xref: /linux/drivers/irqchip/irq-gic-common.c (revision 63307d015b91e626c97bb82e88054af3d0b74643)
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 
13 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
14 
15 static const struct gic_kvm_info *gic_kvm_info;
16 
17 const struct gic_kvm_info *gic_get_kvm_info(void)
18 {
19 	return gic_kvm_info;
20 }
21 
22 void gic_set_kvm_info(const struct gic_kvm_info *info)
23 {
24 	BUG_ON(gic_kvm_info != NULL);
25 	gic_kvm_info = info;
26 }
27 
28 void gic_enable_of_quirks(const struct device_node *np,
29 			  const struct gic_quirk *quirks, void *data)
30 {
31 	for (; quirks->desc; quirks++) {
32 		if (!of_device_is_compatible(np, quirks->compatible))
33 			continue;
34 		if (quirks->init(data))
35 			pr_info("GIC: enabling workaround for %s\n",
36 				quirks->desc);
37 	}
38 }
39 
40 void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
41 		void *data)
42 {
43 	for (; quirks->desc; quirks++) {
44 		if (quirks->iidr != (quirks->mask & iidr))
45 			continue;
46 		if (quirks->init(data))
47 			pr_info("GIC: enabling workaround for %s\n",
48 				quirks->desc);
49 	}
50 }
51 
52 int gic_configure_irq(unsigned int irq, unsigned int type,
53 		       void __iomem *base, void (*sync_access)(void))
54 {
55 	u32 confmask = 0x2 << ((irq % 16) * 2);
56 	u32 confoff = (irq / 16) * 4;
57 	u32 val, oldval;
58 	int ret = 0;
59 	unsigned long flags;
60 
61 	/*
62 	 * Read current configuration register, and insert the config
63 	 * for "irq", depending on "type".
64 	 */
65 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
66 	val = oldval = readl_relaxed(base + GIC_DIST_CONFIG + confoff);
67 	if (type & IRQ_TYPE_LEVEL_MASK)
68 		val &= ~confmask;
69 	else if (type & IRQ_TYPE_EDGE_BOTH)
70 		val |= confmask;
71 
72 	/* If the current configuration is the same, then we are done */
73 	if (val == oldval) {
74 		raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
75 		return 0;
76 	}
77 
78 	/*
79 	 * Write back the new configuration, and possibly re-enable
80 	 * the interrupt. If we fail to write a new configuration for
81 	 * an SPI then WARN and return an error. If we fail to write the
82 	 * configuration for a PPI this is most likely because the GIC
83 	 * does not allow us to set the configuration or we are in a
84 	 * non-secure mode, and hence it may not be catastrophic.
85 	 */
86 	writel_relaxed(val, base + GIC_DIST_CONFIG + confoff);
87 	if (readl_relaxed(base + GIC_DIST_CONFIG + confoff) != val) {
88 		if (WARN_ON(irq >= 32))
89 			ret = -EINVAL;
90 		else
91 			pr_warn("GIC: PPI%d is secure or misconfigured\n",
92 				irq - 16);
93 	}
94 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
95 
96 	if (sync_access)
97 		sync_access();
98 
99 	return ret;
100 }
101 
102 void gic_dist_config(void __iomem *base, int gic_irqs,
103 		     void (*sync_access)(void))
104 {
105 	unsigned int i;
106 
107 	/*
108 	 * Set all global interrupts to be level triggered, active low.
109 	 */
110 	for (i = 32; i < gic_irqs; i += 16)
111 		writel_relaxed(GICD_INT_ACTLOW_LVLTRIG,
112 					base + GIC_DIST_CONFIG + i / 4);
113 
114 	/*
115 	 * Set priority on all global interrupts.
116 	 */
117 	for (i = 32; i < gic_irqs; i += 4)
118 		writel_relaxed(GICD_INT_DEF_PRI_X4, base + GIC_DIST_PRI + i);
119 
120 	/*
121 	 * Deactivate and disable all SPIs. Leave the PPI and SGIs
122 	 * alone as they are in the redistributor registers on GICv3.
123 	 */
124 	for (i = 32; i < gic_irqs; i += 32) {
125 		writel_relaxed(GICD_INT_EN_CLR_X32,
126 			       base + GIC_DIST_ACTIVE_CLEAR + i / 8);
127 		writel_relaxed(GICD_INT_EN_CLR_X32,
128 			       base + GIC_DIST_ENABLE_CLEAR + i / 8);
129 	}
130 
131 	if (sync_access)
132 		sync_access();
133 }
134 
135 void gic_cpu_config(void __iomem *base, void (*sync_access)(void))
136 {
137 	int i;
138 
139 	/*
140 	 * Deal with the banked PPI and SGI interrupts - disable all
141 	 * PPI interrupts, ensure all SGI interrupts are enabled.
142 	 * Make sure everything is deactivated.
143 	 */
144 	writel_relaxed(GICD_INT_EN_CLR_X32, base + GIC_DIST_ACTIVE_CLEAR);
145 	writel_relaxed(GICD_INT_EN_CLR_PPI, base + GIC_DIST_ENABLE_CLEAR);
146 	writel_relaxed(GICD_INT_EN_SET_SGI, base + GIC_DIST_ENABLE_SET);
147 
148 	/*
149 	 * Set priority on PPI and SGI interrupts
150 	 */
151 	for (i = 0; i < 32; i += 4)
152 		writel_relaxed(GICD_INT_DEF_PRI_X4,
153 					base + GIC_DIST_PRI + i * 4 / 4);
154 
155 	if (sync_access)
156 		sync_access();
157 }
158