xref: /freebsd/sys/dev/ntb/ntb.h (revision 47dd1d1b619cc035b82b49a91a25544309ff95ae)
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 
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_link_is_up() - get the current ntb link state
69  * @ntb:        NTB device context
70  * @speed:      OUT - The link speed expressed as PCIe generation number
71  * @width:      OUT - The link width expressed as the number of PCIe lanes
72  *
73  * RETURNS: true or false based on the hardware link state
74  */
75 bool ntb_link_is_up(device_t ntb, enum ntb_speed *speed, enum ntb_width *width);
76 
77 /*
78  * ntb_link_enable() - enable the link on the secondary side of the ntb
79  * @ntb:        NTB device context
80  * @max_speed:  The maximum link speed expressed as PCIe generation number[0]
81  * @max_width:  The maximum link width expressed as the number of PCIe lanes[0]
82  *
83  * Enable the link on the secondary side of the ntb.  This can only be done
84  * from the primary side of the ntb in primary or b2b topology.  The ntb device
85  * should train the link to its maximum speed and width, or the requested speed
86  * and width, whichever is smaller, if supported.
87  *
88  * Return: Zero on success, otherwise an error number.
89  *
90  * [0]: Only NTB_SPEED_AUTO and NTB_WIDTH_AUTO are valid inputs; other speed
91  *      and width input will be ignored.
92  */
93 int ntb_link_enable(device_t ntb, enum ntb_speed speed, enum ntb_width width);
94 
95 /*
96  * ntb_link_disable() - disable the link on the secondary side of the ntb
97  * @ntb:        NTB device context
98  *
99  * Disable the link on the secondary side of the ntb.  This can only be done
100  * from the primary side of the ntb in primary or b2b topology.  The ntb device
101  * should disable the link.  Returning from this call must indicate that a
102  * barrier has passed, though with no more writes may pass in either direction
103  * across the link, except if this call returns an error number.
104  *
105  * Return: Zero on success, otherwise an error number.
106  */
107 int ntb_link_disable(device_t ntb);
108 
109 /*
110  * get enable status of the link on the secondary side of the ntb
111  */
112 bool ntb_link_enabled(device_t ntb);
113 
114 /*
115  * ntb_set_ctx() - associate a driver context with an ntb device
116  * @ntb:        NTB device context
117  * @ctx:        Driver context
118  * @ctx_ops:    Driver context operations
119  *
120  * Associate a driver context and operations with a ntb device.  The context is
121  * provided by the client driver, and the driver may associate a different
122  * context with each ntb device.
123  *
124  * Return: Zero if the context is associated, otherwise an error number.
125  */
126 int ntb_set_ctx(device_t ntb, void *ctx, const struct ntb_ctx_ops *ctx_ops);
127 
128 /*
129  * ntb_set_ctx() - get a driver context associated with an ntb device
130  * @ntb:        NTB device context
131  * @ctx_ops:    Driver context operations
132  *
133  * Get a driver context and operations associated with a ntb device.
134  */
135 void * ntb_get_ctx(device_t ntb, const struct ntb_ctx_ops **ctx_ops);
136 
137 /*
138  * ntb_clear_ctx() - disassociate any driver context from an ntb device
139  * @ntb:        NTB device context
140  *
141  * Clear any association that may exist between a driver context and the ntb
142  * device.
143  */
144 void ntb_clear_ctx(device_t ntb);
145 
146 /*
147  * ntb_mw_count() - Get the number of memory windows available for KPI
148  * consumers.
149  *
150  * (Excludes any MW wholly reserved for register access.)
151  */
152 uint8_t ntb_mw_count(device_t ntb);
153 
154 /*
155  * ntb_mw_get_range() - get the range of a memory window
156  * @ntb:        NTB device context
157  * @idx:        Memory window number
158  * @base:       OUT - the base address for mapping the memory window
159  * @size:       OUT - the size for mapping the memory window
160  * @align:      OUT - the base alignment for translating the memory window
161  * @align_size: OUT - the size alignment for translating the memory window
162  *
163  * Get the range of a memory window.  NULL may be given for any output
164  * parameter if the value is not needed.  The base and size may be used for
165  * mapping the memory window, to access the peer memory.  The alignment and
166  * size may be used for translating the memory window, for the peer to access
167  * memory on the local system.
168  *
169  * Return: Zero on success, otherwise an error number.
170  */
171 int ntb_mw_get_range(device_t ntb, unsigned mw_idx, vm_paddr_t *base,
172     caddr_t *vbase, size_t *size, size_t *align, size_t *align_size,
173     bus_addr_t *plimit);
174 
175 /*
176  * ntb_mw_set_trans() - set the translation of a memory window
177  * @ntb:        NTB device context
178  * @idx:        Memory window number
179  * @addr:       The dma address local memory to expose to the peer
180  * @size:       The size of the local memory to expose to the peer
181  *
182  * Set the translation of a memory window.  The peer may access local memory
183  * through the window starting at the address, up to the size.  The address
184  * must be aligned to the alignment specified by ntb_mw_get_range().  The size
185  * must be aligned to the size alignment specified by ntb_mw_get_range().  The
186  * address must be below the plimit specified by ntb_mw_get_range() (i.e. for
187  * 32-bit BARs).
188  *
189  * Return: Zero on success, otherwise an error number.
190  */
191 int ntb_mw_set_trans(device_t ntb, unsigned mw_idx, bus_addr_t addr,
192     size_t size);
193 
194 /*
195  * ntb_mw_clear_trans() - clear the translation of a memory window
196  * @ntb:	NTB device context
197  * @idx:	Memory window number
198  *
199  * Clear the translation of a memory window.  The peer may no longer access
200  * local memory through the window.
201  *
202  * Return: Zero on success, otherwise an error number.
203  */
204 int ntb_mw_clear_trans(device_t ntb, unsigned mw_idx);
205 
206 /*
207  * ntb_mw_get_wc - Get the write-combine status of a memory window
208  *
209  * Returns:  Zero on success, setting *wc; otherwise an error number (e.g. if
210  * idx is an invalid memory window).
211  *
212  * Mode is a VM_MEMATTR_* type.
213  */
214 int ntb_mw_get_wc(device_t ntb, unsigned mw_idx, vm_memattr_t *mode);
215 
216 /*
217  * ntb_mw_set_wc - Set the write-combine status of a memory window
218  *
219  * If 'mode' matches the current status, this does nothing and succeeds.  Mode
220  * is a VM_MEMATTR_* type.
221  *
222  * Returns:  Zero on success, setting the caching attribute on the virtual
223  * mapping of the BAR; otherwise an error number (e.g. if idx is an invalid
224  * memory window, or if changing the caching attribute fails).
225  */
226 int ntb_mw_set_wc(device_t ntb, unsigned mw_idx, vm_memattr_t mode);
227 
228 /*
229  * ntb_spad_count() - get the total scratch regs usable
230  * @ntb: pointer to ntb_softc instance
231  *
232  * This function returns the max 32bit scratchpad registers usable by the
233  * upper layer.
234  *
235  * RETURNS: total number of scratch pad registers available
236  */
237 uint8_t ntb_spad_count(device_t ntb);
238 
239 /*
240  * ntb_get_max_spads() - zero local scratch registers
241  * @ntb: pointer to ntb_softc instance
242  *
243  * This functions overwrites all local scratchpad registers with zeroes.
244  */
245 void ntb_spad_clear(device_t ntb);
246 
247 /*
248  * ntb_spad_write() - write to the secondary scratchpad register
249  * @ntb: pointer to ntb_softc instance
250  * @idx: index to the scratchpad register, 0 based
251  * @val: the data value to put into the register
252  *
253  * This function allows writing of a 32bit value to the indexed scratchpad
254  * register. The register resides on the secondary (external) side.
255  *
256  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
257  */
258 int ntb_spad_write(device_t ntb, unsigned int idx, uint32_t val);
259 
260 /*
261  * ntb_spad_read() - read from the primary scratchpad register
262  * @ntb: pointer to ntb_softc instance
263  * @idx: index to scratchpad register, 0 based
264  * @val: pointer to 32bit integer for storing the register value
265  *
266  * This function allows reading of the 32bit scratchpad register on
267  * the primary (internal) side.
268  *
269  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
270  */
271 int ntb_spad_read(device_t ntb, unsigned int idx, uint32_t *val);
272 
273 /*
274  * ntb_peer_spad_write() - write to the secondary scratchpad register
275  * @ntb: pointer to ntb_softc instance
276  * @idx: index to the scratchpad register, 0 based
277  * @val: the data value to put into the register
278  *
279  * This function allows writing of a 32bit value to the indexed scratchpad
280  * register. The register resides on the secondary (external) side.
281  *
282  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
283  */
284 int ntb_peer_spad_write(device_t ntb, unsigned int idx, uint32_t val);
285 
286 /*
287  * ntb_peer_spad_read() - read from the primary scratchpad register
288  * @ntb: pointer to ntb_softc instance
289  * @idx: index to scratchpad register, 0 based
290  * @val: pointer to 32bit integer for storing the register value
291  *
292  * This function allows reading of the 32bit scratchpad register on
293  * the primary (internal) side.
294  *
295  * RETURNS: An appropriate ERRNO error value on error, or zero for success.
296  */
297 int ntb_peer_spad_read(device_t ntb, unsigned int idx, uint32_t *val);
298 
299 /*
300  * ntb_db_valid_mask() - get a mask of doorbell bits supported by the ntb
301  * @ntb:	NTB device context
302  *
303  * Hardware may support different number or arrangement of doorbell bits.
304  *
305  * Return: A mask of doorbell bits supported by the ntb.
306  */
307 uint64_t ntb_db_valid_mask(device_t ntb);
308 
309 /*
310  * ntb_db_vector_count() - get the number of doorbell interrupt vectors
311  * @ntb:	NTB device context.
312  *
313  * Hardware may support different number of interrupt vectors.
314  *
315  * Return: The number of doorbell interrupt vectors.
316  */
317 int ntb_db_vector_count(device_t ntb);
318 
319 /*
320  * ntb_db_vector_mask() - get a mask of doorbell bits serviced by a vector
321  * @ntb:	NTB device context
322  * @vector:	Doorbell vector number
323  *
324  * Each interrupt vector may have a different number or arrangement of bits.
325  *
326  * Return: A mask of doorbell bits serviced by a vector.
327  */
328 uint64_t ntb_db_vector_mask(device_t ntb, uint32_t vector);
329 
330 /*
331  * ntb_peer_db_addr() - address and size of the peer doorbell register
332  * @ntb:	NTB device context.
333  * @db_addr:	OUT - The address of the peer doorbell register.
334  * @db_size:	OUT - The number of bytes to write the peer doorbell register.
335  *
336  * Return the address of the peer doorbell register.  This may be used, for
337  * example, by drivers that offload memory copy operations to a dma engine.
338  * The drivers may wish to ring the peer doorbell at the completion of memory
339  * copy operations.  For efficiency, and to simplify ordering of operations
340  * between the dma memory copies and the ringing doorbell, the driver may
341  * append one additional dma memory copy with the doorbell register as the
342  * destination, after the memory copy operations.
343  *
344  * Return: Zero on success, otherwise an error number.
345  *
346  * Note that writing the peer doorbell via a memory window will *not* generate
347  * an interrupt on the remote host; that must be done separately.
348  */
349 int ntb_peer_db_addr(device_t ntb, bus_addr_t *db_addr, vm_size_t *db_size);
350 
351 /*
352  * ntb_db_clear() - clear bits in the local doorbell register
353  * @ntb:	NTB device context.
354  * @db_bits:	Doorbell bits to clear.
355  *
356  * Clear bits in the local doorbell register, arming the bits for the next
357  * doorbell.
358  *
359  * Return: Zero on success, otherwise an error number.
360  */
361 void ntb_db_clear(device_t ntb, uint64_t bits);
362 
363 /*
364  * ntb_db_clear_mask() - clear bits in the local doorbell mask
365  * @ntb:	NTB device context.
366  * @db_bits:	Doorbell bits to clear.
367  *
368  * Clear bits in the local doorbell mask register, allowing doorbell interrupts
369  * from being generated for those doorbell bits.  If a doorbell bit is already
370  * set at the time the mask is cleared, and the corresponding mask bit is
371  * changed from set to clear, then the ntb driver must ensure that
372  * ntb_db_event() is called.  If the hardware does not generate the interrupt
373  * on clearing the mask bit, then the driver must call ntb_db_event() anyway.
374  *
375  * Return: Zero on success, otherwise an error number.
376  */
377 void ntb_db_clear_mask(device_t ntb, uint64_t bits);
378 
379 /*
380  * ntb_db_read() - read the local doorbell register
381  * @ntb:	NTB device context.
382  *
383  * Read the local doorbell register, and return the bits that are set.
384  *
385  * Return: The bits currently set in the local doorbell register.
386  */
387 uint64_t ntb_db_read(device_t ntb);
388 
389 /*
390  * ntb_db_set_mask() - set bits in the local doorbell mask
391  * @ntb:	NTB device context.
392  * @db_bits:	Doorbell mask bits to set.
393  *
394  * Set bits in the local doorbell mask register, preventing doorbell interrupts
395  * from being generated for those doorbell bits.  Bits that were already set
396  * must remain set.
397  *
398  * Return: Zero on success, otherwise an error number.
399  */
400 void ntb_db_set_mask(device_t ntb, uint64_t bits);
401 
402 /*
403  * ntb_peer_db_set() - Set the doorbell on the secondary/external side
404  * @ntb: pointer to ntb_softc instance
405  * @bit: doorbell bits to ring
406  *
407  * This function allows triggering of a doorbell on the secondary/external
408  * side that will initiate an interrupt on the remote host
409  */
410 void ntb_peer_db_set(device_t ntb, uint64_t bits);
411 
412 #endif /* _NTB_H_ */
413