xref: /linux/drivers/infiniband/hw/hfi1/msix.c (revision fc2d791a43d3880496d1c729b8bd74d2c19cb4e7)
1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 /*
3  * Copyright(c) 2018 - 2020 Intel Corporation.
4  */
5 
6 #include "hfi.h"
7 #include "affinity.h"
8 #include "sdma.h"
9 #include "netdev.h"
10 
11 /**
12  * msix_initialize() - Calculate, request and configure MSIx IRQs
13  * @dd: valid hfi1 devdata
14  *
15  */
16 int msix_initialize(struct hfi1_devdata *dd)
17 {
18 	u32 total;
19 	int ret;
20 	struct hfi1_msix_entry *entries;
21 
22 	/*
23 	 * MSIx interrupt count:
24 	 *	one for the general, "slow path" interrupt
25 	 *	one per used SDMA engine
26 	 *	one per kernel receive context
27 	 *      ...any new IRQs should be added here.
28 	 */
29 	total = 1 + dd->num_sdma + dd->n_krcv_queues + dd->num_netdev_contexts;
30 
31 	if (total >= CCE_NUM_MSIX_VECTORS)
32 		return -EINVAL;
33 
34 	ret = pci_alloc_irq_vectors(dd->pcidev, total, total, PCI_IRQ_MSIX);
35 	if (ret < 0) {
36 		dd_dev_err(dd, "pci_alloc_irq_vectors() failed: %d\n", ret);
37 		return ret;
38 	}
39 
40 	entries = kzalloc_objs(*dd->msix_info.msix_entries, total);
41 	if (!entries) {
42 		pci_free_irq_vectors(dd->pcidev);
43 		return -ENOMEM;
44 	}
45 
46 	dd->msix_info.msix_entries = entries;
47 	spin_lock_init(&dd->msix_info.msix_lock);
48 	bitmap_zero(dd->msix_info.in_use_msix, total);
49 	dd->msix_info.max_requested = total;
50 	dd_dev_info(dd, "%u MSI-X interrupts allocated\n", total);
51 
52 	return 0;
53 }
54 
55 /**
56  * msix_request_irq() - Allocate a free MSIx IRQ
57  * @dd: valid devdata
58  * @arg: context information for the IRQ
59  * @handler: IRQ handler
60  * @thread: IRQ thread handler (could be NULL)
61  * @type: affinty IRQ type
62  * @name: IRQ name
63  *
64  * Allocated an MSIx vector if available, and then create the appropriate
65  * meta data needed to keep track of the pci IRQ request.
66  *
67  * Return:
68  *   < 0   Error
69  *   >= 0  MSIx vector
70  *
71  */
72 static int msix_request_irq(struct hfi1_devdata *dd, void *arg,
73 			    irq_handler_t handler, irq_handler_t thread,
74 			    enum irq_type type, const char *name)
75 {
76 	unsigned long nr;
77 	int irq;
78 	int ret;
79 	struct hfi1_msix_entry *me;
80 
81 	/* Allocate an MSIx vector */
82 	spin_lock(&dd->msix_info.msix_lock);
83 	nr = find_first_zero_bit(dd->msix_info.in_use_msix,
84 				 dd->msix_info.max_requested);
85 	if (nr < dd->msix_info.max_requested)
86 		__set_bit(nr, dd->msix_info.in_use_msix);
87 	spin_unlock(&dd->msix_info.msix_lock);
88 
89 	if (nr == dd->msix_info.max_requested)
90 		return -ENOSPC;
91 
92 	if (type < IRQ_SDMA || type >= IRQ_OTHER)
93 		return -EINVAL;
94 
95 	irq = pci_irq_vector(dd->pcidev, nr);
96 	ret = pci_request_irq(dd->pcidev, nr, handler, thread, arg, name);
97 	if (ret) {
98 		dd_dev_err(dd,
99 			   "%s: request for IRQ %d failed, MSIx %lx, err %d\n",
100 			   name, irq, nr, ret);
101 		spin_lock(&dd->msix_info.msix_lock);
102 		__clear_bit(nr, dd->msix_info.in_use_msix);
103 		spin_unlock(&dd->msix_info.msix_lock);
104 		return ret;
105 	}
106 
107 	/*
108 	 * assign arg after pci_request_irq call, so it will be
109 	 * cleaned up
110 	 */
111 	me = &dd->msix_info.msix_entries[nr];
112 	me->irq = irq;
113 	me->arg = arg;
114 	me->type = type;
115 
116 	/* This is a request, so a failure is not fatal */
117 	ret = hfi1_get_irq_affinity(dd, me);
118 	if (ret)
119 		dd_dev_err(dd, "%s: unable to pin IRQ %d\n", name, ret);
120 
121 	return nr;
122 }
123 
124 static int msix_request_rcd_irq_common(struct hfi1_ctxtdata *rcd,
125 				       irq_handler_t handler,
126 				       irq_handler_t thread,
127 				       const char *name)
128 {
129 	int nr = msix_request_irq(rcd->dd, rcd, handler, thread, IRQ_RCVCTXT,
130 				  name);
131 	if (nr < 0)
132 		return nr;
133 
134 	/*
135 	 * Set the interrupt register and mask for this
136 	 * context's interrupt.
137 	 */
138 	rcd->ireg = (IS_RCVAVAIL_START + rcd->ctxt) / 64;
139 	rcd->imask = ((u64)1) << ((IS_RCVAVAIL_START + rcd->ctxt) % 64);
140 	rcd->msix_intr = nr;
141 	remap_intr(rcd->dd, IS_RCVAVAIL_START + rcd->ctxt, nr);
142 
143 	return 0;
144 }
145 
146 /**
147  * msix_request_rcd_irq() - Helper function for RCVAVAIL IRQs
148  * @rcd: valid rcd context
149  *
150  */
151 int msix_request_rcd_irq(struct hfi1_ctxtdata *rcd)
152 {
153 	char name[MAX_NAME_SIZE];
154 
155 	snprintf(name, sizeof(name), DRIVER_NAME "_%d kctxt%d",
156 		 rcd->dd->unit, rcd->ctxt);
157 
158 	return msix_request_rcd_irq_common(rcd, receive_context_interrupt,
159 					   receive_context_thread, name);
160 }
161 
162 /**
163  * msix_netdev_request_rcd_irq  - Helper function for RCVAVAIL IRQs
164  * for netdev context
165  * @rcd: valid netdev contexti
166  */
167 int msix_netdev_request_rcd_irq(struct hfi1_ctxtdata *rcd)
168 {
169 	char name[MAX_NAME_SIZE];
170 
171 	snprintf(name, sizeof(name), DRIVER_NAME "_%d nd kctxt%d",
172 		 rcd->dd->unit, rcd->ctxt);
173 	return msix_request_rcd_irq_common(rcd, receive_context_interrupt_napi,
174 					   NULL, name);
175 }
176 
177 /**
178  * msix_request_sdma_irq  - Helper for getting SDMA IRQ resources
179  * @sde: valid sdma engine
180  *
181  */
182 int msix_request_sdma_irq(struct sdma_engine *sde)
183 {
184 	int nr;
185 	char name[MAX_NAME_SIZE];
186 
187 	snprintf(name, sizeof(name), DRIVER_NAME "_%d sdma%d",
188 		 sde->dd->unit, sde->this_idx);
189 	nr = msix_request_irq(sde->dd, sde, sdma_interrupt, NULL,
190 			      IRQ_SDMA, name);
191 	if (nr < 0)
192 		return nr;
193 	sde->msix_intr = nr;
194 	remap_sdma_interrupts(sde->dd, sde->this_idx, nr);
195 
196 	return 0;
197 }
198 
199 /**
200  * msix_request_general_irq - Helper for getting general IRQ
201  * resources
202  * @dd: valid device data
203  */
204 int msix_request_general_irq(struct hfi1_devdata *dd)
205 {
206 	int nr;
207 	char name[MAX_NAME_SIZE];
208 
209 	snprintf(name, sizeof(name), DRIVER_NAME "_%d", dd->unit);
210 	nr = msix_request_irq(dd, dd, general_interrupt, NULL, IRQ_GENERAL,
211 			      name);
212 	if (nr < 0)
213 		return nr;
214 
215 	/* general interrupt must be MSIx vector 0 */
216 	if (nr) {
217 		msix_free_irq(dd, (u8)nr);
218 		dd_dev_err(dd, "Invalid index %d for GENERAL IRQ\n", nr);
219 		return -EINVAL;
220 	}
221 
222 	return 0;
223 }
224 
225 /**
226  * enable_sdma_srcs - Helper to enable SDMA IRQ srcs
227  * @dd: valid devdata structure
228  * @i: index of SDMA engine
229  */
230 static void enable_sdma_srcs(struct hfi1_devdata *dd, int i)
231 {
232 	set_intr_bits(dd, IS_SDMA_START + i, IS_SDMA_START + i, true);
233 	set_intr_bits(dd, IS_SDMA_PROGRESS_START + i,
234 		      IS_SDMA_PROGRESS_START + i, true);
235 	set_intr_bits(dd, IS_SDMA_IDLE_START + i, IS_SDMA_IDLE_START + i, true);
236 	set_intr_bits(dd, IS_SDMAENG_ERR_START + i, IS_SDMAENG_ERR_START + i,
237 		      true);
238 }
239 
240 /**
241  * msix_request_irqs() - Allocate all MSIx IRQs
242  * @dd: valid devdata structure
243  *
244  * Helper function to request the used MSIx IRQs.
245  *
246  */
247 int msix_request_irqs(struct hfi1_devdata *dd)
248 {
249 	int i;
250 	int ret = msix_request_general_irq(dd);
251 
252 	if (ret)
253 		return ret;
254 
255 	for (i = 0; i < dd->num_sdma; i++) {
256 		struct sdma_engine *sde = &dd->per_sdma[i];
257 
258 		ret = msix_request_sdma_irq(sde);
259 		if (ret)
260 			return ret;
261 		enable_sdma_srcs(sde->dd, i);
262 	}
263 
264 	for (i = 0; i < dd->n_krcv_queues; i++) {
265 		struct hfi1_ctxtdata *rcd = hfi1_rcd_get_by_index_safe(dd, i);
266 
267 		if (rcd)
268 			ret = msix_request_rcd_irq(rcd);
269 		hfi1_rcd_put(rcd);
270 		if (ret)
271 			return ret;
272 	}
273 
274 	return 0;
275 }
276 
277 /**
278  * msix_free_irq() - Free the specified MSIx resources and IRQ
279  * @dd: valid devdata
280  * @msix_intr: MSIx vector to free.
281  *
282  */
283 void msix_free_irq(struct hfi1_devdata *dd, u8 msix_intr)
284 {
285 	struct hfi1_msix_entry *me;
286 
287 	if (msix_intr >= dd->msix_info.max_requested)
288 		return;
289 
290 	me = &dd->msix_info.msix_entries[msix_intr];
291 
292 	if (!me->arg) /* => no irq, no affinity */
293 		return;
294 
295 	hfi1_put_irq_affinity(dd, me);
296 	pci_free_irq(dd->pcidev, msix_intr, me->arg);
297 
298 	me->arg = NULL;
299 
300 	spin_lock(&dd->msix_info.msix_lock);
301 	__clear_bit(msix_intr, dd->msix_info.in_use_msix);
302 	spin_unlock(&dd->msix_info.msix_lock);
303 }
304 
305 /**
306  * msix_clean_up_interrupts  - Free all MSIx IRQ resources
307  * @dd: valid device data data structure
308  *
309  * Free the MSIx and associated PCI resources, if they have been allocated.
310  */
311 void msix_clean_up_interrupts(struct hfi1_devdata *dd)
312 {
313 	int i;
314 	struct hfi1_msix_entry *me = dd->msix_info.msix_entries;
315 
316 	/* remove irqs - must happen before disabling/turning off */
317 	for (i = 0; i < dd->msix_info.max_requested; i++, me++)
318 		msix_free_irq(dd, i);
319 
320 	/* clean structures */
321 	kfree(dd->msix_info.msix_entries);
322 	dd->msix_info.msix_entries = NULL;
323 	dd->msix_info.max_requested = 0;
324 
325 	pci_free_irq_vectors(dd->pcidev);
326 }
327 
328 /**
329  * msix_netdev_synchronize_irq - netdev IRQ synchronize
330  * @dd: valid devdata
331  */
332 void msix_netdev_synchronize_irq(struct hfi1_devdata *dd)
333 {
334 	int i;
335 	int ctxt_count = hfi1_netdev_ctxt_count(dd);
336 
337 	for (i = 0; i < ctxt_count; i++) {
338 		struct hfi1_ctxtdata *rcd = hfi1_netdev_get_ctxt(dd, i);
339 		struct hfi1_msix_entry *me;
340 
341 		me = &dd->msix_info.msix_entries[rcd->msix_intr];
342 
343 		synchronize_irq(me->irq);
344 	}
345 }
346