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 | |
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; |
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 | |
45 | ntb->msi = devm_kzalloc(dev: &ntb->dev, struct_size(ntb->msi, peer_mws, peers), |
46 | GFP_KERNEL); |
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, widx: peer_widx, base: &mw_phys_addr, |
56 | size: &mw_size); |
57 | if (ret) |
58 | goto unroll; |
59 | |
60 | ntb->msi->peer_mws[i] = devm_ioremap(dev: &ntb->dev, offset: mw_phys_addr, |
61 | size: 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(dev: &ntb->dev, addr: ntb->msi->peer_mws[i]); |
74 | |
75 | devm_kfree(dev: &ntb->dev, p: 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 | |
109 | msi_lock_descs(dev: &ntb->pdev->dev); |
110 | desc = msi_first_desc(dev: &ntb->pdev->dev, filter: MSI_DESC_ASSOCIATED); |
111 | addr = desc->msg.address_lo + ((uint64_t)desc->msg.address_hi << 32); |
112 | msi_unlock_descs(dev: &ntb->pdev->dev); |
113 | |
114 | for (peer = 0; peer < ntb_peer_port_count(ntb); peer++) { |
115 | peer_widx = ntb_peer_highest_mw_idx(ntb, pidx: peer); |
116 | if (peer_widx < 0) |
117 | return peer_widx; |
118 | |
119 | ret = ntb_mw_get_align(ntb, pidx: peer, widx: peer_widx, addr_align: &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, pidx: peer); |
129 | if (peer_widx < 0) { |
130 | ret = peer_widx; |
131 | goto error_out; |
132 | } |
133 | |
134 | ret = ntb_mw_get_align(ntb, pidx: peer, widx: peer_widx, NULL, |
135 | size_align: &size_align, size_max: &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, pidx: peer, widx: peer_widx, |
145 | addr, size: 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, pidx: peer); |
158 | if (peer_widx < 0) |
159 | continue; |
160 | |
161 | ntb_mw_clear_trans(ntb, pidx: i, widx: 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, pidx: peer); |
181 | if (peer_widx < 0) |
182 | continue; |
183 | |
184 | ntb_mw_clear_trans(ntb, pidx: peer, widx: 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(dev: &ntb->dev, res: 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 |
263 | * @name: An ascii name for the claiming device, dev_name(dev) if NULL |
264 | * @dev_id: A cookie passed back to the handler function |
265 | * @msi_desc: MSI descriptor data which triggers the interrupt |
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 | { |
285 | struct device *dev = &ntb->pdev->dev; |
286 | struct msi_desc *entry; |
287 | int ret; |
288 | |
289 | if (!ntb->msi) |
290 | return -EINVAL; |
291 | |
292 | msi_lock_descs(dev); |
293 | msi_for_each_desc(entry, dev, MSI_DESC_ASSOCIATED) { |
294 | if (irq_has_action(irq: entry->irq)) |
295 | continue; |
296 | |
297 | ret = devm_request_threaded_irq(dev: &ntb->dev, irq: entry->irq, handler, |
298 | thread_fn, irqflags: 0, devname: name, dev_id); |
299 | if (ret) |
300 | continue; |
301 | |
302 | if (ntb_msi_set_desc(ntb, entry, msi_desc)) { |
303 | devm_free_irq(dev: &ntb->dev, irq: 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(dev: &ntb->dev, irq: entry->irq, dev_id); |
310 | goto unlock; |
311 | } |
312 | |
313 | ret = entry->irq; |
314 | goto unlock; |
315 | } |
316 | ret = -ENODEV; |
317 | |
318 | unlock: |
319 | msi_unlock_descs(dev); |
320 | return ret; |
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(dev: &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, widx: peer_widx, base: &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); |
415 | |