1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2002 ARM Limited, All Rights Reserved.
4 */
5
6#include <linux/interrupt.h>
7#include <linux/io.h>
8#include <linux/irq.h>
9#include <linux/irqchip/arm-gic.h>
10
11#include "irq-gic-common.h"
12
13static DEFINE_RAW_SPINLOCK(irq_controller_lock);
14
15void gic_enable_of_quirks(const struct device_node *np,
16 const struct gic_quirk *quirks, void *data)
17{
18 for (; quirks->desc; quirks++) {
19 if (!quirks->compatible && !quirks->property)
20 continue;
21 if (quirks->compatible &&
22 !of_device_is_compatible(device: np, quirks->compatible))
23 continue;
24 if (quirks->property &&
25 !of_property_read_bool(np, propname: quirks->property))
26 continue;
27 if (quirks->init(data))
28 pr_info("GIC: enabling workaround for %s\n",
29 quirks->desc);
30 }
31}
32
33void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
34 void *data)
35{
36 for (; quirks->desc; quirks++) {
37 if (quirks->compatible || quirks->property)
38 continue;
39 if (quirks->iidr != (quirks->mask & iidr))
40 continue;
41 if (quirks->init(data))
42 pr_info("GIC: enabling workaround for %s\n",
43 quirks->desc);
44 }
45}
46
47int gic_configure_irq(unsigned int irq, unsigned int type,
48 void __iomem *base, void (*sync_access)(void))
49{
50 u32 confmask = 0x2 << ((irq % 16) * 2);
51 u32 confoff = (irq / 16) * 4;
52 u32 val, oldval;
53 int ret = 0;
54 unsigned long flags;
55
56 /*
57 * Read current configuration register, and insert the config
58 * for "irq", depending on "type".
59 */
60 raw_spin_lock_irqsave(&irq_controller_lock, flags);
61 val = oldval = readl_relaxed(base + confoff);
62 if (type & IRQ_TYPE_LEVEL_MASK)
63 val &= ~confmask;
64 else if (type & IRQ_TYPE_EDGE_BOTH)
65 val |= confmask;
66
67 /* If the current configuration is the same, then we are done */
68 if (val == oldval) {
69 raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
70 return 0;
71 }
72
73 /*
74 * Write back the new configuration, and possibly re-enable
75 * the interrupt. If we fail to write a new configuration for
76 * an SPI then WARN and return an error. If we fail to write the
77 * configuration for a PPI this is most likely because the GIC
78 * does not allow us to set the configuration or we are in a
79 * non-secure mode, and hence it may not be catastrophic.
80 */
81 writel_relaxed(val, base + confoff);
82 if (readl_relaxed(base + confoff) != val)
83 ret = -EINVAL;
84
85 raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
86
87 if (sync_access)
88 sync_access();
89
90 return ret;
91}
92
93void gic_dist_config(void __iomem *base, int gic_irqs,
94 void (*sync_access)(void))
95{
96 unsigned int i;
97
98 /*
99 * Set all global interrupts to be level triggered, active low.
100 */
101 for (i = 32; i < gic_irqs; i += 16)
102 writel_relaxed(GICD_INT_ACTLOW_LVLTRIG,
103 base + GIC_DIST_CONFIG + i / 4);
104
105 /*
106 * Set priority on all global interrupts.
107 */
108 for (i = 32; i < gic_irqs; i += 4)
109 writel_relaxed(GICD_INT_DEF_PRI_X4, base + GIC_DIST_PRI + i);
110
111 /*
112 * Deactivate and disable all SPIs. Leave the PPI and SGIs
113 * alone as they are in the redistributor registers on GICv3.
114 */
115 for (i = 32; i < gic_irqs; i += 32) {
116 writel_relaxed(GICD_INT_EN_CLR_X32,
117 base + GIC_DIST_ACTIVE_CLEAR + i / 8);
118 writel_relaxed(GICD_INT_EN_CLR_X32,
119 base + GIC_DIST_ENABLE_CLEAR + i / 8);
120 }
121
122 if (sync_access)
123 sync_access();
124}
125
126void gic_cpu_config(void __iomem *base, int nr, void (*sync_access)(void))
127{
128 int i;
129
130 /*
131 * Deal with the banked PPI and SGI interrupts - disable all
132 * private interrupts. Make sure everything is deactivated.
133 */
134 for (i = 0; i < nr; i += 32) {
135 writel_relaxed(GICD_INT_EN_CLR_X32,
136 base + GIC_DIST_ACTIVE_CLEAR + i / 8);
137 writel_relaxed(GICD_INT_EN_CLR_X32,
138 base + GIC_DIST_ENABLE_CLEAR + i / 8);
139 }
140
141 /*
142 * Set priority on PPI and SGI interrupts
143 */
144 for (i = 0; i < nr; i += 4)
145 writel_relaxed(GICD_INT_DEF_PRI_X4,
146 base + GIC_DIST_PRI + i * 4 / 4);
147
148 if (sync_access)
149 sync_access();
150}
151

source code of linux/drivers/irqchip/irq-gic-common.c