xref: /openbmc/linux/arch/sparc/kernel/pci_msi.c (revision b627b4ed)
1 /* pci_msi.c: Sparc64 MSI support common layer.
2  *
3  * Copyright (C) 2007 David S. Miller (davem@davemloft.net)
4  */
5 #include <linux/kernel.h>
6 #include <linux/interrupt.h>
7 #include <linux/irq.h>
8 
9 #include "pci_impl.h"
10 
11 static irqreturn_t sparc64_msiq_interrupt(int irq, void *cookie)
12 {
13 	struct sparc64_msiq_cookie *msiq_cookie = cookie;
14 	struct pci_pbm_info *pbm = msiq_cookie->pbm;
15 	unsigned long msiqid = msiq_cookie->msiqid;
16 	const struct sparc64_msiq_ops *ops;
17 	unsigned long orig_head, head;
18 	int err;
19 
20 	ops = pbm->msi_ops;
21 
22 	err = ops->get_head(pbm, msiqid, &head);
23 	if (unlikely(err < 0))
24 		goto err_get_head;
25 
26 	orig_head = head;
27 	for (;;) {
28 		unsigned long msi;
29 
30 		err = ops->dequeue_msi(pbm, msiqid, &head, &msi);
31 		if (likely(err > 0)) {
32 			struct irq_desc *desc;
33 			unsigned int virt_irq;
34 
35 			virt_irq = pbm->msi_irq_table[msi - pbm->msi_first];
36 			desc = irq_desc + virt_irq;
37 
38 			desc->handle_irq(virt_irq, desc);
39 		}
40 
41 		if (unlikely(err < 0))
42 			goto err_dequeue;
43 
44 		if (err == 0)
45 			break;
46 	}
47 	if (likely(head != orig_head)) {
48 		err = ops->set_head(pbm, msiqid, head);
49 		if (unlikely(err < 0))
50 			goto err_set_head;
51 	}
52 	return IRQ_HANDLED;
53 
54 err_get_head:
55 	printk(KERN_EMERG "MSI: Get head on msiqid[%lu] gives error %d\n",
56 	       msiqid, err);
57 	goto err_out;
58 
59 err_dequeue:
60 	printk(KERN_EMERG "MSI: Dequeue head[%lu] from msiqid[%lu] "
61 	       "gives error %d\n",
62 	       head, msiqid, err);
63 	goto err_out;
64 
65 err_set_head:
66 	printk(KERN_EMERG "MSI: Set head[%lu] on msiqid[%lu] "
67 	       "gives error %d\n",
68 	       head, msiqid, err);
69 	goto err_out;
70 
71 err_out:
72 	return IRQ_NONE;
73 }
74 
75 static u32 pick_msiq(struct pci_pbm_info *pbm)
76 {
77 	static DEFINE_SPINLOCK(rotor_lock);
78 	unsigned long flags;
79 	u32 ret, rotor;
80 
81 	spin_lock_irqsave(&rotor_lock, flags);
82 
83 	rotor = pbm->msiq_rotor;
84 	ret = pbm->msiq_first + rotor;
85 
86 	if (++rotor >= pbm->msiq_num)
87 		rotor = 0;
88 	pbm->msiq_rotor = rotor;
89 
90 	spin_unlock_irqrestore(&rotor_lock, flags);
91 
92 	return ret;
93 }
94 
95 
96 static int alloc_msi(struct pci_pbm_info *pbm)
97 {
98 	int i;
99 
100 	for (i = 0; i < pbm->msi_num; i++) {
101 		if (!test_and_set_bit(i, pbm->msi_bitmap))
102 			return i + pbm->msi_first;
103 	}
104 
105 	return -ENOENT;
106 }
107 
108 static void free_msi(struct pci_pbm_info *pbm, int msi_num)
109 {
110 	msi_num -= pbm->msi_first;
111 	clear_bit(msi_num, pbm->msi_bitmap);
112 }
113 
114 static struct irq_chip msi_irq = {
115 	.typename	= "PCI-MSI",
116 	.mask		= mask_msi_irq,
117 	.unmask		= unmask_msi_irq,
118 	.enable		= unmask_msi_irq,
119 	.disable	= mask_msi_irq,
120 	/* XXX affinity XXX */
121 };
122 
123 static int sparc64_setup_msi_irq(unsigned int *virt_irq_p,
124 				 struct pci_dev *pdev,
125 				 struct msi_desc *entry)
126 {
127 	struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
128 	const struct sparc64_msiq_ops *ops = pbm->msi_ops;
129 	struct msi_msg msg;
130 	int msi, err;
131 	u32 msiqid;
132 
133 	*virt_irq_p = virt_irq_alloc(0, 0);
134 	err = -ENOMEM;
135 	if (!*virt_irq_p)
136 		goto out_err;
137 
138 	set_irq_chip_and_handler_name(*virt_irq_p, &msi_irq,
139 				      handle_simple_irq, "MSI");
140 
141 	err = alloc_msi(pbm);
142 	if (unlikely(err < 0))
143 		goto out_virt_irq_free;
144 
145 	msi = err;
146 
147 	msiqid = pick_msiq(pbm);
148 
149 	err = ops->msi_setup(pbm, msiqid, msi,
150 			     (entry->msi_attrib.is_64 ? 1 : 0));
151 	if (err)
152 		goto out_msi_free;
153 
154 	pbm->msi_irq_table[msi - pbm->msi_first] = *virt_irq_p;
155 
156 	if (entry->msi_attrib.is_64) {
157 		msg.address_hi = pbm->msi64_start >> 32;
158 		msg.address_lo = pbm->msi64_start & 0xffffffff;
159 	} else {
160 		msg.address_hi = 0;
161 		msg.address_lo = pbm->msi32_start;
162 	}
163 	msg.data = msi;
164 
165 	set_irq_msi(*virt_irq_p, entry);
166 	write_msi_msg(*virt_irq_p, &msg);
167 
168 	return 0;
169 
170 out_msi_free:
171 	free_msi(pbm, msi);
172 
173 out_virt_irq_free:
174 	set_irq_chip(*virt_irq_p, NULL);
175 	virt_irq_free(*virt_irq_p);
176 	*virt_irq_p = 0;
177 
178 out_err:
179 	return err;
180 }
181 
182 static void sparc64_teardown_msi_irq(unsigned int virt_irq,
183 				     struct pci_dev *pdev)
184 {
185 	struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
186 	const struct sparc64_msiq_ops *ops = pbm->msi_ops;
187 	unsigned int msi_num;
188 	int i, err;
189 
190 	for (i = 0; i < pbm->msi_num; i++) {
191 		if (pbm->msi_irq_table[i] == virt_irq)
192 			break;
193 	}
194 	if (i >= pbm->msi_num) {
195 		printk(KERN_ERR "%s: teardown: No MSI for irq %u\n",
196 		       pbm->name, virt_irq);
197 		return;
198 	}
199 
200 	msi_num = pbm->msi_first + i;
201 	pbm->msi_irq_table[i] = ~0U;
202 
203 	err = ops->msi_teardown(pbm, msi_num);
204 	if (err) {
205 		printk(KERN_ERR "%s: teardown: ops->teardown() on MSI %u, "
206 		       "irq %u, gives error %d\n",
207 		       pbm->name, msi_num, virt_irq, err);
208 		return;
209 	}
210 
211 	free_msi(pbm, msi_num);
212 
213 	set_irq_chip(virt_irq, NULL);
214 	virt_irq_free(virt_irq);
215 }
216 
217 static int msi_bitmap_alloc(struct pci_pbm_info *pbm)
218 {
219 	unsigned long size, bits_per_ulong;
220 
221 	bits_per_ulong = sizeof(unsigned long) * 8;
222 	size = (pbm->msi_num + (bits_per_ulong - 1)) & ~(bits_per_ulong - 1);
223 	size /= 8;
224 	BUG_ON(size % sizeof(unsigned long));
225 
226 	pbm->msi_bitmap = kzalloc(size, GFP_KERNEL);
227 	if (!pbm->msi_bitmap)
228 		return -ENOMEM;
229 
230 	return 0;
231 }
232 
233 static void msi_bitmap_free(struct pci_pbm_info *pbm)
234 {
235 	kfree(pbm->msi_bitmap);
236 	pbm->msi_bitmap = NULL;
237 }
238 
239 static int msi_table_alloc(struct pci_pbm_info *pbm)
240 {
241 	int size, i;
242 
243 	size = pbm->msiq_num * sizeof(struct sparc64_msiq_cookie);
244 	pbm->msiq_irq_cookies = kzalloc(size, GFP_KERNEL);
245 	if (!pbm->msiq_irq_cookies)
246 		return -ENOMEM;
247 
248 	for (i = 0; i < pbm->msiq_num; i++) {
249 		struct sparc64_msiq_cookie *p;
250 
251 		p = &pbm->msiq_irq_cookies[i];
252 		p->pbm = pbm;
253 		p->msiqid = pbm->msiq_first + i;
254 	}
255 
256 	size = pbm->msi_num * sizeof(unsigned int);
257 	pbm->msi_irq_table = kzalloc(size, GFP_KERNEL);
258 	if (!pbm->msi_irq_table) {
259 		kfree(pbm->msiq_irq_cookies);
260 		pbm->msiq_irq_cookies = NULL;
261 		return -ENOMEM;
262 	}
263 
264 	return 0;
265 }
266 
267 static void msi_table_free(struct pci_pbm_info *pbm)
268 {
269 	kfree(pbm->msiq_irq_cookies);
270 	pbm->msiq_irq_cookies = NULL;
271 
272 	kfree(pbm->msi_irq_table);
273 	pbm->msi_irq_table = NULL;
274 }
275 
276 static int bringup_one_msi_queue(struct pci_pbm_info *pbm,
277 				 const struct sparc64_msiq_ops *ops,
278 				 unsigned long msiqid,
279 				 unsigned long devino)
280 {
281 	int irq = ops->msiq_build_irq(pbm, msiqid, devino);
282 	int err, nid;
283 
284 	if (irq < 0)
285 		return irq;
286 
287 	nid = pbm->numa_node;
288 	if (nid != -1) {
289 		cpumask_t numa_mask = *cpumask_of_node(nid);
290 
291 		irq_set_affinity(irq, &numa_mask);
292 	}
293 	err = request_irq(irq, sparc64_msiq_interrupt, 0,
294 			  "MSIQ",
295 			  &pbm->msiq_irq_cookies[msiqid - pbm->msiq_first]);
296 	if (err)
297 		return err;
298 
299 	return 0;
300 }
301 
302 static int sparc64_bringup_msi_queues(struct pci_pbm_info *pbm,
303 				      const struct sparc64_msiq_ops *ops)
304 {
305 	int i;
306 
307 	for (i = 0; i < pbm->msiq_num; i++) {
308 		unsigned long msiqid = i + pbm->msiq_first;
309 		unsigned long devino = i + pbm->msiq_first_devino;
310 		int err;
311 
312 		err = bringup_one_msi_queue(pbm, ops, msiqid, devino);
313 		if (err)
314 			return err;
315 	}
316 
317 	return 0;
318 }
319 
320 void sparc64_pbm_msi_init(struct pci_pbm_info *pbm,
321 			  const struct sparc64_msiq_ops *ops)
322 {
323 	const u32 *val;
324 	int len;
325 
326 	val = of_get_property(pbm->op->node, "#msi-eqs", &len);
327 	if (!val || len != 4)
328 		goto no_msi;
329 	pbm->msiq_num = *val;
330 	if (pbm->msiq_num) {
331 		const struct msiq_prop {
332 			u32 first_msiq;
333 			u32 num_msiq;
334 			u32 first_devino;
335 		} *mqp;
336 		const struct msi_range_prop {
337 			u32 first_msi;
338 			u32 num_msi;
339 		} *mrng;
340 		const struct addr_range_prop {
341 			u32 msi32_high;
342 			u32 msi32_low;
343 			u32 msi32_len;
344 			u32 msi64_high;
345 			u32 msi64_low;
346 			u32 msi64_len;
347 		} *arng;
348 
349 		val = of_get_property(pbm->op->node, "msi-eq-size", &len);
350 		if (!val || len != 4)
351 			goto no_msi;
352 
353 		pbm->msiq_ent_count = *val;
354 
355 		mqp = of_get_property(pbm->op->node,
356 				      "msi-eq-to-devino", &len);
357 		if (!mqp)
358 			mqp = of_get_property(pbm->op->node,
359 					      "msi-eq-devino", &len);
360 		if (!mqp || len != sizeof(struct msiq_prop))
361 			goto no_msi;
362 
363 		pbm->msiq_first = mqp->first_msiq;
364 		pbm->msiq_first_devino = mqp->first_devino;
365 
366 		val = of_get_property(pbm->op->node, "#msi", &len);
367 		if (!val || len != 4)
368 			goto no_msi;
369 		pbm->msi_num = *val;
370 
371 		mrng = of_get_property(pbm->op->node, "msi-ranges", &len);
372 		if (!mrng || len != sizeof(struct msi_range_prop))
373 			goto no_msi;
374 		pbm->msi_first = mrng->first_msi;
375 
376 		val = of_get_property(pbm->op->node, "msi-data-mask", &len);
377 		if (!val || len != 4)
378 			goto no_msi;
379 		pbm->msi_data_mask = *val;
380 
381 		val = of_get_property(pbm->op->node, "msix-data-width", &len);
382 		if (!val || len != 4)
383 			goto no_msi;
384 		pbm->msix_data_width = *val;
385 
386 		arng = of_get_property(pbm->op->node, "msi-address-ranges",
387 				       &len);
388 		if (!arng || len != sizeof(struct addr_range_prop))
389 			goto no_msi;
390 		pbm->msi32_start = ((u64)arng->msi32_high << 32) |
391 			(u64) arng->msi32_low;
392 		pbm->msi64_start = ((u64)arng->msi64_high << 32) |
393 			(u64) arng->msi64_low;
394 		pbm->msi32_len = arng->msi32_len;
395 		pbm->msi64_len = arng->msi64_len;
396 
397 		if (msi_bitmap_alloc(pbm))
398 			goto no_msi;
399 
400 		if (msi_table_alloc(pbm)) {
401 			msi_bitmap_free(pbm);
402 			goto no_msi;
403 		}
404 
405 		if (ops->msiq_alloc(pbm)) {
406 			msi_table_free(pbm);
407 			msi_bitmap_free(pbm);
408 			goto no_msi;
409 		}
410 
411 		if (sparc64_bringup_msi_queues(pbm, ops)) {
412 			ops->msiq_free(pbm);
413 			msi_table_free(pbm);
414 			msi_bitmap_free(pbm);
415 			goto no_msi;
416 		}
417 
418 		printk(KERN_INFO "%s: MSI Queue first[%u] num[%u] count[%u] "
419 		       "devino[0x%x]\n",
420 		       pbm->name,
421 		       pbm->msiq_first, pbm->msiq_num,
422 		       pbm->msiq_ent_count,
423 		       pbm->msiq_first_devino);
424 		printk(KERN_INFO "%s: MSI first[%u] num[%u] mask[0x%x] "
425 		       "width[%u]\n",
426 		       pbm->name,
427 		       pbm->msi_first, pbm->msi_num, pbm->msi_data_mask,
428 		       pbm->msix_data_width);
429 		printk(KERN_INFO "%s: MSI addr32[0x%llx:0x%x] "
430 		       "addr64[0x%llx:0x%x]\n",
431 		       pbm->name,
432 		       pbm->msi32_start, pbm->msi32_len,
433 		       pbm->msi64_start, pbm->msi64_len);
434 		printk(KERN_INFO "%s: MSI queues at RA [%016lx]\n",
435 		       pbm->name,
436 		       __pa(pbm->msi_queues));
437 
438 		pbm->msi_ops = ops;
439 		pbm->setup_msi_irq = sparc64_setup_msi_irq;
440 		pbm->teardown_msi_irq = sparc64_teardown_msi_irq;
441 	}
442 	return;
443 
444 no_msi:
445 	pbm->msiq_num = 0;
446 	printk(KERN_INFO "%s: No MSI support.\n", pbm->name);
447 }
448