xref: /openbmc/linux/drivers/irqchip/irq-hip04.c (revision 9cfc5c90)
1 /*
2  * Hisilicon HiP04 INTC
3  *
4  * Copyright (C) 2002-2014 ARM Limited.
5  * Copyright (c) 2013-2014 Hisilicon Ltd.
6  * Copyright (c) 2013-2014 Linaro Ltd.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  * Interrupt architecture for the HIP04 INTC:
13  *
14  * o There is one Interrupt Distributor, which receives interrupts
15  *   from system devices and sends them to the Interrupt Controllers.
16  *
17  * o There is one CPU Interface per CPU, which sends interrupts sent
18  *   by the Distributor, and interrupts generated locally, to the
19  *   associated CPU. The base address of the CPU interface is usually
20  *   aliased so that the same address points to different chips depending
21  *   on the CPU it is accessed from.
22  *
23  * Note that IRQs 0-31 are special - they are local to each CPU.
24  * As such, the enable set/clear, pending set/clear and active bit
25  * registers are banked per-cpu for these sources.
26  */
27 
28 #include <linux/init.h>
29 #include <linux/kernel.h>
30 #include <linux/err.h>
31 #include <linux/module.h>
32 #include <linux/list.h>
33 #include <linux/smp.h>
34 #include <linux/cpu.h>
35 #include <linux/cpu_pm.h>
36 #include <linux/cpumask.h>
37 #include <linux/io.h>
38 #include <linux/of.h>
39 #include <linux/of_address.h>
40 #include <linux/of_irq.h>
41 #include <linux/irqdomain.h>
42 #include <linux/interrupt.h>
43 #include <linux/slab.h>
44 #include <linux/irqchip.h>
45 #include <linux/irqchip/arm-gic.h>
46 
47 #include <asm/irq.h>
48 #include <asm/exception.h>
49 #include <asm/smp_plat.h>
50 
51 #include "irq-gic-common.h"
52 
53 #define HIP04_MAX_IRQS		510
54 
55 struct hip04_irq_data {
56 	void __iomem *dist_base;
57 	void __iomem *cpu_base;
58 	struct irq_domain *domain;
59 	unsigned int nr_irqs;
60 };
61 
62 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
63 
64 /*
65  * The GIC mapping of CPU interfaces does not necessarily match
66  * the logical CPU numbering.  Let's use a mapping as returned
67  * by the GIC itself.
68  */
69 #define NR_HIP04_CPU_IF 16
70 static u16 hip04_cpu_map[NR_HIP04_CPU_IF] __read_mostly;
71 
72 static struct hip04_irq_data hip04_data __read_mostly;
73 
74 static inline void __iomem *hip04_dist_base(struct irq_data *d)
75 {
76 	struct hip04_irq_data *hip04_data = irq_data_get_irq_chip_data(d);
77 	return hip04_data->dist_base;
78 }
79 
80 static inline void __iomem *hip04_cpu_base(struct irq_data *d)
81 {
82 	struct hip04_irq_data *hip04_data = irq_data_get_irq_chip_data(d);
83 	return hip04_data->cpu_base;
84 }
85 
86 static inline unsigned int hip04_irq(struct irq_data *d)
87 {
88 	return d->hwirq;
89 }
90 
91 /*
92  * Routines to acknowledge, disable and enable interrupts
93  */
94 static void hip04_mask_irq(struct irq_data *d)
95 {
96 	u32 mask = 1 << (hip04_irq(d) % 32);
97 
98 	raw_spin_lock(&irq_controller_lock);
99 	writel_relaxed(mask, hip04_dist_base(d) + GIC_DIST_ENABLE_CLEAR +
100 		       (hip04_irq(d) / 32) * 4);
101 	raw_spin_unlock(&irq_controller_lock);
102 }
103 
104 static void hip04_unmask_irq(struct irq_data *d)
105 {
106 	u32 mask = 1 << (hip04_irq(d) % 32);
107 
108 	raw_spin_lock(&irq_controller_lock);
109 	writel_relaxed(mask, hip04_dist_base(d) + GIC_DIST_ENABLE_SET +
110 		       (hip04_irq(d) / 32) * 4);
111 	raw_spin_unlock(&irq_controller_lock);
112 }
113 
114 static void hip04_eoi_irq(struct irq_data *d)
115 {
116 	writel_relaxed(hip04_irq(d), hip04_cpu_base(d) + GIC_CPU_EOI);
117 }
118 
119 static int hip04_irq_set_type(struct irq_data *d, unsigned int type)
120 {
121 	void __iomem *base = hip04_dist_base(d);
122 	unsigned int irq = hip04_irq(d);
123 	int ret;
124 
125 	/* Interrupt configuration for SGIs can't be changed */
126 	if (irq < 16)
127 		return -EINVAL;
128 
129 	/* SPIs have restrictions on the supported types */
130 	if (irq >= 32 && type != IRQ_TYPE_LEVEL_HIGH &&
131 			 type != IRQ_TYPE_EDGE_RISING)
132 		return -EINVAL;
133 
134 	raw_spin_lock(&irq_controller_lock);
135 
136 	ret = gic_configure_irq(irq, type, base, NULL);
137 
138 	raw_spin_unlock(&irq_controller_lock);
139 
140 	return ret;
141 }
142 
143 #ifdef CONFIG_SMP
144 static int hip04_irq_set_affinity(struct irq_data *d,
145 				  const struct cpumask *mask_val,
146 				  bool force)
147 {
148 	void __iomem *reg;
149 	unsigned int cpu, shift = (hip04_irq(d) % 2) * 16;
150 	u32 val, mask, bit;
151 
152 	if (!force)
153 		cpu = cpumask_any_and(mask_val, cpu_online_mask);
154 	else
155 		cpu = cpumask_first(mask_val);
156 
157 	if (cpu >= NR_HIP04_CPU_IF || cpu >= nr_cpu_ids)
158 		return -EINVAL;
159 
160 	raw_spin_lock(&irq_controller_lock);
161 	reg = hip04_dist_base(d) + GIC_DIST_TARGET + ((hip04_irq(d) * 2) & ~3);
162 	mask = 0xffff << shift;
163 	bit = hip04_cpu_map[cpu] << shift;
164 	val = readl_relaxed(reg) & ~mask;
165 	writel_relaxed(val | bit, reg);
166 	raw_spin_unlock(&irq_controller_lock);
167 
168 	return IRQ_SET_MASK_OK;
169 }
170 #endif
171 
172 static void __exception_irq_entry hip04_handle_irq(struct pt_regs *regs)
173 {
174 	u32 irqstat, irqnr;
175 	void __iomem *cpu_base = hip04_data.cpu_base;
176 
177 	do {
178 		irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
179 		irqnr = irqstat & GICC_IAR_INT_ID_MASK;
180 
181 		if (likely(irqnr > 15 && irqnr <= HIP04_MAX_IRQS)) {
182 			handle_domain_irq(hip04_data.domain, irqnr, regs);
183 			continue;
184 		}
185 		if (irqnr < 16) {
186 			writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI);
187 #ifdef CONFIG_SMP
188 			handle_IPI(irqnr, regs);
189 #endif
190 			continue;
191 		}
192 		break;
193 	} while (1);
194 }
195 
196 static struct irq_chip hip04_irq_chip = {
197 	.name			= "HIP04 INTC",
198 	.irq_mask		= hip04_mask_irq,
199 	.irq_unmask		= hip04_unmask_irq,
200 	.irq_eoi		= hip04_eoi_irq,
201 	.irq_set_type		= hip04_irq_set_type,
202 #ifdef CONFIG_SMP
203 	.irq_set_affinity	= hip04_irq_set_affinity,
204 #endif
205 	.flags			= IRQCHIP_SET_TYPE_MASKED |
206 				  IRQCHIP_SKIP_SET_WAKE |
207 				  IRQCHIP_MASK_ON_SUSPEND,
208 };
209 
210 static u16 hip04_get_cpumask(struct hip04_irq_data *intc)
211 {
212 	void __iomem *base = intc->dist_base;
213 	u32 mask, i;
214 
215 	for (i = mask = 0; i < 32; i += 2) {
216 		mask = readl_relaxed(base + GIC_DIST_TARGET + i * 2);
217 		mask |= mask >> 16;
218 		if (mask)
219 			break;
220 	}
221 
222 	if (!mask)
223 		pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");
224 
225 	return mask;
226 }
227 
228 static void __init hip04_irq_dist_init(struct hip04_irq_data *intc)
229 {
230 	unsigned int i;
231 	u32 cpumask;
232 	unsigned int nr_irqs = intc->nr_irqs;
233 	void __iomem *base = intc->dist_base;
234 
235 	writel_relaxed(0, base + GIC_DIST_CTRL);
236 
237 	/*
238 	 * Set all global interrupts to this CPU only.
239 	 */
240 	cpumask = hip04_get_cpumask(intc);
241 	cpumask |= cpumask << 16;
242 	for (i = 32; i < nr_irqs; i += 2)
243 		writel_relaxed(cpumask, base + GIC_DIST_TARGET + ((i * 2) & ~3));
244 
245 	gic_dist_config(base, nr_irqs, NULL);
246 
247 	writel_relaxed(1, base + GIC_DIST_CTRL);
248 }
249 
250 static void hip04_irq_cpu_init(struct hip04_irq_data *intc)
251 {
252 	void __iomem *dist_base = intc->dist_base;
253 	void __iomem *base = intc->cpu_base;
254 	unsigned int cpu_mask, cpu = smp_processor_id();
255 	int i;
256 
257 	/*
258 	 * Get what the GIC says our CPU mask is.
259 	 */
260 	BUG_ON(cpu >= NR_HIP04_CPU_IF);
261 	cpu_mask = hip04_get_cpumask(intc);
262 	hip04_cpu_map[cpu] = cpu_mask;
263 
264 	/*
265 	 * Clear our mask from the other map entries in case they're
266 	 * still undefined.
267 	 */
268 	for (i = 0; i < NR_HIP04_CPU_IF; i++)
269 		if (i != cpu)
270 			hip04_cpu_map[i] &= ~cpu_mask;
271 
272 	gic_cpu_config(dist_base, NULL);
273 
274 	writel_relaxed(0xf0, base + GIC_CPU_PRIMASK);
275 	writel_relaxed(1, base + GIC_CPU_CTRL);
276 }
277 
278 #ifdef CONFIG_SMP
279 static void hip04_raise_softirq(const struct cpumask *mask, unsigned int irq)
280 {
281 	int cpu;
282 	unsigned long flags, map = 0;
283 
284 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
285 
286 	/* Convert our logical CPU mask into a physical one. */
287 	for_each_cpu(cpu, mask)
288 		map |= hip04_cpu_map[cpu];
289 
290 	/*
291 	 * Ensure that stores to Normal memory are visible to the
292 	 * other CPUs before they observe us issuing the IPI.
293 	 */
294 	dmb(ishst);
295 
296 	/* this always happens on GIC0 */
297 	writel_relaxed(map << 8 | irq, hip04_data.dist_base + GIC_DIST_SOFTINT);
298 
299 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
300 }
301 #endif
302 
303 static int hip04_irq_domain_map(struct irq_domain *d, unsigned int irq,
304 				irq_hw_number_t hw)
305 {
306 	if (hw < 32) {
307 		irq_set_percpu_devid(irq);
308 		irq_set_chip_and_handler(irq, &hip04_irq_chip,
309 					 handle_percpu_devid_irq);
310 		irq_set_status_flags(irq, IRQ_NOAUTOEN);
311 	} else {
312 		irq_set_chip_and_handler(irq, &hip04_irq_chip,
313 					 handle_fasteoi_irq);
314 		irq_set_probe(irq);
315 	}
316 	irq_set_chip_data(irq, d->host_data);
317 	return 0;
318 }
319 
320 static int hip04_irq_domain_xlate(struct irq_domain *d,
321 				  struct device_node *controller,
322 				  const u32 *intspec, unsigned int intsize,
323 				  unsigned long *out_hwirq,
324 				  unsigned int *out_type)
325 {
326 	unsigned long ret = 0;
327 
328 	if (irq_domain_get_of_node(d) != controller)
329 		return -EINVAL;
330 	if (intsize < 3)
331 		return -EINVAL;
332 
333 	/* Get the interrupt number and add 16 to skip over SGIs */
334 	*out_hwirq = intspec[1] + 16;
335 
336 	/* For SPIs, we need to add 16 more to get the irq ID number */
337 	if (!intspec[0])
338 		*out_hwirq += 16;
339 
340 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
341 
342 	return ret;
343 }
344 
345 #ifdef CONFIG_SMP
346 static int hip04_irq_secondary_init(struct notifier_block *nfb,
347 				    unsigned long action,
348 				    void *hcpu)
349 {
350 	if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
351 		hip04_irq_cpu_init(&hip04_data);
352 	return NOTIFY_OK;
353 }
354 
355 /*
356  * Notifier for enabling the INTC CPU interface. Set an arbitrarily high
357  * priority because the GIC needs to be up before the ARM generic timers.
358  */
359 static struct notifier_block hip04_irq_cpu_notifier = {
360 	.notifier_call	= hip04_irq_secondary_init,
361 	.priority	= 100,
362 };
363 #endif
364 
365 static const struct irq_domain_ops hip04_irq_domain_ops = {
366 	.map	= hip04_irq_domain_map,
367 	.xlate	= hip04_irq_domain_xlate,
368 };
369 
370 static int __init
371 hip04_of_init(struct device_node *node, struct device_node *parent)
372 {
373 	irq_hw_number_t hwirq_base = 16;
374 	int nr_irqs, irq_base, i;
375 
376 	if (WARN_ON(!node))
377 		return -ENODEV;
378 
379 	hip04_data.dist_base = of_iomap(node, 0);
380 	WARN(!hip04_data.dist_base, "fail to map hip04 intc dist registers\n");
381 
382 	hip04_data.cpu_base = of_iomap(node, 1);
383 	WARN(!hip04_data.cpu_base, "unable to map hip04 intc cpu registers\n");
384 
385 	/*
386 	 * Initialize the CPU interface map to all CPUs.
387 	 * It will be refined as each CPU probes its ID.
388 	 */
389 	for (i = 0; i < NR_HIP04_CPU_IF; i++)
390 		hip04_cpu_map[i] = 0xffff;
391 
392 	/*
393 	 * Find out how many interrupts are supported.
394 	 * The HIP04 INTC only supports up to 510 interrupt sources.
395 	 */
396 	nr_irqs = readl_relaxed(hip04_data.dist_base + GIC_DIST_CTR) & 0x1f;
397 	nr_irqs = (nr_irqs + 1) * 32;
398 	if (nr_irqs > HIP04_MAX_IRQS)
399 		nr_irqs = HIP04_MAX_IRQS;
400 	hip04_data.nr_irqs = nr_irqs;
401 
402 	nr_irqs -= hwirq_base; /* calculate # of irqs to allocate */
403 
404 	irq_base = irq_alloc_descs(-1, hwirq_base, nr_irqs, numa_node_id());
405 	if (IS_ERR_VALUE(irq_base)) {
406 		pr_err("failed to allocate IRQ numbers\n");
407 		return -EINVAL;
408 	}
409 
410 	hip04_data.domain = irq_domain_add_legacy(node, nr_irqs, irq_base,
411 						  hwirq_base,
412 						  &hip04_irq_domain_ops,
413 						  &hip04_data);
414 
415 	if (WARN_ON(!hip04_data.domain))
416 		return -EINVAL;
417 
418 #ifdef CONFIG_SMP
419 	set_smp_cross_call(hip04_raise_softirq);
420 	register_cpu_notifier(&hip04_irq_cpu_notifier);
421 #endif
422 	set_handle_irq(hip04_handle_irq);
423 
424 	hip04_irq_dist_init(&hip04_data);
425 	hip04_irq_cpu_init(&hip04_data);
426 
427 	return 0;
428 }
429 IRQCHIP_DECLARE(hip04_intc, "hisilicon,hip04-intc", hip04_of_init);
430