GSI subsystem
* @gsi: GSI address previously passed to a successful gsi_setup() call
*/
void gsi_teardown(struct gsi *gsi);
/**
* gsi_channel_tre_max() - Channel maximum number of in-flight TREs
* @gsi: GSI pointer
* @channel_id: Channel whose limit is to be returned
*
* Return: The maximum number of TREs outstanding on the channel
*/
u32 gsi_channel_tre_max(struct gsi *gsi, u32 channel_id);
/**
* gsi_channel_start() - Start an allocated GSI channel
* @gsi: GSI pointer
* @channel_id: Channel to start
*
* Return: 0 if successful, or a negative error code
*/
int gsi_channel_start(struct gsi *gsi, u32 channel_id);
/**
* gsi_channel_stop() - Stop a started GSI channel
* @gsi: GSI pointer returned by gsi_setup()
* @channel_id: Channel to stop
*
* Return: 0 if successful, or a negative error code
*/
int gsi_channel_stop(struct gsi *gsi, u32 channel_id);
/**
* gsi_modem_channel_flow_control() - Set channel flow control state (IPA v4.2+)
* @gsi: GSI pointer returned by gsi_setup()
* @channel_id: Modem TX channel to control
* @enable: Whether to enable flow control (i.e., prevent flow)
*/
void gsi_modem_channel_flow_control(struct gsi *gsi, u32 channel_id,
bool enable);
/**
* gsi_channel_reset() - Reset an allocated GSI channel
* @gsi: GSI pointer
* @channel_id: Channel to be reset
* @doorbell: Whether to (possibly) enable the doorbell engine
*
* Reset a channel and reconfigure it. The @doorbell flag indicates
* that the doorbell engine should be enabled if needed.
*
* GSI hardware relinquishes ownership of all pending receive buffer
* transactions and they will complete with their cancelled flag set.
*/
void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool doorbell);
/**
* gsi_suspend() - Prepare the GSI subsystem for suspend
* @gsi: GSI pointer
*/
void gsi_suspend(struct gsi *gsi);
/**
* gsi_resume() - Resume the GSI subsystem following suspend
* @gsi: GSI pointer
*/
void gsi_resume(struct gsi *gsi);
/**
* gsi_channel_suspend() - Suspend a GSI channel
* @gsi: GSI pointer
* @channel_id: Channel to suspend
*
* For IPA v4.0+, suspend is implemented by stopping the channel.
*/
int gsi_channel_suspend(struct gsi *gsi, u32 channel_id);
/**
* gsi_channel_resume() - Resume a suspended GSI channel
* @gsi: GSI pointer
* @channel_id: Channel to resume
*
* For IPA v4.0+, the stopped channel is started again.
*/
int gsi_channel_resume(struct gsi *gsi, u32 channel_id);
/**
* gsi_init() - Initialize the GSI subsystem
* @gsi: Address of GSI structure embedded in an IPA structure
* @pdev: IPA platform device
* @version: IPA hardware version (implies GSI version)
* @count: Number of entries in the configuration data array
* @data: Endpoint and channel configuration data
*
* Return: 0 if successful, or a negative error code
*
* Early stage initialization of the GSI subsystem, performing tasks
* that can be done before the GSI hardware is ready to use.
*/
int gsi_init(struct gsi *gsi, struct platform_device *pdev,
enum ipa_version version, u32 count,
const struct ipa_gsi_endpoint_data *data);
/**
* gsi_exit() - Exit the GSI subsystem
* @gsi: GSI address previously passed to a successful gsi_init() call
*/
void gsi_exit(struct gsi *gsi);
#endif /* _GSI_H_ */
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