xref: /openbmc/linux/arch/powerpc/sysdev/xive/native.c (revision fcc8487d)
1 /*
2  * Copyright 2016,2017 IBM Corporation.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  */
9 
10 #define pr_fmt(fmt) "xive: " fmt
11 
12 #include <linux/types.h>
13 #include <linux/irq.h>
14 #include <linux/debugfs.h>
15 #include <linux/smp.h>
16 #include <linux/interrupt.h>
17 #include <linux/seq_file.h>
18 #include <linux/init.h>
19 #include <linux/of.h>
20 #include <linux/slab.h>
21 #include <linux/spinlock.h>
22 #include <linux/delay.h>
23 #include <linux/cpumask.h>
24 #include <linux/mm.h>
25 
26 #include <asm/prom.h>
27 #include <asm/io.h>
28 #include <asm/smp.h>
29 #include <asm/irq.h>
30 #include <asm/errno.h>
31 #include <asm/xive.h>
32 #include <asm/xive-regs.h>
33 #include <asm/opal.h>
34 
35 #include "xive-internal.h"
36 
37 
38 static u32 xive_provision_size;
39 static u32 *xive_provision_chips;
40 static u32 xive_provision_chip_count;
41 static u32 xive_queue_shift;
42 static u32 xive_pool_vps = XIVE_INVALID_VP;
43 static struct kmem_cache *xive_provision_cache;
44 
45 int xive_native_populate_irq_data(u32 hw_irq, struct xive_irq_data *data)
46 {
47 	__be64 flags, eoi_page, trig_page;
48 	__be32 esb_shift, src_chip;
49 	u64 opal_flags;
50 	s64 rc;
51 
52 	memset(data, 0, sizeof(*data));
53 
54 	rc = opal_xive_get_irq_info(hw_irq, &flags, &eoi_page, &trig_page,
55 				    &esb_shift, &src_chip);
56 	if (rc) {
57 		pr_err("opal_xive_get_irq_info(0x%x) returned %lld\n",
58 		       hw_irq, rc);
59 		return -EINVAL;
60 	}
61 
62 	opal_flags = be64_to_cpu(flags);
63 	if (opal_flags & OPAL_XIVE_IRQ_STORE_EOI)
64 		data->flags |= XIVE_IRQ_FLAG_STORE_EOI;
65 	if (opal_flags & OPAL_XIVE_IRQ_LSI)
66 		data->flags |= XIVE_IRQ_FLAG_LSI;
67 	if (opal_flags & OPAL_XIVE_IRQ_SHIFT_BUG)
68 		data->flags |= XIVE_IRQ_FLAG_SHIFT_BUG;
69 	if (opal_flags & OPAL_XIVE_IRQ_MASK_VIA_FW)
70 		data->flags |= XIVE_IRQ_FLAG_MASK_FW;
71 	if (opal_flags & OPAL_XIVE_IRQ_EOI_VIA_FW)
72 		data->flags |= XIVE_IRQ_FLAG_EOI_FW;
73 	data->eoi_page = be64_to_cpu(eoi_page);
74 	data->trig_page = be64_to_cpu(trig_page);
75 	data->esb_shift = be32_to_cpu(esb_shift);
76 	data->src_chip = be32_to_cpu(src_chip);
77 
78 	data->eoi_mmio = ioremap(data->eoi_page, 1u << data->esb_shift);
79 	if (!data->eoi_mmio) {
80 		pr_err("Failed to map EOI page for irq 0x%x\n", hw_irq);
81 		return -ENOMEM;
82 	}
83 
84 	if (!data->trig_page)
85 		return 0;
86 	if (data->trig_page == data->eoi_page) {
87 		data->trig_mmio = data->eoi_mmio;
88 		return 0;
89 	}
90 
91 	data->trig_mmio = ioremap(data->trig_page, 1u << data->esb_shift);
92 	if (!data->trig_mmio) {
93 		pr_err("Failed to map trigger page for irq 0x%x\n", hw_irq);
94 		return -ENOMEM;
95 	}
96 	return 0;
97 }
98 
99 int xive_native_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 sw_irq)
100 {
101 	s64 rc;
102 
103 	for (;;) {
104 		rc = opal_xive_set_irq_config(hw_irq, target, prio, sw_irq);
105 		if (rc != OPAL_BUSY)
106 			break;
107 		msleep(1);
108 	}
109 	return rc == 0 ? 0 : -ENXIO;
110 }
111 
112 /* This can be called multiple time to change a queue configuration */
113 int xive_native_configure_queue(u32 vp_id, struct xive_q *q, u8 prio,
114 				__be32 *qpage, u32 order, bool can_escalate)
115 {
116 	s64 rc = 0;
117 	__be64 qeoi_page_be;
118 	__be32 esc_irq_be;
119 	u64 flags, qpage_phys;
120 
121 	/* If there's an actual queue page, clean it */
122 	if (order) {
123 		if (WARN_ON(!qpage))
124 			return -EINVAL;
125 		qpage_phys = __pa(qpage);
126 	} else
127 		qpage_phys = 0;
128 
129 	/* Initialize the rest of the fields */
130 	q->msk = order ? ((1u << (order - 2)) - 1) : 0;
131 	q->idx = 0;
132 	q->toggle = 0;
133 
134 	rc = opal_xive_get_queue_info(vp_id, prio, NULL, NULL,
135 				      &qeoi_page_be,
136 				      &esc_irq_be,
137 				      NULL);
138 	if (rc) {
139 		pr_err("Error %lld getting queue info prio %d\n", rc, prio);
140 		rc = -EIO;
141 		goto fail;
142 	}
143 	q->eoi_phys = be64_to_cpu(qeoi_page_be);
144 
145 	/* Default flags */
146 	flags = OPAL_XIVE_EQ_ALWAYS_NOTIFY | OPAL_XIVE_EQ_ENABLED;
147 
148 	/* Escalation needed ? */
149 	if (can_escalate) {
150 		q->esc_irq = be32_to_cpu(esc_irq_be);
151 		flags |= OPAL_XIVE_EQ_ESCALATE;
152 	}
153 
154 	/* Configure and enable the queue in HW */
155 	for (;;) {
156 		rc = opal_xive_set_queue_info(vp_id, prio, qpage_phys, order, flags);
157 		if (rc != OPAL_BUSY)
158 			break;
159 		msleep(1);
160 	}
161 	if (rc) {
162 		pr_err("Error %lld setting queue for prio %d\n", rc, prio);
163 		rc = -EIO;
164 	} else {
165 		/*
166 		 * KVM code requires all of the above to be visible before
167 		 * q->qpage is set due to how it manages IPI EOIs
168 		 */
169 		wmb();
170 		q->qpage = qpage;
171 	}
172 fail:
173 	return rc;
174 }
175 
176 static void __xive_native_disable_queue(u32 vp_id, struct xive_q *q, u8 prio)
177 {
178 	s64 rc;
179 
180 	/* Disable the queue in HW */
181 	for (;;) {
182 		rc = opal_xive_set_queue_info(vp_id, prio, 0, 0, 0);
183 		if (rc != OPAL_BUSY)
184 			break;
185 		msleep(1);
186 	}
187 	if (rc)
188 		pr_err("Error %lld disabling queue for prio %d\n", rc, prio);
189 }
190 
191 void xive_native_disable_queue(u32 vp_id, struct xive_q *q, u8 prio)
192 {
193 	__xive_native_disable_queue(vp_id, q, prio);
194 }
195 
196 static int xive_native_setup_queue(unsigned int cpu, struct xive_cpu *xc, u8 prio)
197 {
198 	struct xive_q *q = &xc->queue[prio];
199 	unsigned int alloc_order;
200 	struct page *pages;
201 	__be32 *qpage;
202 
203 	alloc_order = (xive_queue_shift > PAGE_SHIFT) ?
204 		(xive_queue_shift - PAGE_SHIFT) : 0;
205 	pages = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, alloc_order);
206 	if (!pages)
207 		return -ENOMEM;
208 	qpage = (__be32 *)page_address(pages);
209 	memset(qpage, 0, 1 << xive_queue_shift);
210 	return xive_native_configure_queue(get_hard_smp_processor_id(cpu),
211 					   q, prio, qpage, xive_queue_shift, false);
212 }
213 
214 static void xive_native_cleanup_queue(unsigned int cpu, struct xive_cpu *xc, u8 prio)
215 {
216 	struct xive_q *q = &xc->queue[prio];
217 	unsigned int alloc_order;
218 
219 	/*
220 	 * We use the variant with no iounmap as this is called on exec
221 	 * from an IPI and iounmap isn't safe
222 	 */
223 	__xive_native_disable_queue(get_hard_smp_processor_id(cpu), q, prio);
224 	alloc_order = (xive_queue_shift > PAGE_SHIFT) ?
225 		(xive_queue_shift - PAGE_SHIFT) : 0;
226 	free_pages((unsigned long)q->qpage, alloc_order);
227 	q->qpage = NULL;
228 }
229 
230 static bool xive_native_match(struct device_node *node)
231 {
232 	return of_device_is_compatible(node, "ibm,opal-xive-vc");
233 }
234 
235 #ifdef CONFIG_SMP
236 static int xive_native_get_ipi(unsigned int cpu, struct xive_cpu *xc)
237 {
238 	struct device_node *np;
239 	unsigned int chip_id;
240 	s64 irq;
241 
242 	/* Find the chip ID */
243 	np = of_get_cpu_node(cpu, NULL);
244 	if (np) {
245 		if (of_property_read_u32(np, "ibm,chip-id", &chip_id) < 0)
246 			chip_id = 0;
247 	}
248 
249 	/* Allocate an IPI and populate info about it */
250 	for (;;) {
251 		irq = opal_xive_allocate_irq(chip_id);
252 		if (irq == OPAL_BUSY) {
253 			msleep(1);
254 			continue;
255 		}
256 		if (irq < 0) {
257 			pr_err("Failed to allocate IPI on CPU %d\n", cpu);
258 			return -ENXIO;
259 		}
260 		xc->hw_ipi = irq;
261 		break;
262 	}
263 	return 0;
264 }
265 
266 u32 xive_native_alloc_irq(void)
267 {
268 	s64 rc;
269 
270 	for (;;) {
271 		rc = opal_xive_allocate_irq(OPAL_XIVE_ANY_CHIP);
272 		if (rc != OPAL_BUSY)
273 			break;
274 		msleep(1);
275 	}
276 	if (rc < 0)
277 		return 0;
278 	return rc;
279 }
280 
281 void xive_native_free_irq(u32 irq)
282 {
283 	for (;;) {
284 		s64 rc = opal_xive_free_irq(irq);
285 		if (rc != OPAL_BUSY)
286 			break;
287 		msleep(1);
288 	}
289 }
290 
291 static void xive_native_put_ipi(unsigned int cpu, struct xive_cpu *xc)
292 {
293 	s64 rc;
294 
295 	/* Free the IPI */
296 	if (!xc->hw_ipi)
297 		return;
298 	for (;;) {
299 		rc = opal_xive_free_irq(xc->hw_ipi);
300 		if (rc == OPAL_BUSY) {
301 			msleep(1);
302 			continue;
303 		}
304 		xc->hw_ipi = 0;
305 		break;
306 	}
307 }
308 #endif /* CONFIG_SMP */
309 
310 static void xive_native_shutdown(void)
311 {
312 	/* Switch the XIVE to emulation mode */
313 	opal_xive_reset(OPAL_XIVE_MODE_EMU);
314 }
315 
316 /*
317  * Perform an "ack" cycle on the current thread, thus
318  * grabbing the pending active priorities and updating
319  * the CPPR to the most favored one.
320  */
321 static void xive_native_update_pending(struct xive_cpu *xc)
322 {
323 	u8 he, cppr;
324 	u16 ack;
325 
326 	/* Perform the acknowledge hypervisor to register cycle */
327 	ack = be16_to_cpu(__raw_readw(xive_tima + TM_SPC_ACK_HV_REG));
328 
329 	/* Synchronize subsequent queue accesses */
330 	mb();
331 
332 	/*
333 	 * Grab the CPPR and the "HE" field which indicates the source
334 	 * of the hypervisor interrupt (if any)
335 	 */
336 	cppr = ack & 0xff;
337 	he = GETFIELD(TM_QW3_NSR_HE, (ack >> 8));
338 	switch(he) {
339 	case TM_QW3_NSR_HE_NONE: /* Nothing to see here */
340 		break;
341 	case TM_QW3_NSR_HE_PHYS: /* Physical thread interrupt */
342 		if (cppr == 0xff)
343 			return;
344 		/* Mark the priority pending */
345 		xc->pending_prio |= 1 << cppr;
346 
347 		/*
348 		 * A new interrupt should never have a CPPR less favored
349 		 * than our current one.
350 		 */
351 		if (cppr >= xc->cppr)
352 			pr_err("CPU %d odd ack CPPR, got %d at %d\n",
353 			       smp_processor_id(), cppr, xc->cppr);
354 
355 		/* Update our idea of what the CPPR is */
356 		xc->cppr = cppr;
357 		break;
358 	case TM_QW3_NSR_HE_POOL: /* HV Pool interrupt (unused) */
359 	case TM_QW3_NSR_HE_LSI:  /* Legacy FW LSI (unused) */
360 		pr_err("CPU %d got unexpected interrupt type HE=%d\n",
361 		       smp_processor_id(), he);
362 		return;
363 	}
364 }
365 
366 static void xive_native_eoi(u32 hw_irq)
367 {
368 	/*
369 	 * Not normally used except if specific interrupts need
370 	 * a workaround on EOI.
371 	 */
372 	opal_int_eoi(hw_irq);
373 }
374 
375 static void xive_native_setup_cpu(unsigned int cpu, struct xive_cpu *xc)
376 {
377 	s64 rc;
378 	u32 vp;
379 	__be64 vp_cam_be;
380 	u64 vp_cam;
381 
382 	if (xive_pool_vps == XIVE_INVALID_VP)
383 		return;
384 
385 	/* Enable the pool VP */
386 	vp = xive_pool_vps + get_hard_smp_processor_id(cpu);
387 	pr_debug("CPU %d setting up pool VP 0x%x\n", cpu, vp);
388 	for (;;) {
389 		rc = opal_xive_set_vp_info(vp, OPAL_XIVE_VP_ENABLED, 0);
390 		if (rc != OPAL_BUSY)
391 			break;
392 		msleep(1);
393 	}
394 	if (rc) {
395 		pr_err("Failed to enable pool VP on CPU %d\n", cpu);
396 		return;
397 	}
398 
399 	/* Grab it's CAM value */
400 	rc = opal_xive_get_vp_info(vp, NULL, &vp_cam_be, NULL, NULL);
401 	if (rc) {
402 		pr_err("Failed to get pool VP info CPU %d\n", cpu);
403 		return;
404 	}
405 	vp_cam = be64_to_cpu(vp_cam_be);
406 
407 	pr_debug("VP CAM = %llx\n", vp_cam);
408 
409 	/* Push it on the CPU (set LSMFB to 0xff to skip backlog scan) */
410 	pr_debug("(Old HW value: %08x)\n",
411 		 in_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD2));
412 	out_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD0, 0xff);
413 	out_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD2,
414 		 TM_QW2W2_VP | vp_cam);
415 	pr_debug("(New HW value: %08x)\n",
416 		 in_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD2));
417 }
418 
419 static void xive_native_teardown_cpu(unsigned int cpu, struct xive_cpu *xc)
420 {
421 	s64 rc;
422 	u32 vp;
423 
424 	if (xive_pool_vps == XIVE_INVALID_VP)
425 		return;
426 
427 	/* Pull the pool VP from the CPU */
428 	in_be64(xive_tima + TM_SPC_PULL_POOL_CTX);
429 
430 	/* Disable it */
431 	vp = xive_pool_vps + get_hard_smp_processor_id(cpu);
432 	for (;;) {
433 		rc = opal_xive_set_vp_info(vp, 0, 0);
434 		if (rc != OPAL_BUSY)
435 			break;
436 		msleep(1);
437 	}
438 }
439 
440 static void xive_native_sync_source(u32 hw_irq)
441 {
442 	opal_xive_sync(XIVE_SYNC_EAS, hw_irq);
443 }
444 
445 static const struct xive_ops xive_native_ops = {
446 	.populate_irq_data	= xive_native_populate_irq_data,
447 	.configure_irq		= xive_native_configure_irq,
448 	.setup_queue		= xive_native_setup_queue,
449 	.cleanup_queue		= xive_native_cleanup_queue,
450 	.match			= xive_native_match,
451 	.shutdown		= xive_native_shutdown,
452 	.update_pending		= xive_native_update_pending,
453 	.eoi			= xive_native_eoi,
454 	.setup_cpu		= xive_native_setup_cpu,
455 	.teardown_cpu		= xive_native_teardown_cpu,
456 	.sync_source		= xive_native_sync_source,
457 #ifdef CONFIG_SMP
458 	.get_ipi		= xive_native_get_ipi,
459 	.put_ipi		= xive_native_put_ipi,
460 #endif /* CONFIG_SMP */
461 	.name			= "native",
462 };
463 
464 static bool xive_parse_provisioning(struct device_node *np)
465 {
466 	int rc;
467 
468 	if (of_property_read_u32(np, "ibm,xive-provision-page-size",
469 				 &xive_provision_size) < 0)
470 		return true;
471 	rc = of_property_count_elems_of_size(np, "ibm,xive-provision-chips", 4);
472 	if (rc < 0) {
473 		pr_err("Error %d getting provision chips array\n", rc);
474 		return false;
475 	}
476 	xive_provision_chip_count = rc;
477 	if (rc == 0)
478 		return true;
479 
480 	xive_provision_chips = kzalloc(4 * xive_provision_chip_count,
481 				       GFP_KERNEL);
482 	if (WARN_ON(!xive_provision_chips))
483 		return false;
484 
485 	rc = of_property_read_u32_array(np, "ibm,xive-provision-chips",
486 					xive_provision_chips,
487 					xive_provision_chip_count);
488 	if (rc < 0) {
489 		pr_err("Error %d reading provision chips array\n", rc);
490 		return false;
491 	}
492 
493 	xive_provision_cache = kmem_cache_create("xive-provision",
494 						 xive_provision_size,
495 						 xive_provision_size,
496 						 0, NULL);
497 	if (!xive_provision_cache) {
498 		pr_err("Failed to allocate provision cache\n");
499 		return false;
500 	}
501 	return true;
502 }
503 
504 u32 xive_native_default_eq_shift(void)
505 {
506 	return xive_queue_shift;
507 }
508 
509 bool xive_native_init(void)
510 {
511 	struct device_node *np;
512 	struct resource r;
513 	void __iomem *tima;
514 	struct property *prop;
515 	u8 max_prio = 7;
516 	const __be32 *p;
517 	u32 val;
518 	s64 rc;
519 
520 	if (xive_cmdline_disabled)
521 		return false;
522 
523 	pr_devel("xive_native_init()\n");
524 	np = of_find_compatible_node(NULL, NULL, "ibm,opal-xive-pe");
525 	if (!np) {
526 		pr_devel("not found !\n");
527 		return false;
528 	}
529 	pr_devel("Found %s\n", np->full_name);
530 
531 	/* Resource 1 is HV window */
532 	if (of_address_to_resource(np, 1, &r)) {
533 		pr_err("Failed to get thread mgmnt area resource\n");
534 		return false;
535 	}
536 	tima = ioremap(r.start, resource_size(&r));
537 	if (!tima) {
538 		pr_err("Failed to map thread mgmnt area\n");
539 		return false;
540 	}
541 
542 	/* Read number of priorities */
543 	if (of_property_read_u32(np, "ibm,xive-#priorities", &val) == 0)
544 		max_prio = val - 1;
545 
546 	/* Iterate the EQ sizes and pick one */
547 	of_property_for_each_u32(np, "ibm,xive-eq-sizes", prop, p, val) {
548 		xive_queue_shift = val;
549 		if (val == PAGE_SHIFT)
550 			break;
551 	}
552 
553 	/* Grab size of provisioning pages */
554 	xive_parse_provisioning(np);
555 
556 	/* Switch the XIVE to exploitation mode */
557 	rc = opal_xive_reset(OPAL_XIVE_MODE_EXPL);
558 	if (rc) {
559 		pr_err("Switch to exploitation mode failed with error %lld\n", rc);
560 		return false;
561 	}
562 
563 	/* Initialize XIVE core with our backend */
564 	if (!xive_core_init(&xive_native_ops, tima, TM_QW3_HV_PHYS,
565 			    max_prio)) {
566 		opal_xive_reset(OPAL_XIVE_MODE_EMU);
567 		return false;
568 	}
569 	pr_info("Using %dkB queues\n", 1 << (xive_queue_shift - 10));
570 	return true;
571 }
572 
573 static bool xive_native_provision_pages(void)
574 {
575 	u32 i;
576 	void *p;
577 
578 	for (i = 0; i < xive_provision_chip_count; i++) {
579 		u32 chip = xive_provision_chips[i];
580 
581 		/*
582 		 * XXX TODO: Try to make the allocation local to the node where
583 		 * the chip resides.
584 		 */
585 		p = kmem_cache_alloc(xive_provision_cache, GFP_KERNEL);
586 		if (!p) {
587 			pr_err("Failed to allocate provisioning page\n");
588 			return false;
589 		}
590 		opal_xive_donate_page(chip, __pa(p));
591 	}
592 	return true;
593 }
594 
595 u32 xive_native_alloc_vp_block(u32 max_vcpus)
596 {
597 	s64 rc;
598 	u32 order;
599 
600 	order = fls(max_vcpus) - 1;
601 	if (max_vcpus > (1 << order))
602 		order++;
603 
604 	pr_info("VP block alloc, for max VCPUs %d use order %d\n",
605 		max_vcpus, order);
606 
607 	for (;;) {
608 		rc = opal_xive_alloc_vp_block(order);
609 		switch (rc) {
610 		case OPAL_BUSY:
611 			msleep(1);
612 			break;
613 		case OPAL_XIVE_PROVISIONING:
614 			if (!xive_native_provision_pages())
615 				return XIVE_INVALID_VP;
616 			break;
617 		default:
618 			if (rc < 0) {
619 				pr_err("OPAL failed to allocate VCPUs order %d, err %lld\n",
620 				       order, rc);
621 				return XIVE_INVALID_VP;
622 			}
623 			return rc;
624 		}
625 	}
626 }
627 EXPORT_SYMBOL_GPL(xive_native_alloc_vp_block);
628 
629 void xive_native_free_vp_block(u32 vp_base)
630 {
631 	s64 rc;
632 
633 	if (vp_base == XIVE_INVALID_VP)
634 		return;
635 
636 	rc = opal_xive_free_vp_block(vp_base);
637 	if (rc < 0)
638 		pr_warn("OPAL error %lld freeing VP block\n", rc);
639 }
640 EXPORT_SYMBOL_GPL(xive_native_free_vp_block);
641