1 /*
2 * Copyright (C) 2002 ARM Limited, All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/irq.h>
20 #include <linux/irqchip/arm-gic.h>
21
22 #include "irq-gic-common.h"
23
24 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
25
26 static const struct gic_kvm_info *gic_kvm_info;
27
gic_get_kvm_info(void)28 const struct gic_kvm_info *gic_get_kvm_info(void)
29 {
30 return gic_kvm_info;
31 }
32
gic_set_kvm_info(const struct gic_kvm_info * info)33 void gic_set_kvm_info(const struct gic_kvm_info *info)
34 {
35 BUG_ON(gic_kvm_info != NULL);
36 gic_kvm_info = info;
37 }
38
gic_enable_quirks(u32 iidr,const struct gic_quirk * quirks,void * data)39 void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
40 void *data)
41 {
42 for (; quirks->desc; quirks++) {
43 if (quirks->iidr != (quirks->mask & iidr))
44 continue;
45 if (quirks->init(data))
46 pr_info("GIC: enabling workaround for %s\n",
47 quirks->desc);
48 }
49 }
50
gic_configure_irq(unsigned int irq,unsigned int type,void __iomem * base,void (* sync_access)(void))51 int gic_configure_irq(unsigned int irq, unsigned int type,
52 void __iomem *base, void (*sync_access)(void))
53 {
54 u32 confmask = 0x2 << ((irq % 16) * 2);
55 u32 confoff = (irq / 16) * 4;
56 u32 val, oldval;
57 int ret = 0;
58 unsigned long flags;
59
60 /*
61 * Read current configuration register, and insert the config
62 * for "irq", depending on "type".
63 */
64 raw_spin_lock_irqsave(&irq_controller_lock, flags);
65 val = oldval = readl_relaxed(base + GIC_DIST_CONFIG + confoff);
66 if (type & IRQ_TYPE_LEVEL_MASK)
67 val &= ~confmask;
68 else if (type & IRQ_TYPE_EDGE_BOTH)
69 val |= confmask;
70
71 /* If the current configuration is the same, then we are done */
72 if (val == oldval) {
73 raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
74 return 0;
75 }
76
77 /*
78 * Write back the new configuration, and possibly re-enable
79 * the interrupt. If we fail to write a new configuration for
80 * an SPI then WARN and return an error. If we fail to write the
81 * configuration for a PPI this is most likely because the GIC
82 * does not allow us to set the configuration or we are in a
83 * non-secure mode, and hence it may not be catastrophic.
84 */
85 writel_relaxed(val, base + GIC_DIST_CONFIG + confoff);
86 if (readl_relaxed(base + GIC_DIST_CONFIG + confoff) != val) {
87 if (WARN_ON(irq >= 32))
88 ret = -EINVAL;
89 else
90 pr_warn("GIC: PPI%d is secure or misconfigured\n",
91 irq - 16);
92 }
93 raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
94
95 if (sync_access)
96 sync_access();
97
98 return ret;
99 }
100
gic_dist_config(void __iomem * base,int gic_irqs,void (* sync_access)(void))101 void gic_dist_config(void __iomem *base, int gic_irqs,
102 void (*sync_access)(void))
103 {
104 unsigned int i;
105
106 /*
107 * Set all global interrupts to be level triggered, active low.
108 */
109 for (i = 32; i < gic_irqs; i += 16)
110 writel_relaxed(GICD_INT_ACTLOW_LVLTRIG,
111 base + GIC_DIST_CONFIG + i / 4);
112
113 /*
114 * Set priority on all global interrupts.
115 */
116 for (i = 32; i < gic_irqs; i += 4)
117 writel_relaxed(GICD_INT_DEF_PRI_X4, base + GIC_DIST_PRI + i);
118
119 /*
120 * Deactivate and disable all SPIs. Leave the PPI and SGIs
121 * alone as they are in the redistributor registers on GICv3.
122 */
123 for (i = 32; i < gic_irqs; i += 32) {
124 writel_relaxed(GICD_INT_EN_CLR_X32,
125 base + GIC_DIST_ACTIVE_CLEAR + i / 8);
126 writel_relaxed(GICD_INT_EN_CLR_X32,
127 base + GIC_DIST_ENABLE_CLEAR + i / 8);
128 }
129
130 if (sync_access)
131 sync_access();
132 }
133
gic_cpu_config(void __iomem * base,void (* sync_access)(void))134 void gic_cpu_config(void __iomem *base, void (*sync_access)(void))
135 {
136 int i;
137
138 /*
139 * Deal with the banked PPI and SGI interrupts - disable all
140 * PPI interrupts, ensure all SGI interrupts are enabled.
141 * Make sure everything is deactivated.
142 */
143 writel_relaxed(GICD_INT_EN_CLR_X32, base + GIC_DIST_ACTIVE_CLEAR);
144 writel_relaxed(GICD_INT_EN_CLR_PPI, base + GIC_DIST_ENABLE_CLEAR);
145 writel_relaxed(GICD_INT_EN_SET_SGI, base + GIC_DIST_ENABLE_SET);
146
147 /*
148 * Set priority on PPI and SGI interrupts
149 */
150 for (i = 0; i < 32; i += 4)
151 writel_relaxed(GICD_INT_DEF_PRI_X4,
152 base + GIC_DIST_PRI + i * 4 / 4);
153
154 if (sync_access)
155 sync_access();
156 }
157