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alistair23-linux/drivers/firewire/core.h
Stefan Richter 02d37bed18 firewire: core: integrate software-forced bus resets with bus management 
Bus resets which are triggered
  - by the kernel drivers after updates of the local nodes' config ROM,
  - by userspace software via ioctl
shall be deferred until after >=2 seconds after the last bus reset.

If multiple modifications of the local nodes' config ROM happen in a row,
only a single bus reset should happen after them.

When the local node's link goes from inactive to active or vice versa,
and at the two occasions of bus resets mentioned above --- and if the
current gap count differs from 63 --- the bus reset should be preceded
by a PHY configuration packet that reaffirms the gap count.  Otherwise a
bus manager would have to reset the bus again right after that.

This is necessary to promote bus stability, e.g. leave grace periods for
allocations and reallocations of isochronous channels and bandwidth,
SBP-2 reconnections etc.; see IEEE 1394 clause 8.2.1.

This change implements all of the above by moving bus reset initiation
into a delayed work (except for bus resets which are triggered by the
bus manager workqueue job and are performed there immediately).  It
comes with a necessary addition to the card driver methods that allows
to get the current gap count from PHY registers.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-07-13 09:58:27 +02:00

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#ifndef _FIREWIRE_CORE_H
#define _FIREWIRE_CORE_H
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/idr.h>
#include <linux/mm_types.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <asm/atomic.h>
struct device;
struct fw_card;
struct fw_device;
struct fw_iso_buffer;
struct fw_iso_context;
struct fw_iso_packet;
struct fw_node;
struct fw_packet;
/* -card */
/* bitfields within the PHY registers */
#define PHY_LINK_ACTIVE 0x80
#define PHY_CONTENDER 0x40
#define PHY_BUS_RESET 0x40
#define PHY_EXTENDED_REGISTERS 0xe0
#define PHY_BUS_SHORT_RESET 0x40
#define PHY_INT_STATUS_BITS 0x3c
#define PHY_ENABLE_ACCEL 0x02
#define PHY_ENABLE_MULTI 0x01
#define PHY_PAGE_SELECT 0xe0
#define BANDWIDTH_AVAILABLE_INITIAL 4915
#define BROADCAST_CHANNEL_INITIAL (1 << 31 | 31)
#define BROADCAST_CHANNEL_VALID (1 << 30)
#define CSR_STATE_BIT_CMSTR (1 << 8)
#define CSR_STATE_BIT_ABDICATE (1 << 10)
struct fw_card_driver {
/*
* Enable the given card with the given initial config rom.
* This function is expected to activate the card, and either
* enable the PHY or set the link_on bit and initiate a bus
* reset.
*/
int (*enable)(struct fw_card *card,
const __be32 *config_rom, size_t length);
int (*read_phy_reg)(struct fw_card *card, int address);
int (*update_phy_reg)(struct fw_card *card, int address,
int clear_bits, int set_bits);
/*
* Update the config rom for an enabled card. This function
* should change the config rom that is presented on the bus
* and initiate a bus reset.
*/
int (*set_config_rom)(struct fw_card *card,
const __be32 *config_rom, size_t length);
void (*send_request)(struct fw_card *card, struct fw_packet *packet);
void (*send_response)(struct fw_card *card, struct fw_packet *packet);
/* Calling cancel is valid once a packet has been submitted. */
int (*cancel_packet)(struct fw_card *card, struct fw_packet *packet);
/*
* Allow the specified node ID to do direct DMA out and in of
* host memory. The card will disable this for all node when
* a bus reset happens, so driver need to reenable this after
* bus reset. Returns 0 on success, -ENODEV if the card
* doesn't support this, -ESTALE if the generation doesn't
* match.
*/
int (*enable_phys_dma)(struct fw_card *card,
int node_id, int generation);
u32 (*read_csr)(struct fw_card *card, int csr_offset);
void (*write_csr)(struct fw_card *card, int csr_offset, u32 value);
struct fw_iso_context *
(*allocate_iso_context)(struct fw_card *card,
int type, int channel, size_t header_size);
void (*free_iso_context)(struct fw_iso_context *ctx);
int (*start_iso)(struct fw_iso_context *ctx,
s32 cycle, u32 sync, u32 tags);
int (*queue_iso)(struct fw_iso_context *ctx,
struct fw_iso_packet *packet,
struct fw_iso_buffer *buffer,
unsigned long payload);
int (*stop_iso)(struct fw_iso_context *ctx);
};
void fw_card_initialize(struct fw_card *card,
const struct fw_card_driver *driver, struct device *device);
int fw_card_add(struct fw_card *card,
u32 max_receive, u32 link_speed, u64 guid);
void fw_core_remove_card(struct fw_card *card);
int fw_compute_block_crc(__be32 *block);
void fw_schedule_bus_reset(struct fw_card *card, bool delayed, bool short_reset);
void fw_schedule_bm_work(struct fw_card *card, unsigned long delay);
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);
}
/* -cdev */
extern const struct file_operations fw_device_ops;
void fw_device_cdev_update(struct fw_device *device);
void fw_device_cdev_remove(struct fw_device *device);
/* -device */
extern struct rw_semaphore fw_device_rwsem;
extern struct idr fw_device_idr;
extern int fw_cdev_major;
struct fw_device *fw_device_get_by_devt(dev_t devt);
int fw_device_set_broadcast_channel(struct device *dev, void *gen);
void fw_node_event(struct fw_card *card, struct fw_node *node, int event);
/* -iso */
int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma);
void fw_iso_resource_manage(struct fw_card *card, int generation,
u64 channels_mask, int *channel, int *bandwidth,
bool allocate, __be32 buffer[2]);
/* -topology */
enum {
FW_NODE_CREATED,
FW_NODE_UPDATED,
FW_NODE_DESTROYED,
FW_NODE_LINK_ON,
FW_NODE_LINK_OFF,
FW_NODE_INITIATED_RESET,
};
struct fw_node {
u16 node_id;
u8 color;
u8 port_count;
u8 link_on:1;
u8 initiated_reset:1;
u8 b_path:1;
u8 phy_speed:2; /* As in the self ID packet. */
u8 max_speed:2; /* Minimum of all phy-speeds on the path from the
* local node to this node. */
u8 max_depth:4; /* Maximum depth to any leaf node */
u8 max_hops:4; /* Max hops in this sub tree */
atomic_t ref_count;
/* For serializing node topology into a list. */
struct list_head link;
/* Upper layer specific data. */
void *data;
struct fw_node *ports[0];
};
static inline struct fw_node *fw_node_get(struct fw_node *node)
{
atomic_inc(&node->ref_count);
return node;
}
static inline void fw_node_put(struct fw_node *node)
{
if (atomic_dec_and_test(&node->ref_count))
kfree(node);
}
void fw_core_handle_bus_reset(struct fw_card *card, int node_id,
int generation, int self_id_count, u32 *self_ids, bool bm_abdicate);
void fw_destroy_nodes(struct fw_card *card);
/*
* Check whether new_generation is the immediate successor of old_generation.
* Take counter roll-over at 255 (as per OHCI) into account.
*/
static inline bool is_next_generation(int new_generation, int old_generation)
{
return (new_generation & 0xff) == ((old_generation + 1) & 0xff);
}
/* -transaction */
#define TCODE_IS_READ_REQUEST(tcode) (((tcode) & ~1) == 4)
#define TCODE_IS_BLOCK_PACKET(tcode) (((tcode) & 1) != 0)
#define TCODE_IS_REQUEST(tcode) (((tcode) & 2) == 0)
#define TCODE_IS_RESPONSE(tcode) (((tcode) & 2) != 0)
#define TCODE_HAS_REQUEST_DATA(tcode) (((tcode) & 12) != 4)
#define TCODE_HAS_RESPONSE_DATA(tcode) (((tcode) & 12) != 0)
#define LOCAL_BUS 0xffc0
void fw_core_handle_request(struct fw_card *card, struct fw_packet *request);
void fw_core_handle_response(struct fw_card *card, struct fw_packet *packet);
int fw_get_response_length(struct fw_request *request);
void fw_fill_response(struct fw_packet *response, u32 *request_header,
int rcode, void *payload, size_t length);
#define FW_PHY_CONFIG_NO_NODE_ID -1
#define FW_PHY_CONFIG_CURRENT_GAP_COUNT -1
void fw_send_phy_config(struct fw_card *card,
int node_id, int generation, int gap_count);
#endif /* _FIREWIRE_CORE_H */
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