xref: /freebsd/sys/dev/ntb/ntb.h (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
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 
27 #ifndef _NTB_H_
28 #define _NTB_H_
29 
30 #include "ntb_if.h"
31 
32 SYSCTL_DECL(_hw_ntb);
33 
34 int ntb_register_device(device_t ntb);
35 int ntb_unregister_device(device_t ntb);
36 int ntb_child_location(device_t dev, device_t child, struct sbuf *sb);
37 int ntb_print_child(device_t dev, device_t child);
38 bus_dma_tag_t ntb_get_dma_tag(device_t bus, device_t child);
39 
40 /*
41  * ntb_link_event() - notify driver context of a change in link status
42  * @ntb:        NTB device context
43  *
44  * Notify the driver context that the link status may have changed.  The driver
45  * should call intb_link_is_up() to get the current status.
46  */
47 void ntb_link_event(device_t ntb);
48 
49 /*
50  * ntb_db_event() - notify driver context of a doorbell event
51  * @ntb:        NTB device context
52  * @vector:     Interrupt vector number
53  *
54  * Notify the driver context of a doorbell event.  If hardware supports
55  * multiple interrupt vectors for doorbells, the vector number indicates which
56  * vector received the interrupt.  The vector number is relative to the first
57  * vector used for doorbells, starting at zero, and must be less than
58  * ntb_db_vector_count().  The driver may call ntb_db_read() to check which
59  * doorbell bits need service, and ntb_db_vector_mask() to determine which of
60  * those bits are associated with the vector number.
61  */
62 void ntb_db_event(device_t ntb, uint32_t vec);
63 
64 /**
65  * ntb_port_number() - get the local port number
66  * @ntb:        NTB device context.
67  *
68  * Hardware driver returns local port number in compliance with topology.
69  *
70  * Return: the local port number
71  */
72 int ntb_port_number(device_t ntb);
73 
74 /**
75  * ntb_port_count() - get the number of peer device ports
76  * @ntb:        NTB device context.
77  *
78  * By default hardware driver supports just one peer device.
79  *
80  * Return: the number of peer ports
81  */
82 int ntb_peer_port_count(device_t ntb);
83 
84 /**
85  * ntb_peer_port_number() - get the peer port by given index
86  * @ntb:        NTB device context.
87  * @idx:        Peer port index (should be zero for now).
88  *
89  * By default hardware driver supports just one peer device, so this method
90  * shall return the corresponding value.
91  *
92  * Return: the peer device port or an error number
93  */
94 int ntb_peer_port_number(device_t ntb, int pidx);
95 
96 /*
97  * ntb_peer_port_idx() - get the peer device port index by given port
98  *                       number
99  * @ntb:        NTB device context.
100  * @port:       Peer port number
101  *
102  * By default hardware driver supports just one peer device, so given a
103  * valid peer port number, the return value shall be zero.
104  *
105  * Return: the peer port index or an error number
106  */
107 int ntb_peer_port_idx(device_t ntb, int port);
108 
109 /*
110  * ntb_link_is_up() - get the current ntb link state
111  * @ntb:        NTB device context
112  * @speed:      OUT - The link speed expressed as PCIe generation number
113  * @width:      OUT - The link width expressed as the number of PCIe lanes
114  *
115  * RETURNS: true or false based on the hardware link state
116  */
117 bool ntb_link_is_up(device_t ntb, enum ntb_speed *speed, enum ntb_width *width);
118 
119 /*
120  * ntb_link_enable() - enable the link on the secondary side of the ntb
121  * @ntb:        NTB device context
122  * @max_speed:  The maximum link speed expressed as PCIe generation number[0]
123  * @max_width:  The maximum link width expressed as the number of PCIe lanes[0]
124  *
125  * Enable the link on the secondary side of the ntb.  This can only be done
126  * from the primary side of the ntb in primary or b2b topology.  The ntb device
127  * should train the link to its maximum speed and width, or the requested speed
128  * and width, whichever is smaller, if supported.
129  *
130  * Return: Zero on success, otherwise an error number.
131  *
132  * [0]: Only NTB_SPEED_AUTO and NTB_WIDTH_AUTO are valid inputs; other speed
133  *      and width input will be ignored.
134  */
135 int ntb_link_enable(device_t ntb, enum ntb_speed speed, enum ntb_width width);
136 
137 /*
138  * ntb_link_disable() - disable the link on the secondary side of the ntb
139  * @ntb:        NTB device context
140  *
141  * Disable the link on the secondary side of the ntb.  This can only be done
142  * from the primary side of the ntb in primary or b2b topology.  The ntb device
143  * should disable the link.  Returning from this call must indicate that a
144  * barrier has passed, though with no more writes may pass in either direction
145  * across the link, except if this call returns an error number.
146  *
147  * Return: Zero on success, otherwise an error number.
148  */
149 int ntb_link_disable(device_t ntb);
150 
151 /*
152  * get enable status of the link on the secondary side of the ntb
153  */
154 bool ntb_link_enabled(device_t ntb);
155 
156 /*
157  * ntb_set_ctx() - associate a driver context with an ntb device
158  * @ntb:        NTB device context
159  * @ctx:        Driver context
160  * @ctx_ops:    Driver context operations
161  *
162  * Associate a driver context and operations with a ntb device.  The context is
163  * provided by the client driver, and the driver may associate a different
164  * context with each ntb device.
165  *
166  * Return: Zero if the context is associated, otherwise an error number.
167  */
168 int ntb_set_ctx(device_t ntb, void *ctx, const struct ntb_ctx_ops *ctx_ops);
169 
170 /*
171  * ntb_set_ctx() - get a driver context associated with an ntb device
172  * @ntb:        NTB device context
173  * @ctx_ops:    Driver context operations
174  *
175  * Get a driver context and operations associated with a ntb device.
176  */
177 void * ntb_get_ctx(device_t ntb, const struct ntb_ctx_ops **ctx_ops);
178 
179 /*
180  * ntb_clear_ctx() - disassociate any driver context from an ntb device
181  * @ntb:        NTB device context
182  *
183  * Clear any association that may exist between a driver context and the ntb
184  * device.
185  */
186 void ntb_clear_ctx(device_t ntb);
187 
188 /*
189  * ntb_mw_count() - Get the number of memory windows available for KPI
190  * consumers.
191  *
192  * (Excludes any MW wholly reserved for register access.)
193  */
194 uint8_t ntb_mw_count(device_t ntb);
195 
196 /*
197  * ntb_mw_get_range() - get the range of a memory window
198  * @ntb:        NTB device context
199  * @idx:        Memory window number
200  * @base:       OUT - the base address for mapping the memory window
201  * @size:       OUT - the size for mapping the memory window
202  * @align:      OUT - the base alignment for translating the memory window
203  * @align_size: OUT - the size alignment for translating the memory window
204  *
205  * Get the range of a memory window.  NULL may be given for any output
206  * parameter if the value is not needed.  The base and size may be used for
207  * mapping the memory window, to access the peer memory.  The alignment and
208  * size may be used for translating the memory window, for the peer to access
209  * memory on the local system.
210  *
211  * Return: Zero on success, otherwise an error number.
212  */
213 int ntb_mw_get_range(device_t ntb, unsigned mw_idx, vm_paddr_t *base,
214     caddr_t *vbase, size_t *size, size_t *align, size_t *align_size,
215     bus_addr_t *plimit);
216 
217 /*
218  * ntb_mw_set_trans() - set the translation of a memory window
219  * @ntb:        NTB device context
220  * @idx:        Memory window number
221  * @addr:       The dma address local memory to expose to the peer
222  * @size:       The size of the local memory to expose to the peer
223  *
224  * Set the translation of a memory window.  The peer may access local memory
225  * through the window starting at the address, up to the size.  The address
226  * must be aligned to the alignment specified by ntb_mw_get_range().  The size
227  * must be aligned to the size alignment specified by ntb_mw_get_range().  The
228  * address must be below the plimit specified by ntb_mw_get_range() (i.e. for
229  * 32-bit BARs).
230  *
231  * Return: Zero on success, otherwise an error number.
232  */
233 int ntb_mw_set_trans(device_t ntb, unsigned mw_idx, bus_addr_t addr,
234     size_t size);
235 
236 /*
237  * ntb_mw_clear_trans() - clear the translation of a memory window
238  * @ntb:	NTB device context
239  * @idx:	Memory window number
240  *
241  * Clear the translation of a memory window.  The peer may no longer access
242  * local memory through the window.
243  *
244  * Return: Zero on success, otherwise an error number.
245  */
246 int ntb_mw_clear_trans(device_t ntb, unsigned mw_idx);
247 
248 /*
249  * ntb_mw_get_wc - Get the write-combine status of a memory window
250  *
251  * Returns:  Zero on success, setting *wc; otherwise an error number (e.g. if
252  * idx is an invalid memory window).
253  *
254  * Mode is a VM_MEMATTR_* type.
255  */
256 int ntb_mw_get_wc(device_t ntb, unsigned mw_idx, vm_memattr_t *mode);
257 
258 /*
259  * ntb_mw_set_wc - Set the write-combine status of a memory window
260  *
261  * If 'mode' matches the current status, this does nothing and succeeds.  Mode
262  * is a VM_MEMATTR_* type.
263  *
264  * Returns:  Zero on success, setting the caching attribute on the virtual
265  * mapping of the BAR; otherwise an error number (e.g. if idx is an invalid
266  * memory window, or if changing the caching attribute fails).
267  */
268 int ntb_mw_set_wc(device_t ntb, unsigned mw_idx, vm_memattr_t mode);
269 
270 /*
271  * ntb_spad_count() - get the total scratch regs usable
272  * @ntb: pointer to ntb_softc instance
273  *
274  * This function returns the max 32bit scratchpad registers usable by the
275  * upper layer.
276  *
277  * RETURNS: total number of scratch pad registers available
278  */
279 uint8_t ntb_spad_count(device_t ntb);
280 
281 /*
282  * ntb_spad_clear() - zero local scratch registers
283  * @ntb: pointer to ntb_softc instance
284  *
285  * This functions overwrites all local scratchpad registers with zeroes.
286  */
287 void ntb_spad_clear(device_t ntb);
288 
289 /*
290  * ntb_spad_write() - write to the secondary scratchpad register
291  * @ntb: pointer to ntb_softc instance
292  * @idx: index to the scratchpad register, 0 based
293  * @val: the data value to put into the register
294  *
295  * This function allows writing of a 32bit value to the indexed scratchpad
296  * register. The register resides on the secondary (external) side.
297  *
298  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
299  */
300 int ntb_spad_write(device_t ntb, unsigned int idx, uint32_t val);
301 
302 /*
303  * ntb_spad_read() - read from the primary scratchpad register
304  * @ntb: pointer to ntb_softc instance
305  * @idx: index to scratchpad register, 0 based
306  * @val: pointer to 32bit integer for storing the register value
307  *
308  * This function allows reading of the 32bit scratchpad register on
309  * the primary (internal) side.
310  *
311  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
312  */
313 int ntb_spad_read(device_t ntb, unsigned int idx, uint32_t *val);
314 
315 /*
316  * ntb_peer_spad_write() - write to the secondary scratchpad register
317  * @ntb: pointer to ntb_softc instance
318  * @idx: index to the scratchpad register, 0 based
319  * @val: the data value to put into the register
320  *
321  * This function allows writing of a 32bit value to the indexed scratchpad
322  * register. The register resides on the secondary (external) side.
323  *
324  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
325  */
326 int ntb_peer_spad_write(device_t ntb, unsigned int idx, uint32_t val);
327 
328 /*
329  * ntb_peer_spad_read() - read from the primary scratchpad register
330  * @ntb: pointer to ntb_softc instance
331  * @idx: index to scratchpad register, 0 based
332  * @val: pointer to 32bit integer for storing the register value
333  *
334  * This function allows reading of the 32bit scratchpad register on
335  * the primary (internal) side.
336  *
337  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
338  */
339 int ntb_peer_spad_read(device_t ntb, unsigned int idx, uint32_t *val);
340 
341 /*
342  * ntb_db_valid_mask() - get a mask of doorbell bits supported by the ntb
343  * @ntb:	NTB device context
344  *
345  * Hardware may support different number or arrangement of doorbell bits.
346  *
347  * Return: A mask of doorbell bits supported by the ntb.
348  */
349 uint64_t ntb_db_valid_mask(device_t ntb);
350 
351 /*
352  * ntb_db_vector_count() - get the number of doorbell interrupt vectors
353  * @ntb:	NTB device context.
354  *
355  * Hardware may support different number of interrupt vectors.
356  *
357  * Return: The number of doorbell interrupt vectors.
358  */
359 int ntb_db_vector_count(device_t ntb);
360 
361 /*
362  * ntb_db_vector_mask() - get a mask of doorbell bits serviced by a vector
363  * @ntb:	NTB device context
364  * @vector:	Doorbell vector number
365  *
366  * Each interrupt vector may have a different number or arrangement of bits.
367  *
368  * Return: A mask of doorbell bits serviced by a vector.
369  */
370 uint64_t ntb_db_vector_mask(device_t ntb, uint32_t vector);
371 
372 /*
373  * ntb_peer_db_addr() - address and size of the peer doorbell register
374  * @ntb:	NTB device context.
375  * @db_addr:	OUT - The address of the peer doorbell register.
376  * @db_size:	OUT - The number of bytes to write the peer doorbell register.
377  *
378  * Return the address of the peer doorbell register.  This may be used, for
379  * example, by drivers that offload memory copy operations to a dma engine.
380  * The drivers may wish to ring the peer doorbell at the completion of memory
381  * copy operations.  For efficiency, and to simplify ordering of operations
382  * between the dma memory copies and the ringing doorbell, the driver may
383  * append one additional dma memory copy with the doorbell register as the
384  * destination, after the memory copy operations.
385  *
386  * Return: Zero on success, otherwise an error number.
387  *
388  * Note that writing the peer doorbell via a memory window will *not* generate
389  * an interrupt on the remote host; that must be done separately.
390  */
391 int ntb_peer_db_addr(device_t ntb, bus_addr_t *db_addr, vm_size_t *db_size);
392 
393 /*
394  * ntb_db_clear() - clear bits in the local doorbell register
395  * @ntb:	NTB device context.
396  * @db_bits:	Doorbell bits to clear.
397  *
398  * Clear bits in the local doorbell register, arming the bits for the next
399  * doorbell.
400  *
401  * Return: Zero on success, otherwise an error number.
402  */
403 void ntb_db_clear(device_t ntb, uint64_t bits);
404 
405 /*
406  * ntb_db_clear_mask() - clear bits in the local doorbell mask
407  * @ntb:	NTB device context.
408  * @db_bits:	Doorbell bits to clear.
409  *
410  * Clear bits in the local doorbell mask register, allowing doorbell interrupts
411  * from being generated for those doorbell bits.  If a doorbell bit is already
412  * set at the time the mask is cleared, and the corresponding mask bit is
413  * changed from set to clear, then the ntb driver must ensure that
414  * ntb_db_event() is called.  If the hardware does not generate the interrupt
415  * on clearing the mask bit, then the driver must call ntb_db_event() anyway.
416  *
417  * Return: Zero on success, otherwise an error number.
418  */
419 void ntb_db_clear_mask(device_t ntb, uint64_t bits);
420 
421 /*
422  * ntb_db_read() - read the local doorbell register
423  * @ntb:	NTB device context.
424  *
425  * Read the local doorbell register, and return the bits that are set.
426  *
427  * Return: The bits currently set in the local doorbell register.
428  */
429 uint64_t ntb_db_read(device_t ntb);
430 
431 /*
432  * ntb_db_set_mask() - set bits in the local doorbell mask
433  * @ntb:	NTB device context.
434  * @db_bits:	Doorbell mask bits to set.
435  *
436  * Set bits in the local doorbell mask register, preventing doorbell interrupts
437  * from being generated for those doorbell bits.  Bits that were already set
438  * must remain set.
439  *
440  * Return: Zero on success, otherwise an error number.
441  */
442 void ntb_db_set_mask(device_t ntb, uint64_t bits);
443 
444 /*
445  * ntb_peer_db_set() - Set the doorbell on the secondary/external side
446  * @ntb: pointer to ntb_softc instance
447  * @bit: doorbell bits to ring
448  *
449  * This function allows triggering of a doorbell on the secondary/external
450  * side that will initiate an interrupt on the remote host
451  */
452 void ntb_peer_db_set(device_t ntb, uint64_t bits);
453 
454 #endif /* _NTB_H_ */
455