xref: /linux/arch/riscv/kvm/aia_imsic.c (revision 63eb28bb1402891b1ad2be02a530f29a9dd7f1cd)
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/atomic.h>
11 #include <linux/bitmap.h>
12 #include <linux/irqchip/riscv-imsic.h>
13 #include <linux/kvm_host.h>
14 #include <linux/math.h>
15 #include <linux/spinlock.h>
16 #include <linux/swab.h>
17 #include <kvm/iodev.h>
18 #include <asm/csr.h>
19 #include <asm/kvm_mmu.h>
20 
21 #define IMSIC_MAX_EIX	(IMSIC_MAX_ID / BITS_PER_TYPE(u64))
22 
23 struct imsic_mrif_eix {
24 	unsigned long eip[BITS_PER_TYPE(u64) / BITS_PER_LONG];
25 	unsigned long eie[BITS_PER_TYPE(u64) / BITS_PER_LONG];
26 };
27 
28 struct imsic_mrif {
29 	struct imsic_mrif_eix eix[IMSIC_MAX_EIX];
30 	unsigned long eithreshold;
31 	unsigned long eidelivery;
32 };
33 
34 struct imsic {
35 	struct kvm_io_device iodev;
36 
37 	u32 nr_msis;
38 	u32 nr_eix;
39 	u32 nr_hw_eix;
40 
41 	/*
42 	 * At any point in time, the register state is in
43 	 * one of the following places:
44 	 *
45 	 * 1) Hardware: IMSIC VS-file (vsfile_cpu >= 0)
46 	 * 2) Software: IMSIC SW-file (vsfile_cpu < 0)
47 	 */
48 
49 	/* IMSIC VS-file */
50 	rwlock_t vsfile_lock;
51 	int vsfile_cpu;
52 	int vsfile_hgei;
53 	void __iomem *vsfile_va;
54 	phys_addr_t vsfile_pa;
55 
56 	/* IMSIC SW-file */
57 	struct imsic_mrif *swfile;
58 	phys_addr_t swfile_pa;
59 	raw_spinlock_t swfile_extirq_lock;
60 };
61 
62 #define imsic_vs_csr_read(__c)			\
63 ({						\
64 	unsigned long __r;			\
65 	csr_write(CSR_VSISELECT, __c);		\
66 	__r = csr_read(CSR_VSIREG);		\
67 	__r;					\
68 })
69 
70 #define imsic_read_switchcase(__ireg)			\
71 	case __ireg:					\
72 		return imsic_vs_csr_read(__ireg);
73 #define imsic_read_switchcase_2(__ireg)			\
74 	imsic_read_switchcase(__ireg + 0)		\
75 	imsic_read_switchcase(__ireg + 1)
76 #define imsic_read_switchcase_4(__ireg)			\
77 	imsic_read_switchcase_2(__ireg + 0)		\
78 	imsic_read_switchcase_2(__ireg + 2)
79 #define imsic_read_switchcase_8(__ireg)			\
80 	imsic_read_switchcase_4(__ireg + 0)		\
81 	imsic_read_switchcase_4(__ireg + 4)
82 #define imsic_read_switchcase_16(__ireg)		\
83 	imsic_read_switchcase_8(__ireg + 0)		\
84 	imsic_read_switchcase_8(__ireg + 8)
85 #define imsic_read_switchcase_32(__ireg)		\
86 	imsic_read_switchcase_16(__ireg + 0)		\
87 	imsic_read_switchcase_16(__ireg + 16)
88 #define imsic_read_switchcase_64(__ireg)		\
89 	imsic_read_switchcase_32(__ireg + 0)		\
90 	imsic_read_switchcase_32(__ireg + 32)
91 
imsic_eix_read(int ireg)92 static unsigned long imsic_eix_read(int ireg)
93 {
94 	switch (ireg) {
95 	imsic_read_switchcase_64(IMSIC_EIP0)
96 	imsic_read_switchcase_64(IMSIC_EIE0)
97 	}
98 
99 	return 0;
100 }
101 
102 #define imsic_vs_csr_swap(__c, __v)		\
103 ({						\
104 	unsigned long __r;			\
105 	csr_write(CSR_VSISELECT, __c);		\
106 	__r = csr_swap(CSR_VSIREG, __v);	\
107 	__r;					\
108 })
109 
110 #define imsic_swap_switchcase(__ireg, __v)		\
111 	case __ireg:					\
112 		return imsic_vs_csr_swap(__ireg, __v);
113 #define imsic_swap_switchcase_2(__ireg, __v)		\
114 	imsic_swap_switchcase(__ireg + 0, __v)		\
115 	imsic_swap_switchcase(__ireg + 1, __v)
116 #define imsic_swap_switchcase_4(__ireg, __v)		\
117 	imsic_swap_switchcase_2(__ireg + 0, __v)	\
118 	imsic_swap_switchcase_2(__ireg + 2, __v)
119 #define imsic_swap_switchcase_8(__ireg, __v)		\
120 	imsic_swap_switchcase_4(__ireg + 0, __v)	\
121 	imsic_swap_switchcase_4(__ireg + 4, __v)
122 #define imsic_swap_switchcase_16(__ireg, __v)		\
123 	imsic_swap_switchcase_8(__ireg + 0, __v)	\
124 	imsic_swap_switchcase_8(__ireg + 8, __v)
125 #define imsic_swap_switchcase_32(__ireg, __v)		\
126 	imsic_swap_switchcase_16(__ireg + 0, __v)	\
127 	imsic_swap_switchcase_16(__ireg + 16, __v)
128 #define imsic_swap_switchcase_64(__ireg, __v)		\
129 	imsic_swap_switchcase_32(__ireg + 0, __v)	\
130 	imsic_swap_switchcase_32(__ireg + 32, __v)
131 
imsic_eix_swap(int ireg,unsigned long val)132 static unsigned long imsic_eix_swap(int ireg, unsigned long val)
133 {
134 	switch (ireg) {
135 	imsic_swap_switchcase_64(IMSIC_EIP0, val)
136 	imsic_swap_switchcase_64(IMSIC_EIE0, val)
137 	}
138 
139 	return 0;
140 }
141 
142 #define imsic_vs_csr_write(__c, __v)		\
143 do {						\
144 	csr_write(CSR_VSISELECT, __c);		\
145 	csr_write(CSR_VSIREG, __v);		\
146 } while (0)
147 
148 #define imsic_write_switchcase(__ireg, __v)		\
149 	case __ireg:					\
150 		imsic_vs_csr_write(__ireg, __v);	\
151 		break;
152 #define imsic_write_switchcase_2(__ireg, __v)		\
153 	imsic_write_switchcase(__ireg + 0, __v)		\
154 	imsic_write_switchcase(__ireg + 1, __v)
155 #define imsic_write_switchcase_4(__ireg, __v)		\
156 	imsic_write_switchcase_2(__ireg + 0, __v)	\
157 	imsic_write_switchcase_2(__ireg + 2, __v)
158 #define imsic_write_switchcase_8(__ireg, __v)		\
159 	imsic_write_switchcase_4(__ireg + 0, __v)	\
160 	imsic_write_switchcase_4(__ireg + 4, __v)
161 #define imsic_write_switchcase_16(__ireg, __v)		\
162 	imsic_write_switchcase_8(__ireg + 0, __v)	\
163 	imsic_write_switchcase_8(__ireg + 8, __v)
164 #define imsic_write_switchcase_32(__ireg, __v)		\
165 	imsic_write_switchcase_16(__ireg + 0, __v)	\
166 	imsic_write_switchcase_16(__ireg + 16, __v)
167 #define imsic_write_switchcase_64(__ireg, __v)		\
168 	imsic_write_switchcase_32(__ireg + 0, __v)	\
169 	imsic_write_switchcase_32(__ireg + 32, __v)
170 
imsic_eix_write(int ireg,unsigned long val)171 static void imsic_eix_write(int ireg, unsigned long val)
172 {
173 	switch (ireg) {
174 	imsic_write_switchcase_64(IMSIC_EIP0, val)
175 	imsic_write_switchcase_64(IMSIC_EIE0, val)
176 	}
177 }
178 
179 #define imsic_vs_csr_set(__c, __v)		\
180 do {						\
181 	csr_write(CSR_VSISELECT, __c);		\
182 	csr_set(CSR_VSIREG, __v);		\
183 } while (0)
184 
185 #define imsic_set_switchcase(__ireg, __v)		\
186 	case __ireg:					\
187 		imsic_vs_csr_set(__ireg, __v);		\
188 		break;
189 #define imsic_set_switchcase_2(__ireg, __v)		\
190 	imsic_set_switchcase(__ireg + 0, __v)		\
191 	imsic_set_switchcase(__ireg + 1, __v)
192 #define imsic_set_switchcase_4(__ireg, __v)		\
193 	imsic_set_switchcase_2(__ireg + 0, __v)		\
194 	imsic_set_switchcase_2(__ireg + 2, __v)
195 #define imsic_set_switchcase_8(__ireg, __v)		\
196 	imsic_set_switchcase_4(__ireg + 0, __v)		\
197 	imsic_set_switchcase_4(__ireg + 4, __v)
198 #define imsic_set_switchcase_16(__ireg, __v)		\
199 	imsic_set_switchcase_8(__ireg + 0, __v)		\
200 	imsic_set_switchcase_8(__ireg + 8, __v)
201 #define imsic_set_switchcase_32(__ireg, __v)		\
202 	imsic_set_switchcase_16(__ireg + 0, __v)	\
203 	imsic_set_switchcase_16(__ireg + 16, __v)
204 #define imsic_set_switchcase_64(__ireg, __v)		\
205 	imsic_set_switchcase_32(__ireg + 0, __v)	\
206 	imsic_set_switchcase_32(__ireg + 32, __v)
207 
imsic_eix_set(int ireg,unsigned long val)208 static void imsic_eix_set(int ireg, unsigned long val)
209 {
210 	switch (ireg) {
211 	imsic_set_switchcase_64(IMSIC_EIP0, val)
212 	imsic_set_switchcase_64(IMSIC_EIE0, val)
213 	}
214 }
215 
imsic_mrif_atomic_rmw(struct imsic_mrif * mrif,unsigned long * ptr,unsigned long new_val,unsigned long wr_mask)216 static unsigned long imsic_mrif_atomic_rmw(struct imsic_mrif *mrif,
217 					   unsigned long *ptr,
218 					   unsigned long new_val,
219 					   unsigned long wr_mask)
220 {
221 	unsigned long old_val = 0, tmp = 0;
222 
223 	__asm__ __volatile__ (
224 		"0:	lr.w.aq   %1, %0\n"
225 		"	and       %2, %1, %3\n"
226 		"	or        %2, %2, %4\n"
227 		"	sc.w.rl   %2, %2, %0\n"
228 		"	bnez      %2, 0b"
229 		: "+A" (*ptr), "+r" (old_val), "+r" (tmp)
230 		: "r" (~wr_mask), "r" (new_val & wr_mask)
231 		: "memory");
232 
233 	return old_val;
234 }
235 
imsic_mrif_atomic_or(struct imsic_mrif * mrif,unsigned long * ptr,unsigned long val)236 static unsigned long imsic_mrif_atomic_or(struct imsic_mrif *mrif,
237 					  unsigned long *ptr,
238 					  unsigned long val)
239 {
240 	return atomic_long_fetch_or(val, (atomic_long_t *)ptr);
241 }
242 
243 #define imsic_mrif_atomic_write(__mrif, __ptr, __new_val)	\
244 		imsic_mrif_atomic_rmw(__mrif, __ptr, __new_val, -1UL)
245 #define imsic_mrif_atomic_read(__mrif, __ptr)			\
246 		imsic_mrif_atomic_or(__mrif, __ptr, 0)
247 
imsic_mrif_topei(struct imsic_mrif * mrif,u32 nr_eix,u32 nr_msis)248 static u32 imsic_mrif_topei(struct imsic_mrif *mrif, u32 nr_eix, u32 nr_msis)
249 {
250 	struct imsic_mrif_eix *eix;
251 	u32 i, imin, imax, ei, max_msi;
252 	unsigned long eipend[BITS_PER_TYPE(u64) / BITS_PER_LONG];
253 	unsigned long eithreshold = imsic_mrif_atomic_read(mrif,
254 							&mrif->eithreshold);
255 
256 	max_msi = (eithreshold && (eithreshold <= nr_msis)) ?
257 		   eithreshold : nr_msis;
258 	for (ei = 0; ei < nr_eix; ei++) {
259 		eix = &mrif->eix[ei];
260 		eipend[0] = imsic_mrif_atomic_read(mrif, &eix->eie[0]) &
261 			    imsic_mrif_atomic_read(mrif, &eix->eip[0]);
262 #ifdef CONFIG_32BIT
263 		eipend[1] = imsic_mrif_atomic_read(mrif, &eix->eie[1]) &
264 			    imsic_mrif_atomic_read(mrif, &eix->eip[1]);
265 		if (!eipend[0] && !eipend[1])
266 #else
267 		if (!eipend[0])
268 #endif
269 			continue;
270 
271 		imin = ei * BITS_PER_TYPE(u64);
272 		imax = ((imin + BITS_PER_TYPE(u64)) < max_msi) ?
273 			imin + BITS_PER_TYPE(u64) : max_msi;
274 		for (i = (!imin) ? 1 : imin; i < imax; i++) {
275 			if (test_bit(i - imin, eipend))
276 				return (i << TOPEI_ID_SHIFT) | i;
277 		}
278 	}
279 
280 	return 0;
281 }
282 
imsic_mrif_isel_check(u32 nr_eix,unsigned long isel)283 static int imsic_mrif_isel_check(u32 nr_eix, unsigned long isel)
284 {
285 	u32 num = 0;
286 
287 	switch (isel) {
288 	case IMSIC_EIDELIVERY:
289 	case IMSIC_EITHRESHOLD:
290 		break;
291 	case IMSIC_EIP0 ... IMSIC_EIP63:
292 		num = isel - IMSIC_EIP0;
293 		break;
294 	case IMSIC_EIE0 ... IMSIC_EIE63:
295 		num = isel - IMSIC_EIE0;
296 		break;
297 	default:
298 		return -ENOENT;
299 	}
300 #ifndef CONFIG_32BIT
301 	if (num & 0x1)
302 		return -EINVAL;
303 #endif
304 	if ((num / 2) >= nr_eix)
305 		return -EINVAL;
306 
307 	return 0;
308 }
309 
imsic_mrif_rmw(struct imsic_mrif * mrif,u32 nr_eix,unsigned long isel,unsigned long * val,unsigned long new_val,unsigned long wr_mask)310 static int imsic_mrif_rmw(struct imsic_mrif *mrif, u32 nr_eix,
311 			  unsigned long isel, unsigned long *val,
312 			  unsigned long new_val, unsigned long wr_mask)
313 {
314 	bool pend;
315 	struct imsic_mrif_eix *eix;
316 	unsigned long *ei, num, old_val = 0;
317 
318 	switch (isel) {
319 	case IMSIC_EIDELIVERY:
320 		old_val = imsic_mrif_atomic_rmw(mrif, &mrif->eidelivery,
321 						new_val, wr_mask & 0x1);
322 		break;
323 	case IMSIC_EITHRESHOLD:
324 		old_val = imsic_mrif_atomic_rmw(mrif, &mrif->eithreshold,
325 				new_val, wr_mask & (IMSIC_MAX_ID - 1));
326 		break;
327 	case IMSIC_EIP0 ... IMSIC_EIP63:
328 	case IMSIC_EIE0 ... IMSIC_EIE63:
329 		if (isel >= IMSIC_EIP0 && isel <= IMSIC_EIP63) {
330 			pend = true;
331 			num = isel - IMSIC_EIP0;
332 		} else {
333 			pend = false;
334 			num = isel - IMSIC_EIE0;
335 		}
336 
337 		if ((num / 2) >= nr_eix)
338 			return -EINVAL;
339 		eix = &mrif->eix[num / 2];
340 
341 #ifndef CONFIG_32BIT
342 		if (num & 0x1)
343 			return -EINVAL;
344 		ei = (pend) ? &eix->eip[0] : &eix->eie[0];
345 #else
346 		ei = (pend) ? &eix->eip[num & 0x1] : &eix->eie[num & 0x1];
347 #endif
348 
349 		/* Bit0 of EIP0 or EIE0 is read-only */
350 		if (!num)
351 			wr_mask &= ~BIT(0);
352 
353 		old_val = imsic_mrif_atomic_rmw(mrif, ei, new_val, wr_mask);
354 		break;
355 	default:
356 		return -ENOENT;
357 	}
358 
359 	if (val)
360 		*val = old_val;
361 
362 	return 0;
363 }
364 
365 struct imsic_vsfile_read_data {
366 	int hgei;
367 	u32 nr_eix;
368 	bool clear;
369 	struct imsic_mrif *mrif;
370 };
371 
imsic_vsfile_local_read(void * data)372 static void imsic_vsfile_local_read(void *data)
373 {
374 	u32 i;
375 	struct imsic_mrif_eix *eix;
376 	struct imsic_vsfile_read_data *idata = data;
377 	struct imsic_mrif *mrif = idata->mrif;
378 	unsigned long new_hstatus, old_hstatus, old_vsiselect;
379 
380 	old_vsiselect = csr_read(CSR_VSISELECT);
381 	old_hstatus = csr_read(CSR_HSTATUS);
382 	new_hstatus = old_hstatus & ~HSTATUS_VGEIN;
383 	new_hstatus |= ((unsigned long)idata->hgei) << HSTATUS_VGEIN_SHIFT;
384 	csr_write(CSR_HSTATUS, new_hstatus);
385 
386 	/*
387 	 * We don't use imsic_mrif_atomic_xyz() functions to store
388 	 * values in MRIF because imsic_vsfile_read() is always called
389 	 * with pointer to temporary MRIF on stack.
390 	 */
391 
392 	if (idata->clear) {
393 		mrif->eidelivery = imsic_vs_csr_swap(IMSIC_EIDELIVERY, 0);
394 		mrif->eithreshold = imsic_vs_csr_swap(IMSIC_EITHRESHOLD, 0);
395 		for (i = 0; i < idata->nr_eix; i++) {
396 			eix = &mrif->eix[i];
397 			eix->eip[0] = imsic_eix_swap(IMSIC_EIP0 + i * 2, 0);
398 			eix->eie[0] = imsic_eix_swap(IMSIC_EIE0 + i * 2, 0);
399 #ifdef CONFIG_32BIT
400 			eix->eip[1] = imsic_eix_swap(IMSIC_EIP0 + i * 2 + 1, 0);
401 			eix->eie[1] = imsic_eix_swap(IMSIC_EIE0 + i * 2 + 1, 0);
402 #endif
403 		}
404 	} else {
405 		mrif->eidelivery = imsic_vs_csr_read(IMSIC_EIDELIVERY);
406 		mrif->eithreshold = imsic_vs_csr_read(IMSIC_EITHRESHOLD);
407 		for (i = 0; i < idata->nr_eix; i++) {
408 			eix = &mrif->eix[i];
409 			eix->eip[0] = imsic_eix_read(IMSIC_EIP0 + i * 2);
410 			eix->eie[0] = imsic_eix_read(IMSIC_EIE0 + i * 2);
411 #ifdef CONFIG_32BIT
412 			eix->eip[1] = imsic_eix_read(IMSIC_EIP0 + i * 2 + 1);
413 			eix->eie[1] = imsic_eix_read(IMSIC_EIE0 + i * 2 + 1);
414 #endif
415 		}
416 	}
417 
418 	csr_write(CSR_HSTATUS, old_hstatus);
419 	csr_write(CSR_VSISELECT, old_vsiselect);
420 }
421 
imsic_vsfile_read(int vsfile_hgei,int vsfile_cpu,u32 nr_eix,bool clear,struct imsic_mrif * mrif)422 static void imsic_vsfile_read(int vsfile_hgei, int vsfile_cpu, u32 nr_eix,
423 			      bool clear, struct imsic_mrif *mrif)
424 {
425 	struct imsic_vsfile_read_data idata;
426 
427 	/* We can only read clear if we have a IMSIC VS-file */
428 	if (vsfile_cpu < 0 || vsfile_hgei <= 0)
429 		return;
430 
431 	/* We can only read clear on local CPU */
432 	idata.hgei = vsfile_hgei;
433 	idata.nr_eix = nr_eix;
434 	idata.clear = clear;
435 	idata.mrif = mrif;
436 	on_each_cpu_mask(cpumask_of(vsfile_cpu),
437 			 imsic_vsfile_local_read, &idata, 1);
438 }
439 
440 struct imsic_vsfile_rw_data {
441 	int hgei;
442 	int isel;
443 	bool write;
444 	unsigned long val;
445 };
446 
imsic_vsfile_local_rw(void * data)447 static void imsic_vsfile_local_rw(void *data)
448 {
449 	struct imsic_vsfile_rw_data *idata = data;
450 	unsigned long new_hstatus, old_hstatus, old_vsiselect;
451 
452 	old_vsiselect = csr_read(CSR_VSISELECT);
453 	old_hstatus = csr_read(CSR_HSTATUS);
454 	new_hstatus = old_hstatus & ~HSTATUS_VGEIN;
455 	new_hstatus |= ((unsigned long)idata->hgei) << HSTATUS_VGEIN_SHIFT;
456 	csr_write(CSR_HSTATUS, new_hstatus);
457 
458 	switch (idata->isel) {
459 	case IMSIC_EIDELIVERY:
460 		if (idata->write)
461 			imsic_vs_csr_write(IMSIC_EIDELIVERY, idata->val);
462 		else
463 			idata->val = imsic_vs_csr_read(IMSIC_EIDELIVERY);
464 		break;
465 	case IMSIC_EITHRESHOLD:
466 		if (idata->write)
467 			imsic_vs_csr_write(IMSIC_EITHRESHOLD, idata->val);
468 		else
469 			idata->val = imsic_vs_csr_read(IMSIC_EITHRESHOLD);
470 		break;
471 	case IMSIC_EIP0 ... IMSIC_EIP63:
472 	case IMSIC_EIE0 ... IMSIC_EIE63:
473 #ifndef CONFIG_32BIT
474 		if (idata->isel & 0x1)
475 			break;
476 #endif
477 		if (idata->write)
478 			imsic_eix_write(idata->isel, idata->val);
479 		else
480 			idata->val = imsic_eix_read(idata->isel);
481 		break;
482 	default:
483 		break;
484 	}
485 
486 	csr_write(CSR_HSTATUS, old_hstatus);
487 	csr_write(CSR_VSISELECT, old_vsiselect);
488 }
489 
imsic_vsfile_rw(int vsfile_hgei,int vsfile_cpu,u32 nr_eix,unsigned long isel,bool write,unsigned long * val)490 static int imsic_vsfile_rw(int vsfile_hgei, int vsfile_cpu, u32 nr_eix,
491 			   unsigned long isel, bool write,
492 			   unsigned long *val)
493 {
494 	int rc;
495 	struct imsic_vsfile_rw_data rdata;
496 
497 	/* We can only access register if we have a IMSIC VS-file */
498 	if (vsfile_cpu < 0 || vsfile_hgei <= 0)
499 		return -EINVAL;
500 
501 	/* Check IMSIC register iselect */
502 	rc = imsic_mrif_isel_check(nr_eix, isel);
503 	if (rc)
504 		return rc;
505 
506 	/* We can only access register on local CPU */
507 	rdata.hgei = vsfile_hgei;
508 	rdata.isel = isel;
509 	rdata.write = write;
510 	rdata.val = (write) ? *val : 0;
511 	on_each_cpu_mask(cpumask_of(vsfile_cpu),
512 			 imsic_vsfile_local_rw, &rdata, 1);
513 
514 	if (!write)
515 		*val = rdata.val;
516 
517 	return 0;
518 }
519 
imsic_vsfile_local_clear(int vsfile_hgei,u32 nr_eix)520 static void imsic_vsfile_local_clear(int vsfile_hgei, u32 nr_eix)
521 {
522 	u32 i;
523 	unsigned long new_hstatus, old_hstatus, old_vsiselect;
524 
525 	/* We can only zero-out if we have a IMSIC VS-file */
526 	if (vsfile_hgei <= 0)
527 		return;
528 
529 	old_vsiselect = csr_read(CSR_VSISELECT);
530 	old_hstatus = csr_read(CSR_HSTATUS);
531 	new_hstatus = old_hstatus & ~HSTATUS_VGEIN;
532 	new_hstatus |= ((unsigned long)vsfile_hgei) << HSTATUS_VGEIN_SHIFT;
533 	csr_write(CSR_HSTATUS, new_hstatus);
534 
535 	imsic_vs_csr_write(IMSIC_EIDELIVERY, 0);
536 	imsic_vs_csr_write(IMSIC_EITHRESHOLD, 0);
537 	for (i = 0; i < nr_eix; i++) {
538 		imsic_eix_write(IMSIC_EIP0 + i * 2, 0);
539 		imsic_eix_write(IMSIC_EIE0 + i * 2, 0);
540 #ifdef CONFIG_32BIT
541 		imsic_eix_write(IMSIC_EIP0 + i * 2 + 1, 0);
542 		imsic_eix_write(IMSIC_EIE0 + i * 2 + 1, 0);
543 #endif
544 	}
545 
546 	csr_write(CSR_HSTATUS, old_hstatus);
547 	csr_write(CSR_VSISELECT, old_vsiselect);
548 }
549 
imsic_vsfile_local_update(int vsfile_hgei,u32 nr_eix,struct imsic_mrif * mrif)550 static void imsic_vsfile_local_update(int vsfile_hgei, u32 nr_eix,
551 				      struct imsic_mrif *mrif)
552 {
553 	u32 i;
554 	struct imsic_mrif_eix *eix;
555 	unsigned long new_hstatus, old_hstatus, old_vsiselect;
556 
557 	/* We can only update if we have a HW IMSIC context */
558 	if (vsfile_hgei <= 0)
559 		return;
560 
561 	/*
562 	 * We don't use imsic_mrif_atomic_xyz() functions to read values
563 	 * from MRIF in this function because it is always called with
564 	 * pointer to temporary MRIF on stack.
565 	 */
566 
567 	old_vsiselect = csr_read(CSR_VSISELECT);
568 	old_hstatus = csr_read(CSR_HSTATUS);
569 	new_hstatus = old_hstatus & ~HSTATUS_VGEIN;
570 	new_hstatus |= ((unsigned long)vsfile_hgei) << HSTATUS_VGEIN_SHIFT;
571 	csr_write(CSR_HSTATUS, new_hstatus);
572 
573 	for (i = 0; i < nr_eix; i++) {
574 		eix = &mrif->eix[i];
575 		imsic_eix_set(IMSIC_EIP0 + i * 2, eix->eip[0]);
576 		imsic_eix_set(IMSIC_EIE0 + i * 2, eix->eie[0]);
577 #ifdef CONFIG_32BIT
578 		imsic_eix_set(IMSIC_EIP0 + i * 2 + 1, eix->eip[1]);
579 		imsic_eix_set(IMSIC_EIE0 + i * 2 + 1, eix->eie[1]);
580 #endif
581 	}
582 	imsic_vs_csr_write(IMSIC_EITHRESHOLD, mrif->eithreshold);
583 	imsic_vs_csr_write(IMSIC_EIDELIVERY, mrif->eidelivery);
584 
585 	csr_write(CSR_HSTATUS, old_hstatus);
586 	csr_write(CSR_VSISELECT, old_vsiselect);
587 }
588 
imsic_vsfile_cleanup(struct imsic * imsic)589 static void imsic_vsfile_cleanup(struct imsic *imsic)
590 {
591 	int old_vsfile_hgei, old_vsfile_cpu;
592 	unsigned long flags;
593 
594 	/*
595 	 * We don't use imsic_mrif_atomic_xyz() functions to clear the
596 	 * SW-file in this function because it is always called when the
597 	 * VCPU is being destroyed.
598 	 */
599 
600 	write_lock_irqsave(&imsic->vsfile_lock, flags);
601 	old_vsfile_hgei = imsic->vsfile_hgei;
602 	old_vsfile_cpu = imsic->vsfile_cpu;
603 	imsic->vsfile_cpu = imsic->vsfile_hgei = -1;
604 	imsic->vsfile_va = NULL;
605 	imsic->vsfile_pa = 0;
606 	write_unlock_irqrestore(&imsic->vsfile_lock, flags);
607 
608 	memset(imsic->swfile, 0, sizeof(*imsic->swfile));
609 
610 	if (old_vsfile_cpu >= 0)
611 		kvm_riscv_aia_free_hgei(old_vsfile_cpu, old_vsfile_hgei);
612 }
613 
imsic_swfile_extirq_update(struct kvm_vcpu * vcpu)614 static void imsic_swfile_extirq_update(struct kvm_vcpu *vcpu)
615 {
616 	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
617 	struct imsic_mrif *mrif = imsic->swfile;
618 	unsigned long flags;
619 
620 	/*
621 	 * The critical section is necessary during external interrupt
622 	 * updates to avoid the risk of losing interrupts due to potential
623 	 * interruptions between reading topei and updating pending status.
624 	 */
625 
626 	raw_spin_lock_irqsave(&imsic->swfile_extirq_lock, flags);
627 
628 	if (imsic_mrif_atomic_read(mrif, &mrif->eidelivery) &&
629 	    imsic_mrif_topei(mrif, imsic->nr_eix, imsic->nr_msis))
630 		kvm_riscv_vcpu_set_interrupt(vcpu, IRQ_VS_EXT);
631 	else
632 		kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_EXT);
633 
634 	raw_spin_unlock_irqrestore(&imsic->swfile_extirq_lock, flags);
635 }
636 
imsic_swfile_read(struct kvm_vcpu * vcpu,bool clear,struct imsic_mrif * mrif)637 static void imsic_swfile_read(struct kvm_vcpu *vcpu, bool clear,
638 			      struct imsic_mrif *mrif)
639 {
640 	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
641 
642 	/*
643 	 * We don't use imsic_mrif_atomic_xyz() functions to read and
644 	 * write SW-file and MRIF in this function because it is always
645 	 * called when VCPU is not using SW-file and the MRIF points to
646 	 * a temporary MRIF on stack.
647 	 */
648 
649 	memcpy(mrif, imsic->swfile, sizeof(*mrif));
650 	if (clear) {
651 		memset(imsic->swfile, 0, sizeof(*imsic->swfile));
652 		kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_EXT);
653 	}
654 }
655 
imsic_swfile_update(struct kvm_vcpu * vcpu,struct imsic_mrif * mrif)656 static void imsic_swfile_update(struct kvm_vcpu *vcpu,
657 				struct imsic_mrif *mrif)
658 {
659 	u32 i;
660 	struct imsic_mrif_eix *seix, *eix;
661 	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
662 	struct imsic_mrif *smrif = imsic->swfile;
663 
664 	imsic_mrif_atomic_write(smrif, &smrif->eidelivery, mrif->eidelivery);
665 	imsic_mrif_atomic_write(smrif, &smrif->eithreshold, mrif->eithreshold);
666 	for (i = 0; i < imsic->nr_eix; i++) {
667 		seix = &smrif->eix[i];
668 		eix = &mrif->eix[i];
669 		imsic_mrif_atomic_or(smrif, &seix->eip[0], eix->eip[0]);
670 		imsic_mrif_atomic_or(smrif, &seix->eie[0], eix->eie[0]);
671 #ifdef CONFIG_32BIT
672 		imsic_mrif_atomic_or(smrif, &seix->eip[1], eix->eip[1]);
673 		imsic_mrif_atomic_or(smrif, &seix->eie[1], eix->eie[1]);
674 #endif
675 	}
676 
677 	imsic_swfile_extirq_update(vcpu);
678 }
679 
kvm_riscv_vcpu_aia_imsic_has_interrupt(struct kvm_vcpu * vcpu)680 bool kvm_riscv_vcpu_aia_imsic_has_interrupt(struct kvm_vcpu *vcpu)
681 {
682 	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
683 	unsigned long flags;
684 	bool ret = false;
685 
686 	/*
687 	 * The IMSIC SW-file directly injects interrupt via hvip so
688 	 * only check for interrupt when IMSIC VS-file is being used.
689 	 */
690 
691 	read_lock_irqsave(&imsic->vsfile_lock, flags);
692 	if (imsic->vsfile_cpu > -1)
693 		ret = !!(csr_read(CSR_HGEIP) & BIT(imsic->vsfile_hgei));
694 	read_unlock_irqrestore(&imsic->vsfile_lock, flags);
695 
696 	return ret;
697 }
698 
kvm_riscv_vcpu_aia_imsic_load(struct kvm_vcpu * vcpu,int cpu)699 void kvm_riscv_vcpu_aia_imsic_load(struct kvm_vcpu *vcpu, int cpu)
700 {
701 	/*
702 	 * No need to explicitly clear HGEIE CSR bits because the
703 	 * hgei interrupt handler (aka hgei_interrupt()) will always
704 	 * clear it for us.
705 	 */
706 }
707 
kvm_riscv_vcpu_aia_imsic_put(struct kvm_vcpu * vcpu)708 void kvm_riscv_vcpu_aia_imsic_put(struct kvm_vcpu *vcpu)
709 {
710 	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
711 	unsigned long flags;
712 
713 	if (!kvm_vcpu_is_blocking(vcpu))
714 		return;
715 
716 	read_lock_irqsave(&imsic->vsfile_lock, flags);
717 	if (imsic->vsfile_cpu > -1)
718 		csr_set(CSR_HGEIE, BIT(imsic->vsfile_hgei));
719 	read_unlock_irqrestore(&imsic->vsfile_lock, flags);
720 }
721 
kvm_riscv_vcpu_aia_imsic_release(struct kvm_vcpu * vcpu)722 void kvm_riscv_vcpu_aia_imsic_release(struct kvm_vcpu *vcpu)
723 {
724 	unsigned long flags;
725 	struct imsic_mrif tmrif;
726 	int old_vsfile_hgei, old_vsfile_cpu;
727 	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
728 
729 	/* Read and clear IMSIC VS-file details */
730 	write_lock_irqsave(&imsic->vsfile_lock, flags);
731 	old_vsfile_hgei = imsic->vsfile_hgei;
732 	old_vsfile_cpu = imsic->vsfile_cpu;
733 	imsic->vsfile_cpu = imsic->vsfile_hgei = -1;
734 	imsic->vsfile_va = NULL;
735 	imsic->vsfile_pa = 0;
736 	write_unlock_irqrestore(&imsic->vsfile_lock, flags);
737 
738 	/* Do nothing, if no IMSIC VS-file to release */
739 	if (old_vsfile_cpu < 0)
740 		return;
741 
742 	/*
743 	 * At this point, all interrupt producers are still using
744 	 * the old IMSIC VS-file so we first re-direct all interrupt
745 	 * producers.
746 	 */
747 
748 	/* Purge the G-stage mapping */
749 	kvm_riscv_mmu_iounmap(vcpu->kvm, vcpu->arch.aia_context.imsic_addr,
750 			      IMSIC_MMIO_PAGE_SZ);
751 
752 	/* TODO: Purge the IOMMU mapping ??? */
753 
754 	/*
755 	 * At this point, all interrupt producers have been re-directed
756 	 * to somewhere else so we move register state from the old IMSIC
757 	 * VS-file to the IMSIC SW-file.
758 	 */
759 
760 	/* Read and clear register state from old IMSIC VS-file */
761 	memset(&tmrif, 0, sizeof(tmrif));
762 	imsic_vsfile_read(old_vsfile_hgei, old_vsfile_cpu, imsic->nr_hw_eix,
763 			  true, &tmrif);
764 
765 	/* Update register state in IMSIC SW-file */
766 	imsic_swfile_update(vcpu, &tmrif);
767 
768 	/* Free-up old IMSIC VS-file */
769 	kvm_riscv_aia_free_hgei(old_vsfile_cpu, old_vsfile_hgei);
770 }
771 
kvm_riscv_vcpu_aia_imsic_update(struct kvm_vcpu * vcpu)772 int kvm_riscv_vcpu_aia_imsic_update(struct kvm_vcpu *vcpu)
773 {
774 	unsigned long flags;
775 	phys_addr_t new_vsfile_pa;
776 	struct imsic_mrif tmrif;
777 	void __iomem *new_vsfile_va;
778 	struct kvm *kvm = vcpu->kvm;
779 	struct kvm_run *run = vcpu->run;
780 	struct kvm_vcpu_aia *vaia = &vcpu->arch.aia_context;
781 	struct imsic *imsic = vaia->imsic_state;
782 	int ret = 0, new_vsfile_hgei = -1, old_vsfile_hgei, old_vsfile_cpu;
783 
784 	/* Do nothing for emulation mode */
785 	if (kvm->arch.aia.mode == KVM_DEV_RISCV_AIA_MODE_EMUL)
786 		return 1;
787 
788 	/* Read old IMSIC VS-file details */
789 	read_lock_irqsave(&imsic->vsfile_lock, flags);
790 	old_vsfile_hgei = imsic->vsfile_hgei;
791 	old_vsfile_cpu = imsic->vsfile_cpu;
792 	read_unlock_irqrestore(&imsic->vsfile_lock, flags);
793 
794 	/* Do nothing if we are continuing on same CPU */
795 	if (old_vsfile_cpu == vcpu->cpu)
796 		return 1;
797 
798 	/* Allocate new IMSIC VS-file */
799 	ret = kvm_riscv_aia_alloc_hgei(vcpu->cpu, vcpu,
800 				       &new_vsfile_va, &new_vsfile_pa);
801 	if (ret <= 0) {
802 		/* For HW acceleration mode, we can't continue */
803 		if (kvm->arch.aia.mode == KVM_DEV_RISCV_AIA_MODE_HWACCEL) {
804 			run->fail_entry.hardware_entry_failure_reason =
805 								CSR_HSTATUS;
806 			run->fail_entry.cpu = vcpu->cpu;
807 			run->exit_reason = KVM_EXIT_FAIL_ENTRY;
808 			return 0;
809 		}
810 
811 		/* Release old IMSIC VS-file */
812 		if (old_vsfile_cpu >= 0)
813 			kvm_riscv_vcpu_aia_imsic_release(vcpu);
814 
815 		/* For automatic mode, we continue */
816 		goto done;
817 	}
818 	new_vsfile_hgei = ret;
819 
820 	/*
821 	 * At this point, all interrupt producers are still using
822 	 * to the old IMSIC VS-file so we first move all interrupt
823 	 * producers to the new IMSIC VS-file.
824 	 */
825 
826 	/* Ensure HGEIE CSR bit is zero before using the new IMSIC VS-file */
827 	csr_clear(CSR_HGEIE, BIT(new_vsfile_hgei));
828 
829 	/* Zero-out new IMSIC VS-file */
830 	imsic_vsfile_local_clear(new_vsfile_hgei, imsic->nr_hw_eix);
831 
832 	/* Update G-stage mapping for the new IMSIC VS-file */
833 	ret = kvm_riscv_mmu_ioremap(kvm, vcpu->arch.aia_context.imsic_addr,
834 				    new_vsfile_pa, IMSIC_MMIO_PAGE_SZ,
835 				    true, true);
836 	if (ret)
837 		goto fail_free_vsfile_hgei;
838 
839 	/* TODO: Update the IOMMU mapping ??? */
840 
841 	/* Update new IMSIC VS-file details in IMSIC context */
842 	write_lock_irqsave(&imsic->vsfile_lock, flags);
843 	imsic->vsfile_hgei = new_vsfile_hgei;
844 	imsic->vsfile_cpu = vcpu->cpu;
845 	imsic->vsfile_va = new_vsfile_va;
846 	imsic->vsfile_pa = new_vsfile_pa;
847 	write_unlock_irqrestore(&imsic->vsfile_lock, flags);
848 
849 	/*
850 	 * At this point, all interrupt producers have been moved
851 	 * to the new IMSIC VS-file so we move register state from
852 	 * the old IMSIC VS/SW-file to the new IMSIC VS-file.
853 	 */
854 
855 	memset(&tmrif, 0, sizeof(tmrif));
856 	if (old_vsfile_cpu >= 0) {
857 		/* Read and clear register state from old IMSIC VS-file */
858 		imsic_vsfile_read(old_vsfile_hgei, old_vsfile_cpu,
859 				  imsic->nr_hw_eix, true, &tmrif);
860 
861 		/* Free-up old IMSIC VS-file */
862 		kvm_riscv_aia_free_hgei(old_vsfile_cpu, old_vsfile_hgei);
863 	} else {
864 		/* Read and clear register state from IMSIC SW-file */
865 		imsic_swfile_read(vcpu, true, &tmrif);
866 	}
867 
868 	/* Restore register state in the new IMSIC VS-file */
869 	imsic_vsfile_local_update(new_vsfile_hgei, imsic->nr_hw_eix, &tmrif);
870 
871 done:
872 	/* Set VCPU HSTATUS.VGEIN to new IMSIC VS-file */
873 	vcpu->arch.guest_context.hstatus &= ~HSTATUS_VGEIN;
874 	if (new_vsfile_hgei > 0)
875 		vcpu->arch.guest_context.hstatus |=
876 			((unsigned long)new_vsfile_hgei) << HSTATUS_VGEIN_SHIFT;
877 
878 	/* Continue run-loop */
879 	return 1;
880 
881 fail_free_vsfile_hgei:
882 	kvm_riscv_aia_free_hgei(vcpu->cpu, new_vsfile_hgei);
883 	return ret;
884 }
885 
kvm_riscv_vcpu_aia_imsic_rmw(struct kvm_vcpu * vcpu,unsigned long isel,unsigned long * val,unsigned long new_val,unsigned long wr_mask)886 int kvm_riscv_vcpu_aia_imsic_rmw(struct kvm_vcpu *vcpu, unsigned long isel,
887 				 unsigned long *val, unsigned long new_val,
888 				 unsigned long wr_mask)
889 {
890 	u32 topei;
891 	struct imsic_mrif_eix *eix;
892 	int r, rc = KVM_INSN_CONTINUE_NEXT_SEPC;
893 	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
894 
895 	if (isel == KVM_RISCV_AIA_IMSIC_TOPEI) {
896 		/* Read pending and enabled interrupt with highest priority */
897 		topei = imsic_mrif_topei(imsic->swfile, imsic->nr_eix,
898 					 imsic->nr_msis);
899 		if (val)
900 			*val = topei;
901 
902 		/* Writes ignore value and clear top pending interrupt */
903 		if (topei && wr_mask) {
904 			topei >>= TOPEI_ID_SHIFT;
905 			if (topei) {
906 				eix = &imsic->swfile->eix[topei /
907 							  BITS_PER_TYPE(u64)];
908 				clear_bit(topei & (BITS_PER_TYPE(u64) - 1),
909 					  eix->eip);
910 			}
911 		}
912 	} else {
913 		r = imsic_mrif_rmw(imsic->swfile, imsic->nr_eix, isel,
914 				   val, new_val, wr_mask);
915 		/* Forward unknown IMSIC register to user-space */
916 		if (r)
917 			rc = (r == -ENOENT) ? 0 : KVM_INSN_ILLEGAL_TRAP;
918 	}
919 
920 	if (wr_mask)
921 		imsic_swfile_extirq_update(vcpu);
922 
923 	return rc;
924 }
925 
kvm_riscv_aia_imsic_rw_attr(struct kvm * kvm,unsigned long type,bool write,unsigned long * val)926 int kvm_riscv_aia_imsic_rw_attr(struct kvm *kvm, unsigned long type,
927 				bool write, unsigned long *val)
928 {
929 	u32 isel, vcpu_id;
930 	unsigned long flags;
931 	struct imsic *imsic;
932 	struct kvm_vcpu *vcpu;
933 	int rc, vsfile_hgei, vsfile_cpu;
934 
935 	if (!kvm_riscv_aia_initialized(kvm))
936 		return -ENODEV;
937 
938 	vcpu_id = KVM_DEV_RISCV_AIA_IMSIC_GET_VCPU(type);
939 	vcpu = kvm_get_vcpu_by_id(kvm, vcpu_id);
940 	if (!vcpu)
941 		return -ENODEV;
942 
943 	isel = KVM_DEV_RISCV_AIA_IMSIC_GET_ISEL(type);
944 	imsic = vcpu->arch.aia_context.imsic_state;
945 
946 	read_lock_irqsave(&imsic->vsfile_lock, flags);
947 
948 	rc = 0;
949 	vsfile_hgei = imsic->vsfile_hgei;
950 	vsfile_cpu = imsic->vsfile_cpu;
951 	if (vsfile_cpu < 0) {
952 		if (write) {
953 			rc = imsic_mrif_rmw(imsic->swfile, imsic->nr_eix,
954 					    isel, NULL, *val, -1UL);
955 			imsic_swfile_extirq_update(vcpu);
956 		} else
957 			rc = imsic_mrif_rmw(imsic->swfile, imsic->nr_eix,
958 					    isel, val, 0, 0);
959 	}
960 
961 	read_unlock_irqrestore(&imsic->vsfile_lock, flags);
962 
963 	if (!rc && vsfile_cpu >= 0)
964 		rc = imsic_vsfile_rw(vsfile_hgei, vsfile_cpu, imsic->nr_eix,
965 				     isel, write, val);
966 
967 	return rc;
968 }
969 
kvm_riscv_aia_imsic_has_attr(struct kvm * kvm,unsigned long type)970 int kvm_riscv_aia_imsic_has_attr(struct kvm *kvm, unsigned long type)
971 {
972 	u32 isel, vcpu_id;
973 	struct imsic *imsic;
974 	struct kvm_vcpu *vcpu;
975 
976 	if (!kvm_riscv_aia_initialized(kvm))
977 		return -ENODEV;
978 
979 	vcpu_id = KVM_DEV_RISCV_AIA_IMSIC_GET_VCPU(type);
980 	vcpu = kvm_get_vcpu_by_id(kvm, vcpu_id);
981 	if (!vcpu)
982 		return -ENODEV;
983 
984 	isel = KVM_DEV_RISCV_AIA_IMSIC_GET_ISEL(type);
985 	imsic = vcpu->arch.aia_context.imsic_state;
986 	return imsic_mrif_isel_check(imsic->nr_eix, isel);
987 }
988 
kvm_riscv_vcpu_aia_imsic_reset(struct kvm_vcpu * vcpu)989 void kvm_riscv_vcpu_aia_imsic_reset(struct kvm_vcpu *vcpu)
990 {
991 	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
992 
993 	if (!imsic)
994 		return;
995 
996 	kvm_riscv_vcpu_aia_imsic_release(vcpu);
997 
998 	memset(imsic->swfile, 0, sizeof(*imsic->swfile));
999 }
1000 
kvm_riscv_vcpu_aia_imsic_inject(struct kvm_vcpu * vcpu,u32 guest_index,u32 offset,u32 iid)1001 int kvm_riscv_vcpu_aia_imsic_inject(struct kvm_vcpu *vcpu,
1002 				    u32 guest_index, u32 offset, u32 iid)
1003 {
1004 	unsigned long flags;
1005 	struct imsic_mrif_eix *eix;
1006 	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
1007 
1008 	/* We only emulate one IMSIC MMIO page for each Guest VCPU */
1009 	if (!imsic || !iid || guest_index ||
1010 	    (offset != IMSIC_MMIO_SETIPNUM_LE &&
1011 	     offset != IMSIC_MMIO_SETIPNUM_BE))
1012 		return -ENODEV;
1013 
1014 	iid = (offset == IMSIC_MMIO_SETIPNUM_BE) ? __swab32(iid) : iid;
1015 	if (imsic->nr_msis <= iid)
1016 		return -EINVAL;
1017 
1018 	read_lock_irqsave(&imsic->vsfile_lock, flags);
1019 
1020 	if (imsic->vsfile_cpu >= 0) {
1021 		writel(iid, imsic->vsfile_va + IMSIC_MMIO_SETIPNUM_LE);
1022 	} else {
1023 		eix = &imsic->swfile->eix[iid / BITS_PER_TYPE(u64)];
1024 		set_bit(iid & (BITS_PER_TYPE(u64) - 1), eix->eip);
1025 		imsic_swfile_extirq_update(vcpu);
1026 	}
1027 
1028 	read_unlock_irqrestore(&imsic->vsfile_lock, flags);
1029 
1030 	return 0;
1031 }
1032 
imsic_mmio_read(struct kvm_vcpu * vcpu,struct kvm_io_device * dev,gpa_t addr,int len,void * val)1033 static int imsic_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
1034 			   gpa_t addr, int len, void *val)
1035 {
1036 	if (len != 4 || (addr & 0x3) != 0)
1037 		return -EOPNOTSUPP;
1038 
1039 	*((u32 *)val) = 0;
1040 
1041 	return 0;
1042 }
1043 
imsic_mmio_write(struct kvm_vcpu * vcpu,struct kvm_io_device * dev,gpa_t addr,int len,const void * val)1044 static int imsic_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
1045 			    gpa_t addr, int len, const void *val)
1046 {
1047 	struct kvm_msi msi = { 0 };
1048 
1049 	if (len != 4 || (addr & 0x3) != 0)
1050 		return -EOPNOTSUPP;
1051 
1052 	msi.address_hi = addr >> 32;
1053 	msi.address_lo = (u32)addr;
1054 	msi.data = *((const u32 *)val);
1055 	kvm_riscv_aia_inject_msi(vcpu->kvm, &msi);
1056 
1057 	return 0;
1058 };
1059 
1060 static struct kvm_io_device_ops imsic_iodoev_ops = {
1061 	.read = imsic_mmio_read,
1062 	.write = imsic_mmio_write,
1063 };
1064 
kvm_riscv_vcpu_aia_imsic_init(struct kvm_vcpu * vcpu)1065 int kvm_riscv_vcpu_aia_imsic_init(struct kvm_vcpu *vcpu)
1066 {
1067 	int ret = 0;
1068 	struct imsic *imsic;
1069 	struct page *swfile_page;
1070 	struct kvm *kvm = vcpu->kvm;
1071 
1072 	/* Fail if we have zero IDs */
1073 	if (!kvm->arch.aia.nr_ids)
1074 		return -EINVAL;
1075 
1076 	/* Allocate IMSIC context */
1077 	imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
1078 	if (!imsic)
1079 		return -ENOMEM;
1080 	vcpu->arch.aia_context.imsic_state = imsic;
1081 
1082 	/* Setup IMSIC context  */
1083 	imsic->nr_msis = kvm->arch.aia.nr_ids + 1;
1084 	rwlock_init(&imsic->vsfile_lock);
1085 	imsic->nr_eix = BITS_TO_U64(imsic->nr_msis);
1086 	imsic->nr_hw_eix = BITS_TO_U64(kvm_riscv_aia_max_ids);
1087 	imsic->vsfile_hgei = imsic->vsfile_cpu = -1;
1088 
1089 	/* Setup IMSIC SW-file */
1090 	swfile_page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
1091 				  get_order(sizeof(*imsic->swfile)));
1092 	if (!swfile_page) {
1093 		ret = -ENOMEM;
1094 		goto fail_free_imsic;
1095 	}
1096 	imsic->swfile = page_to_virt(swfile_page);
1097 	imsic->swfile_pa = page_to_phys(swfile_page);
1098 	raw_spin_lock_init(&imsic->swfile_extirq_lock);
1099 
1100 	/* Setup IO device */
1101 	kvm_iodevice_init(&imsic->iodev, &imsic_iodoev_ops);
1102 	mutex_lock(&kvm->slots_lock);
1103 	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS,
1104 				      vcpu->arch.aia_context.imsic_addr,
1105 				      KVM_DEV_RISCV_IMSIC_SIZE,
1106 				      &imsic->iodev);
1107 	mutex_unlock(&kvm->slots_lock);
1108 	if (ret)
1109 		goto fail_free_swfile;
1110 
1111 	return 0;
1112 
1113 fail_free_swfile:
1114 	free_pages((unsigned long)imsic->swfile,
1115 		   get_order(sizeof(*imsic->swfile)));
1116 fail_free_imsic:
1117 	vcpu->arch.aia_context.imsic_state = NULL;
1118 	kfree(imsic);
1119 	return ret;
1120 }
1121 
kvm_riscv_vcpu_aia_imsic_cleanup(struct kvm_vcpu * vcpu)1122 void kvm_riscv_vcpu_aia_imsic_cleanup(struct kvm_vcpu *vcpu)
1123 {
1124 	struct kvm *kvm = vcpu->kvm;
1125 	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
1126 
1127 	if (!imsic)
1128 		return;
1129 
1130 	imsic_vsfile_cleanup(imsic);
1131 
1132 	mutex_lock(&kvm->slots_lock);
1133 	kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &imsic->iodev);
1134 	mutex_unlock(&kvm->slots_lock);
1135 
1136 	free_pages((unsigned long)imsic->swfile,
1137 		   get_order(sizeof(*imsic->swfile)));
1138 
1139 	vcpu->arch.aia_context.imsic_state = NULL;
1140 	kfree(imsic);
1141 }
1142