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#include <linux/kernel.h>
11
12#include "irq-gic-common.h"
13
14static DEFINE_RAW_SPINLOCK(irq_controller_lock);
15
16void gic_enable_of_quirks(const struct device_node *np,
17 const struct gic_quirk *quirks, void *data)
18{
19 for (; quirks->desc; quirks++) {
20 if (!quirks->compatible && !quirks->property)
21 continue;
22 if (quirks->compatible &&
23 !of_device_is_compatible(device: np, quirks->compatible))
24 continue;
25 if (quirks->property &&
26 !of_property_read_bool(np, propname: quirks->property))
27 continue;
28 if (quirks->init(data))
29 pr_info("GIC: enabling workaround for %s\n",
30 quirks->desc);
31 }
32}
33
34void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
35 void *data)
36{
37 for (; quirks->desc; quirks++) {
38 if (quirks->compatible || quirks->property)
39 continue;
40 if (quirks->iidr != (quirks->mask & iidr))
41 continue;
42 if (quirks->init(data))
43 pr_info("GIC: enabling workaround for %s\n",
44 quirks->desc);
45 }
46}
47
48int gic_configure_irq(unsigned int irq, unsigned int type,
49 void __iomem *base)
50{
51 u32 confmask = 0x2 << ((irq % 16) * 2);
52 u32 confoff = (irq / 16) * 4;
53 u32 val, oldval;
54 int ret = 0;
55 unsigned long flags;
56
57 /*
58 * Read current configuration register, and insert the config
59 * for "irq", depending on "type".
60 */
61 raw_spin_lock_irqsave(&irq_controller_lock, flags);
62 val = oldval = readl_relaxed(base + confoff);
63 if (type & IRQ_TYPE_LEVEL_MASK)
64 val &= ~confmask;
65 else if (type & IRQ_TYPE_EDGE_BOTH)
66 val |= confmask;
67
68 /* If the current configuration is the same, then we are done */
69 if (val == oldval) {
70 raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
71 return 0;
72 }
73
74 /*
75 * Write back the new configuration, and possibly re-enable
76 * the interrupt. If we fail to write a new configuration for
77 * an SPI then WARN and return an error. If we fail to write the
78 * configuration for a PPI this is most likely because the GIC
79 * does not allow us to set the configuration or we are in a
80 * non-secure mode, and hence it may not be catastrophic.
81 */
82 writel_relaxed(val, base + confoff);
83 if (readl_relaxed(base + confoff) != val)
84 ret = -EINVAL;
85
86 raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
87
88 return ret;
89}
90
91void gic_dist_config(void __iomem *base, int gic_irqs, u8 priority)
92{
93 unsigned int i;
94
95 /*
96 * Set all global interrupts to be level triggered, active low.
97 */
98 for (i = 32; i < gic_irqs; i += 16)
99 writel_relaxed(GICD_INT_ACTLOW_LVLTRIG,
100 base + GIC_DIST_CONFIG + i / 4);
101
102 /*
103 * Set priority on all global interrupts.
104 */
105 for (i = 32; i < gic_irqs; i += 4)
106 writel_relaxed(REPEAT_BYTE_U32(priority),
107 base + GIC_DIST_PRI + i);
108
109 /*
110 * Deactivate and disable all SPIs. Leave the PPI and SGIs
111 * alone as they are in the redistributor registers on GICv3.
112 */
113 for (i = 32; i < gic_irqs; i += 32) {
114 writel_relaxed(GICD_INT_EN_CLR_X32,
115 base + GIC_DIST_ACTIVE_CLEAR + i / 8);
116 writel_relaxed(GICD_INT_EN_CLR_X32,
117 base + GIC_DIST_ENABLE_CLEAR + i / 8);
118 }
119}
120
121void gic_cpu_config(void __iomem *base, int nr, u8 priority)
122{
123 int i;
124
125 /*
126 * Deal with the banked PPI and SGI interrupts - disable all
127 * private interrupts. Make sure everything is deactivated.
128 */
129 for (i = 0; i < nr; i += 32) {
130 writel_relaxed(GICD_INT_EN_CLR_X32,
131 base + GIC_DIST_ACTIVE_CLEAR + i / 8);
132 writel_relaxed(GICD_INT_EN_CLR_X32,
133 base + GIC_DIST_ENABLE_CLEAR + i / 8);
134 }
135
136 /*
137 * Set priority on PPI and SGI interrupts
138 */
139 for (i = 0; i < nr; i += 4)
140 writel_relaxed(REPEAT_BYTE_U32(priority),
141 base + GIC_DIST_PRI + i * 4 / 4);
142}
143

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