1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Interrupt management for most GSC and related devices.
4 *
5 * (c) Copyright 1999 Alex deVries for The Puffin Group
6 * (c) Copyright 1999 Grant Grundler for Hewlett-Packard
7 * (c) Copyright 1999 Matthew Wilcox
8 * (c) Copyright 2000 Helge Deller
9 * (c) Copyright 2001 Matthew Wilcox for Hewlett-Packard
10 */
11
12#include <linux/bitops.h>
13#include <linux/errno.h>
14#include <linux/init.h>
15#include <linux/interrupt.h>
16#include <linux/ioport.h>
17#include <linux/module.h>
18#include <linux/types.h>
19
20#include <asm/hardware.h>
21#include <asm/io.h>
22
23#include "gsc.h"
24
25#undef DEBUG
26
27#ifdef DEBUG
28#define DEBPRINTK printk
29#else
30#define DEBPRINTK(x,...)
31#endif
32
33int gsc_alloc_irq(struct gsc_irq *i)
34{
35	int irq = txn_alloc_irq(GSC_EIM_WIDTH);
36	if (irq < 0) {
37		printk("cannot get irq\n");
38		return irq;
39	}
40
41	i->txn_addr = txn_alloc_addr(irq);
42	i->txn_data = txn_alloc_data(irq);
43	i->irq = irq;
44
45	return irq;
46}
47
48int gsc_claim_irq(struct gsc_irq *i, int irq)
49{
50	int c = irq;
51
52	irq += CPU_IRQ_BASE; /* virtualize the IRQ first */
53
54	irq = txn_claim_irq(irq);
55	if (irq < 0) {
56		printk("cannot claim irq %d\n", c);
57		return irq;
58	}
59
60	i->txn_addr = txn_alloc_addr(irq);
61	i->txn_data = txn_alloc_data(irq);
62	i->irq = irq;
63
64	return irq;
65}
66
67EXPORT_SYMBOL(gsc_alloc_irq);
68EXPORT_SYMBOL(gsc_claim_irq);
69
70/* Common interrupt demultiplexer used by Asp, Lasi & Wax.  */
71irqreturn_t gsc_asic_intr(int gsc_asic_irq, void *dev)
72{
73	unsigned long irr;
74	struct gsc_asic *gsc_asic = dev;
75
76	irr = gsc_readl(gsc_asic->hpa + OFFSET_IRR);
77	if (irr == 0)
78		return IRQ_NONE;
79
80	DEBPRINTK("%s intr, mask=0x%x\n", gsc_asic->name, irr);
81
82	do {
83		int local_irq = __ffs(irr);
84		unsigned int irq = gsc_asic->global_irq[local_irq];
85		generic_handle_irq(irq);
86		irr &= ~(1 << local_irq);
87	} while (irr);
88
89	return IRQ_HANDLED;
90}
91
92int gsc_find_local_irq(unsigned int irq, int *global_irqs, int limit)
93{
94	int local_irq;
95
96	for (local_irq = 0; local_irq < limit; local_irq++) {
97		if (global_irqs[local_irq] == irq)
98			return local_irq;
99	}
100
101	return NO_IRQ;
102}
103
104static void gsc_asic_mask_irq(struct irq_data *d)
105{
106	struct gsc_asic *irq_dev = irq_data_get_irq_chip_data(d);
107	int local_irq = gsc_find_local_irq(d->irq, irq_dev->global_irq, 32);
108	u32 imr;
109
110	DEBPRINTK(KERN_DEBUG "%s(%d) %s: IMR 0x%x\n", __func__, d->irq,
111			irq_dev->name, imr);
112
113	/* Disable the IRQ line by clearing the bit in the IMR */
114	imr = gsc_readl(irq_dev->hpa + OFFSET_IMR);
115	imr &= ~(1 << local_irq);
116	gsc_writel(imr, irq_dev->hpa + OFFSET_IMR);
117}
118
119static void gsc_asic_unmask_irq(struct irq_data *d)
120{
121	struct gsc_asic *irq_dev = irq_data_get_irq_chip_data(d);
122	int local_irq = gsc_find_local_irq(d->irq, irq_dev->global_irq, 32);
123	u32 imr;
124
125	DEBPRINTK(KERN_DEBUG "%s(%d) %s: IMR 0x%x\n", __func__, d->irq,
126			irq_dev->name, imr);
127
128	/* Enable the IRQ line by setting the bit in the IMR */
129	imr = gsc_readl(irq_dev->hpa + OFFSET_IMR);
130	imr |= 1 << local_irq;
131	gsc_writel(imr, irq_dev->hpa + OFFSET_IMR);
132	/*
133	 * FIXME: read IPR to make sure the IRQ isn't already pending.
134	 *   If so, we need to read IRR and manually call do_irq().
135	 */
136}
137
138#ifdef CONFIG_SMP
139static int gsc_set_affinity_irq(struct irq_data *d, const struct cpumask *dest,
140				bool force)
141{
142	struct gsc_asic *gsc_dev = irq_data_get_irq_chip_data(d);
143	struct cpumask tmask;
144	int cpu_irq;
145
146	if (!cpumask_and(&tmask, dest, cpu_online_mask))
147		return -EINVAL;
148
149	cpu_irq = cpu_check_affinity(d, &tmask);
150	if (cpu_irq < 0)
151		return cpu_irq;
152
153	gsc_dev->gsc_irq.txn_addr = txn_affinity_addr(d->irq, cpu_irq);
154	gsc_dev->eim = ((u32) gsc_dev->gsc_irq.txn_addr) | gsc_dev->gsc_irq.txn_data;
155
156	/* switch IRQ's for devices below LASI/WAX to other CPU */
157	gsc_writel(gsc_dev->eim, gsc_dev->hpa + OFFSET_IAR);
158
159	irq_data_update_effective_affinity(d, &tmask);
160
161	return IRQ_SET_MASK_OK;
162}
163#endif
164
165
166static struct irq_chip gsc_asic_interrupt_type = {
167	.name		=	"GSC-ASIC",
168	.irq_unmask	=	gsc_asic_unmask_irq,
169	.irq_mask	=	gsc_asic_mask_irq,
170#ifdef CONFIG_SMP
171	.irq_set_affinity =	gsc_set_affinity_irq,
172#endif
173};
174
175int gsc_assign_irq(struct irq_chip *type, void *data)
176{
177	static int irq = GSC_IRQ_BASE;
178
179	if (irq > GSC_IRQ_MAX)
180		return NO_IRQ;
181
182	irq_set_chip_and_handler(irq, type, handle_simple_irq);
183	irq_set_chip_data(irq, data);
184
185	return irq++;
186}
187
188void gsc_asic_assign_irq(struct gsc_asic *asic, int local_irq, int *irqp)
189{
190	int irq = asic->global_irq[local_irq];
191
192	if (irq <= 0) {
193		irq = gsc_assign_irq(&gsc_asic_interrupt_type, asic);
194		if (irq == NO_IRQ)
195			return;
196
197		asic->global_irq[local_irq] = irq;
198	}
199	*irqp = irq;
200}
201
202struct gsc_fixup_struct {
203	void (*choose_irq)(struct parisc_device *, void *);
204	void *ctrl;
205};
206
207static int gsc_fixup_irqs_callback(struct device *dev, void *data)
208{
209	struct parisc_device *padev = to_parisc_device(dev);
210	struct gsc_fixup_struct *gf = data;
211
212	/* work-around for 715/64 and others which have parent
213	   at path [5] and children at path [5/0/x] */
214	if (padev->id.hw_type == HPHW_FAULTY)
215		gsc_fixup_irqs(padev, gf->ctrl, gf->choose_irq);
216	gf->choose_irq(padev, gf->ctrl);
217
218	return 0;
219}
220
221void gsc_fixup_irqs(struct parisc_device *parent, void *ctrl,
222			void (*choose_irq)(struct parisc_device *, void *))
223{
224	struct gsc_fixup_struct data = {
225		.choose_irq	= choose_irq,
226		.ctrl		= ctrl,
227	};
228
229	device_for_each_child(&parent->dev, &data, gsc_fixup_irqs_callback);
230}
231
232int gsc_common_setup(struct parisc_device *parent, struct gsc_asic *gsc_asic)
233{
234	struct resource *res;
235	int i;
236
237	gsc_asic->gsc = parent;
238
239	/* Initialise local irq -> global irq mapping */
240	for (i = 0; i < 32; i++) {
241		gsc_asic->global_irq[i] = NO_IRQ;
242	}
243
244	/* allocate resource region */
245	res = request_mem_region(gsc_asic->hpa, 0x100000, gsc_asic->name);
246	if (res) {
247		res->flags = IORESOURCE_MEM; 	/* do not mark it busy ! */
248	}
249
250#if 0
251	printk(KERN_WARNING "%s IRQ %d EIM 0x%x", gsc_asic->name,
252			parent->irq, gsc_asic->eim);
253	if (gsc_readl(gsc_asic->hpa + OFFSET_IMR))
254		printk("  IMR is non-zero! (0x%x)",
255				gsc_readl(gsc_asic->hpa + OFFSET_IMR));
256	printk("\n");
257#endif
258
259	return 0;
260}
261