xref: /linux/arch/riscv/kvm/aia.c (revision 9cebfe6504488198b012e746bc6b313f88b95439)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2021 Western Digital Corporation or its affiliates.
4  * Copyright (C) 2022 Ventana Micro Systems Inc.
5  *
6  * Authors:
7  *	Anup Patel <apatel@ventanamicro.com>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/bitops.h>
12 #include <linux/irq.h>
13 #include <linux/irqchip/riscv-imsic.h>
14 #include <linux/irqdomain.h>
15 #include <linux/kvm_host.h>
16 #include <linux/nospec.h>
17 #include <linux/percpu.h>
18 #include <linux/spinlock.h>
19 #include <asm/cpufeature.h>
20 #include <asm/kvm_nacl.h>
21 
22 struct aia_hgei_control {
23 	raw_spinlock_t lock;
24 	bool free_bitmap_initialized;
25 	unsigned long free_bitmap;
26 	struct kvm_vcpu *owners[BITS_PER_LONG];
27 	unsigned int nr_hgei;
28 };
29 static DEFINE_PER_CPU(struct aia_hgei_control, aia_hgei);
30 static int hgei_parent_irq;
31 
32 atomic_t kvm_riscv_aia_nr_hgei;
33 unsigned int kvm_riscv_aia_max_ids;
34 DEFINE_STATIC_KEY_FALSE(kvm_riscv_aia_available);
35 
36 static inline unsigned long aia_hvictl_value(bool ext_irq_pending)
37 {
38 	unsigned long hvictl;
39 
40 	/*
41 	 * HVICTL.IID == 9 and HVICTL.IPRIO == 0 represents
42 	 * no interrupt in HVICTL.
43 	 */
44 
45 	hvictl = (IRQ_S_EXT << HVICTL_IID_SHIFT) & HVICTL_IID;
46 	hvictl |= ext_irq_pending;
47 	return hvictl;
48 }
49 
50 #ifdef CONFIG_32BIT
51 void kvm_riscv_vcpu_aia_flush_interrupts(struct kvm_vcpu *vcpu)
52 {
53 	struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
54 	unsigned long mask, val;
55 
56 	lockdep_assert_held(&vcpu->arch.irqs_pending_lock);
57 
58 	if (!kvm_riscv_aia_available())
59 		return;
60 
61 	mask = vcpu->arch.irqs_pending_mask[1];
62 	if (mask) {
63 		vcpu->arch.irqs_pending_mask[1] = 0;
64 		val = vcpu->arch.irqs_pending[1] & mask;
65 
66 		csr->hviph &= ~mask;
67 		csr->hviph |= val;
68 	}
69 }
70 
71 void kvm_riscv_vcpu_aia_sync_interrupts(struct kvm_vcpu *vcpu)
72 {
73 	struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
74 
75 	lockdep_assert_held(&vcpu->arch.irqs_pending_lock);
76 
77 	if (kvm_riscv_aia_available())
78 		csr->vsieh = ncsr_read(CSR_VSIEH);
79 }
80 #endif
81 
82 bool kvm_riscv_vcpu_aia_has_interrupts(struct kvm_vcpu *vcpu, u64 mask)
83 {
84 	unsigned long seip;
85 #ifdef CONFIG_32BIT
86 	unsigned long flags;
87 	bool pending;
88 #endif
89 
90 	if (!kvm_riscv_aia_available())
91 		return false;
92 
93 #ifdef CONFIG_32BIT
94 	raw_spin_lock_irqsave(&vcpu->arch.irqs_pending_lock, flags);
95 	pending = vcpu->arch.irqs_pending[1] &
96 		  (vcpu->arch.aia_context.guest_csr.vsieh &
97 		   upper_32_bits(mask));
98 	raw_spin_unlock_irqrestore(&vcpu->arch.irqs_pending_lock, flags);
99 
100 	if (pending)
101 		return true;
102 #endif
103 
104 	seip = vcpu->arch.guest_csr.vsie;
105 	seip &= (unsigned long)mask;
106 	seip &= BIT(IRQ_S_EXT);
107 
108 	if (!kvm_riscv_aia_initialized(vcpu->kvm) || !seip)
109 		return false;
110 
111 	return kvm_riscv_vcpu_aia_imsic_has_interrupt(vcpu);
112 }
113 
114 void kvm_riscv_vcpu_aia_update_hvip(struct kvm_vcpu *vcpu)
115 {
116 	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
117 
118 	if (!kvm_riscv_aia_available())
119 		return;
120 
121 #ifdef CONFIG_32BIT
122 	ncsr_write(CSR_HVIPH, vcpu->arch.aia_context.guest_csr.hviph);
123 #endif
124 	ncsr_write(CSR_HVICTL, aia_hvictl_value(!!(csr->hvip & BIT(IRQ_VS_EXT))));
125 }
126 
127 void kvm_riscv_vcpu_aia_load(struct kvm_vcpu *vcpu, int cpu)
128 {
129 	struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
130 	void *nsh;
131 
132 	if (!kvm_riscv_aia_available())
133 		return;
134 
135 	if (kvm_riscv_nacl_sync_csr_available()) {
136 		nsh = nacl_shmem();
137 		nacl_csr_write(nsh, CSR_VSISELECT, csr->vsiselect);
138 		nacl_csr_write(nsh, CSR_HVIPRIO1, csr->hviprio1);
139 		nacl_csr_write(nsh, CSR_HVIPRIO2, csr->hviprio2);
140 #ifdef CONFIG_32BIT
141 		nacl_csr_write(nsh, CSR_VSIEH, csr->vsieh);
142 		nacl_csr_write(nsh, CSR_HVIPH, csr->hviph);
143 		nacl_csr_write(nsh, CSR_HVIPRIO1H, csr->hviprio1h);
144 		nacl_csr_write(nsh, CSR_HVIPRIO2H, csr->hviprio2h);
145 #endif
146 	} else {
147 		csr_write(CSR_VSISELECT, csr->vsiselect);
148 		csr_write(CSR_HVIPRIO1, csr->hviprio1);
149 		csr_write(CSR_HVIPRIO2, csr->hviprio2);
150 #ifdef CONFIG_32BIT
151 		csr_write(CSR_VSIEH, csr->vsieh);
152 		csr_write(CSR_HVIPH, csr->hviph);
153 		csr_write(CSR_HVIPRIO1H, csr->hviprio1h);
154 		csr_write(CSR_HVIPRIO2H, csr->hviprio2h);
155 #endif
156 	}
157 
158 	if (kvm_riscv_aia_initialized(vcpu->kvm))
159 		kvm_riscv_vcpu_aia_imsic_load(vcpu, cpu);
160 }
161 
162 void kvm_riscv_vcpu_aia_put(struct kvm_vcpu *vcpu)
163 {
164 	struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
165 	void *nsh;
166 
167 	if (!kvm_riscv_aia_available())
168 		return;
169 
170 	if (kvm_riscv_aia_initialized(vcpu->kvm))
171 		kvm_riscv_vcpu_aia_imsic_put(vcpu);
172 
173 	if (kvm_riscv_nacl_available()) {
174 		nsh = nacl_shmem();
175 		csr->vsiselect = nacl_csr_read(nsh, CSR_VSISELECT);
176 		csr->hviprio1 = nacl_csr_read(nsh, CSR_HVIPRIO1);
177 		csr->hviprio2 = nacl_csr_read(nsh, CSR_HVIPRIO2);
178 #ifdef CONFIG_32BIT
179 		csr->vsieh = nacl_csr_read(nsh, CSR_VSIEH);
180 		csr->hviph = nacl_csr_read(nsh, CSR_HVIPH);
181 		csr->hviprio1h = nacl_csr_read(nsh, CSR_HVIPRIO1H);
182 		csr->hviprio2h = nacl_csr_read(nsh, CSR_HVIPRIO2H);
183 #endif
184 	} else {
185 		csr->vsiselect = csr_read(CSR_VSISELECT);
186 		csr->hviprio1 = csr_read(CSR_HVIPRIO1);
187 		csr->hviprio2 = csr_read(CSR_HVIPRIO2);
188 #ifdef CONFIG_32BIT
189 		csr->vsieh = csr_read(CSR_VSIEH);
190 		csr->hviph = csr_read(CSR_HVIPH);
191 		csr->hviprio1h = csr_read(CSR_HVIPRIO1H);
192 		csr->hviprio2h = csr_read(CSR_HVIPRIO2H);
193 #endif
194 	}
195 }
196 
197 int kvm_riscv_vcpu_aia_get_csr(struct kvm_vcpu *vcpu,
198 			       unsigned long reg_num,
199 			       unsigned long *out_val)
200 {
201 	struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
202 	unsigned long regs_max = sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long);
203 
204 	if (!riscv_isa_extension_available(vcpu->arch.isa, SSAIA))
205 		return -ENOENT;
206 	if (reg_num >= regs_max)
207 		return -ENOENT;
208 
209 	reg_num = array_index_nospec(reg_num, regs_max);
210 
211 	*out_val = 0;
212 	if (kvm_riscv_aia_available())
213 		*out_val = ((unsigned long *)csr)[reg_num];
214 
215 	return 0;
216 }
217 
218 int kvm_riscv_vcpu_aia_set_csr(struct kvm_vcpu *vcpu,
219 			       unsigned long reg_num,
220 			       unsigned long val)
221 {
222 	struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
223 	unsigned long regs_max = sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long);
224 #ifdef CONFIG_32BIT
225 	unsigned long flags;
226 #endif
227 
228 	if (!riscv_isa_extension_available(vcpu->arch.isa, SSAIA))
229 		return -ENOENT;
230 	if (reg_num >= regs_max)
231 		return -ENOENT;
232 
233 	reg_num = array_index_nospec(reg_num, regs_max);
234 
235 	if (kvm_riscv_aia_available()) {
236 		((unsigned long *)csr)[reg_num] = val;
237 
238 #ifdef CONFIG_32BIT
239 		if (reg_num == KVM_REG_RISCV_CSR_AIA_REG(siph)) {
240 			raw_spin_lock_irqsave(&vcpu->arch.irqs_pending_lock, flags);
241 			vcpu->arch.irqs_pending_mask[1] = 0;
242 			raw_spin_unlock_irqrestore(&vcpu->arch.irqs_pending_lock,
243 						   flags);
244 		}
245 #endif
246 	}
247 
248 	return 0;
249 }
250 
251 int kvm_riscv_vcpu_aia_rmw_topei(struct kvm_vcpu *vcpu,
252 				 unsigned int csr_num,
253 				 unsigned long *val,
254 				 unsigned long new_val,
255 				 unsigned long wr_mask)
256 {
257 	/* If AIA not available then redirect trap */
258 	if (!kvm_riscv_aia_available())
259 		return KVM_INSN_ILLEGAL_TRAP;
260 
261 	/* If AIA not initialized then forward to user space */
262 	if (!kvm_riscv_aia_initialized(vcpu->kvm))
263 		return KVM_INSN_EXIT_TO_USER_SPACE;
264 
265 	return kvm_riscv_vcpu_aia_imsic_rmw(vcpu, KVM_RISCV_AIA_IMSIC_TOPEI,
266 					    val, new_val, wr_mask);
267 }
268 
269 /*
270  * External IRQ priority always read-only zero. This means default
271  * priority order  is always preferred for external IRQs unless
272  * HVICTL.IID == 9 and HVICTL.IPRIO != 0
273  */
274 static int aia_irq2bitpos[] = {
275 0,     8,   -1,   -1,   16,   24,   -1,   -1, /* 0 - 7 */
276 32,   -1,   -1,   -1,   -1,   40,   48,   56, /* 8 - 15 */
277 64,   72,   80,   88,   96,  104,  112,  120, /* 16 - 23 */
278 -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1, /* 24 - 31 */
279 -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1, /* 32 - 39 */
280 -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1, /* 40 - 47 */
281 -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1, /* 48 - 55 */
282 -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1, /* 56 - 63 */
283 };
284 
285 static u8 aia_get_iprio8(struct kvm_vcpu *vcpu, unsigned int irq)
286 {
287 	unsigned long hviprio;
288 	int bitpos = aia_irq2bitpos[irq];
289 
290 	if (bitpos < 0)
291 		return 0;
292 
293 	switch (bitpos / BITS_PER_LONG) {
294 	case 0:
295 		hviprio = ncsr_read(CSR_HVIPRIO1);
296 		break;
297 	case 1:
298 #ifndef CONFIG_32BIT
299 		hviprio = ncsr_read(CSR_HVIPRIO2);
300 		break;
301 #else
302 		hviprio = ncsr_read(CSR_HVIPRIO1H);
303 		break;
304 	case 2:
305 		hviprio = ncsr_read(CSR_HVIPRIO2);
306 		break;
307 	case 3:
308 		hviprio = ncsr_read(CSR_HVIPRIO2H);
309 		break;
310 #endif
311 	default:
312 		return 0;
313 	}
314 
315 	return (hviprio >> (bitpos % BITS_PER_LONG)) & TOPI_IPRIO_MASK;
316 }
317 
318 static void aia_set_iprio8(struct kvm_vcpu *vcpu, unsigned int irq, u8 prio)
319 {
320 	unsigned long hviprio;
321 	int bitpos = aia_irq2bitpos[irq];
322 
323 	if (bitpos < 0)
324 		return;
325 
326 	switch (bitpos / BITS_PER_LONG) {
327 	case 0:
328 		hviprio = ncsr_read(CSR_HVIPRIO1);
329 		break;
330 	case 1:
331 #ifndef CONFIG_32BIT
332 		hviprio = ncsr_read(CSR_HVIPRIO2);
333 		break;
334 #else
335 		hviprio = ncsr_read(CSR_HVIPRIO1H);
336 		break;
337 	case 2:
338 		hviprio = ncsr_read(CSR_HVIPRIO2);
339 		break;
340 	case 3:
341 		hviprio = ncsr_read(CSR_HVIPRIO2H);
342 		break;
343 #endif
344 	default:
345 		return;
346 	}
347 
348 	hviprio &= ~(TOPI_IPRIO_MASK << (bitpos % BITS_PER_LONG));
349 	hviprio |= (unsigned long)prio << (bitpos % BITS_PER_LONG);
350 
351 	switch (bitpos / BITS_PER_LONG) {
352 	case 0:
353 		ncsr_write(CSR_HVIPRIO1, hviprio);
354 		break;
355 	case 1:
356 #ifndef CONFIG_32BIT
357 		ncsr_write(CSR_HVIPRIO2, hviprio);
358 		break;
359 #else
360 		ncsr_write(CSR_HVIPRIO1H, hviprio);
361 		break;
362 	case 2:
363 		ncsr_write(CSR_HVIPRIO2, hviprio);
364 		break;
365 	case 3:
366 		ncsr_write(CSR_HVIPRIO2H, hviprio);
367 		break;
368 #endif
369 	default:
370 		return;
371 	}
372 }
373 
374 static int aia_rmw_iprio(struct kvm_vcpu *vcpu, unsigned int isel,
375 			 unsigned long *val, unsigned long new_val,
376 			 unsigned long wr_mask)
377 {
378 	int i, first_irq, nirqs;
379 	unsigned long old_val;
380 	u8 prio;
381 
382 #ifndef CONFIG_32BIT
383 	if (isel & 0x1)
384 		return KVM_INSN_ILLEGAL_TRAP;
385 #endif
386 
387 	nirqs = 4 * (BITS_PER_LONG / 32);
388 	first_irq = (isel - ISELECT_IPRIO0) * 4;
389 
390 	old_val = 0;
391 	for (i = 0; i < nirqs; i++) {
392 		prio = aia_get_iprio8(vcpu, first_irq + i);
393 		old_val |= (unsigned long)prio << (TOPI_IPRIO_BITS * i);
394 	}
395 
396 	if (val)
397 		*val = old_val;
398 
399 	if (wr_mask) {
400 		new_val = (old_val & ~wr_mask) | (new_val & wr_mask);
401 		for (i = 0; i < nirqs; i++) {
402 			prio = (new_val >> (TOPI_IPRIO_BITS * i)) &
403 				TOPI_IPRIO_MASK;
404 			aia_set_iprio8(vcpu, first_irq + i, prio);
405 		}
406 	}
407 
408 	return KVM_INSN_CONTINUE_NEXT_SEPC;
409 }
410 
411 int kvm_riscv_vcpu_aia_rmw_ireg(struct kvm_vcpu *vcpu, unsigned int csr_num,
412 				unsigned long *val, unsigned long new_val,
413 				unsigned long wr_mask)
414 {
415 	unsigned int isel;
416 
417 	/* If AIA not available then redirect trap */
418 	if (!kvm_riscv_aia_available())
419 		return KVM_INSN_ILLEGAL_TRAP;
420 
421 	/* First try to emulate in kernel space */
422 	isel = ncsr_read(CSR_VSISELECT) & ISELECT_MASK;
423 	if (isel >= ISELECT_IPRIO0 && isel <= ISELECT_IPRIO15)
424 		return aia_rmw_iprio(vcpu, isel, val, new_val, wr_mask);
425 	else if (isel >= IMSIC_FIRST && isel <= IMSIC_LAST &&
426 		 kvm_riscv_aia_initialized(vcpu->kvm))
427 		return kvm_riscv_vcpu_aia_imsic_rmw(vcpu, isel, val, new_val,
428 						    wr_mask);
429 
430 	/* We can't handle it here so redirect to user space */
431 	return KVM_INSN_EXIT_TO_USER_SPACE;
432 }
433 
434 int kvm_riscv_aia_alloc_hgei(int cpu, struct kvm_vcpu *owner,
435 			     void __iomem **hgei_va, phys_addr_t *hgei_pa)
436 {
437 	int ret = -ENOENT;
438 	unsigned long flags;
439 	const struct imsic_global_config *gc;
440 	const struct imsic_local_config *lc;
441 	struct aia_hgei_control *hgctrl = per_cpu_ptr(&aia_hgei, cpu);
442 
443 	if (!kvm_riscv_aia_available() || !hgctrl)
444 		return -ENODEV;
445 
446 	raw_spin_lock_irqsave(&hgctrl->lock, flags);
447 
448 	if (hgctrl->free_bitmap) {
449 		ret = __ffs(hgctrl->free_bitmap);
450 		hgctrl->free_bitmap &= ~BIT(ret);
451 		hgctrl->owners[ret] = owner;
452 	}
453 
454 	raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
455 
456 	gc = imsic_get_global_config();
457 	lc = (gc) ? per_cpu_ptr(gc->local, cpu) : NULL;
458 	if (lc && ret > 0) {
459 		if (hgei_va)
460 			*hgei_va = lc->msi_va + (ret * IMSIC_MMIO_PAGE_SZ);
461 		if (hgei_pa)
462 			*hgei_pa = lc->msi_pa + (ret * IMSIC_MMIO_PAGE_SZ);
463 	}
464 
465 	return ret;
466 }
467 
468 void kvm_riscv_aia_free_hgei(int cpu, int hgei)
469 {
470 	unsigned long flags;
471 	struct aia_hgei_control *hgctrl = per_cpu_ptr(&aia_hgei, cpu);
472 
473 	if (!kvm_riscv_aia_available() || !hgctrl)
474 		return;
475 
476 	raw_spin_lock_irqsave(&hgctrl->lock, flags);
477 
478 	if (hgei > 0 && hgei <= hgctrl->nr_hgei) {
479 		if (!(hgctrl->free_bitmap & BIT(hgei))) {
480 			hgctrl->free_bitmap |= BIT(hgei);
481 			hgctrl->owners[hgei] = NULL;
482 		}
483 	}
484 
485 	raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
486 }
487 
488 static irqreturn_t hgei_interrupt(int irq, void *dev_id)
489 {
490 	int i;
491 	unsigned long hgei_mask, flags;
492 	struct aia_hgei_control *hgctrl = get_cpu_ptr(&aia_hgei);
493 
494 	hgei_mask = csr_read(CSR_HGEIP) & csr_read(CSR_HGEIE);
495 	csr_clear(CSR_HGEIE, hgei_mask);
496 
497 	raw_spin_lock_irqsave(&hgctrl->lock, flags);
498 
499 	for_each_set_bit(i, &hgei_mask, BITS_PER_LONG) {
500 		if (hgctrl->owners[i])
501 			kvm_vcpu_kick(hgctrl->owners[i]);
502 	}
503 
504 	raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
505 
506 	put_cpu_ptr(&aia_hgei);
507 	return IRQ_HANDLED;
508 }
509 
510 static int aia_hgei_init(void)
511 {
512 	struct aia_hgei_control *hgctrl;
513 	struct irq_domain *domain;
514 	int cpu, rc;
515 
516 	/* Initialize per-CPU guest external interrupt line management */
517 	for_each_possible_cpu(cpu) {
518 		hgctrl = per_cpu_ptr(&aia_hgei, cpu);
519 		raw_spin_lock_init(&hgctrl->lock);
520 		hgctrl->free_bitmap_initialized = false;
521 		hgctrl->free_bitmap = 0;
522 	}
523 
524 	/* Find INTC irq domain */
525 	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
526 					  DOMAIN_BUS_ANY);
527 	if (!domain) {
528 		kvm_err("unable to find INTC domain\n");
529 		return -ENOENT;
530 	}
531 
532 	/* Map per-CPU SGEI interrupt from INTC domain */
533 	hgei_parent_irq = irq_create_mapping(domain, IRQ_S_GEXT);
534 	if (!hgei_parent_irq) {
535 		kvm_err("unable to map SGEI IRQ\n");
536 		return -ENOMEM;
537 	}
538 
539 	/* Request per-CPU SGEI interrupt */
540 	rc = request_percpu_irq(hgei_parent_irq, hgei_interrupt,
541 				"riscv-kvm", &aia_hgei);
542 	if (rc) {
543 		kvm_err("failed to request SGEI IRQ\n");
544 		return rc;
545 	}
546 
547 	return 0;
548 }
549 
550 static void aia_hgei_exit(void)
551 {
552 	/* Free per-CPU SGEI interrupt */
553 	free_percpu_irq(hgei_parent_irq, &aia_hgei);
554 }
555 
556 void kvm_riscv_aia_enable(void)
557 {
558 	const struct imsic_global_config *gc;
559 	const struct imsic_local_config *lc;
560 	struct aia_hgei_control *hgctrl;
561 	unsigned long flags;
562 	int aia_nr_hgei;
563 
564 	if (!kvm_riscv_aia_available())
565 		return;
566 
567 	gc = imsic_get_global_config();
568 	lc = (gc) ? this_cpu_ptr(gc->local) : NULL;
569 	hgctrl = this_cpu_ptr(&aia_hgei);
570 
571 	/* Figure-out number of bits in HGEIE */
572 	csr_write(CSR_HGEIE, -1UL);
573 	hgctrl->nr_hgei = fls_long(csr_read(CSR_HGEIE));
574 	csr_write(CSR_HGEIE, 0);
575 	if (hgctrl->nr_hgei)
576 		hgctrl->nr_hgei--;
577 
578 	/*
579 	 * Number of usable per-HART HGEI lines should be minimum of
580 	 * per-HART IMSIC guest files and number of bits in HGEIE.
581 	 */
582 	if (lc)
583 		hgctrl->nr_hgei = min((ulong)hgctrl->nr_hgei, lc->nr_guest_files);
584 	else
585 		hgctrl->nr_hgei = 0;
586 
587 	/* Update the number of IMSIC guest files across all HARTs */
588 	aia_nr_hgei = atomic_read(&kvm_riscv_aia_nr_hgei);
589 	do {
590 		if (aia_nr_hgei <= hgctrl->nr_hgei)
591 			break;
592 	} while (!atomic_try_cmpxchg(&kvm_riscv_aia_nr_hgei, &aia_nr_hgei, hgctrl->nr_hgei));
593 
594 	raw_spin_lock_irqsave(&hgctrl->lock, flags);
595 	if (!hgctrl->free_bitmap_initialized) {
596 		hgctrl->free_bitmap = (hgctrl->nr_hgei) ? GENMASK_ULL(hgctrl->nr_hgei, 1) : 0;
597 		hgctrl->free_bitmap_initialized = true;
598 	}
599 	raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
600 
601 	csr_write(CSR_HVICTL, aia_hvictl_value(false));
602 	csr_write(CSR_HVIPRIO1, 0x0);
603 	csr_write(CSR_HVIPRIO2, 0x0);
604 #ifdef CONFIG_32BIT
605 	csr_write(CSR_HVIPH, 0x0);
606 	csr_write(CSR_HIDELEGH, 0x0);
607 	csr_write(CSR_HVIPRIO1H, 0x0);
608 	csr_write(CSR_HVIPRIO2H, 0x0);
609 #endif
610 
611 	/* Enable per-CPU SGEI interrupt */
612 	enable_percpu_irq(hgei_parent_irq,
613 			  irq_get_trigger_type(hgei_parent_irq));
614 	csr_set(CSR_HIE, BIT(IRQ_S_GEXT));
615 	/* Enable IRQ filtering for overflow interrupt only if sscofpmf is present */
616 	if (__riscv_isa_extension_available(NULL, RISCV_ISA_EXT_SSCOFPMF))
617 		csr_set(CSR_HVIEN, BIT(IRQ_PMU_OVF));
618 }
619 
620 void kvm_riscv_aia_disable(void)
621 {
622 	int i;
623 	unsigned long flags;
624 	struct kvm_vcpu *vcpu;
625 	struct aia_hgei_control *hgctrl;
626 
627 	if (!kvm_riscv_aia_available())
628 		return;
629 	hgctrl = get_cpu_ptr(&aia_hgei);
630 
631 	if (__riscv_isa_extension_available(NULL, RISCV_ISA_EXT_SSCOFPMF))
632 		csr_clear(CSR_HVIEN, BIT(IRQ_PMU_OVF));
633 	/* Disable per-CPU SGEI interrupt */
634 	csr_clear(CSR_HIE, BIT(IRQ_S_GEXT));
635 	disable_percpu_irq(hgei_parent_irq);
636 
637 	csr_write(CSR_HVICTL, aia_hvictl_value(false));
638 
639 	raw_spin_lock_irqsave(&hgctrl->lock, flags);
640 
641 	for (i = 0; i <= hgctrl->nr_hgei; i++) {
642 		vcpu = hgctrl->owners[i];
643 		if (!vcpu)
644 			continue;
645 
646 		/*
647 		 * We release hgctrl->lock before notifying IMSIC
648 		 * so that we don't have lock ordering issues.
649 		 */
650 		raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
651 
652 		/* Notify IMSIC */
653 		kvm_riscv_vcpu_aia_imsic_release(vcpu);
654 
655 		/*
656 		 * Wakeup VCPU if it was blocked so that it can
657 		 * run on other HARTs
658 		 */
659 		if (csr_read(CSR_HGEIE) & BIT(i)) {
660 			csr_clear(CSR_HGEIE, BIT(i));
661 			kvm_vcpu_kick(vcpu);
662 		}
663 
664 		raw_spin_lock_irqsave(&hgctrl->lock, flags);
665 	}
666 
667 	raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
668 
669 	put_cpu_ptr(&aia_hgei);
670 }
671 
672 int kvm_riscv_aia_init(void)
673 {
674 	int rc;
675 	const struct imsic_global_config *gc;
676 
677 	if (!riscv_isa_extension_available(NULL, SxAIA))
678 		return -ENODEV;
679 	gc = imsic_get_global_config();
680 
681 	/* Set initial value of IMSIC guest files across all HARTs */
682 	if (gc)
683 		atomic_set(&kvm_riscv_aia_nr_hgei, gc->nr_guest_files);
684 	else
685 		atomic_set(&kvm_riscv_aia_nr_hgei, 0);
686 
687 	/* Find number of guest MSI IDs */
688 	kvm_riscv_aia_max_ids = IMSIC_MAX_ID;
689 	if (gc)
690 		kvm_riscv_aia_max_ids = gc->nr_guest_ids + 1;
691 
692 	/* Initialize guest external interrupt line management */
693 	rc = aia_hgei_init();
694 	if (rc)
695 		return rc;
696 
697 	/* Register device operations */
698 	rc = kvm_register_device_ops(&kvm_riscv_aia_device_ops,
699 				     KVM_DEV_TYPE_RISCV_AIA);
700 	if (rc) {
701 		aia_hgei_exit();
702 		return rc;
703 	}
704 
705 	/* Enable KVM AIA support */
706 	static_branch_enable(&kvm_riscv_aia_available);
707 
708 	return 0;
709 }
710 
711 void kvm_riscv_aia_exit(void)
712 {
713 	if (!kvm_riscv_aia_available())
714 		return;
715 
716 	/* Unregister device operations */
717 	kvm_unregister_device_ops(KVM_DEV_TYPE_RISCV_AIA);
718 
719 	/* Cleanup the HGEI state */
720 	aia_hgei_exit();
721 }
722