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  1/*
  2 * Marvell Armada 370 and Armada XP SoC IRQ handling
  3 *
  4 * Copyright (C) 2012 Marvell
  5 *
  6 * Lior Amsalem <alior@marvell.com>
  7 * Gregory CLEMENT <gregory.clement@free-electrons.com>
  8 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  9 * Ben Dooks <ben.dooks@codethink.co.uk>
 10 *
 11 * This file is licensed under the terms of the GNU General Public
 12 * License version 2.  This program is licensed "as is" without any
 13 * warranty of any kind, whether express or implied.
 14 */
 15
 16#include <linux/kernel.h>
 17#include <linux/module.h>
 18#include <linux/init.h>
 19#include <linux/irq.h>
 20#include <linux/interrupt.h>
 21#include <linux/irqchip.h>
 22#include <linux/irqchip/chained_irq.h>
 23#include <linux/cpu.h>
 24#include <linux/io.h>
 25#include <linux/of_address.h>
 26#include <linux/of_irq.h>
 27#include <linux/of_pci.h>
 28#include <linux/irqdomain.h>
 29#include <linux/slab.h>
 30#include <linux/syscore_ops.h>
 31#include <linux/msi.h>
 32#include <asm/mach/arch.h>
 33#include <asm/exception.h>
 34#include <asm/smp_plat.h>
 35#include <asm/mach/irq.h>
 36
 37/* Interrupt Controller Registers Map */
 38#define ARMADA_370_XP_INT_SET_MASK_OFFS		(0x48)
 39#define ARMADA_370_XP_INT_CLEAR_MASK_OFFS	(0x4C)
 40#define ARMADA_370_XP_INT_FABRIC_MASK_OFFS	(0x54)
 41#define ARMADA_370_XP_INT_CAUSE_PERF(cpu)	(1 << cpu)
 42
 43#define ARMADA_370_XP_INT_CONTROL		(0x00)
 44#define ARMADA_370_XP_INT_SET_ENABLE_OFFS	(0x30)
 45#define ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS	(0x34)
 46#define ARMADA_370_XP_INT_SOURCE_CTL(irq)	(0x100 + irq*4)
 47#define ARMADA_370_XP_INT_SOURCE_CPU_MASK	0xF
 48#define ARMADA_370_XP_INT_IRQ_FIQ_MASK(cpuid)	((BIT(0) | BIT(8)) << cpuid)
 49
 50#define ARMADA_370_XP_CPU_INTACK_OFFS		(0x44)
 51#define ARMADA_375_PPI_CAUSE			(0x10)
 52
 53#define ARMADA_370_XP_SW_TRIG_INT_OFFS           (0x4)
 54#define ARMADA_370_XP_IN_DRBEL_MSK_OFFS          (0xc)
 55#define ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS        (0x8)
 56
 57#define ARMADA_370_XP_MAX_PER_CPU_IRQS		(28)
 58
 59#define IPI_DOORBELL_START                      (0)
 60#define IPI_DOORBELL_END                        (8)
 61#define IPI_DOORBELL_MASK                       0xFF
 62#define PCI_MSI_DOORBELL_START                  (16)
 63#define PCI_MSI_DOORBELL_NR                     (16)
 64#define PCI_MSI_DOORBELL_END                    (32)
 65#define PCI_MSI_DOORBELL_MASK                   0xFFFF0000
 66
 67static void __iomem *per_cpu_int_base;
 68static void __iomem *main_int_base;
 69static struct irq_domain *armada_370_xp_mpic_domain;
 70static u32 doorbell_mask_reg;
 71static int parent_irq;
 72#ifdef CONFIG_PCI_MSI
 73static struct irq_domain *armada_370_xp_msi_domain;
 74static struct irq_domain *armada_370_xp_msi_inner_domain;
 75static DECLARE_BITMAP(msi_used, PCI_MSI_DOORBELL_NR);
 76static DEFINE_MUTEX(msi_used_lock);
 77static phys_addr_t msi_doorbell_addr;
 78#endif
 79
 80static inline bool is_percpu_irq(irq_hw_number_t irq)
 81{
 82	if (irq <= ARMADA_370_XP_MAX_PER_CPU_IRQS)
 83		return true;
 84
 85	return false;
 86}
 87
 88/*
 89 * In SMP mode:
 90 * For shared global interrupts, mask/unmask global enable bit
 91 * For CPU interrupts, mask/unmask the calling CPU's bit
 92 */
 93static void armada_370_xp_irq_mask(struct irq_data *d)
 94{
 95	irq_hw_number_t hwirq = irqd_to_hwirq(d);
 96
 97	if (!is_percpu_irq(hwirq))
 98		writel(hwirq, main_int_base +
 99				ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS);
100	else
101		writel(hwirq, per_cpu_int_base +
102				ARMADA_370_XP_INT_SET_MASK_OFFS);
103}
104
105static void armada_370_xp_irq_unmask(struct irq_data *d)
106{
107	irq_hw_number_t hwirq = irqd_to_hwirq(d);
108
109	if (!is_percpu_irq(hwirq))
110		writel(hwirq, main_int_base +
111				ARMADA_370_XP_INT_SET_ENABLE_OFFS);
112	else
113		writel(hwirq, per_cpu_int_base +
114				ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
115}
116
117#ifdef CONFIG_PCI_MSI
118
119static struct irq_chip armada_370_xp_msi_irq_chip = {
120	.name = "MPIC MSI",
121	.irq_mask = pci_msi_mask_irq,
122	.irq_unmask = pci_msi_unmask_irq,
123};
124
125static struct msi_domain_info armada_370_xp_msi_domain_info = {
126	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
127		   MSI_FLAG_MULTI_PCI_MSI),
128	.chip	= &armada_370_xp_msi_irq_chip,
129};
130
131static void armada_370_xp_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
132{
133	msg->address_lo = lower_32_bits(msi_doorbell_addr);
134	msg->address_hi = upper_32_bits(msi_doorbell_addr);
135	msg->data = 0xf00 | (data->hwirq + PCI_MSI_DOORBELL_START);
136}
137
138static int armada_370_xp_msi_set_affinity(struct irq_data *irq_data,
139					  const struct cpumask *mask, bool force)
140{
141	 return -EINVAL;
142}
143
144static struct irq_chip armada_370_xp_msi_bottom_irq_chip = {
145	.name			= "MPIC MSI",
146	.irq_compose_msi_msg	= armada_370_xp_compose_msi_msg,
147	.irq_set_affinity	= armada_370_xp_msi_set_affinity,
148};
149
150static int armada_370_xp_msi_alloc(struct irq_domain *domain, unsigned int virq,
151				   unsigned int nr_irqs, void *args)
152{
153	int hwirq, i;
154
155	mutex_lock(&msi_used_lock);
156
157	hwirq = bitmap_find_next_zero_area(msi_used, PCI_MSI_DOORBELL_NR,
158					   0, nr_irqs, 0);
159	if (hwirq >= PCI_MSI_DOORBELL_NR) {
160		mutex_unlock(&msi_used_lock);
161		return -ENOSPC;
162	}
163
164	bitmap_set(msi_used, hwirq, nr_irqs);
165	mutex_unlock(&msi_used_lock);
166
167	for (i = 0; i < nr_irqs; i++) {
168		irq_domain_set_info(domain, virq + i, hwirq + i,
169				    &armada_370_xp_msi_bottom_irq_chip,
170				    domain->host_data, handle_simple_irq,
171				    NULL, NULL);
172	}
173
174	return hwirq;
175}
176
177static void armada_370_xp_msi_free(struct irq_domain *domain,
178				   unsigned int virq, unsigned int nr_irqs)
179{
180	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
181
182	mutex_lock(&msi_used_lock);
183	bitmap_clear(msi_used, d->hwirq, nr_irqs);
184	mutex_unlock(&msi_used_lock);
185}
186
187static const struct irq_domain_ops armada_370_xp_msi_domain_ops = {
188	.alloc	= armada_370_xp_msi_alloc,
189	.free	= armada_370_xp_msi_free,
190};
191
192static int armada_370_xp_msi_init(struct device_node *node,
193				  phys_addr_t main_int_phys_base)
194{
195	u32 reg;
196
197	msi_doorbell_addr = main_int_phys_base +
198		ARMADA_370_XP_SW_TRIG_INT_OFFS;
199
200	armada_370_xp_msi_inner_domain =
201		irq_domain_add_linear(NULL, PCI_MSI_DOORBELL_NR,
202				      &armada_370_xp_msi_domain_ops, NULL);
203	if (!armada_370_xp_msi_inner_domain)
204		return -ENOMEM;
205
206	armada_370_xp_msi_domain =
207		pci_msi_create_irq_domain(of_node_to_fwnode(node),
208					  &armada_370_xp_msi_domain_info,
209					  armada_370_xp_msi_inner_domain);
210	if (!armada_370_xp_msi_domain) {
211		irq_domain_remove(armada_370_xp_msi_inner_domain);
212		return -ENOMEM;
213	}
214
215	reg = readl(per_cpu_int_base + ARMADA_370_XP_IN_DRBEL_MSK_OFFS)
216		| PCI_MSI_DOORBELL_MASK;
217
218	writel(reg, per_cpu_int_base +
219	       ARMADA_370_XP_IN_DRBEL_MSK_OFFS);
220
221	/* Unmask IPI interrupt */
222	writel(1, per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
223
224	return 0;
225}
226#else
227static inline int armada_370_xp_msi_init(struct device_node *node,
228					 phys_addr_t main_int_phys_base)
229{
230	return 0;
231}
232#endif
233
234#ifdef CONFIG_SMP
235static DEFINE_RAW_SPINLOCK(irq_controller_lock);
236
237static int armada_xp_set_affinity(struct irq_data *d,
238				  const struct cpumask *mask_val, bool force)
239{
240	irq_hw_number_t hwirq = irqd_to_hwirq(d);
241	unsigned long reg, mask;
242	int cpu;
243
244	/* Select a single core from the affinity mask which is online */
245	cpu = cpumask_any_and(mask_val, cpu_online_mask);
246	mask = 1UL << cpu_logical_map(cpu);
247
248	raw_spin_lock(&irq_controller_lock);
249	reg = readl(main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
250	reg = (reg & (~ARMADA_370_XP_INT_SOURCE_CPU_MASK)) | mask;
251	writel(reg, main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
252	raw_spin_unlock(&irq_controller_lock);
253
254	return IRQ_SET_MASK_OK;
255}
256#endif
257
258static struct irq_chip armada_370_xp_irq_chip = {
259	.name		= "MPIC",
260	.irq_mask       = armada_370_xp_irq_mask,
261	.irq_mask_ack   = armada_370_xp_irq_mask,
262	.irq_unmask     = armada_370_xp_irq_unmask,
263#ifdef CONFIG_SMP
264	.irq_set_affinity = armada_xp_set_affinity,
265#endif
266	.flags		= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND,
267};
268
269static int armada_370_xp_mpic_irq_map(struct irq_domain *h,
270				      unsigned int virq, irq_hw_number_t hw)
271{
272	armada_370_xp_irq_mask(irq_get_irq_data(virq));
273	if (!is_percpu_irq(hw))
274		writel(hw, per_cpu_int_base +
275			ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
276	else
277		writel(hw, main_int_base + ARMADA_370_XP_INT_SET_ENABLE_OFFS);
278	irq_set_status_flags(virq, IRQ_LEVEL);
279
280	if (is_percpu_irq(hw)) {
281		irq_set_percpu_devid(virq);
282		irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
283					handle_percpu_devid_irq);
284
285	} else {
286		irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
287					handle_level_irq);
288	}
289	irq_set_probe(virq);
290	irq_clear_status_flags(virq, IRQ_NOAUTOEN);
291
292	return 0;
293}
294
295static void armada_xp_mpic_smp_cpu_init(void)
296{
297	u32 control;
298	int nr_irqs, i;
299
300	control = readl(main_int_base + ARMADA_370_XP_INT_CONTROL);
301	nr_irqs = (control >> 2) & 0x3ff;
302
303	for (i = 0; i < nr_irqs; i++)
304		writel(i, per_cpu_int_base + ARMADA_370_XP_INT_SET_MASK_OFFS);
305
306	/* Clear pending IPIs */
307	writel(0, per_cpu_int_base + ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
308
309	/* Enable first 8 IPIs */
310	writel(IPI_DOORBELL_MASK, per_cpu_int_base +
311		ARMADA_370_XP_IN_DRBEL_MSK_OFFS);
312
313	/* Unmask IPI interrupt */
314	writel(0, per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
315}
316
317static void armada_xp_mpic_perf_init(void)
318{
319	unsigned long cpuid = cpu_logical_map(smp_processor_id());
320
321	/* Enable Performance Counter Overflow interrupts */
322	writel(ARMADA_370_XP_INT_CAUSE_PERF(cpuid),
323	       per_cpu_int_base + ARMADA_370_XP_INT_FABRIC_MASK_OFFS);
324}
325
326#ifdef CONFIG_SMP
327static void armada_mpic_send_doorbell(const struct cpumask *mask,
328				      unsigned int irq)
329{
330	int cpu;
331	unsigned long map = 0;
332
333	/* Convert our logical CPU mask into a physical one. */
334	for_each_cpu(cpu, mask)
335		map |= 1 << cpu_logical_map(cpu);
336
337	/*
338	 * Ensure that stores to Normal memory are visible to the
339	 * other CPUs before issuing the IPI.
340	 */
341	dsb();
342
343	/* submit softirq */
344	writel((map << 8) | irq, main_int_base +
345		ARMADA_370_XP_SW_TRIG_INT_OFFS);
346}
347
348static int armada_xp_mpic_starting_cpu(unsigned int cpu)
349{
350	armada_xp_mpic_perf_init();
351	armada_xp_mpic_smp_cpu_init();
352	return 0;
353}
354
355static int mpic_cascaded_starting_cpu(unsigned int cpu)
356{
357	armada_xp_mpic_perf_init();
358	enable_percpu_irq(parent_irq, IRQ_TYPE_NONE);
359	return 0;
360}
361#endif
362
363static const struct irq_domain_ops armada_370_xp_mpic_irq_ops = {
364	.map = armada_370_xp_mpic_irq_map,
365	.xlate = irq_domain_xlate_onecell,
366};
367
368#ifdef CONFIG_PCI_MSI
369static void armada_370_xp_handle_msi_irq(struct pt_regs *regs, bool is_chained)
370{
371	u32 msimask, msinr;
372
373	msimask = readl_relaxed(per_cpu_int_base +
374				ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS)
375		& PCI_MSI_DOORBELL_MASK;
376
377	writel(~msimask, per_cpu_int_base +
378	       ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
379
380	for (msinr = PCI_MSI_DOORBELL_START;
381	     msinr < PCI_MSI_DOORBELL_END; msinr++) {
382		int irq;
383
384		if (!(msimask & BIT(msinr)))
385			continue;
386
387		if (is_chained) {
388			irq = irq_find_mapping(armada_370_xp_msi_inner_domain,
389					       msinr - PCI_MSI_DOORBELL_START);
390			generic_handle_irq(irq);
391		} else {
392			irq = msinr - PCI_MSI_DOORBELL_START;
393			handle_domain_irq(armada_370_xp_msi_inner_domain,
394					  irq, regs);
395		}
396	}
397}
398#else
399static void armada_370_xp_handle_msi_irq(struct pt_regs *r, bool b) {}
400#endif
401
402static void armada_370_xp_mpic_handle_cascade_irq(struct irq_desc *desc)
403{
404	struct irq_chip *chip = irq_desc_get_chip(desc);
405	unsigned long irqmap, irqn, irqsrc, cpuid;
406	unsigned int cascade_irq;
407
408	chained_irq_enter(chip, desc);
409
410	irqmap = readl_relaxed(per_cpu_int_base + ARMADA_375_PPI_CAUSE);
411	cpuid = cpu_logical_map(smp_processor_id());
412
413	for_each_set_bit(irqn, &irqmap, BITS_PER_LONG) {
414		irqsrc = readl_relaxed(main_int_base +
415				       ARMADA_370_XP_INT_SOURCE_CTL(irqn));
416
417		/* Check if the interrupt is not masked on current CPU.
418		 * Test IRQ (0-1) and FIQ (8-9) mask bits.
419		 */
420		if (!(irqsrc & ARMADA_370_XP_INT_IRQ_FIQ_MASK(cpuid)))
421			continue;
422
423		if (irqn == 1) {
424			armada_370_xp_handle_msi_irq(NULL, true);
425			continue;
426		}
427
428		cascade_irq = irq_find_mapping(armada_370_xp_mpic_domain, irqn);
429		generic_handle_irq(cascade_irq);
430	}
431
432	chained_irq_exit(chip, desc);
433}
434
435static void __exception_irq_entry
436armada_370_xp_handle_irq(struct pt_regs *regs)
437{
438	u32 irqstat, irqnr;
439
440	do {
441		irqstat = readl_relaxed(per_cpu_int_base +
442					ARMADA_370_XP_CPU_INTACK_OFFS);
443		irqnr = irqstat & 0x3FF;
444
445		if (irqnr > 1022)
446			break;
447
448		if (irqnr > 1) {
449			handle_domain_irq(armada_370_xp_mpic_domain,
450					  irqnr, regs);
451			continue;
452		}
453
454		/* MSI handling */
455		if (irqnr == 1)
456			armada_370_xp_handle_msi_irq(regs, false);
457
458#ifdef CONFIG_SMP
459		/* IPI Handling */
460		if (irqnr == 0) {
461			u32 ipimask, ipinr;
462
463			ipimask = readl_relaxed(per_cpu_int_base +
464						ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS)
465				& IPI_DOORBELL_MASK;
466
467			writel(~ipimask, per_cpu_int_base +
468				ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
469
470			/* Handle all pending doorbells */
471			for (ipinr = IPI_DOORBELL_START;
472			     ipinr < IPI_DOORBELL_END; ipinr++) {
473				if (ipimask & (0x1 << ipinr))
474					handle_IPI(ipinr, regs);
475			}
476			continue;
477		}
478#endif
479
480	} while (1);
481}
482
483static int armada_370_xp_mpic_suspend(void)
484{
485	doorbell_mask_reg = readl(per_cpu_int_base +
486				  ARMADA_370_XP_IN_DRBEL_MSK_OFFS);
487	return 0;
488}
489
490static void armada_370_xp_mpic_resume(void)
491{
492	int nirqs;
493	irq_hw_number_t irq;
494
495	/* Re-enable interrupts */
496	nirqs = (readl(main_int_base + ARMADA_370_XP_INT_CONTROL) >> 2) & 0x3ff;
497	for (irq = 0; irq < nirqs; irq++) {
498		struct irq_data *data;
499		int virq;
500
501		virq = irq_linear_revmap(armada_370_xp_mpic_domain, irq);
502		if (virq == 0)
503			continue;
504
505		if (!is_percpu_irq(irq))
506			writel(irq, per_cpu_int_base +
507			       ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
508		else
509			writel(irq, main_int_base +
510			       ARMADA_370_XP_INT_SET_ENABLE_OFFS);
511
512		data = irq_get_irq_data(virq);
513		if (!irqd_irq_disabled(data))
514			armada_370_xp_irq_unmask(data);
515	}
516
517	/* Reconfigure doorbells for IPIs and MSIs */
518	writel(doorbell_mask_reg,
519	       per_cpu_int_base + ARMADA_370_XP_IN_DRBEL_MSK_OFFS);
520	if (doorbell_mask_reg & IPI_DOORBELL_MASK)
521		writel(0, per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
522	if (doorbell_mask_reg & PCI_MSI_DOORBELL_MASK)
523		writel(1, per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
524}
525
526static struct syscore_ops armada_370_xp_mpic_syscore_ops = {
527	.suspend	= armada_370_xp_mpic_suspend,
528	.resume		= armada_370_xp_mpic_resume,
529};
530
531static int __init armada_370_xp_mpic_of_init(struct device_node *node,
532					     struct device_node *parent)
533{
534	struct resource main_int_res, per_cpu_int_res;
535	int nr_irqs, i;
536	u32 control;
537
538	BUG_ON(of_address_to_resource(node, 0, &main_int_res));
539	BUG_ON(of_address_to_resource(node, 1, &per_cpu_int_res));
540
541	BUG_ON(!request_mem_region(main_int_res.start,
542				   resource_size(&main_int_res),
543				   node->full_name));
544	BUG_ON(!request_mem_region(per_cpu_int_res.start,
545				   resource_size(&per_cpu_int_res),
546				   node->full_name));
547
548	main_int_base = ioremap(main_int_res.start,
549				resource_size(&main_int_res));
550	BUG_ON(!main_int_base);
551
552	per_cpu_int_base = ioremap(per_cpu_int_res.start,
553				   resource_size(&per_cpu_int_res));
554	BUG_ON(!per_cpu_int_base);
555
556	control = readl(main_int_base + ARMADA_370_XP_INT_CONTROL);
557	nr_irqs = (control >> 2) & 0x3ff;
558
559	for (i = 0; i < nr_irqs; i++)
560		writel(i, main_int_base + ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS);
561
562	armada_370_xp_mpic_domain =
563		irq_domain_add_linear(node, nr_irqs,
564				&armada_370_xp_mpic_irq_ops, NULL);
565	BUG_ON(!armada_370_xp_mpic_domain);
566	armada_370_xp_mpic_domain->bus_token = DOMAIN_BUS_WIRED;
567
568	/* Setup for the boot CPU */
569	armada_xp_mpic_perf_init();
570	armada_xp_mpic_smp_cpu_init();
571
572	armada_370_xp_msi_init(node, main_int_res.start);
573
574	parent_irq = irq_of_parse_and_map(node, 0);
575	if (parent_irq <= 0) {
576		irq_set_default_host(armada_370_xp_mpic_domain);
577		set_handle_irq(armada_370_xp_handle_irq);
578#ifdef CONFIG_SMP
579		set_smp_cross_call(armada_mpic_send_doorbell);
580		cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_ARMADA_XP_STARTING,
581					  "irqchip/armada/ipi:starting",
582					  armada_xp_mpic_starting_cpu, NULL);
583#endif
584	} else {
585#ifdef CONFIG_SMP
586		cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_ARMADA_XP_STARTING,
587					  "irqchip/armada/cascade:starting",
588					  mpic_cascaded_starting_cpu, NULL);
589#endif
590		irq_set_chained_handler(parent_irq,
591					armada_370_xp_mpic_handle_cascade_irq);
592	}
593
594	register_syscore_ops(&armada_370_xp_mpic_syscore_ops);
595
596	return 0;
597}
598
599IRQCHIP_DECLARE(armada_370_xp_mpic, "marvell,mpic", armada_370_xp_mpic_of_init);