xref: /freebsd/sys/dev/ntb/ntb.h (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * Copyright (c) 2016 Alexander Motin <mav@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef _NTB_H_
30 #define _NTB_H_
31 
32 #include "ntb_if.h"
33 
34 extern devclass_t ntb_hw_devclass;
35 SYSCTL_DECL(_hw_ntb);
36 
37 int ntb_register_device(device_t ntb);
38 int ntb_unregister_device(device_t ntb);
39 int ntb_child_location_str(device_t dev, device_t child, char *buf,
40     size_t buflen);
41 int ntb_print_child(device_t dev, device_t child);
42 bus_dma_tag_t ntb_get_dma_tag(device_t bus, device_t child);
43 
44 /*
45  * ntb_link_event() - notify driver context of a change in link status
46  * @ntb:        NTB device context
47  *
48  * Notify the driver context that the link status may have changed.  The driver
49  * should call intb_link_is_up() to get the current status.
50  */
51 void ntb_link_event(device_t ntb);
52 
53 /*
54  * ntb_db_event() - notify driver context of a doorbell event
55  * @ntb:        NTB device context
56  * @vector:     Interrupt vector number
57  *
58  * Notify the driver context of a doorbell event.  If hardware supports
59  * multiple interrupt vectors for doorbells, the vector number indicates which
60  * vector received the interrupt.  The vector number is relative to the first
61  * vector used for doorbells, starting at zero, and must be less than
62  * ntb_db_vector_count().  The driver may call ntb_db_read() to check which
63  * doorbell bits need service, and ntb_db_vector_mask() to determine which of
64  * those bits are associated with the vector number.
65  */
66 void ntb_db_event(device_t ntb, uint32_t vec);
67 
68 /**
69  * ntb_port_number() - get the local port number
70  * @ntb:        NTB device context.
71  *
72  * Hardware driver returns local port number in compliance with topology.
73  *
74  * Return: the local port number
75  */
76 int ntb_port_number(device_t ntb);
77 
78 /**
79  * ntb_port_count() - get the number of peer device ports
80  * @ntb:        NTB device context.
81  *
82  * By default hardware driver supports just one peer device.
83  *
84  * Return: the number of peer ports
85  */
86 int ntb_peer_port_count(device_t ntb);
87 
88 /**
89  * ntb_peer_port_number() - get the peer port by given index
90  * @ntb:        NTB device context.
91  * @idx:        Peer port index (should be zero for now).
92  *
93  * By default hardware driver supports just one peer device, so this method
94  * shall return the corresponding value.
95  *
96  * Return: the peer device port or an error number
97  */
98 int ntb_peer_port_number(device_t ntb, int pidx);
99 
100 /*
101  * ntb_peer_port_idx() - get the peer device port index by given port
102  *                       number
103  * @ntb:        NTB device context.
104  * @port:       Peer port number
105  *
106  * By default hardware driver supports just one peer device, so given a
107  * valid peer port number, the return value shall be zero.
108  *
109  * Return: the peer port index or an error number
110  */
111 int ntb_peer_port_idx(device_t ntb, int port);
112 
113 /*
114  * ntb_link_is_up() - get the current ntb link state
115  * @ntb:        NTB device context
116  * @speed:      OUT - The link speed expressed as PCIe generation number
117  * @width:      OUT - The link width expressed as the number of PCIe lanes
118  *
119  * RETURNS: true or false based on the hardware link state
120  */
121 bool ntb_link_is_up(device_t ntb, enum ntb_speed *speed, enum ntb_width *width);
122 
123 /*
124  * ntb_link_enable() - enable the link on the secondary side of the ntb
125  * @ntb:        NTB device context
126  * @max_speed:  The maximum link speed expressed as PCIe generation number[0]
127  * @max_width:  The maximum link width expressed as the number of PCIe lanes[0]
128  *
129  * Enable the link on the secondary side of the ntb.  This can only be done
130  * from the primary side of the ntb in primary or b2b topology.  The ntb device
131  * should train the link to its maximum speed and width, or the requested speed
132  * and width, whichever is smaller, if supported.
133  *
134  * Return: Zero on success, otherwise an error number.
135  *
136  * [0]: Only NTB_SPEED_AUTO and NTB_WIDTH_AUTO are valid inputs; other speed
137  *      and width input will be ignored.
138  */
139 int ntb_link_enable(device_t ntb, enum ntb_speed speed, enum ntb_width width);
140 
141 /*
142  * ntb_link_disable() - disable the link on the secondary side of the ntb
143  * @ntb:        NTB device context
144  *
145  * Disable the link on the secondary side of the ntb.  This can only be done
146  * from the primary side of the ntb in primary or b2b topology.  The ntb device
147  * should disable the link.  Returning from this call must indicate that a
148  * barrier has passed, though with no more writes may pass in either direction
149  * across the link, except if this call returns an error number.
150  *
151  * Return: Zero on success, otherwise an error number.
152  */
153 int ntb_link_disable(device_t ntb);
154 
155 /*
156  * get enable status of the link on the secondary side of the ntb
157  */
158 bool ntb_link_enabled(device_t ntb);
159 
160 /*
161  * ntb_set_ctx() - associate a driver context with an ntb device
162  * @ntb:        NTB device context
163  * @ctx:        Driver context
164  * @ctx_ops:    Driver context operations
165  *
166  * Associate a driver context and operations with a ntb device.  The context is
167  * provided by the client driver, and the driver may associate a different
168  * context with each ntb device.
169  *
170  * Return: Zero if the context is associated, otherwise an error number.
171  */
172 int ntb_set_ctx(device_t ntb, void *ctx, const struct ntb_ctx_ops *ctx_ops);
173 
174 /*
175  * ntb_set_ctx() - get a driver context associated with an ntb device
176  * @ntb:        NTB device context
177  * @ctx_ops:    Driver context operations
178  *
179  * Get a driver context and operations associated with a ntb device.
180  */
181 void * ntb_get_ctx(device_t ntb, const struct ntb_ctx_ops **ctx_ops);
182 
183 /*
184  * ntb_clear_ctx() - disassociate any driver context from an ntb device
185  * @ntb:        NTB device context
186  *
187  * Clear any association that may exist between a driver context and the ntb
188  * device.
189  */
190 void ntb_clear_ctx(device_t ntb);
191 
192 /*
193  * ntb_mw_count() - Get the number of memory windows available for KPI
194  * consumers.
195  *
196  * (Excludes any MW wholly reserved for register access.)
197  */
198 uint8_t ntb_mw_count(device_t ntb);
199 
200 /*
201  * ntb_mw_get_range() - get the range of a memory window
202  * @ntb:        NTB device context
203  * @idx:        Memory window number
204  * @base:       OUT - the base address for mapping the memory window
205  * @size:       OUT - the size for mapping the memory window
206  * @align:      OUT - the base alignment for translating the memory window
207  * @align_size: OUT - the size alignment for translating the memory window
208  *
209  * Get the range of a memory window.  NULL may be given for any output
210  * parameter if the value is not needed.  The base and size may be used for
211  * mapping the memory window, to access the peer memory.  The alignment and
212  * size may be used for translating the memory window, for the peer to access
213  * memory on the local system.
214  *
215  * Return: Zero on success, otherwise an error number.
216  */
217 int ntb_mw_get_range(device_t ntb, unsigned mw_idx, vm_paddr_t *base,
218     caddr_t *vbase, size_t *size, size_t *align, size_t *align_size,
219     bus_addr_t *plimit);
220 
221 /*
222  * ntb_mw_set_trans() - set the translation of a memory window
223  * @ntb:        NTB device context
224  * @idx:        Memory window number
225  * @addr:       The dma address local memory to expose to the peer
226  * @size:       The size of the local memory to expose to the peer
227  *
228  * Set the translation of a memory window.  The peer may access local memory
229  * through the window starting at the address, up to the size.  The address
230  * must be aligned to the alignment specified by ntb_mw_get_range().  The size
231  * must be aligned to the size alignment specified by ntb_mw_get_range().  The
232  * address must be below the plimit specified by ntb_mw_get_range() (i.e. for
233  * 32-bit BARs).
234  *
235  * Return: Zero on success, otherwise an error number.
236  */
237 int ntb_mw_set_trans(device_t ntb, unsigned mw_idx, bus_addr_t addr,
238     size_t size);
239 
240 /*
241  * ntb_mw_clear_trans() - clear the translation of a memory window
242  * @ntb:	NTB device context
243  * @idx:	Memory window number
244  *
245  * Clear the translation of a memory window.  The peer may no longer access
246  * local memory through the window.
247  *
248  * Return: Zero on success, otherwise an error number.
249  */
250 int ntb_mw_clear_trans(device_t ntb, unsigned mw_idx);
251 
252 /*
253  * ntb_mw_get_wc - Get the write-combine status of a memory window
254  *
255  * Returns:  Zero on success, setting *wc; otherwise an error number (e.g. if
256  * idx is an invalid memory window).
257  *
258  * Mode is a VM_MEMATTR_* type.
259  */
260 int ntb_mw_get_wc(device_t ntb, unsigned mw_idx, vm_memattr_t *mode);
261 
262 /*
263  * ntb_mw_set_wc - Set the write-combine status of a memory window
264  *
265  * If 'mode' matches the current status, this does nothing and succeeds.  Mode
266  * is a VM_MEMATTR_* type.
267  *
268  * Returns:  Zero on success, setting the caching attribute on the virtual
269  * mapping of the BAR; otherwise an error number (e.g. if idx is an invalid
270  * memory window, or if changing the caching attribute fails).
271  */
272 int ntb_mw_set_wc(device_t ntb, unsigned mw_idx, vm_memattr_t mode);
273 
274 /*
275  * ntb_spad_count() - get the total scratch regs usable
276  * @ntb: pointer to ntb_softc instance
277  *
278  * This function returns the max 32bit scratchpad registers usable by the
279  * upper layer.
280  *
281  * RETURNS: total number of scratch pad registers available
282  */
283 uint8_t ntb_spad_count(device_t ntb);
284 
285 /*
286  * ntb_get_max_spads() - zero local scratch registers
287  * @ntb: pointer to ntb_softc instance
288  *
289  * This functions overwrites all local scratchpad registers with zeroes.
290  */
291 void ntb_spad_clear(device_t ntb);
292 
293 /*
294  * ntb_spad_write() - write to the secondary scratchpad register
295  * @ntb: pointer to ntb_softc instance
296  * @idx: index to the scratchpad register, 0 based
297  * @val: the data value to put into the register
298  *
299  * This function allows writing of a 32bit value to the indexed scratchpad
300  * register. The register resides on the secondary (external) side.
301  *
302  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
303  */
304 int ntb_spad_write(device_t ntb, unsigned int idx, uint32_t val);
305 
306 /*
307  * ntb_spad_read() - read from the primary scratchpad register
308  * @ntb: pointer to ntb_softc instance
309  * @idx: index to scratchpad register, 0 based
310  * @val: pointer to 32bit integer for storing the register value
311  *
312  * This function allows reading of the 32bit scratchpad register on
313  * the primary (internal) side.
314  *
315  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
316  */
317 int ntb_spad_read(device_t ntb, unsigned int idx, uint32_t *val);
318 
319 /*
320  * ntb_peer_spad_write() - write to the secondary scratchpad register
321  * @ntb: pointer to ntb_softc instance
322  * @idx: index to the scratchpad register, 0 based
323  * @val: the data value to put into the register
324  *
325  * This function allows writing of a 32bit value to the indexed scratchpad
326  * register. The register resides on the secondary (external) side.
327  *
328  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
329  */
330 int ntb_peer_spad_write(device_t ntb, unsigned int idx, uint32_t val);
331 
332 /*
333  * ntb_peer_spad_read() - read from the primary scratchpad register
334  * @ntb: pointer to ntb_softc instance
335  * @idx: index to scratchpad register, 0 based
336  * @val: pointer to 32bit integer for storing the register value
337  *
338  * This function allows reading of the 32bit scratchpad register on
339  * the primary (internal) side.
340  *
341  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
342  */
343 int ntb_peer_spad_read(device_t ntb, unsigned int idx, uint32_t *val);
344 
345 /*
346  * ntb_db_valid_mask() - get a mask of doorbell bits supported by the ntb
347  * @ntb:	NTB device context
348  *
349  * Hardware may support different number or arrangement of doorbell bits.
350  *
351  * Return: A mask of doorbell bits supported by the ntb.
352  */
353 uint64_t ntb_db_valid_mask(device_t ntb);
354 
355 /*
356  * ntb_db_vector_count() - get the number of doorbell interrupt vectors
357  * @ntb:	NTB device context.
358  *
359  * Hardware may support different number of interrupt vectors.
360  *
361  * Return: The number of doorbell interrupt vectors.
362  */
363 int ntb_db_vector_count(device_t ntb);
364 
365 /*
366  * ntb_db_vector_mask() - get a mask of doorbell bits serviced by a vector
367  * @ntb:	NTB device context
368  * @vector:	Doorbell vector number
369  *
370  * Each interrupt vector may have a different number or arrangement of bits.
371  *
372  * Return: A mask of doorbell bits serviced by a vector.
373  */
374 uint64_t ntb_db_vector_mask(device_t ntb, uint32_t vector);
375 
376 /*
377  * ntb_peer_db_addr() - address and size of the peer doorbell register
378  * @ntb:	NTB device context.
379  * @db_addr:	OUT - The address of the peer doorbell register.
380  * @db_size:	OUT - The number of bytes to write the peer doorbell register.
381  *
382  * Return the address of the peer doorbell register.  This may be used, for
383  * example, by drivers that offload memory copy operations to a dma engine.
384  * The drivers may wish to ring the peer doorbell at the completion of memory
385  * copy operations.  For efficiency, and to simplify ordering of operations
386  * between the dma memory copies and the ringing doorbell, the driver may
387  * append one additional dma memory copy with the doorbell register as the
388  * destination, after the memory copy operations.
389  *
390  * Return: Zero on success, otherwise an error number.
391  *
392  * Note that writing the peer doorbell via a memory window will *not* generate
393  * an interrupt on the remote host; that must be done separately.
394  */
395 int ntb_peer_db_addr(device_t ntb, bus_addr_t *db_addr, vm_size_t *db_size);
396 
397 /*
398  * ntb_db_clear() - clear bits in the local doorbell register
399  * @ntb:	NTB device context.
400  * @db_bits:	Doorbell bits to clear.
401  *
402  * Clear bits in the local doorbell register, arming the bits for the next
403  * doorbell.
404  *
405  * Return: Zero on success, otherwise an error number.
406  */
407 void ntb_db_clear(device_t ntb, uint64_t bits);
408 
409 /*
410  * ntb_db_clear_mask() - clear bits in the local doorbell mask
411  * @ntb:	NTB device context.
412  * @db_bits:	Doorbell bits to clear.
413  *
414  * Clear bits in the local doorbell mask register, allowing doorbell interrupts
415  * from being generated for those doorbell bits.  If a doorbell bit is already
416  * set at the time the mask is cleared, and the corresponding mask bit is
417  * changed from set to clear, then the ntb driver must ensure that
418  * ntb_db_event() is called.  If the hardware does not generate the interrupt
419  * on clearing the mask bit, then the driver must call ntb_db_event() anyway.
420  *
421  * Return: Zero on success, otherwise an error number.
422  */
423 void ntb_db_clear_mask(device_t ntb, uint64_t bits);
424 
425 /*
426  * ntb_db_read() - read the local doorbell register
427  * @ntb:	NTB device context.
428  *
429  * Read the local doorbell register, and return the bits that are set.
430  *
431  * Return: The bits currently set in the local doorbell register.
432  */
433 uint64_t ntb_db_read(device_t ntb);
434 
435 /*
436  * ntb_db_set_mask() - set bits in the local doorbell mask
437  * @ntb:	NTB device context.
438  * @db_bits:	Doorbell mask bits to set.
439  *
440  * Set bits in the local doorbell mask register, preventing doorbell interrupts
441  * from being generated for those doorbell bits.  Bits that were already set
442  * must remain set.
443  *
444  * Return: Zero on success, otherwise an error number.
445  */
446 void ntb_db_set_mask(device_t ntb, uint64_t bits);
447 
448 /*
449  * ntb_peer_db_set() - Set the doorbell on the secondary/external side
450  * @ntb: pointer to ntb_softc instance
451  * @bit: doorbell bits to ring
452  *
453  * This function allows triggering of a doorbell on the secondary/external
454  * side that will initiate an interrupt on the remote host
455  */
456 void ntb_peer_db_set(device_t ntb, uint64_t bits);
457 
458 #endif /* _NTB_H_ */
459