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26b3a37b LG |
1 | // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) |
2 | ||
3 | #include <linux/irq.h> | |
4 | #include <linux/module.h> | |
5 | #include <linux/ntb.h> | |
6 | #include <linux/msi.h> | |
7 | #include <linux/pci.h> | |
8 | ||
26b3a37b LG |
9 | struct ntb_msi { |
10 | u64 base_addr; | |
11 | u64 end_addr; | |
12 | ||
13 | void (*desc_changed)(void *ctx); | |
14 | ||
15 | u32 __iomem *peer_mws[]; | |
16 | }; | |
17 | ||
18 | /** | |
19 | * ntb_msi_init() - Initialize the MSI context | |
20 | * @ntb: NTB device context | |
21 | * | |
22 | * This function must be called before any other ntb_msi function. | |
23 | * It initializes the context for MSI operations and maps | |
24 | * the peer memory windows. | |
25 | * | |
26 | * This function reserves the last N outbound memory windows (where N | |
27 | * is the number of peers). | |
28 | * | |
29 | * Return: Zero on success, otherwise a negative error number. | |
30 | */ | |
31 | int ntb_msi_init(struct ntb_dev *ntb, | |
32 | void (*desc_changed)(void *ctx)) | |
33 | { | |
34 | phys_addr_t mw_phys_addr; | |
35 | resource_size_t mw_size; | |
26b3a37b LG |
36 | int peer_widx; |
37 | int peers; | |
38 | int ret; | |
39 | int i; | |
40 | ||
41 | peers = ntb_peer_port_count(ntb); | |
42 | if (peers <= 0) | |
43 | return -EINVAL; | |
44 | ||
30532568 GS |
45 | ntb->msi = devm_kzalloc(&ntb->dev, struct_size(ntb->msi, peer_mws, peers), |
46 | GFP_KERNEL); | |
26b3a37b LG |
47 | if (!ntb->msi) |
48 | return -ENOMEM; | |
49 | ||
50 | ntb->msi->desc_changed = desc_changed; | |
51 | ||
52 | for (i = 0; i < peers; i++) { | |
53 | peer_widx = ntb_peer_mw_count(ntb) - 1 - i; | |
54 | ||
55 | ret = ntb_peer_mw_get_addr(ntb, peer_widx, &mw_phys_addr, | |
56 | &mw_size); | |
57 | if (ret) | |
58 | goto unroll; | |
59 | ||
60 | ntb->msi->peer_mws[i] = devm_ioremap(&ntb->dev, mw_phys_addr, | |
61 | mw_size); | |
62 | if (!ntb->msi->peer_mws[i]) { | |
63 | ret = -EFAULT; | |
64 | goto unroll; | |
65 | } | |
66 | } | |
67 | ||
68 | return 0; | |
69 | ||
70 | unroll: | |
71 | for (i = 0; i < peers; i++) | |
72 | if (ntb->msi->peer_mws[i]) | |
73 | devm_iounmap(&ntb->dev, ntb->msi->peer_mws[i]); | |
74 | ||
75 | devm_kfree(&ntb->dev, ntb->msi); | |
76 | ntb->msi = NULL; | |
77 | return ret; | |
78 | } | |
79 | EXPORT_SYMBOL(ntb_msi_init); | |
80 | ||
81 | /** | |
82 | * ntb_msi_setup_mws() - Initialize the MSI inbound memory windows | |
83 | * @ntb: NTB device context | |
84 | * | |
85 | * This function sets up the required inbound memory windows. It should be | |
86 | * called from a work function after a link up event. | |
87 | * | |
88 | * Over the entire network, this function will reserves the last N | |
89 | * inbound memory windows for each peer (where N is the number of peers). | |
90 | * | |
91 | * ntb_msi_init() must be called before this function. | |
92 | * | |
93 | * Return: Zero on success, otherwise a negative error number. | |
94 | */ | |
95 | int ntb_msi_setup_mws(struct ntb_dev *ntb) | |
96 | { | |
97 | struct msi_desc *desc; | |
98 | u64 addr; | |
99 | int peer, peer_widx; | |
100 | resource_size_t addr_align, size_align, size_max; | |
101 | resource_size_t mw_size = SZ_32K; | |
102 | resource_size_t mw_min_size = mw_size; | |
103 | int i; | |
104 | int ret; | |
105 | ||
106 | if (!ntb->msi) | |
107 | return -EINVAL; | |
108 | ||
68e31835 TG |
109 | msi_lock_descs(&ntb->pdev->dev); |
110 | desc = msi_first_desc(&ntb->pdev->dev, MSI_DESC_ASSOCIATED); | |
26b3a37b | 111 | addr = desc->msg.address_lo + ((uint64_t)desc->msg.address_hi << 32); |
68e31835 | 112 | msi_unlock_descs(&ntb->pdev->dev); |
26b3a37b LG |
113 | |
114 | for (peer = 0; peer < ntb_peer_port_count(ntb); peer++) { | |
115 | peer_widx = ntb_peer_highest_mw_idx(ntb, peer); | |
116 | if (peer_widx < 0) | |
117 | return peer_widx; | |
118 | ||
119 | ret = ntb_mw_get_align(ntb, peer, peer_widx, &addr_align, | |
120 | NULL, NULL); | |
121 | if (ret) | |
122 | return ret; | |
123 | ||
124 | addr &= ~(addr_align - 1); | |
125 | } | |
126 | ||
127 | for (peer = 0; peer < ntb_peer_port_count(ntb); peer++) { | |
128 | peer_widx = ntb_peer_highest_mw_idx(ntb, peer); | |
129 | if (peer_widx < 0) { | |
130 | ret = peer_widx; | |
131 | goto error_out; | |
132 | } | |
133 | ||
134 | ret = ntb_mw_get_align(ntb, peer, peer_widx, NULL, | |
135 | &size_align, &size_max); | |
136 | if (ret) | |
137 | goto error_out; | |
138 | ||
139 | mw_size = round_up(mw_size, size_align); | |
140 | mw_size = max(mw_size, size_max); | |
141 | if (mw_size < mw_min_size) | |
142 | mw_min_size = mw_size; | |
143 | ||
144 | ret = ntb_mw_set_trans(ntb, peer, peer_widx, | |
145 | addr, mw_size); | |
146 | if (ret) | |
147 | goto error_out; | |
148 | } | |
149 | ||
150 | ntb->msi->base_addr = addr; | |
151 | ntb->msi->end_addr = addr + mw_min_size; | |
152 | ||
153 | return 0; | |
154 | ||
155 | error_out: | |
156 | for (i = 0; i < peer; i++) { | |
157 | peer_widx = ntb_peer_highest_mw_idx(ntb, peer); | |
158 | if (peer_widx < 0) | |
159 | continue; | |
160 | ||
161 | ntb_mw_clear_trans(ntb, i, peer_widx); | |
162 | } | |
163 | ||
164 | return ret; | |
165 | } | |
166 | EXPORT_SYMBOL(ntb_msi_setup_mws); | |
167 | ||
168 | /** | |
169 | * ntb_msi_clear_mws() - Clear all inbound memory windows | |
170 | * @ntb: NTB device context | |
171 | * | |
172 | * This function tears down the resources used by ntb_msi_setup_mws(). | |
173 | */ | |
174 | void ntb_msi_clear_mws(struct ntb_dev *ntb) | |
175 | { | |
176 | int peer; | |
177 | int peer_widx; | |
178 | ||
179 | for (peer = 0; peer < ntb_peer_port_count(ntb); peer++) { | |
180 | peer_widx = ntb_peer_highest_mw_idx(ntb, peer); | |
181 | if (peer_widx < 0) | |
182 | continue; | |
183 | ||
184 | ntb_mw_clear_trans(ntb, peer, peer_widx); | |
185 | } | |
186 | } | |
187 | EXPORT_SYMBOL(ntb_msi_clear_mws); | |
188 | ||
189 | struct ntb_msi_devres { | |
190 | struct ntb_dev *ntb; | |
191 | struct msi_desc *entry; | |
192 | struct ntb_msi_desc *msi_desc; | |
193 | }; | |
194 | ||
195 | static int ntb_msi_set_desc(struct ntb_dev *ntb, struct msi_desc *entry, | |
196 | struct ntb_msi_desc *msi_desc) | |
197 | { | |
198 | u64 addr; | |
199 | ||
200 | addr = entry->msg.address_lo + | |
201 | ((uint64_t)entry->msg.address_hi << 32); | |
202 | ||
203 | if (addr < ntb->msi->base_addr || addr >= ntb->msi->end_addr) { | |
204 | dev_warn_once(&ntb->dev, | |
205 | "IRQ %d: MSI Address not within the memory window (%llx, [%llx %llx])\n", | |
206 | entry->irq, addr, ntb->msi->base_addr, | |
207 | ntb->msi->end_addr); | |
208 | return -EFAULT; | |
209 | } | |
210 | ||
211 | msi_desc->addr_offset = addr - ntb->msi->base_addr; | |
212 | msi_desc->data = entry->msg.data; | |
213 | ||
214 | return 0; | |
215 | } | |
216 | ||
217 | static void ntb_msi_write_msg(struct msi_desc *entry, void *data) | |
218 | { | |
219 | struct ntb_msi_devres *dr = data; | |
220 | ||
221 | WARN_ON(ntb_msi_set_desc(dr->ntb, entry, dr->msi_desc)); | |
222 | ||
223 | if (dr->ntb->msi->desc_changed) | |
224 | dr->ntb->msi->desc_changed(dr->ntb->ctx); | |
225 | } | |
226 | ||
227 | static void ntbm_msi_callback_release(struct device *dev, void *res) | |
228 | { | |
229 | struct ntb_msi_devres *dr = res; | |
230 | ||
231 | dr->entry->write_msi_msg = NULL; | |
232 | dr->entry->write_msi_msg_data = NULL; | |
233 | } | |
234 | ||
235 | static int ntbm_msi_setup_callback(struct ntb_dev *ntb, struct msi_desc *entry, | |
236 | struct ntb_msi_desc *msi_desc) | |
237 | { | |
238 | struct ntb_msi_devres *dr; | |
239 | ||
240 | dr = devres_alloc(ntbm_msi_callback_release, | |
241 | sizeof(struct ntb_msi_devres), GFP_KERNEL); | |
242 | if (!dr) | |
243 | return -ENOMEM; | |
244 | ||
245 | dr->ntb = ntb; | |
246 | dr->entry = entry; | |
247 | dr->msi_desc = msi_desc; | |
248 | ||
249 | devres_add(&ntb->dev, dr); | |
250 | ||
251 | dr->entry->write_msi_msg = ntb_msi_write_msg; | |
252 | dr->entry->write_msi_msg_data = dr; | |
253 | ||
254 | return 0; | |
255 | } | |
256 | ||
257 | /** | |
258 | * ntbm_msi_request_threaded_irq() - allocate an MSI interrupt | |
259 | * @ntb: NTB device context | |
260 | * @handler: Function to be called when the IRQ occurs | |
261 | * @thread_fn: Function to be called in a threaded interrupt context. NULL | |
262 | * for clients which handle everything in @handler | |
e70dc094 | 263 | * @name: An ascii name for the claiming device, dev_name(dev) if NULL |
26b3a37b | 264 | * @dev_id: A cookie passed back to the handler function |
e70dc094 | 265 | * @msi_desc: MSI descriptor data which triggers the interrupt |
26b3a37b LG |
266 | * |
267 | * This function assigns an interrupt handler to an unused | |
268 | * MSI interrupt and returns the descriptor used to trigger | |
269 | * it. The descriptor can then be sent to a peer to trigger | |
270 | * the interrupt. | |
271 | * | |
272 | * The interrupt resource is managed with devres so it will | |
273 | * be automatically freed when the NTB device is torn down. | |
274 | * | |
275 | * If an IRQ allocated with this function needs to be freed | |
276 | * separately, ntbm_free_irq() must be used. | |
277 | * | |
278 | * Return: IRQ number assigned on success, otherwise a negative error number. | |
279 | */ | |
280 | int ntbm_msi_request_threaded_irq(struct ntb_dev *ntb, irq_handler_t handler, | |
281 | irq_handler_t thread_fn, | |
282 | const char *name, void *dev_id, | |
283 | struct ntb_msi_desc *msi_desc) | |
284 | { | |
68e31835 | 285 | struct device *dev = &ntb->pdev->dev; |
26b3a37b | 286 | struct msi_desc *entry; |
26b3a37b LG |
287 | int ret; |
288 | ||
289 | if (!ntb->msi) | |
290 | return -EINVAL; | |
291 | ||
68e31835 TG |
292 | msi_lock_descs(dev); |
293 | msi_for_each_desc(entry, dev, MSI_DESC_ASSOCIATED) { | |
1110918e | 294 | if (irq_has_action(entry->irq)) |
26b3a37b LG |
295 | continue; |
296 | ||
297 | ret = devm_request_threaded_irq(&ntb->dev, entry->irq, handler, | |
298 | thread_fn, 0, name, dev_id); | |
299 | if (ret) | |
300 | continue; | |
301 | ||
302 | if (ntb_msi_set_desc(ntb, entry, msi_desc)) { | |
303 | devm_free_irq(&ntb->dev, entry->irq, dev_id); | |
304 | continue; | |
305 | } | |
306 | ||
307 | ret = ntbm_msi_setup_callback(ntb, entry, msi_desc); | |
308 | if (ret) { | |
309 | devm_free_irq(&ntb->dev, entry->irq, dev_id); | |
68e31835 | 310 | goto unlock; |
26b3a37b LG |
311 | } |
312 | ||
68e31835 TG |
313 | ret = entry->irq; |
314 | goto unlock; | |
26b3a37b | 315 | } |
68e31835 | 316 | ret = -ENODEV; |
26b3a37b | 317 | |
68e31835 TG |
318 | unlock: |
319 | msi_unlock_descs(dev); | |
320 | return ret; | |
26b3a37b LG |
321 | } |
322 | EXPORT_SYMBOL(ntbm_msi_request_threaded_irq); | |
323 | ||
324 | static int ntbm_msi_callback_match(struct device *dev, void *res, void *data) | |
325 | { | |
326 | struct ntb_dev *ntb = dev_ntb(dev); | |
327 | struct ntb_msi_devres *dr = res; | |
328 | ||
329 | return dr->ntb == ntb && dr->entry == data; | |
330 | } | |
331 | ||
332 | /** | |
333 | * ntbm_msi_free_irq() - free an interrupt | |
334 | * @ntb: NTB device context | |
335 | * @irq: Interrupt line to free | |
336 | * @dev_id: Device identity to free | |
337 | * | |
338 | * This function should be used to manually free IRQs allocated with | |
339 | * ntbm_request_[threaded_]irq(). | |
340 | */ | |
341 | void ntbm_msi_free_irq(struct ntb_dev *ntb, unsigned int irq, void *dev_id) | |
342 | { | |
343 | struct msi_desc *entry = irq_get_msi_desc(irq); | |
344 | ||
345 | entry->write_msi_msg = NULL; | |
346 | entry->write_msi_msg_data = NULL; | |
347 | ||
348 | WARN_ON(devres_destroy(&ntb->dev, ntbm_msi_callback_release, | |
349 | ntbm_msi_callback_match, entry)); | |
350 | ||
351 | devm_free_irq(&ntb->dev, irq, dev_id); | |
352 | } | |
353 | EXPORT_SYMBOL(ntbm_msi_free_irq); | |
354 | ||
355 | /** | |
356 | * ntb_msi_peer_trigger() - Trigger an interrupt handler on a peer | |
357 | * @ntb: NTB device context | |
358 | * @peer: Peer index | |
359 | * @desc: MSI descriptor data which triggers the interrupt | |
360 | * | |
361 | * This function triggers an interrupt on a peer. It requires | |
362 | * the descriptor structure to have been passed from that peer | |
363 | * by some other means. | |
364 | * | |
365 | * Return: Zero on success, otherwise a negative error number. | |
366 | */ | |
367 | int ntb_msi_peer_trigger(struct ntb_dev *ntb, int peer, | |
368 | struct ntb_msi_desc *desc) | |
369 | { | |
370 | int idx; | |
371 | ||
372 | if (!ntb->msi) | |
373 | return -EINVAL; | |
374 | ||
375 | idx = desc->addr_offset / sizeof(*ntb->msi->peer_mws[peer]); | |
376 | ||
377 | iowrite32(desc->data, &ntb->msi->peer_mws[peer][idx]); | |
378 | ||
379 | return 0; | |
380 | } | |
381 | EXPORT_SYMBOL(ntb_msi_peer_trigger); | |
382 | ||
383 | /** | |
384 | * ntb_msi_peer_addr() - Get the DMA address to trigger a peer's MSI interrupt | |
385 | * @ntb: NTB device context | |
386 | * @peer: Peer index | |
387 | * @desc: MSI descriptor data which triggers the interrupt | |
388 | * @msi_addr: Physical address to trigger the interrupt | |
389 | * | |
390 | * This function allows using DMA engines to trigger an interrupt | |
391 | * (for example, trigger an interrupt to process the data after | |
392 | * sending it). To trigger the interrupt, write @desc.data to the address | |
393 | * returned in @msi_addr | |
394 | * | |
395 | * Return: Zero on success, otherwise a negative error number. | |
396 | */ | |
397 | int ntb_msi_peer_addr(struct ntb_dev *ntb, int peer, | |
398 | struct ntb_msi_desc *desc, | |
399 | phys_addr_t *msi_addr) | |
400 | { | |
401 | int peer_widx = ntb_peer_mw_count(ntb) - 1 - peer; | |
402 | phys_addr_t mw_phys_addr; | |
403 | int ret; | |
404 | ||
405 | ret = ntb_peer_mw_get_addr(ntb, peer_widx, &mw_phys_addr, NULL); | |
406 | if (ret) | |
407 | return ret; | |
408 | ||
409 | if (msi_addr) | |
410 | *msi_addr = mw_phys_addr + desc->addr_offset; | |
411 | ||
412 | return 0; | |
413 | } | |
414 | EXPORT_SYMBOL(ntb_msi_peer_addr); |