xref: /linux/drivers/irqchip/irq-gic-v5-irs.c (revision 949d0a46ad1b9ab3450fb6ed69ff1e3e13c657bd)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2024-2025 ARM Limited, All Rights Reserved.
4  */
5 
6 #define pr_fmt(fmt)	"GICv5 IRS: " fmt
7 
8 #include <linux/acpi.h>
9 #include <linux/kmemleak.h>
10 #include <linux/log2.h>
11 #include <linux/of.h>
12 #include <linux/of_address.h>
13 
14 #include <linux/irqchip.h>
15 #include <linux/irqchip/arm-gic-v5.h>
16 
17 /*
18  * Hardcoded ID_BITS limit for systems supporting only a 1-level IST
19  * table. Systems supporting only a 1-level IST table aren't expected
20  * to require more than 2^12 LPIs. Tweak as required.
21  */
22 #define LPI_ID_BITS_LINEAR		12
23 
24 #define IRS_FLAGS_NON_COHERENT		BIT(0)
25 
26 static DEFINE_PER_CPU_READ_MOSTLY(struct gicv5_irs_chip_data *, per_cpu_irs_data);
27 static LIST_HEAD(irs_nodes);
28 
irs_readl_relaxed(struct gicv5_irs_chip_data * irs_data,const u32 reg_offset)29 static u32 irs_readl_relaxed(struct gicv5_irs_chip_data *irs_data,
30 			     const u32 reg_offset)
31 {
32 	return readl_relaxed(irs_data->irs_base + reg_offset);
33 }
34 
irs_writel_relaxed(struct gicv5_irs_chip_data * irs_data,const u32 val,const u32 reg_offset)35 static void irs_writel_relaxed(struct gicv5_irs_chip_data *irs_data,
36 			       const u32 val, const u32 reg_offset)
37 {
38 	writel_relaxed(val, irs_data->irs_base + reg_offset);
39 }
40 
irs_readq_relaxed(struct gicv5_irs_chip_data * irs_data,const u32 reg_offset)41 static u64 irs_readq_relaxed(struct gicv5_irs_chip_data *irs_data,
42 			     const u32 reg_offset)
43 {
44 	return readq_relaxed(irs_data->irs_base + reg_offset);
45 }
46 
irs_writeq_relaxed(struct gicv5_irs_chip_data * irs_data,const u64 val,const u32 reg_offset)47 static void irs_writeq_relaxed(struct gicv5_irs_chip_data *irs_data,
48 			       const u64 val, const u32 reg_offset)
49 {
50 	writeq_relaxed(val, irs_data->irs_base + reg_offset);
51 }
52 
53 /*
54  * The polling wait (in gicv5_wait_for_op_s_atomic()) on a GIC register
55  * provides the memory barriers (through MMIO accessors)
56  * required to synchronize CPU and GIC access to IST memory.
57  */
gicv5_irs_ist_synchronise(struct gicv5_irs_chip_data * irs_data)58 static int gicv5_irs_ist_synchronise(struct gicv5_irs_chip_data *irs_data)
59 {
60 	return gicv5_wait_for_op_atomic(irs_data->irs_base, GICV5_IRS_IST_STATUSR,
61 					GICV5_IRS_IST_STATUSR_IDLE, NULL);
62 }
63 
gicv5_irs_init_ist_linear(struct gicv5_irs_chip_data * irs_data,unsigned int lpi_id_bits,unsigned int istsz)64 static int __init gicv5_irs_init_ist_linear(struct gicv5_irs_chip_data *irs_data,
65 					    unsigned int lpi_id_bits,
66 					    unsigned int istsz)
67 {
68 	size_t l2istsz;
69 	u32 n, cfgr;
70 	void *ist;
71 	u64 baser;
72 	int ret;
73 
74 	/* Taken from GICv5 specifications 10.2.1.13 IRS_IST_BASER */
75 	n = max(5, lpi_id_bits + 1 + istsz);
76 
77 	l2istsz = BIT(n + 1);
78 	/*
79 	 * Check memory requirements. For a linear IST we cap the
80 	 * number of ID bits to a value that should never exceed
81 	 * kmalloc interface memory allocation limits, so this
82 	 * check is really belt and braces.
83 	 */
84 	if (l2istsz > KMALLOC_MAX_SIZE) {
85 		u8 lpi_id_cap = ilog2(KMALLOC_MAX_SIZE) - 2 + istsz;
86 
87 		pr_warn("Limiting LPI ID bits from %u to %u\n",
88 			lpi_id_bits, lpi_id_cap);
89 		lpi_id_bits = lpi_id_cap;
90 		l2istsz = KMALLOC_MAX_SIZE;
91 	}
92 
93 	ist = kzalloc(l2istsz, GFP_KERNEL);
94 	if (!ist)
95 		return -ENOMEM;
96 
97 	if (irs_data->flags & IRS_FLAGS_NON_COHERENT)
98 		dcache_clean_inval_poc((unsigned long)ist,
99 				       (unsigned long)ist + l2istsz);
100 	else
101 		dsb(ishst);
102 
103 	cfgr = FIELD_PREP(GICV5_IRS_IST_CFGR_STRUCTURE,
104 			  GICV5_IRS_IST_CFGR_STRUCTURE_LINEAR)	|
105 	       FIELD_PREP(GICV5_IRS_IST_CFGR_ISTSZ, istsz)	|
106 	       FIELD_PREP(GICV5_IRS_IST_CFGR_L2SZ,
107 			  GICV5_IRS_IST_CFGR_L2SZ_4K)		|
108 	       FIELD_PREP(GICV5_IRS_IST_CFGR_LPI_ID_BITS, lpi_id_bits);
109 	irs_writel_relaxed(irs_data, cfgr, GICV5_IRS_IST_CFGR);
110 
111 	gicv5_global_data.ist.l2 = false;
112 
113 	baser = (virt_to_phys(ist) & GICV5_IRS_IST_BASER_ADDR_MASK) |
114 		FIELD_PREP(GICV5_IRS_IST_BASER_VALID, 0x1);
115 	irs_writeq_relaxed(irs_data, baser, GICV5_IRS_IST_BASER);
116 
117 	ret = gicv5_irs_ist_synchronise(irs_data);
118 	if (ret) {
119 		kfree(ist);
120 		return ret;
121 	}
122 	kmemleak_ignore(ist);
123 
124 	return 0;
125 }
126 
gicv5_irs_init_ist_two_level(struct gicv5_irs_chip_data * irs_data,unsigned int lpi_id_bits,unsigned int istsz,unsigned int l2sz)127 static int __init gicv5_irs_init_ist_two_level(struct gicv5_irs_chip_data *irs_data,
128 					       unsigned int lpi_id_bits,
129 					       unsigned int istsz,
130 					       unsigned int l2sz)
131 {
132 	__le64 *l1ist;
133 	u32 cfgr, n;
134 	size_t l1sz;
135 	u64 baser;
136 	int ret;
137 
138 	/* Taken from GICv5 specifications 10.2.1.13 IRS_IST_BASER */
139 	n = max(5, lpi_id_bits - ((10 - istsz) + (2 * l2sz)) + 2);
140 
141 	l1sz = BIT(n + 1);
142 
143 	l1ist = kzalloc(l1sz, GFP_KERNEL);
144 	if (!l1ist)
145 		return -ENOMEM;
146 
147 	if (irs_data->flags & IRS_FLAGS_NON_COHERENT)
148 		dcache_clean_inval_poc((unsigned long)l1ist,
149 				       (unsigned long)l1ist + l1sz);
150 	else
151 		dsb(ishst);
152 
153 	cfgr = FIELD_PREP(GICV5_IRS_IST_CFGR_STRUCTURE,
154 			  GICV5_IRS_IST_CFGR_STRUCTURE_TWO_LEVEL)	|
155 	       FIELD_PREP(GICV5_IRS_IST_CFGR_ISTSZ, istsz)		|
156 	       FIELD_PREP(GICV5_IRS_IST_CFGR_L2SZ, l2sz)		|
157 	       FIELD_PREP(GICV5_IRS_IST_CFGR_LPI_ID_BITS, lpi_id_bits);
158 	irs_writel_relaxed(irs_data, cfgr, GICV5_IRS_IST_CFGR);
159 
160 	/*
161 	 * The L2SZ determine bits required at L2 level. Number of bytes
162 	 * required by metadata is reported through istsz - the number of bits
163 	 * covered by L2 entries scales accordingly.
164 	 */
165 	gicv5_global_data.ist.l2_size = BIT(11 + (2 * l2sz) + 1);
166 	gicv5_global_data.ist.l2_bits = (10 - istsz) + (2 * l2sz);
167 	gicv5_global_data.ist.l1ist_addr = l1ist;
168 	gicv5_global_data.ist.l2 = true;
169 
170 	baser = (virt_to_phys(l1ist) & GICV5_IRS_IST_BASER_ADDR_MASK) |
171 		FIELD_PREP(GICV5_IRS_IST_BASER_VALID, 0x1);
172 	irs_writeq_relaxed(irs_data, baser, GICV5_IRS_IST_BASER);
173 
174 	ret = gicv5_irs_ist_synchronise(irs_data);
175 	if (ret) {
176 		kfree(l1ist);
177 		return ret;
178 	}
179 
180 	return 0;
181 }
182 
183 /*
184  * Alloc L2 IST entries on demand.
185  *
186  * Locking/serialization is guaranteed by irqdomain core code by
187  * taking the hierarchical domain struct irq_domain.root->mutex.
188  */
gicv5_irs_iste_alloc(const u32 lpi)189 int gicv5_irs_iste_alloc(const u32 lpi)
190 {
191 	struct gicv5_irs_chip_data *irs_data;
192 	unsigned int index;
193 	u32 l2istr, l2bits;
194 	__le64 *l1ist;
195 	size_t l2size;
196 	void *l2ist;
197 	int ret;
198 
199 	if (!gicv5_global_data.ist.l2)
200 		return 0;
201 
202 	irs_data = per_cpu(per_cpu_irs_data, smp_processor_id());
203 	if (!irs_data)
204 		return -ENOENT;
205 
206 	l2size = gicv5_global_data.ist.l2_size;
207 	l2bits = gicv5_global_data.ist.l2_bits;
208 	l1ist = gicv5_global_data.ist.l1ist_addr;
209 	index = lpi >> l2bits;
210 
211 	if (FIELD_GET(GICV5_ISTL1E_VALID, le64_to_cpu(l1ist[index])))
212 		return 0;
213 
214 	l2ist = kzalloc(l2size, GFP_KERNEL);
215 	if (!l2ist)
216 		return -ENOMEM;
217 
218 	l1ist[index] = cpu_to_le64(virt_to_phys(l2ist) & GICV5_ISTL1E_L2_ADDR_MASK);
219 
220 	if (irs_data->flags & IRS_FLAGS_NON_COHERENT) {
221 		dcache_clean_inval_poc((unsigned long)l2ist,
222 				       (unsigned long)l2ist + l2size);
223 		dcache_clean_poc((unsigned long)(l1ist + index),
224 				 (unsigned long)(l1ist + index) + sizeof(*l1ist));
225 	} else {
226 		dsb(ishst);
227 	}
228 
229 	l2istr = FIELD_PREP(GICV5_IRS_MAP_L2_ISTR_ID, lpi);
230 	irs_writel_relaxed(irs_data, l2istr, GICV5_IRS_MAP_L2_ISTR);
231 
232 	ret = gicv5_irs_ist_synchronise(irs_data);
233 	if (ret) {
234 		l1ist[index] = 0;
235 		kfree(l2ist);
236 		return ret;
237 	}
238 	kmemleak_ignore(l2ist);
239 
240 	/*
241 	 * Make sure we invalidate the cache line pulled before the IRS
242 	 * had a chance to update the L1 entry and mark it valid.
243 	 */
244 	if (irs_data->flags & IRS_FLAGS_NON_COHERENT) {
245 		/*
246 		 * gicv5_irs_ist_synchronise() includes memory
247 		 * barriers (MMIO accessors) required to guarantee that the
248 		 * following dcache invalidation is not executed before the
249 		 * IST mapping operation has completed.
250 		 */
251 		dcache_inval_poc((unsigned long)(l1ist + index),
252 				 (unsigned long)(l1ist + index) + sizeof(*l1ist));
253 	}
254 
255 	return 0;
256 }
257 
258 /*
259  * Try to match the L2 IST size to the pagesize, and if this is not possible
260  * pick the smallest supported L2 size in order to minimise the requirement for
261  * physically contiguous blocks of memory as page-sized allocations are
262  * guaranteed to be physically contiguous, and are by definition the easiest to
263  * find.
264  *
265  * Fall back to the smallest supported size (in the event that the pagesize
266  * itself is not supported) again serves to make it easier to find physically
267  * contiguous blocks of memory.
268  */
gicv5_irs_l2_sz(u32 idr2)269 static unsigned int gicv5_irs_l2_sz(u32 idr2)
270 {
271 	switch (PAGE_SIZE) {
272 	case SZ_64K:
273 		if (GICV5_IRS_IST_L2SZ_SUPPORT_64KB(idr2))
274 			return GICV5_IRS_IST_CFGR_L2SZ_64K;
275 		fallthrough;
276 	case SZ_4K:
277 		if (GICV5_IRS_IST_L2SZ_SUPPORT_4KB(idr2))
278 			return GICV5_IRS_IST_CFGR_L2SZ_4K;
279 		fallthrough;
280 	case SZ_16K:
281 		if (GICV5_IRS_IST_L2SZ_SUPPORT_16KB(idr2))
282 			return GICV5_IRS_IST_CFGR_L2SZ_16K;
283 		break;
284 	}
285 
286 	if (GICV5_IRS_IST_L2SZ_SUPPORT_4KB(idr2))
287 		return GICV5_IRS_IST_CFGR_L2SZ_4K;
288 
289 	return GICV5_IRS_IST_CFGR_L2SZ_64K;
290 }
291 
gicv5_irs_init_ist(struct gicv5_irs_chip_data * irs_data)292 static int __init gicv5_irs_init_ist(struct gicv5_irs_chip_data *irs_data)
293 {
294 	u32 lpi_id_bits, idr2_id_bits, idr2_min_lpi_id_bits, l2_iste_sz, l2sz;
295 	u32 l2_iste_sz_split, idr2;
296 	bool two_levels, istmd;
297 	u64 baser;
298 	int ret;
299 
300 	baser = irs_readq_relaxed(irs_data, GICV5_IRS_IST_BASER);
301 	if (FIELD_GET(GICV5_IRS_IST_BASER_VALID, baser)) {
302 		pr_err("IST is marked as valid already; cannot allocate\n");
303 		return -EPERM;
304 	}
305 
306 	idr2 = irs_readl_relaxed(irs_data, GICV5_IRS_IDR2);
307 	two_levels = !!FIELD_GET(GICV5_IRS_IDR2_IST_LEVELS, idr2);
308 
309 	idr2_id_bits = FIELD_GET(GICV5_IRS_IDR2_ID_BITS, idr2);
310 	idr2_min_lpi_id_bits = FIELD_GET(GICV5_IRS_IDR2_MIN_LPI_ID_BITS, idr2);
311 
312 	/*
313 	 * For two level tables we are always supporting the maximum allowed
314 	 * number of IDs.
315 	 *
316 	 * For 1-level tables, we should support a number of bits that
317 	 * is >= min_lpi_id_bits but cap it to LPI_ID_BITS_LINEAR lest
318 	 * the level 1-table gets too large and its memory allocation
319 	 * may fail.
320 	 */
321 	if (two_levels) {
322 		lpi_id_bits = idr2_id_bits;
323 	} else {
324 		lpi_id_bits = max(LPI_ID_BITS_LINEAR, idr2_min_lpi_id_bits);
325 		lpi_id_bits = min(lpi_id_bits, idr2_id_bits);
326 	}
327 
328 	/*
329 	 * Cap the ID bits according to the CPUIF supported ID bits
330 	 */
331 	lpi_id_bits = min(lpi_id_bits, gicv5_global_data.cpuif_id_bits);
332 
333 	if (two_levels)
334 		l2sz = gicv5_irs_l2_sz(idr2);
335 
336 	istmd = !!FIELD_GET(GICV5_IRS_IDR2_ISTMD, idr2);
337 
338 	l2_iste_sz = GICV5_IRS_IST_CFGR_ISTSZ_4;
339 
340 	if (istmd) {
341 		l2_iste_sz_split = FIELD_GET(GICV5_IRS_IDR2_ISTMD_SZ, idr2);
342 
343 		if (lpi_id_bits < l2_iste_sz_split)
344 			l2_iste_sz = GICV5_IRS_IST_CFGR_ISTSZ_8;
345 		else
346 			l2_iste_sz = GICV5_IRS_IST_CFGR_ISTSZ_16;
347 	}
348 
349 	/*
350 	 * Follow GICv5 specification recommendation to opt in for two
351 	 * level tables (ref: 10.2.1.14 IRS_IST_CFGR).
352 	 */
353 	if (two_levels && (lpi_id_bits > ((10 - l2_iste_sz) + (2 * l2sz)))) {
354 		ret = gicv5_irs_init_ist_two_level(irs_data, lpi_id_bits,
355 						   l2_iste_sz, l2sz);
356 	} else {
357 		ret = gicv5_irs_init_ist_linear(irs_data, lpi_id_bits,
358 						l2_iste_sz);
359 	}
360 	if (ret)
361 		return ret;
362 
363 	gicv5_init_lpis(BIT(lpi_id_bits));
364 
365 	return 0;
366 }
367 
368 struct iaffid_entry {
369 	u16	iaffid;
370 	bool	valid;
371 };
372 
373 static DEFINE_PER_CPU(struct iaffid_entry, cpu_iaffid);
374 
gicv5_irs_cpu_to_iaffid(int cpuid,u16 * iaffid)375 int gicv5_irs_cpu_to_iaffid(int cpuid, u16 *iaffid)
376 {
377 	if (!per_cpu(cpu_iaffid, cpuid).valid) {
378 		pr_err("IAFFID for CPU %d has not been initialised\n", cpuid);
379 		return -ENODEV;
380 	}
381 
382 	*iaffid = per_cpu(cpu_iaffid, cpuid).iaffid;
383 
384 	return 0;
385 }
386 
gicv5_irs_lookup_by_spi_id(u32 spi_id)387 struct gicv5_irs_chip_data *gicv5_irs_lookup_by_spi_id(u32 spi_id)
388 {
389 	struct gicv5_irs_chip_data *irs_data;
390 	u32 min, max;
391 
392 	list_for_each_entry(irs_data, &irs_nodes, entry) {
393 		if (!irs_data->spi_range)
394 			continue;
395 
396 		min = irs_data->spi_min;
397 		max = irs_data->spi_min + irs_data->spi_range - 1;
398 		if (spi_id >= min && spi_id <= max)
399 			return irs_data;
400 	}
401 
402 	return NULL;
403 }
404 
gicv5_irs_wait_for_spi_op(struct gicv5_irs_chip_data * irs_data)405 static int gicv5_irs_wait_for_spi_op(struct gicv5_irs_chip_data *irs_data)
406 {
407 	u32 statusr;
408 	int ret;
409 
410 	ret = gicv5_wait_for_op_atomic(irs_data->irs_base, GICV5_IRS_SPI_STATUSR,
411 				       GICV5_IRS_SPI_STATUSR_IDLE, &statusr);
412 	if (ret)
413 		return ret;
414 
415 	return !!FIELD_GET(GICV5_IRS_SPI_STATUSR_V, statusr) ? 0 : -EIO;
416 }
417 
gicv5_irs_wait_for_irs_pe(struct gicv5_irs_chip_data * irs_data,bool selr)418 static int gicv5_irs_wait_for_irs_pe(struct gicv5_irs_chip_data *irs_data,
419 				     bool selr)
420 {
421 	bool valid = true;
422 	u32 statusr;
423 	int ret;
424 
425 	ret = gicv5_wait_for_op_atomic(irs_data->irs_base, GICV5_IRS_PE_STATUSR,
426 				       GICV5_IRS_PE_STATUSR_IDLE, &statusr);
427 	if (ret)
428 		return ret;
429 
430 	if (selr)
431 		valid = !!FIELD_GET(GICV5_IRS_PE_STATUSR_V, statusr);
432 
433 	return valid ? 0 : -EIO;
434 }
435 
gicv5_irs_wait_for_pe_selr(struct gicv5_irs_chip_data * irs_data)436 static int gicv5_irs_wait_for_pe_selr(struct gicv5_irs_chip_data *irs_data)
437 {
438 	return gicv5_irs_wait_for_irs_pe(irs_data, true);
439 }
440 
gicv5_irs_wait_for_pe_cr0(struct gicv5_irs_chip_data * irs_data)441 static int gicv5_irs_wait_for_pe_cr0(struct gicv5_irs_chip_data *irs_data)
442 {
443 	return gicv5_irs_wait_for_irs_pe(irs_data, false);
444 }
445 
gicv5_spi_irq_set_type(struct irq_data * d,unsigned int type)446 int gicv5_spi_irq_set_type(struct irq_data *d, unsigned int type)
447 {
448 	struct gicv5_irs_chip_data *irs_data = d->chip_data;
449 	u32 selr, cfgr;
450 	bool level;
451 	int ret;
452 
453 	/*
454 	 * There is no distinction between HIGH/LOW for level IRQs
455 	 * and RISING/FALLING for edge IRQs in the architecture,
456 	 * hence consider them equivalent.
457 	 */
458 	switch (type) {
459 	case IRQ_TYPE_EDGE_RISING:
460 	case IRQ_TYPE_EDGE_FALLING:
461 		level = false;
462 		break;
463 	case IRQ_TYPE_LEVEL_HIGH:
464 	case IRQ_TYPE_LEVEL_LOW:
465 		level = true;
466 		break;
467 	default:
468 		return -EINVAL;
469 	}
470 
471 	guard(raw_spinlock)(&irs_data->spi_config_lock);
472 
473 	selr = FIELD_PREP(GICV5_IRS_SPI_SELR_ID, d->hwirq);
474 	irs_writel_relaxed(irs_data, selr, GICV5_IRS_SPI_SELR);
475 	ret = gicv5_irs_wait_for_spi_op(irs_data);
476 	if (ret)
477 		return ret;
478 
479 	cfgr = FIELD_PREP(GICV5_IRS_SPI_CFGR_TM, level);
480 	irs_writel_relaxed(irs_data, cfgr, GICV5_IRS_SPI_CFGR);
481 
482 	return gicv5_irs_wait_for_spi_op(irs_data);
483 }
484 
gicv5_irs_wait_for_idle(struct gicv5_irs_chip_data * irs_data)485 static int gicv5_irs_wait_for_idle(struct gicv5_irs_chip_data *irs_data)
486 {
487 	return gicv5_wait_for_op_atomic(irs_data->irs_base, GICV5_IRS_CR0,
488 					GICV5_IRS_CR0_IDLE, NULL);
489 }
490 
gicv5_irs_syncr(void)491 void gicv5_irs_syncr(void)
492 {
493 	struct gicv5_irs_chip_data *irs_data;
494 	u32 syncr;
495 
496 	irs_data = list_first_entry_or_null(&irs_nodes, struct gicv5_irs_chip_data, entry);
497 	if (WARN_ON_ONCE(!irs_data))
498 		return;
499 
500 	syncr = FIELD_PREP(GICV5_IRS_SYNCR_SYNC, 1);
501 	irs_writel_relaxed(irs_data, syncr, GICV5_IRS_SYNCR);
502 
503 	gicv5_wait_for_op(irs_data->irs_base, GICV5_IRS_SYNC_STATUSR,
504 			  GICV5_IRS_SYNC_STATUSR_IDLE);
505 }
506 
gicv5_irs_register_cpu(int cpuid)507 int gicv5_irs_register_cpu(int cpuid)
508 {
509 	struct gicv5_irs_chip_data *irs_data;
510 	u32 selr, cr0;
511 	u16 iaffid;
512 	int ret;
513 
514 	ret = gicv5_irs_cpu_to_iaffid(cpuid, &iaffid);
515 	if (ret) {
516 		pr_err("IAFFID for CPU %d has not been initialised\n", cpuid);
517 		return ret;
518 	}
519 
520 	irs_data = per_cpu(per_cpu_irs_data, cpuid);
521 	if (!irs_data) {
522 		pr_err("No IRS associated with CPU %u\n", cpuid);
523 		return -ENXIO;
524 	}
525 
526 	selr = FIELD_PREP(GICV5_IRS_PE_SELR_IAFFID, iaffid);
527 	irs_writel_relaxed(irs_data, selr, GICV5_IRS_PE_SELR);
528 
529 	ret = gicv5_irs_wait_for_pe_selr(irs_data);
530 	if (ret) {
531 		pr_err("IAFFID 0x%x used in IRS_PE_SELR is invalid\n", iaffid);
532 		return -ENXIO;
533 	}
534 
535 	cr0 = FIELD_PREP(GICV5_IRS_PE_CR0_DPS, 0x1);
536 	irs_writel_relaxed(irs_data, cr0, GICV5_IRS_PE_CR0);
537 
538 	ret = gicv5_irs_wait_for_pe_cr0(irs_data);
539 	if (ret)
540 		return ret;
541 
542 	pr_debug("CPU %d enabled PE IAFFID 0x%x\n", cpuid, iaffid);
543 
544 	return 0;
545 }
546 
gicv5_irs_init_bases(struct gicv5_irs_chip_data * irs_data,void __iomem * irs_base,bool noncoherent)547 static void __init gicv5_irs_init_bases(struct gicv5_irs_chip_data *irs_data,
548 					void __iomem *irs_base,
549 					bool noncoherent)
550 {
551 	u32 cr0, cr1;
552 
553 	irs_data->irs_base = irs_base;
554 
555 	if (noncoherent) {
556 		/*
557 		 * A non-coherent IRS implies that some cache levels cannot be
558 		 * used coherently by the cores and GIC. Our only option is to mark
559 		 * memory attributes for the GIC as non-cacheable; by default,
560 		 * non-cacheable memory attributes imply outer-shareable
561 		 * shareability, the value written into IRS_CR1_SH is ignored.
562 		 */
563 		cr1 = FIELD_PREP(GICV5_IRS_CR1_VPED_WA, GICV5_NO_WRITE_ALLOC)	|
564 			FIELD_PREP(GICV5_IRS_CR1_VPED_RA, GICV5_NO_READ_ALLOC)	|
565 			FIELD_PREP(GICV5_IRS_CR1_VMD_WA, GICV5_NO_WRITE_ALLOC)	|
566 			FIELD_PREP(GICV5_IRS_CR1_VMD_RA, GICV5_NO_READ_ALLOC)	|
567 			FIELD_PREP(GICV5_IRS_CR1_VPET_RA, GICV5_NO_READ_ALLOC)	|
568 			FIELD_PREP(GICV5_IRS_CR1_VMT_RA, GICV5_NO_READ_ALLOC)	|
569 			FIELD_PREP(GICV5_IRS_CR1_IST_WA, GICV5_NO_WRITE_ALLOC)	|
570 			FIELD_PREP(GICV5_IRS_CR1_IST_RA, GICV5_NO_READ_ALLOC)	|
571 			FIELD_PREP(GICV5_IRS_CR1_IC, GICV5_NON_CACHE)		|
572 			FIELD_PREP(GICV5_IRS_CR1_OC, GICV5_NON_CACHE);
573 		irs_data->flags |= IRS_FLAGS_NON_COHERENT;
574 	} else {
575 		cr1 = FIELD_PREP(GICV5_IRS_CR1_VPED_WA, GICV5_WRITE_ALLOC)	|
576 			FIELD_PREP(GICV5_IRS_CR1_VPED_RA, GICV5_READ_ALLOC)	|
577 			FIELD_PREP(GICV5_IRS_CR1_VMD_WA, GICV5_WRITE_ALLOC)	|
578 			FIELD_PREP(GICV5_IRS_CR1_VMD_RA, GICV5_READ_ALLOC)	|
579 			FIELD_PREP(GICV5_IRS_CR1_VPET_RA, GICV5_READ_ALLOC)	|
580 			FIELD_PREP(GICV5_IRS_CR1_VMT_RA, GICV5_READ_ALLOC)	|
581 			FIELD_PREP(GICV5_IRS_CR1_IST_WA, GICV5_WRITE_ALLOC)	|
582 			FIELD_PREP(GICV5_IRS_CR1_IST_RA, GICV5_READ_ALLOC)	|
583 			FIELD_PREP(GICV5_IRS_CR1_IC, GICV5_WB_CACHE)		|
584 			FIELD_PREP(GICV5_IRS_CR1_OC, GICV5_WB_CACHE)		|
585 			FIELD_PREP(GICV5_IRS_CR1_SH, GICV5_INNER_SHARE);
586 	}
587 
588 	irs_writel_relaxed(irs_data, cr1, GICV5_IRS_CR1);
589 
590 	cr0 = FIELD_PREP(GICV5_IRS_CR0_IRSEN, 0x1);
591 	irs_writel_relaxed(irs_data, cr0, GICV5_IRS_CR0);
592 	gicv5_irs_wait_for_idle(irs_data);
593 }
594 
gicv5_irs_of_init_affinity(struct device_node * node,struct gicv5_irs_chip_data * irs_data,u8 iaffid_bits)595 static int __init gicv5_irs_of_init_affinity(struct device_node *node,
596 					     struct gicv5_irs_chip_data *irs_data,
597 					     u8 iaffid_bits)
598 {
599 	/*
600 	 * Detect IAFFID<->CPU mappings from the device tree and
601 	 * record IRS<->CPU topology information.
602 	 */
603 	u16 iaffid_mask = GENMASK(iaffid_bits - 1, 0);
604 	int ret, i, ncpus, niaffids;
605 
606 	ncpus = of_count_phandle_with_args(node, "cpus", NULL);
607 	if (ncpus < 0)
608 		return -EINVAL;
609 
610 	niaffids = of_property_count_elems_of_size(node, "arm,iaffids",
611 						   sizeof(u16));
612 	if (niaffids != ncpus)
613 		return -EINVAL;
614 
615 	u16 *iaffids __free(kfree) = kcalloc(niaffids, sizeof(*iaffids), GFP_KERNEL);
616 	if (!iaffids)
617 		return -ENOMEM;
618 
619 	ret = of_property_read_u16_array(node, "arm,iaffids", iaffids, niaffids);
620 	if (ret)
621 		return ret;
622 
623 	for (i = 0; i < ncpus; i++) {
624 		struct device_node *cpu_node;
625 		int cpu;
626 
627 		cpu_node = of_parse_phandle(node, "cpus", i);
628 		if (!cpu_node) {
629 			pr_warn(FW_BUG "Erroneous CPU node phandle\n");
630 			continue;
631 		}
632 
633 		cpu = of_cpu_node_to_id(cpu_node);
634 		of_node_put(cpu_node);
635 		if (cpu < 0)
636 			continue;
637 
638 		if (iaffids[i] & ~iaffid_mask) {
639 			pr_warn("CPU %d iaffid 0x%x exceeds IRS iaffid bits\n",
640 				cpu, iaffids[i]);
641 			continue;
642 		}
643 
644 		per_cpu(cpu_iaffid, cpu).iaffid = iaffids[i];
645 		per_cpu(cpu_iaffid, cpu).valid = true;
646 
647 		/* We also know that the CPU is connected to this IRS */
648 		per_cpu(per_cpu_irs_data, cpu) = irs_data;
649 	}
650 
651 	return ret;
652 }
653 
irs_setup_pri_bits(u32 idr1)654 static void irs_setup_pri_bits(u32 idr1)
655 {
656 	switch (FIELD_GET(GICV5_IRS_IDR1_PRIORITY_BITS, idr1)) {
657 	case GICV5_IRS_IDR1_PRIORITY_BITS_1BITS:
658 		gicv5_global_data.irs_pri_bits = 1;
659 		break;
660 	case GICV5_IRS_IDR1_PRIORITY_BITS_2BITS:
661 		gicv5_global_data.irs_pri_bits = 2;
662 		break;
663 	case GICV5_IRS_IDR1_PRIORITY_BITS_3BITS:
664 		gicv5_global_data.irs_pri_bits = 3;
665 		break;
666 	case GICV5_IRS_IDR1_PRIORITY_BITS_4BITS:
667 		gicv5_global_data.irs_pri_bits = 4;
668 		break;
669 	case GICV5_IRS_IDR1_PRIORITY_BITS_5BITS:
670 		gicv5_global_data.irs_pri_bits = 5;
671 		break;
672 	default:
673 		pr_warn("Detected wrong IDR priority bits value 0x%lx\n",
674 			FIELD_GET(GICV5_IRS_IDR1_PRIORITY_BITS, idr1));
675 		gicv5_global_data.irs_pri_bits = 1;
676 		break;
677 	}
678 }
679 
gicv5_irs_init(struct gicv5_irs_chip_data * irs_data)680 static int __init gicv5_irs_init(struct gicv5_irs_chip_data *irs_data)
681 {
682 	u32 spi_count, idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR2);
683 
684 	if (WARN(!FIELD_GET(GICV5_IRS_IDR2_LPI, idr),
685 		 "LPI support not available - no IPIs, can't proceed\n")) {
686 		return -ENODEV;
687 	}
688 
689 	idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR7);
690 	irs_data->spi_min = FIELD_GET(GICV5_IRS_IDR7_SPI_BASE, idr);
691 
692 	idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR6);
693 	irs_data->spi_range = FIELD_GET(GICV5_IRS_IDR6_SPI_IRS_RANGE, idr);
694 
695 	/*
696 	 * Do the global setting only on the first IRS.
697 	 * Global properties (iaffid_bits, global spi count) are guaranteed to
698 	 * be consistent across IRSes by the architecture.
699 	 */
700 	if (list_empty(&irs_nodes)) {
701 		idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR0);
702 		gicv5_global_data.virt_capable = !!FIELD_GET(GICV5_IRS_IDR0_VIRT, idr);
703 
704 		idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR1);
705 		irs_setup_pri_bits(idr);
706 
707 		idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR5);
708 
709 		spi_count = FIELD_GET(GICV5_IRS_IDR5_SPI_RANGE, idr);
710 		gicv5_global_data.global_spi_count = spi_count;
711 
712 		gicv5_init_lpi_domain();
713 
714 		pr_debug("Detected %u SPIs globally\n", spi_count);
715 	}
716 
717 	list_add_tail(&irs_data->entry, &irs_nodes);
718 
719 	return 0;
720 }
721 
gicv5_irs_of_init(struct device_node * node)722 static int __init gicv5_irs_of_init(struct device_node *node)
723 {
724 	struct gicv5_irs_chip_data *irs_data;
725 	void __iomem *irs_base;
726 	u8 iaffid_bits;
727 	u32 idr;
728 	int ret;
729 
730 	irs_data = kzalloc_obj(*irs_data);
731 	if (!irs_data)
732 		return -ENOMEM;
733 
734 	raw_spin_lock_init(&irs_data->spi_config_lock);
735 
736 	ret = of_property_match_string(node, "reg-names", "ns-config");
737 	if (ret < 0) {
738 		pr_err("%pOF: ns-config reg-name not present\n", node);
739 		goto out_err;
740 	}
741 
742 	irs_base = of_io_request_and_map(node, ret, of_node_full_name(node));
743 	if (IS_ERR(irs_base)) {
744 		pr_err("%pOF: unable to map GICv5 IRS registers\n", node);
745 		ret = PTR_ERR(irs_base);
746 		goto out_err;
747 	}
748 
749 	irs_data->fwnode = of_fwnode_handle(node);
750 	gicv5_irs_init_bases(irs_data, irs_base, of_property_read_bool(node, "dma-noncoherent"));
751 
752 	idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR1);
753 	iaffid_bits = FIELD_GET(GICV5_IRS_IDR1_IAFFID_BITS, idr) + 1;
754 
755 	ret = gicv5_irs_of_init_affinity(node, irs_data, iaffid_bits);
756 	if (ret) {
757 		pr_err("Failed to parse CPU IAFFIDs from the device tree!\n");
758 		goto out_iomem;
759 	}
760 
761 	ret = gicv5_irs_init(irs_data);
762 	if (ret)
763 		goto out_iomem;
764 
765 	if (irs_data->spi_range) {
766 		pr_info("%s detected SPI range [%u-%u]\n",
767 						of_node_full_name(node),
768 						irs_data->spi_min,
769 						irs_data->spi_min +
770 						irs_data->spi_range - 1);
771 	}
772 
773 	return ret;
774 
775 out_iomem:
776 	iounmap(irs_base);
777 out_err:
778 	kfree(irs_data);
779 	return ret;
780 }
781 
gicv5_irs_remove(void)782 void __init gicv5_irs_remove(void)
783 {
784 	struct gicv5_irs_chip_data *irs_data, *tmp_data;
785 
786 	gicv5_free_lpi_domain();
787 	gicv5_deinit_lpis();
788 
789 	list_for_each_entry_safe(irs_data, tmp_data, &irs_nodes, entry) {
790 		iounmap(irs_data->irs_base);
791 		list_del(&irs_data->entry);
792 		kfree(irs_data);
793 	}
794 }
795 
gicv5_irs_enable(void)796 int __init gicv5_irs_enable(void)
797 {
798 	struct gicv5_irs_chip_data *irs_data;
799 	int ret;
800 
801 	irs_data = list_first_entry_or_null(&irs_nodes,
802 					    struct gicv5_irs_chip_data, entry);
803 	if (!irs_data)
804 		return -ENODEV;
805 
806 	ret = gicv5_irs_init_ist(irs_data);
807 	if (ret) {
808 		pr_err("Failed to init IST\n");
809 		return ret;
810 	}
811 
812 	return 0;
813 }
814 
gicv5_irs_its_probe(void)815 void __init gicv5_irs_its_probe(void)
816 {
817 	struct gicv5_irs_chip_data *irs_data;
818 
819 	if (acpi_disabled)
820 		list_for_each_entry(irs_data, &irs_nodes, entry)
821 			gicv5_its_of_probe(to_of_node(irs_data->fwnode));
822 	else
823 		gicv5_its_acpi_probe();
824 }
825 
gicv5_irs_of_probe(struct device_node * parent)826 int __init gicv5_irs_of_probe(struct device_node *parent)
827 {
828 	struct device_node *np;
829 	int ret;
830 
831 	for_each_available_child_of_node(parent, np) {
832 		if (!of_device_is_compatible(np, "arm,gic-v5-irs"))
833 			continue;
834 
835 		ret = gicv5_irs_of_init(np);
836 		if (ret)
837 			pr_err("Failed to init IRS %s\n", np->full_name);
838 	}
839 
840 	return list_empty(&irs_nodes) ? -ENODEV : 0;
841 }
842 
843 #ifdef CONFIG_ACPI
844 
845 #define ACPI_GICV5_IRS_MEM_SIZE (SZ_64K)
846 static struct gicv5_irs_chip_data *current_irs_data __initdata;
847 static int current_irsid __initdata = -1;
848 static u8 current_iaffid_bits __initdata;
849 
gic_acpi_parse_iaffid(union acpi_subtable_headers * header,const unsigned long end)850 static int __init gic_acpi_parse_iaffid(union acpi_subtable_headers *header,
851 					const unsigned long end)
852 {
853 	struct acpi_madt_generic_interrupt *gicc = (struct acpi_madt_generic_interrupt *)header;
854 	int cpu;
855 
856 	if (!(gicc->flags & (ACPI_MADT_ENABLED | ACPI_MADT_GICC_ONLINE_CAPABLE)))
857 		return 0;
858 
859 	if (gicc->irs_id != current_irsid)
860 		return 0;
861 
862 	cpu = get_logical_index(gicc->arm_mpidr);
863 
864 	if (gicc->iaffid & ~GENMASK(current_iaffid_bits - 1, 0)) {
865 		pr_warn("CPU %d iaffid 0x%x exceeds IRS iaffid bits\n", cpu, gicc->iaffid);
866 		return 0;
867 	}
868 
869 	/* Bind the IAFFID and the CPU */
870 	per_cpu(cpu_iaffid, cpu).iaffid = gicc->iaffid;
871 	per_cpu(cpu_iaffid, cpu).valid = true;
872 	pr_debug("Processed IAFFID %u for CPU%d", per_cpu(cpu_iaffid, cpu).iaffid, cpu);
873 
874 	/* We also know that the CPU is connected to this IRS */
875 	per_cpu(per_cpu_irs_data, cpu) = current_irs_data;
876 
877 	return 0;
878 }
879 
gicv5_irs_acpi_init_affinity(u32 irsid,struct gicv5_irs_chip_data * irs_data)880 static int __init gicv5_irs_acpi_init_affinity(u32 irsid, struct gicv5_irs_chip_data *irs_data)
881 {
882 	u32 idr;
883 
884 	current_irsid = irsid;
885 	current_irs_data = irs_data;
886 
887 	idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR1);
888 	current_iaffid_bits = FIELD_GET(GICV5_IRS_IDR1_IAFFID_BITS, idr) + 1;
889 
890 	acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT, gic_acpi_parse_iaffid, 0);
891 
892 	return 0;
893 }
894 
gic_request_region(resource_size_t base,resource_size_t size,const char * name)895 static struct resource * __init gic_request_region(resource_size_t base, resource_size_t size,
896 						   const char *name)
897 {
898 	struct resource *r = request_mem_region(base, size, name);
899 
900 	if (!r)
901 		pr_warn_once(FW_BUG "%s region %pa has overlapping address\n", name, &base);
902 
903 	return r;
904 }
905 
gic_acpi_parse_madt_irs(union acpi_subtable_headers * header,const unsigned long end)906 static int __init gic_acpi_parse_madt_irs(union acpi_subtable_headers *header,
907 					  const unsigned long end)
908 {
909 	struct acpi_madt_gicv5_irs *irs = (struct acpi_madt_gicv5_irs *)header;
910 	struct gicv5_irs_chip_data *irs_data;
911 	void __iomem *irs_base;
912 	struct resource *r;
913 	int ret;
914 
915 	/* Per-IRS data structure */
916 	irs_data = kzalloc_obj(*irs_data);
917 	if (!irs_data)
918 		return -ENOMEM;
919 
920 	/* This spinlock is used for SPI config changes */
921 	raw_spin_lock_init(&irs_data->spi_config_lock);
922 
923 	r = gic_request_region(irs->config_base_address, ACPI_GICV5_IRS_MEM_SIZE, "GICv5 IRS");
924 	if (!r) {
925 		ret = -EBUSY;
926 		goto out_free;
927 	}
928 
929 	irs_base = ioremap(irs->config_base_address, ACPI_GICV5_IRS_MEM_SIZE);
930 	if (!irs_base) {
931 		pr_err("Unable to map GIC IRS registers\n");
932 		ret = -ENOMEM;
933 		goto out_release;
934 	}
935 
936 	gicv5_irs_init_bases(irs_data, irs_base, irs->flags & ACPI_MADT_IRS_NON_COHERENT);
937 
938 	gicv5_irs_acpi_init_affinity(irs->irs_id, irs_data);
939 
940 	ret = gicv5_irs_init(irs_data);
941 	if (ret)
942 		goto out_map;
943 
944 	if (irs_data->spi_range) {
945 		pr_info("%s @%llx detected SPI range [%u-%u]\n", "IRS", irs->config_base_address,
946 									irs_data->spi_min,
947 									irs_data->spi_min +
948 									irs_data->spi_range - 1);
949 	}
950 
951 	return 0;
952 
953 out_map:
954 	iounmap(irs_base);
955 out_release:
956 	release_mem_region(r->start, resource_size(r));
957 out_free:
958 	kfree(irs_data);
959 	return ret;
960 }
961 
gicv5_irs_acpi_probe(void)962 int __init gicv5_irs_acpi_probe(void)
963 {
964 	acpi_table_parse_madt(ACPI_MADT_TYPE_GICV5_IRS, gic_acpi_parse_madt_irs, 0);
965 
966 	return list_empty(&irs_nodes) ? -ENODEV : 0;
967 }
968 #endif
969