xref: /openbmc/linux/drivers/irqchip/irq-hip04.c (revision d0e22329)
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 	irq_data_update_effective_affinity(d, cpumask_of(cpu));
169 
170 	return IRQ_SET_MASK_OK;
171 }
172 #endif
173 
174 static void __exception_irq_entry hip04_handle_irq(struct pt_regs *regs)
175 {
176 	u32 irqstat, irqnr;
177 	void __iomem *cpu_base = hip04_data.cpu_base;
178 
179 	do {
180 		irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
181 		irqnr = irqstat & GICC_IAR_INT_ID_MASK;
182 
183 		if (likely(irqnr > 15 && irqnr <= HIP04_MAX_IRQS)) {
184 			handle_domain_irq(hip04_data.domain, irqnr, regs);
185 			continue;
186 		}
187 		if (irqnr < 16) {
188 			writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI);
189 #ifdef CONFIG_SMP
190 			handle_IPI(irqnr, regs);
191 #endif
192 			continue;
193 		}
194 		break;
195 	} while (1);
196 }
197 
198 static struct irq_chip hip04_irq_chip = {
199 	.name			= "HIP04 INTC",
200 	.irq_mask		= hip04_mask_irq,
201 	.irq_unmask		= hip04_unmask_irq,
202 	.irq_eoi		= hip04_eoi_irq,
203 	.irq_set_type		= hip04_irq_set_type,
204 #ifdef CONFIG_SMP
205 	.irq_set_affinity	= hip04_irq_set_affinity,
206 #endif
207 	.flags			= IRQCHIP_SET_TYPE_MASKED |
208 				  IRQCHIP_SKIP_SET_WAKE |
209 				  IRQCHIP_MASK_ON_SUSPEND,
210 };
211 
212 static u16 hip04_get_cpumask(struct hip04_irq_data *intc)
213 {
214 	void __iomem *base = intc->dist_base;
215 	u32 mask, i;
216 
217 	for (i = mask = 0; i < 32; i += 2) {
218 		mask = readl_relaxed(base + GIC_DIST_TARGET + i * 2);
219 		mask |= mask >> 16;
220 		if (mask)
221 			break;
222 	}
223 
224 	if (!mask)
225 		pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");
226 
227 	return mask;
228 }
229 
230 static void __init hip04_irq_dist_init(struct hip04_irq_data *intc)
231 {
232 	unsigned int i;
233 	u32 cpumask;
234 	unsigned int nr_irqs = intc->nr_irqs;
235 	void __iomem *base = intc->dist_base;
236 
237 	writel_relaxed(0, base + GIC_DIST_CTRL);
238 
239 	/*
240 	 * Set all global interrupts to this CPU only.
241 	 */
242 	cpumask = hip04_get_cpumask(intc);
243 	cpumask |= cpumask << 16;
244 	for (i = 32; i < nr_irqs; i += 2)
245 		writel_relaxed(cpumask, base + GIC_DIST_TARGET + ((i * 2) & ~3));
246 
247 	gic_dist_config(base, nr_irqs, NULL);
248 
249 	writel_relaxed(1, base + GIC_DIST_CTRL);
250 }
251 
252 static void hip04_irq_cpu_init(struct hip04_irq_data *intc)
253 {
254 	void __iomem *dist_base = intc->dist_base;
255 	void __iomem *base = intc->cpu_base;
256 	unsigned int cpu_mask, cpu = smp_processor_id();
257 	int i;
258 
259 	/*
260 	 * Get what the GIC says our CPU mask is.
261 	 */
262 	BUG_ON(cpu >= NR_HIP04_CPU_IF);
263 	cpu_mask = hip04_get_cpumask(intc);
264 	hip04_cpu_map[cpu] = cpu_mask;
265 
266 	/*
267 	 * Clear our mask from the other map entries in case they're
268 	 * still undefined.
269 	 */
270 	for (i = 0; i < NR_HIP04_CPU_IF; i++)
271 		if (i != cpu)
272 			hip04_cpu_map[i] &= ~cpu_mask;
273 
274 	gic_cpu_config(dist_base, NULL);
275 
276 	writel_relaxed(0xf0, base + GIC_CPU_PRIMASK);
277 	writel_relaxed(1, base + GIC_CPU_CTRL);
278 }
279 
280 #ifdef CONFIG_SMP
281 static void hip04_raise_softirq(const struct cpumask *mask, unsigned int irq)
282 {
283 	int cpu;
284 	unsigned long flags, map = 0;
285 
286 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
287 
288 	/* Convert our logical CPU mask into a physical one. */
289 	for_each_cpu(cpu, mask)
290 		map |= hip04_cpu_map[cpu];
291 
292 	/*
293 	 * Ensure that stores to Normal memory are visible to the
294 	 * other CPUs before they observe us issuing the IPI.
295 	 */
296 	dmb(ishst);
297 
298 	/* this always happens on GIC0 */
299 	writel_relaxed(map << 8 | irq, hip04_data.dist_base + GIC_DIST_SOFTINT);
300 
301 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
302 }
303 #endif
304 
305 static int hip04_irq_domain_map(struct irq_domain *d, unsigned int irq,
306 				irq_hw_number_t hw)
307 {
308 	if (hw < 32) {
309 		irq_set_percpu_devid(irq);
310 		irq_set_chip_and_handler(irq, &hip04_irq_chip,
311 					 handle_percpu_devid_irq);
312 		irq_set_status_flags(irq, IRQ_NOAUTOEN);
313 	} else {
314 		irq_set_chip_and_handler(irq, &hip04_irq_chip,
315 					 handle_fasteoi_irq);
316 		irq_set_probe(irq);
317 		irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(irq)));
318 	}
319 	irq_set_chip_data(irq, d->host_data);
320 	return 0;
321 }
322 
323 static int hip04_irq_domain_xlate(struct irq_domain *d,
324 				  struct device_node *controller,
325 				  const u32 *intspec, unsigned int intsize,
326 				  unsigned long *out_hwirq,
327 				  unsigned int *out_type)
328 {
329 	unsigned long ret = 0;
330 
331 	if (irq_domain_get_of_node(d) != controller)
332 		return -EINVAL;
333 	if (intsize < 3)
334 		return -EINVAL;
335 
336 	/* Get the interrupt number and add 16 to skip over SGIs */
337 	*out_hwirq = intspec[1] + 16;
338 
339 	/* For SPIs, we need to add 16 more to get the irq ID number */
340 	if (!intspec[0])
341 		*out_hwirq += 16;
342 
343 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
344 
345 	return ret;
346 }
347 
348 static int hip04_irq_starting_cpu(unsigned int cpu)
349 {
350 	hip04_irq_cpu_init(&hip04_data);
351 	return 0;
352 }
353 
354 static const struct irq_domain_ops hip04_irq_domain_ops = {
355 	.map	= hip04_irq_domain_map,
356 	.xlate	= hip04_irq_domain_xlate,
357 };
358 
359 static int __init
360 hip04_of_init(struct device_node *node, struct device_node *parent)
361 {
362 	irq_hw_number_t hwirq_base = 16;
363 	int nr_irqs, irq_base, i;
364 
365 	if (WARN_ON(!node))
366 		return -ENODEV;
367 
368 	hip04_data.dist_base = of_iomap(node, 0);
369 	WARN(!hip04_data.dist_base, "fail to map hip04 intc dist registers\n");
370 
371 	hip04_data.cpu_base = of_iomap(node, 1);
372 	WARN(!hip04_data.cpu_base, "unable to map hip04 intc cpu registers\n");
373 
374 	/*
375 	 * Initialize the CPU interface map to all CPUs.
376 	 * It will be refined as each CPU probes its ID.
377 	 */
378 	for (i = 0; i < NR_HIP04_CPU_IF; i++)
379 		hip04_cpu_map[i] = 0xffff;
380 
381 	/*
382 	 * Find out how many interrupts are supported.
383 	 * The HIP04 INTC only supports up to 510 interrupt sources.
384 	 */
385 	nr_irqs = readl_relaxed(hip04_data.dist_base + GIC_DIST_CTR) & 0x1f;
386 	nr_irqs = (nr_irqs + 1) * 32;
387 	if (nr_irqs > HIP04_MAX_IRQS)
388 		nr_irqs = HIP04_MAX_IRQS;
389 	hip04_data.nr_irqs = nr_irqs;
390 
391 	nr_irqs -= hwirq_base; /* calculate # of irqs to allocate */
392 
393 	irq_base = irq_alloc_descs(-1, hwirq_base, nr_irqs, numa_node_id());
394 	if (irq_base < 0) {
395 		pr_err("failed to allocate IRQ numbers\n");
396 		return -EINVAL;
397 	}
398 
399 	hip04_data.domain = irq_domain_add_legacy(node, nr_irqs, irq_base,
400 						  hwirq_base,
401 						  &hip04_irq_domain_ops,
402 						  &hip04_data);
403 
404 	if (WARN_ON(!hip04_data.domain))
405 		return -EINVAL;
406 
407 #ifdef CONFIG_SMP
408 	set_smp_cross_call(hip04_raise_softirq);
409 #endif
410 	set_handle_irq(hip04_handle_irq);
411 
412 	hip04_irq_dist_init(&hip04_data);
413 	cpuhp_setup_state(CPUHP_AP_IRQ_HIP04_STARTING, "irqchip/hip04:starting",
414 			  hip04_irq_starting_cpu, NULL);
415 	return 0;
416 }
417 IRQCHIP_DECLARE(hip04_intc, "hisilicon,hip04-intc", hip04_of_init);
418