1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
/*
* IEEE 1394 for Linux
*
* kernel ISO transmission/reception
*
* Copyright (C) 2002 Maas Digital LLC
*
* This code is licensed under the GPL. See the file COPYING in the root
* directory of the kernel sources for details.
*/
#ifndef IEEE1394_ISO_H
#define IEEE1394_ISO_H
#include "hosts.h"
#include "dma.h"
/* high-level ISO interface */
/* This API sends and receives isochronous packets on a large,
virtually-contiguous kernel memory buffer. The buffer may be mapped
into a user-space process for zero-copy transmission and reception.
There are no explicit boundaries between packets in the buffer. A
packet may be transmitted or received at any location. However,
low-level drivers may impose certain restrictions on alignment or
size of packets. (e.g. in OHCI no packet may cross a page boundary,
and packets should be quadlet-aligned)
*/
/* Packet descriptor - the API maintains a ring buffer of these packet
descriptors in kernel memory (hpsb_iso.infos[]). */
struct hpsb_iso_packet_info {
/* offset of data payload relative to the first byte of the buffer */
__u32 offset;
/* length of the data payload, in bytes (not including the isochronous header) */
__u16 len;
/* (recv only) the cycle number (mod 8000) on which the packet was received */
__u16 cycle;
/* (recv only) channel on which the packet was received */
__u8 channel;
/* 2-bit 'tag' and 4-bit 'sy' fields of the isochronous header */
__u8 tag;
__u8 sy;
};
enum hpsb_iso_type { HPSB_ISO_RECV = 0, HPSB_ISO_XMIT = 1 };
/* The mode of the dma when receiving iso data. Must be supported by chip */
enum raw1394_iso_dma_recv_mode {
HPSB_ISO_DMA_DEFAULT = -1,
HPSB_ISO_DMA_OLD_ABI = 0,
HPSB_ISO_DMA_BUFFERFILL = 1,
HPSB_ISO_DMA_PACKET_PER_BUFFER = 2
};
struct hpsb_iso {
enum hpsb_iso_type type;
/* pointer to low-level driver and its private data */
struct hpsb_host *host;
void *hostdata;
/* a function to be called (from interrupt context) after
outgoing packets have been sent, or incoming packets have
arrived */
void (*callback)(struct hpsb_iso*);
/* wait for buffer space */
wait_queue_head_t waitq;
int speed; /* IEEE1394_SPEED_100, 200, or 400 */
int channel; /* -1 if multichannel */
int dma_mode; /* dma receive mode */
/* greatest # of packets between interrupts - controls
the maximum latency of the buffer */
int irq_interval;
/* the buffer for packet data payloads */
struct dma_region data_buf;
/* size of data_buf, in bytes (always a multiple of PAGE_SIZE) */
unsigned int buf_size;
/* # of packets in the ringbuffer */
unsigned int buf_packets;
/* protects packet cursors */
spinlock_t lock;
/* the index of the next packet that will be produced
or consumed by the user */
int first_packet;
/* the index of the next packet that will be transmitted
or received by the 1394 hardware */
int pkt_dma;
/* how many packets, starting at first_packet:
(transmit) are ready to be filled with data
(receive) contain received data */
int n_ready_packets;
/* how many times the buffer has overflowed or underflowed */
atomic_t overflows;
/* private flags to track initialization progress */
#define HPSB_ISO_DRIVER_INIT (1<<0)
#define HPSB_ISO_DRIVER_STARTED (1<<1)
unsigned int flags;
/* # of packets left to prebuffer (xmit only) */
int prebuffer;
/* starting cycle for DMA (xmit only) */
int start_cycle;
/* cycle at which next packet will be transmitted,
-1 if not known */
int xmit_cycle;
/* ringbuffer of packet descriptors in regular kernel memory
* XXX Keep this last, since we use over-allocated memory from
* this entry to fill this field. */
struct hpsb_iso_packet_info *infos;
};
/* functions available to high-level drivers (e.g. raw1394) */
/* allocate the buffer and DMA context */
struct hpsb_iso* hpsb_iso_xmit_init(struct hpsb_host *host,
unsigned int data_buf_size,
unsigned int buf_packets,
int channel,
int speed,
int irq_interval,
void (*callback)(struct hpsb_iso*));
/* note: if channel = -1, multi-channel receive is enabled */
struct hpsb_iso* hpsb_iso_recv_init(struct hpsb_host *host,
unsigned int data_buf_size,
unsigned int buf_packets,
int channel,
int dma_mode,
int irq_interval,
void (*callback)(struct hpsb_iso*));
/* multi-channel only */
int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel);
int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel);
int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask);
/* start/stop DMA */
int hpsb_iso_xmit_start(struct hpsb_iso *iso, int start_on_cycle, int prebuffer);
int hpsb_iso_recv_start(struct hpsb_iso *iso, int start_on_cycle, int tag_mask, int sync);
void hpsb_iso_stop(struct hpsb_iso *iso);
/* deallocate buffer and DMA context */
void hpsb_iso_shutdown(struct hpsb_iso *iso);
/* queue a packet for transmission. 'offset' is relative to the beginning of the
DMA buffer, where the packet's data payload should already have been placed */
int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len, u8 tag, u8 sy);
/* wait until all queued packets have been transmitted to the bus */
int hpsb_iso_xmit_sync(struct hpsb_iso *iso);
/* N packets have been read out of the buffer, re-use the buffer space */
int hpsb_iso_recv_release_packets(struct hpsb_iso *recv, unsigned int n_packets);
/* check for arrival of new packets immediately (even if irq_interval
has not yet been reached) */
int hpsb_iso_recv_flush(struct hpsb_iso *iso);
/* returns # of packets ready to send or receive */
int hpsb_iso_n_ready(struct hpsb_iso *iso);
/* the following are callbacks available to low-level drivers */
/* call after a packet has been transmitted to the bus (interrupt context is OK)
'cycle' is the _exact_ cycle the packet was sent on
'error' should be non-zero if some sort of error occurred when sending the packet
*/
void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error);
/* call after a packet has been received (interrupt context OK) */
void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
u16 cycle, u8 channel, u8 tag, u8 sy);
/* call to wake waiting processes after buffer space has opened up. */
void hpsb_iso_wake(struct hpsb_iso *iso);
#endif /* IEEE1394_ISO_H */
|
