xref: /freebsd/sys/dev/ntb/ntb.h (revision f7c32ed617858bcd22f8d1b03199099d50125721)
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(device_t dev, device_t child, struct sbuf *sb);
40 int ntb_print_child(device_t dev, device_t child);
41 bus_dma_tag_t ntb_get_dma_tag(device_t bus, device_t child);
42 
43 /*
44  * ntb_link_event() - notify driver context of a change in link status
45  * @ntb:        NTB device context
46  *
47  * Notify the driver context that the link status may have changed.  The driver
48  * should call intb_link_is_up() to get the current status.
49  */
50 void ntb_link_event(device_t ntb);
51 
52 /*
53  * ntb_db_event() - notify driver context of a doorbell event
54  * @ntb:        NTB device context
55  * @vector:     Interrupt vector number
56  *
57  * Notify the driver context of a doorbell event.  If hardware supports
58  * multiple interrupt vectors for doorbells, the vector number indicates which
59  * vector received the interrupt.  The vector number is relative to the first
60  * vector used for doorbells, starting at zero, and must be less than
61  * ntb_db_vector_count().  The driver may call ntb_db_read() to check which
62  * doorbell bits need service, and ntb_db_vector_mask() to determine which of
63  * those bits are associated with the vector number.
64  */
65 void ntb_db_event(device_t ntb, uint32_t vec);
66 
67 /**
68  * ntb_port_number() - get the local port number
69  * @ntb:        NTB device context.
70  *
71  * Hardware driver returns local port number in compliance with topology.
72  *
73  * Return: the local port number
74  */
75 int ntb_port_number(device_t ntb);
76 
77 /**
78  * ntb_port_count() - get the number of peer device ports
79  * @ntb:        NTB device context.
80  *
81  * By default hardware driver supports just one peer device.
82  *
83  * Return: the number of peer ports
84  */
85 int ntb_peer_port_count(device_t ntb);
86 
87 /**
88  * ntb_peer_port_number() - get the peer port by given index
89  * @ntb:        NTB device context.
90  * @idx:        Peer port index (should be zero for now).
91  *
92  * By default hardware driver supports just one peer device, so this method
93  * shall return the corresponding value.
94  *
95  * Return: the peer device port or an error number
96  */
97 int ntb_peer_port_number(device_t ntb, int pidx);
98 
99 /*
100  * ntb_peer_port_idx() - get the peer device port index by given port
101  *                       number
102  * @ntb:        NTB device context.
103  * @port:       Peer port number
104  *
105  * By default hardware driver supports just one peer device, so given a
106  * valid peer port number, the return value shall be zero.
107  *
108  * Return: the peer port index or an error number
109  */
110 int ntb_peer_port_idx(device_t ntb, int port);
111 
112 /*
113  * ntb_link_is_up() - get the current ntb link state
114  * @ntb:        NTB device context
115  * @speed:      OUT - The link speed expressed as PCIe generation number
116  * @width:      OUT - The link width expressed as the number of PCIe lanes
117  *
118  * RETURNS: true or false based on the hardware link state
119  */
120 bool ntb_link_is_up(device_t ntb, enum ntb_speed *speed, enum ntb_width *width);
121 
122 /*
123  * ntb_link_enable() - enable the link on the secondary side of the ntb
124  * @ntb:        NTB device context
125  * @max_speed:  The maximum link speed expressed as PCIe generation number[0]
126  * @max_width:  The maximum link width expressed as the number of PCIe lanes[0]
127  *
128  * Enable the link on the secondary side of the ntb.  This can only be done
129  * from the primary side of the ntb in primary or b2b topology.  The ntb device
130  * should train the link to its maximum speed and width, or the requested speed
131  * and width, whichever is smaller, if supported.
132  *
133  * Return: Zero on success, otherwise an error number.
134  *
135  * [0]: Only NTB_SPEED_AUTO and NTB_WIDTH_AUTO are valid inputs; other speed
136  *      and width input will be ignored.
137  */
138 int ntb_link_enable(device_t ntb, enum ntb_speed speed, enum ntb_width width);
139 
140 /*
141  * ntb_link_disable() - disable the link on the secondary side of the ntb
142  * @ntb:        NTB device context
143  *
144  * Disable the link on the secondary side of the ntb.  This can only be done
145  * from the primary side of the ntb in primary or b2b topology.  The ntb device
146  * should disable the link.  Returning from this call must indicate that a
147  * barrier has passed, though with no more writes may pass in either direction
148  * across the link, except if this call returns an error number.
149  *
150  * Return: Zero on success, otherwise an error number.
151  */
152 int ntb_link_disable(device_t ntb);
153 
154 /*
155  * get enable status of the link on the secondary side of the ntb
156  */
157 bool ntb_link_enabled(device_t ntb);
158 
159 /*
160  * ntb_set_ctx() - associate a driver context with an ntb device
161  * @ntb:        NTB device context
162  * @ctx:        Driver context
163  * @ctx_ops:    Driver context operations
164  *
165  * Associate a driver context and operations with a ntb device.  The context is
166  * provided by the client driver, and the driver may associate a different
167  * context with each ntb device.
168  *
169  * Return: Zero if the context is associated, otherwise an error number.
170  */
171 int ntb_set_ctx(device_t ntb, void *ctx, const struct ntb_ctx_ops *ctx_ops);
172 
173 /*
174  * ntb_set_ctx() - get a driver context associated with an ntb device
175  * @ntb:        NTB device context
176  * @ctx_ops:    Driver context operations
177  *
178  * Get a driver context and operations associated with a ntb device.
179  */
180 void * ntb_get_ctx(device_t ntb, const struct ntb_ctx_ops **ctx_ops);
181 
182 /*
183  * ntb_clear_ctx() - disassociate any driver context from an ntb device
184  * @ntb:        NTB device context
185  *
186  * Clear any association that may exist between a driver context and the ntb
187  * device.
188  */
189 void ntb_clear_ctx(device_t ntb);
190 
191 /*
192  * ntb_mw_count() - Get the number of memory windows available for KPI
193  * consumers.
194  *
195  * (Excludes any MW wholly reserved for register access.)
196  */
197 uint8_t ntb_mw_count(device_t ntb);
198 
199 /*
200  * ntb_mw_get_range() - get the range of a memory window
201  * @ntb:        NTB device context
202  * @idx:        Memory window number
203  * @base:       OUT - the base address for mapping the memory window
204  * @size:       OUT - the size for mapping the memory window
205  * @align:      OUT - the base alignment for translating the memory window
206  * @align_size: OUT - the size alignment for translating the memory window
207  *
208  * Get the range of a memory window.  NULL may be given for any output
209  * parameter if the value is not needed.  The base and size may be used for
210  * mapping the memory window, to access the peer memory.  The alignment and
211  * size may be used for translating the memory window, for the peer to access
212  * memory on the local system.
213  *
214  * Return: Zero on success, otherwise an error number.
215  */
216 int ntb_mw_get_range(device_t ntb, unsigned mw_idx, vm_paddr_t *base,
217     caddr_t *vbase, size_t *size, size_t *align, size_t *align_size,
218     bus_addr_t *plimit);
219 
220 /*
221  * ntb_mw_set_trans() - set the translation of a memory window
222  * @ntb:        NTB device context
223  * @idx:        Memory window number
224  * @addr:       The dma address local memory to expose to the peer
225  * @size:       The size of the local memory to expose to the peer
226  *
227  * Set the translation of a memory window.  The peer may access local memory
228  * through the window starting at the address, up to the size.  The address
229  * must be aligned to the alignment specified by ntb_mw_get_range().  The size
230  * must be aligned to the size alignment specified by ntb_mw_get_range().  The
231  * address must be below the plimit specified by ntb_mw_get_range() (i.e. for
232  * 32-bit BARs).
233  *
234  * Return: Zero on success, otherwise an error number.
235  */
236 int ntb_mw_set_trans(device_t ntb, unsigned mw_idx, bus_addr_t addr,
237     size_t size);
238 
239 /*
240  * ntb_mw_clear_trans() - clear the translation of a memory window
241  * @ntb:	NTB device context
242  * @idx:	Memory window number
243  *
244  * Clear the translation of a memory window.  The peer may no longer access
245  * local memory through the window.
246  *
247  * Return: Zero on success, otherwise an error number.
248  */
249 int ntb_mw_clear_trans(device_t ntb, unsigned mw_idx);
250 
251 /*
252  * ntb_mw_get_wc - Get the write-combine status of a memory window
253  *
254  * Returns:  Zero on success, setting *wc; otherwise an error number (e.g. if
255  * idx is an invalid memory window).
256  *
257  * Mode is a VM_MEMATTR_* type.
258  */
259 int ntb_mw_get_wc(device_t ntb, unsigned mw_idx, vm_memattr_t *mode);
260 
261 /*
262  * ntb_mw_set_wc - Set the write-combine status of a memory window
263  *
264  * If 'mode' matches the current status, this does nothing and succeeds.  Mode
265  * is a VM_MEMATTR_* type.
266  *
267  * Returns:  Zero on success, setting the caching attribute on the virtual
268  * mapping of the BAR; otherwise an error number (e.g. if idx is an invalid
269  * memory window, or if changing the caching attribute fails).
270  */
271 int ntb_mw_set_wc(device_t ntb, unsigned mw_idx, vm_memattr_t mode);
272 
273 /*
274  * ntb_spad_count() - get the total scratch regs usable
275  * @ntb: pointer to ntb_softc instance
276  *
277  * This function returns the max 32bit scratchpad registers usable by the
278  * upper layer.
279  *
280  * RETURNS: total number of scratch pad registers available
281  */
282 uint8_t ntb_spad_count(device_t ntb);
283 
284 /*
285  * ntb_get_max_spads() - zero local scratch registers
286  * @ntb: pointer to ntb_softc instance
287  *
288  * This functions overwrites all local scratchpad registers with zeroes.
289  */
290 void ntb_spad_clear(device_t ntb);
291 
292 /*
293  * ntb_spad_write() - write to the secondary scratchpad register
294  * @ntb: pointer to ntb_softc instance
295  * @idx: index to the scratchpad register, 0 based
296  * @val: the data value to put into the register
297  *
298  * This function allows writing of a 32bit value to the indexed scratchpad
299  * register. The register resides on the secondary (external) side.
300  *
301  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
302  */
303 int ntb_spad_write(device_t ntb, unsigned int idx, uint32_t val);
304 
305 /*
306  * ntb_spad_read() - read from the primary scratchpad register
307  * @ntb: pointer to ntb_softc instance
308  * @idx: index to scratchpad register, 0 based
309  * @val: pointer to 32bit integer for storing the register value
310  *
311  * This function allows reading of the 32bit scratchpad register on
312  * the primary (internal) side.
313  *
314  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
315  */
316 int ntb_spad_read(device_t ntb, unsigned int idx, uint32_t *val);
317 
318 /*
319  * ntb_peer_spad_write() - write to the secondary scratchpad register
320  * @ntb: pointer to ntb_softc instance
321  * @idx: index to the scratchpad register, 0 based
322  * @val: the data value to put into the register
323  *
324  * This function allows writing of a 32bit value to the indexed scratchpad
325  * register. The register resides on the secondary (external) side.
326  *
327  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
328  */
329 int ntb_peer_spad_write(device_t ntb, unsigned int idx, uint32_t val);
330 
331 /*
332  * ntb_peer_spad_read() - read from the primary scratchpad register
333  * @ntb: pointer to ntb_softc instance
334  * @idx: index to scratchpad register, 0 based
335  * @val: pointer to 32bit integer for storing the register value
336  *
337  * This function allows reading of the 32bit scratchpad register on
338  * the primary (internal) side.
339  *
340  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
341  */
342 int ntb_peer_spad_read(device_t ntb, unsigned int idx, uint32_t *val);
343 
344 /*
345  * ntb_db_valid_mask() - get a mask of doorbell bits supported by the ntb
346  * @ntb:	NTB device context
347  *
348  * Hardware may support different number or arrangement of doorbell bits.
349  *
350  * Return: A mask of doorbell bits supported by the ntb.
351  */
352 uint64_t ntb_db_valid_mask(device_t ntb);
353 
354 /*
355  * ntb_db_vector_count() - get the number of doorbell interrupt vectors
356  * @ntb:	NTB device context.
357  *
358  * Hardware may support different number of interrupt vectors.
359  *
360  * Return: The number of doorbell interrupt vectors.
361  */
362 int ntb_db_vector_count(device_t ntb);
363 
364 /*
365  * ntb_db_vector_mask() - get a mask of doorbell bits serviced by a vector
366  * @ntb:	NTB device context
367  * @vector:	Doorbell vector number
368  *
369  * Each interrupt vector may have a different number or arrangement of bits.
370  *
371  * Return: A mask of doorbell bits serviced by a vector.
372  */
373 uint64_t ntb_db_vector_mask(device_t ntb, uint32_t vector);
374 
375 /*
376  * ntb_peer_db_addr() - address and size of the peer doorbell register
377  * @ntb:	NTB device context.
378  * @db_addr:	OUT - The address of the peer doorbell register.
379  * @db_size:	OUT - The number of bytes to write the peer doorbell register.
380  *
381  * Return the address of the peer doorbell register.  This may be used, for
382  * example, by drivers that offload memory copy operations to a dma engine.
383  * The drivers may wish to ring the peer doorbell at the completion of memory
384  * copy operations.  For efficiency, and to simplify ordering of operations
385  * between the dma memory copies and the ringing doorbell, the driver may
386  * append one additional dma memory copy with the doorbell register as the
387  * destination, after the memory copy operations.
388  *
389  * Return: Zero on success, otherwise an error number.
390  *
391  * Note that writing the peer doorbell via a memory window will *not* generate
392  * an interrupt on the remote host; that must be done separately.
393  */
394 int ntb_peer_db_addr(device_t ntb, bus_addr_t *db_addr, vm_size_t *db_size);
395 
396 /*
397  * ntb_db_clear() - clear bits in the local doorbell register
398  * @ntb:	NTB device context.
399  * @db_bits:	Doorbell bits to clear.
400  *
401  * Clear bits in the local doorbell register, arming the bits for the next
402  * doorbell.
403  *
404  * Return: Zero on success, otherwise an error number.
405  */
406 void ntb_db_clear(device_t ntb, uint64_t bits);
407 
408 /*
409  * ntb_db_clear_mask() - clear bits in the local doorbell mask
410  * @ntb:	NTB device context.
411  * @db_bits:	Doorbell bits to clear.
412  *
413  * Clear bits in the local doorbell mask register, allowing doorbell interrupts
414  * from being generated for those doorbell bits.  If a doorbell bit is already
415  * set at the time the mask is cleared, and the corresponding mask bit is
416  * changed from set to clear, then the ntb driver must ensure that
417  * ntb_db_event() is called.  If the hardware does not generate the interrupt
418  * on clearing the mask bit, then the driver must call ntb_db_event() anyway.
419  *
420  * Return: Zero on success, otherwise an error number.
421  */
422 void ntb_db_clear_mask(device_t ntb, uint64_t bits);
423 
424 /*
425  * ntb_db_read() - read the local doorbell register
426  * @ntb:	NTB device context.
427  *
428  * Read the local doorbell register, and return the bits that are set.
429  *
430  * Return: The bits currently set in the local doorbell register.
431  */
432 uint64_t ntb_db_read(device_t ntb);
433 
434 /*
435  * ntb_db_set_mask() - set bits in the local doorbell mask
436  * @ntb:	NTB device context.
437  * @db_bits:	Doorbell mask bits to set.
438  *
439  * Set bits in the local doorbell mask register, preventing doorbell interrupts
440  * from being generated for those doorbell bits.  Bits that were already set
441  * must remain set.
442  *
443  * Return: Zero on success, otherwise an error number.
444  */
445 void ntb_db_set_mask(device_t ntb, uint64_t bits);
446 
447 /*
448  * ntb_peer_db_set() - Set the doorbell on the secondary/external side
449  * @ntb: pointer to ntb_softc instance
450  * @bit: doorbell bits to ring
451  *
452  * This function allows triggering of a doorbell on the secondary/external
453  * side that will initiate an interrupt on the remote host
454  */
455 void ntb_peer_db_set(device_t ntb, uint64_t bits);
456 
457 #endif /* _NTB_H_ */
458