kernel / include / linux / firewire.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_FIREWIRE_H
#define _LINUX_FIREWIRE_H

#include <linux/completion.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/sysfs.h>
#include <linux/timer.h>
#include <linux/types.h>
#include <linux/workqueue.h>

#include <linux/atomic.h>
#include <asm/byteorder.h>

#define CSR_REGISTER_BASE		0xfffff0000000ULL

/* register offsets are relative to CSR_REGISTER_BASE */
#define CSR_STATE_CLEAR			0x0
#define CSR_STATE_SET			0x4
#define CSR_NODE_IDS			0x8
#define CSR_RESET_START			0xc
#define CSR_SPLIT_TIMEOUT_HI		0x18
#define CSR_SPLIT_TIMEOUT_LO		0x1c
#define CSR_CYCLE_TIME			0x200
#define CSR_BUS_TIME			0x204
#define CSR_BUSY_TIMEOUT		0x210
#define CSR_PRIORITY_BUDGET		0x218
#define CSR_BUS_MANAGER_ID		0x21c
#define CSR_BANDWIDTH_AVAILABLE		0x220
#define CSR_CHANNELS_AVAILABLE		0x224
#define CSR_CHANNELS_AVAILABLE_HI	0x224
#define CSR_CHANNELS_AVAILABLE_LO	0x228
#define CSR_MAINT_UTILITY		0x230
#define CSR_BROADCAST_CHANNEL		0x234
#define CSR_CONFIG_ROM			0x400
#define CSR_CONFIG_ROM_END		0x800
#define CSR_OMPR			0x900
#define CSR_OPCR(i)			(0x904 + (i) * 4)
#define CSR_IMPR			0x980
#define CSR_IPCR(i)			(0x984 + (i) * 4)
#define CSR_FCP_COMMAND			0xB00
#define CSR_FCP_RESPONSE		0xD00
#define CSR_FCP_END			0xF00
#define CSR_TOPOLOGY_MAP		0x1000
#define CSR_TOPOLOGY_MAP_END		0x1400
#define CSR_SPEED_MAP			0x2000
#define CSR_SPEED_MAP_END		0x3000

#define CSR_OFFSET		0x40
#define CSR_LEAF		0x80
#define CSR_DIRECTORY		0xc0

#define CSR_DESCRIPTOR		0x01
#define CSR_VENDOR		0x03
#define CSR_HARDWARE_VERSION	0x04
#define CSR_UNIT		0x11
#define CSR_SPECIFIER_ID	0x12
#define CSR_VERSION		0x13
#define CSR_DEPENDENT_INFO	0x14
#define CSR_MODEL		0x17
#define CSR_DIRECTORY_ID	0x20

struct fw_csr_iterator {
	const u32 *p;
	const u32 *end;
};

void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p);
int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value);
int fw_csr_string(const u32 *directory, int key, char *buf, size_t size);

extern const struct bus_type fw_bus_type;

struct fw_card_driver;
struct fw_node;

struct fw_card {
	const struct fw_card_driver *driver;
	struct device *device;
	struct kref kref;
	struct completion done;

	int node_id;
	int generation;
	u64 reset_jiffies;

	struct {
		int current_tlabel;
		u64 tlabel_mask;
		struct list_head list;
		spinlock_t lock;
	} transactions;

	struct {
		u32 hi;
		u32 lo;
		unsigned int cycles;
		unsigned int jiffies;
		spinlock_t lock;
	} split_timeout;

	unsigned long long guid;
	unsigned max_receive;
	int link_speed;
	int config_rom_generation;

	spinlock_t lock;

	struct fw_node *local_node;
	struct fw_node *root_node;
	struct fw_node *irm_node;
	u8 color; /* must be u8 to match the definition in struct fw_node */
	int gap_count;
	bool beta_repeaters_present;

	int index;
	struct list_head link;

	struct delayed_work br_work; /* bus reset job */
	bool br_short;

	struct delayed_work bm_work; /* bus manager job */
	int bm_retries;
	int bm_generation;
	int bm_node_id;
	bool bm_abdicate;

	bool priority_budget_implemented;	/* controller feature */
	bool broadcast_channel_auto_allocated;	/* controller feature */

	bool broadcast_channel_allocated;
	u32 broadcast_channel;

	struct {
		__be32 buffer[(CSR_TOPOLOGY_MAP_END - CSR_TOPOLOGY_MAP) / 4];
		spinlock_t lock;
	} topology_map;

	__be32 maint_utility_register;

	struct workqueue_struct *isoc_wq;
	struct workqueue_struct *async_wq;
};

static inline struct fw_card *fw_card_get(struct fw_card *card)
{
	kref_get(&card->kref);

	return card;
}

void fw_card_release(struct kref *kref);

static inline void fw_card_put(struct fw_card *card)
{
	kref_put(&card->kref, fw_card_release);
}

int fw_card_read_cycle_time(struct fw_card *card, u32 *cycle_time);

struct fw_attribute_group {
	struct attribute_group *groups[2];
	struct attribute_group group;
	struct attribute *attrs[13];
};

enum fw_device_state {
	FW_DEVICE_INITIALIZING,
	FW_DEVICE_RUNNING,
	FW_DEVICE_GONE,
	FW_DEVICE_SHUTDOWN,
};

/*
 * Note, fw_device.generation always has to be read before fw_device.node_id.
 * Use SMP memory barriers to ensure this.  Otherwise requests will be sent
 * to an outdated node_id if the generation was updated in the meantime due
 * to a bus reset.
 *
 * Likewise, fw-core will take care to update .node_id before .generation so
 * that whenever fw_device.generation is current WRT the actual bus generation,
 * fw_device.node_id is guaranteed to be current too.
 *
 * The same applies to fw_device.card->node_id vs. fw_device.generation.
 *
 * fw_device.config_rom and fw_device.config_rom_length may be accessed during
 * the lifetime of any fw_unit belonging to the fw_device, before device_del()
 * was called on the last fw_unit.  Alternatively, they may be accessed while
 * holding fw_device_rwsem.
 */
struct fw_device {
	atomic_t state;
	struct fw_node *node;
	int node_id;
	int generation;
	unsigned max_speed;
	struct fw_card *card;
	struct device device;

	struct mutex client_list_mutex;
	struct list_head client_list;

	const u32 *config_rom;
	size_t config_rom_length;
	int config_rom_retries;
	unsigned is_local:1;
	unsigned max_rec:4;
	unsigned cmc:1;
	unsigned irmc:1;
	unsigned bc_implemented:2;

	work_func_t workfn;
	struct delayed_work work;
	struct fw_attribute_group attribute_group;
};

#define fw_device(dev)	container_of_const(dev, struct fw_device, device)

static inline int fw_device_is_shutdown(struct fw_device *device)
{
	return atomic_read(&device->state) == FW_DEVICE_SHUTDOWN;
}

int fw_device_enable_phys_dma(struct fw_device *device);

/*
 * fw_unit.directory must not be accessed after device_del(&fw_unit.device).
 */
struct fw_unit {
	struct device device;
	const u32 *directory;
	struct fw_attribute_group attribute_group;
};

#define fw_unit(dev)	container_of_const(dev, struct fw_unit, device)

static inline struct fw_unit *fw_unit_get(struct fw_unit *unit)
{
	get_device(&unit->device);

	return unit;
}

static inline void fw_unit_put(struct fw_unit *unit)
{
	put_device(&unit->device);
}

#define fw_parent_device(unit)	fw_device(unit->device.parent)

struct ieee1394_device_id;

struct fw_driver {
	struct device_driver driver;
	int (*probe)(struct fw_unit *unit, const struct ieee1394_device_id *id);
	/* Called when the parent device sits through a bus reset. */
	void (*update)(struct fw_unit *unit);
	void (*remove)(struct fw_unit *unit);
	const struct ieee1394_device_id *id_table;
};

struct fw_packet;
struct fw_request;

typedef void (*fw_packet_callback_t)(struct fw_packet *packet,
				     struct fw_card *card, int status);
typedef void (*fw_transaction_callback_t)(struct fw_card *card, int rcode,
					  void *data, size_t length,
					  void *callback_data);
typedef void (*fw_transaction_callback_with_tstamp_t)(struct fw_card *card, int rcode,
					u32 request_tstamp, u32 response_tstamp, void *data,
					size_t length, void *callback_data);

union fw_transaction_callback {
	fw_transaction_callback_t without_tstamp;
	fw_transaction_callback_with_tstamp_t with_tstamp;
};

/*
 * This callback handles an inbound request subaction.  It is called in
 * RCU read-side context, therefore must not sleep.
 *
 * The callback should not initiate outbound request subactions directly.
 * Otherwise there is a danger of recursion of inbound and outbound
 * transactions from and to the local node.
 *
 * The callback is responsible that fw_send_response() is called on the @request, except for FCP
 * registers for which the core takes care of that.
 */
typedef void (*fw_address_callback_t)(struct fw_card *card,
				      struct fw_request *request,
				      int tcode, int destination, int source,
				      int generation,
				      unsigned long long offset,
				      void *data, size_t length,
				      void *callback_data);

struct fw_packet {
	int speed;
	int generation;
	u32 header[4];
	size_t header_length;
	void *payload;
	size_t payload_length;
	dma_addr_t payload_bus;
	bool payload_mapped;
	u32 timestamp;

	/*
	 * This callback is called when the packet transmission has completed.
	 * For successful transmission, the status code is the ack received
	 * from the destination.  Otherwise it is one of the juju-specific
	 * rcodes:  RCODE_SEND_ERROR, _CANCELLED, _BUSY, _GENERATION, _NO_ACK.
	 * The callback can be called from workqueue and thus must never block.
	 */
	fw_packet_callback_t callback;
	int ack;
	struct list_head link;
	void *driver_data;
};

struct fw_transaction {
	int node_id; /* The generation is implied; it is always the current. */
	int tlabel;
	struct list_head link;
	struct fw_card *card;
	bool is_split_transaction;
	struct timer_list split_timeout_timer;
	u32 split_timeout_cycle;

	struct fw_packet packet;

	/*
	 * The data passed to the callback is valid only during the
	 * callback.
	 */
	union fw_transaction_callback callback;
	bool with_tstamp;
	void *callback_data;
};

struct fw_address_handler {
	u64 offset;
	u64 length;
	fw_address_callback_t address_callback;
	void *callback_data;

	// Only for core functions.
	struct list_head link;
	struct kref kref;
	struct completion done;
};

struct fw_address_region {
	u64 start;
	u64 end;
};

extern const struct fw_address_region fw_high_memory_region;

int fw_core_add_address_handler(struct fw_address_handler *handler,
				const struct fw_address_region *region);
void fw_core_remove_address_handler(struct fw_address_handler *handler);
void fw_send_response(struct fw_card *card,
		      struct fw_request *request, int rcode);
int fw_get_request_speed(struct fw_request *request);
u32 fw_request_get_timestamp(const struct fw_request *request);

void __fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode,
		int destination_id, int generation, int speed, unsigned long long offset,
		void *payload, size_t length, union fw_transaction_callback callback,
		bool with_tstamp, void *callback_data);

/**
 * fw_send_request() - submit a request packet for transmission to generate callback for response
 *		       subaction without time stamp.
 * @card:		interface to send the request at
 * @t:			transaction instance to which the request belongs
 * @tcode:		transaction code
 * @destination_id:	destination node ID, consisting of bus_ID and phy_ID
 * @generation:		bus generation in which request and response are valid
 * @speed:		transmission speed
 * @offset:		48bit wide offset into destination's address space
 * @payload:		data payload for the request subaction
 * @length:		length of the payload, in bytes
 * @callback:		function to be called when the transaction is completed
 * @callback_data:	data to be passed to the transaction completion callback
 *
 * A variation of __fw_send_request() to generate callback for response subaction without time
 * stamp.
 *
 * The callback is invoked in the workqueue context in most cases. However, if an error is detected
 * before queueing or the destination address refers to the local node, it is invoked in the
 * current context instead.
 */
static inline void fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode,
				   int destination_id, int generation, int speed,
				   unsigned long long offset, void *payload, size_t length,
				   fw_transaction_callback_t callback, void *callback_data)
{
	union fw_transaction_callback cb = {
		.without_tstamp = callback,
	};
	__fw_send_request(card, t, tcode, destination_id, generation, speed, offset, payload,
			  length, cb, false, callback_data);
}

/**
 * fw_send_request_with_tstamp() - submit a request packet for transmission to generate callback for
 *				   response with time stamp.
 * @card:		interface to send the request at
 * @t:			transaction instance to which the request belongs
 * @tcode:		transaction code
 * @destination_id:	destination node ID, consisting of bus_ID and phy_ID
 * @generation:		bus generation in which request and response are valid
 * @speed:		transmission speed
 * @offset:		48bit wide offset into destination's address space
 * @payload:		data payload for the request subaction
 * @length:		length of the payload, in bytes
 * @callback:		function to be called when the transaction is completed
 * @callback_data:	data to be passed to the transaction completion callback
 *
 * A variation of __fw_send_request() to generate callback for response subaction with time stamp.
 *
 * The callback is invoked in the workqueue context in most cases. However, if an error is detected
 * before queueing or the destination address refers to the local node, it is invoked in the current
 * context instead.
 */
static inline void fw_send_request_with_tstamp(struct fw_card *card, struct fw_transaction *t,
	int tcode, int destination_id, int generation, int speed, unsigned long long offset,
	void *payload, size_t length, fw_transaction_callback_with_tstamp_t callback,
	void *callback_data)
{
	union fw_transaction_callback cb = {
		.with_tstamp = callback,
	};
	__fw_send_request(card, t, tcode, destination_id, generation, speed, offset, payload,
			  length, cb, true, callback_data);
}

int fw_cancel_transaction(struct fw_card *card,
			  struct fw_transaction *transaction);
int fw_run_transaction(struct fw_card *card, int tcode, int destination_id,
		       int generation, int speed, unsigned long long offset,
		       void *payload, size_t length);
const char *fw_rcode_string(int rcode);

static inline int fw_stream_packet_destination_id(int tag, int channel, int sy)
{
	return tag << 14 | channel << 8 | sy;
}

void fw_schedule_bus_reset(struct fw_card *card, bool delayed,
			   bool short_reset);

struct fw_descriptor {
	struct list_head link;
	size_t length;
	u32 immediate;
	u32 key;
	const u32 *data;
};

int fw_core_add_descriptor(struct fw_descriptor *desc);
void fw_core_remove_descriptor(struct fw_descriptor *desc);

/*
 * The iso packet format allows for an immediate header/payload part
 * stored in 'header' immediately after the packet info plus an
 * indirect payload part that is pointer to by the 'payload' field.
 * Applications can use one or the other or both to implement simple
 * low-bandwidth streaming (e.g. audio) or more advanced
 * scatter-gather streaming (e.g. assembling video frame automatically).
 */
struct fw_iso_packet {
	u16 payload_length;	/* Length of indirect payload		*/
	u32 interrupt:1;	/* Generate interrupt on this packet	*/
	u32 skip:1;		/* tx: Set to not send packet at all	*/
				/* rx: Sync bit, wait for matching sy	*/
	u32 tag:2;		/* tx: Tag in packet header		*/
	u32 sy:4;		/* tx: Sy in packet header		*/
	u32 header_length:8;	/* Size of immediate header		*/
	u32 header[];		/* tx: Top of 1394 isoch. data_block	*/
};

#define FW_ISO_CONTEXT_TRANSMIT			0
#define FW_ISO_CONTEXT_RECEIVE			1
#define FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL	2

#define FW_ISO_CONTEXT_MATCH_TAG0	 1
#define FW_ISO_CONTEXT_MATCH_TAG1	 2
#define FW_ISO_CONTEXT_MATCH_TAG2	 4
#define FW_ISO_CONTEXT_MATCH_TAG3	 8
#define FW_ISO_CONTEXT_MATCH_ALL_TAGS	15

/*
 * An iso buffer is just a set of pages mapped for DMA in the
 * specified direction.  Since the pages are to be used for DMA, they
 * are not mapped into the kernel virtual address space.  We store the
 * DMA address in the page private. The helper function
 * fw_iso_buffer_map() will map the pages into a given vma.
 */
struct fw_iso_buffer {
	enum dma_data_direction direction;
	struct page **pages;
	int page_count;
	int page_count_mapped;
};

int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
		       int page_count, enum dma_data_direction direction);
void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer, struct fw_card *card);
size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed);

struct fw_iso_context;
typedef void (*fw_iso_callback_t)(struct fw_iso_context *context,
				  u32 cycle, size_t header_length,
				  void *header, void *data);
typedef void (*fw_iso_mc_callback_t)(struct fw_iso_context *context,
				     dma_addr_t completed, void *data);

union fw_iso_callback {
	fw_iso_callback_t sc;
	fw_iso_mc_callback_t mc;
};

struct fw_iso_context {
	struct fw_card *card;
	struct work_struct work;
	int type;
	int channel;
	int speed;
	bool drop_overflow_headers;
	size_t header_size;
	union fw_iso_callback callback;
	void *callback_data;
};

struct fw_iso_context *fw_iso_context_create(struct fw_card *card,
		int type, int channel, int speed, size_t header_size,
		fw_iso_callback_t callback, void *callback_data);
int fw_iso_context_set_channels(struct fw_iso_context *ctx, u64 *channels);
int fw_iso_context_queue(struct fw_iso_context *ctx,
			 struct fw_iso_packet *packet,
			 struct fw_iso_buffer *buffer,
			 unsigned long payload);
void fw_iso_context_queue_flush(struct fw_iso_context *ctx);
int fw_iso_context_flush_completions(struct fw_iso_context *ctx);

/**
 * fw_iso_context_schedule_flush_completions() - schedule work item to process isochronous context.
 * @ctx: the isochronous context
 *
 * Schedule a work item on workqueue to process the isochronous context. The registered callback
 * function is called by the worker when a queued packet buffer with the interrupt flag is
 * completed, either after transmission in the IT context or after being filled in the IR context.
 * The callback function is also called when the header buffer in the context becomes full, If it
 * is required to process the context in the current context, fw_iso_context_flush_completions() is
 * available instead.
 *
 * Context: Any context.
 */
static inline void fw_iso_context_schedule_flush_completions(struct fw_iso_context *ctx)
{
	queue_work(ctx->card->isoc_wq, &ctx->work);
}

int fw_iso_context_start(struct fw_iso_context *ctx,
			 int cycle, int sync, int tags);
int fw_iso_context_stop(struct fw_iso_context *ctx);
void fw_iso_context_destroy(struct fw_iso_context *ctx);
void fw_iso_resource_manage(struct fw_card *card, int generation,
			    u64 channels_mask, int *channel, int *bandwidth,
			    bool allocate);

extern struct workqueue_struct *fw_workqueue;

#endif /* _LINUX_FIREWIRE_H */