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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 /* ASP chip (svers 0x70) does not support reprogramming */
158 if (gsc_dev->gsc->id.sversion != 0x70)
159 gsc_writel(gsc_dev->eim, gsc_dev->hpa + OFFSET_IAR);
160
161 irq_data_update_effective_affinity(d, &tmask);
162
163 return IRQ_SET_MASK_OK;
164}
165#endif
166
167
168static struct irq_chip gsc_asic_interrupt_type = {
169 .name = "GSC-ASIC",
170 .irq_unmask = gsc_asic_unmask_irq,
171 .irq_mask = gsc_asic_mask_irq,
172#ifdef CONFIG_SMP
173 .irq_set_affinity = gsc_set_affinity_irq,
174#endif
175};
176
177int gsc_assign_irq(struct irq_chip *type, void *data)
178{
179 static int irq = GSC_IRQ_BASE;
180
181 if (irq > GSC_IRQ_MAX)
182 return NO_IRQ;
183
184 irq_set_chip_and_handler(irq, type, handle_simple_irq);
185 irq_set_chip_data(irq, data);
186
187 return irq++;
188}
189
190void gsc_asic_assign_irq(struct gsc_asic *asic, int local_irq, int *irqp)
191{
192 int irq = asic->global_irq[local_irq];
193
194 if (irq <= 0) {
195 irq = gsc_assign_irq(&gsc_asic_interrupt_type, asic);
196 if (irq == NO_IRQ)
197 return;
198
199 asic->global_irq[local_irq] = irq;
200 }
201 *irqp = irq;
202}
203
204struct gsc_fixup_struct {
205 void (*choose_irq)(struct parisc_device *, void *);
206 void *ctrl;
207};
208
209static int gsc_fixup_irqs_callback(struct device *dev, void *data)
210{
211 struct parisc_device *padev = to_parisc_device(dev);
212 struct gsc_fixup_struct *gf = data;
213
214 /* work-around for 715/64 and others which have parent
215 at path [5] and children at path [5/0/x] */
216 if (padev->id.hw_type == HPHW_FAULTY)
217 gsc_fixup_irqs(padev, gf->ctrl, gf->choose_irq);
218 gf->choose_irq(padev, gf->ctrl);
219
220 return 0;
221}
222
223void gsc_fixup_irqs(struct parisc_device *parent, void *ctrl,
224 void (*choose_irq)(struct parisc_device *, void *))
225{
226 struct gsc_fixup_struct data = {
227 .choose_irq = choose_irq,
228 .ctrl = ctrl,
229 };
230
231 device_for_each_child(&parent->dev, &data, gsc_fixup_irqs_callback);
232}
233
234int gsc_common_setup(struct parisc_device *parent, struct gsc_asic *gsc_asic)
235{
236 struct resource *res;
237 int i;
238
239 gsc_asic->gsc = parent;
240
241 /* Initialise local irq -> global irq mapping */
242 for (i = 0; i < 32; i++) {
243 gsc_asic->global_irq[i] = NO_IRQ;
244 }
245
246 /* allocate resource region */
247 res = request_mem_region(gsc_asic->hpa, 0x100000, gsc_asic->name);
248 if (res) {
249 res->flags = IORESOURCE_MEM; /* do not mark it busy ! */
250 }
251
252#if 0
253 printk(KERN_WARNING "%s IRQ %d EIM 0x%x", gsc_asic->name,
254 parent->irq, gsc_asic->eim);
255 if (gsc_readl(gsc_asic->hpa + OFFSET_IMR))
256 printk(" IMR is non-zero! (0x%x)",
257 gsc_readl(gsc_asic->hpa + OFFSET_IMR));
258 printk("\n");
259#endif
260
261 return 0;
262}