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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2005-08-18 16:31:00 -0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2005-08-18 16:31:00 -0400
commitf27ecacc54cc0e5397c9b35f6c25065f07c4448d (patch)
tree38df53b999f4da0cb4af91d5d61ab9c36d566039 /arch/arm/common
parent099d44e869f1886b5eb02a5145ca97b5e4142e28 (diff)
[ARM] Add support for ARM GIC
Add support for the ARM Generic Interrupt Controller. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/common')
-rw-r--r--arch/arm/common/Kconfig3
-rw-r--r--arch/arm/common/Makefile1
-rw-r--r--arch/arm/common/gic.c166
3 files changed, 170 insertions, 0 deletions
diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index 692af6b5e8ff..666ba393575b 100644
--- a/arch/arm/common/Kconfig
+++ b/arch/arm/common/Kconfig
@@ -1,6 +1,9 @@
1config ICST525 1config ICST525
2 bool 2 bool
3 3
4config ARM_GIC
5 bool
6
4config ICST307 7config ICST307
5 bool 8 bool
6 9
diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index 11f20a43ee3a..a87886564b19 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -4,6 +4,7 @@
4 4
5obj-y += rtctime.o 5obj-y += rtctime.o
6obj-$(CONFIG_ARM_AMBA) += amba.o 6obj-$(CONFIG_ARM_AMBA) += amba.o
7obj-$(CONFIG_ARM_GIC) += gic.o
7obj-$(CONFIG_ICST525) += icst525.o 8obj-$(CONFIG_ICST525) += icst525.o
8obj-$(CONFIG_ICST307) += icst307.o 9obj-$(CONFIG_ICST307) += icst307.o
9obj-$(CONFIG_SA1111) += sa1111.o 10obj-$(CONFIG_SA1111) += sa1111.o
diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
new file mode 100644
index 000000000000..51dbf5489b6b
--- /dev/null
+++ b/arch/arm/common/gic.c
@@ -0,0 +1,166 @@
1/*
2 * linux/arch/arm/common/gic.c
3 *
4 * Copyright (C) 2002 ARM Limited, All Rights Reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * Interrupt architecture for the GIC:
11 *
12 * o There is one Interrupt Distributor, which receives interrupts
13 * from system devices and sends them to the Interrupt Controllers.
14 *
15 * o There is one CPU Interface per CPU, which sends interrupts sent
16 * by the Distributor, and interrupts generated locally, to the
17 * associated CPU.
18 *
19 * Note that IRQs 0-31 are special - they are local to each CPU.
20 * As such, the enable set/clear, pending set/clear and active bit
21 * registers are banked per-cpu for these sources.
22 */
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/list.h>
26#include <linux/smp.h>
27
28#include <asm/irq.h>
29#include <asm/io.h>
30#include <asm/mach/irq.h>
31#include <asm/hardware/gic.h>
32
33static void __iomem *gic_dist_base;
34static void __iomem *gic_cpu_base;
35
36/*
37 * Routines to acknowledge, disable and enable interrupts
38 *
39 * Linux assumes that when we're done with an interrupt we need to
40 * unmask it, in the same way we need to unmask an interrupt when
41 * we first enable it.
42 *
43 * The GIC has a seperate notion of "end of interrupt" to re-enable
44 * an interrupt after handling, in order to support hardware
45 * prioritisation.
46 *
47 * We can make the GIC behave in the way that Linux expects by making
48 * our "acknowledge" routine disable the interrupt, then mark it as
49 * complete.
50 */
51static void gic_ack_irq(unsigned int irq)
52{
53 u32 mask = 1 << (irq % 32);
54 writel(mask, gic_dist_base + GIC_DIST_ENABLE_CLEAR + (irq / 32) * 4);
55 writel(irq, gic_cpu_base + GIC_CPU_EOI);
56}
57
58static void gic_mask_irq(unsigned int irq)
59{
60 u32 mask = 1 << (irq % 32);
61 writel(mask, gic_dist_base + GIC_DIST_ENABLE_CLEAR + (irq / 32) * 4);
62}
63
64static void gic_unmask_irq(unsigned int irq)
65{
66 u32 mask = 1 << (irq % 32);
67 writel(mask, gic_dist_base + GIC_DIST_ENABLE_SET + (irq / 32) * 4);
68}
69
70static void gic_set_cpu(struct irqdesc *desc, unsigned int irq, unsigned int cpu)
71{
72 void __iomem *reg = gic_dist_base + GIC_DIST_TARGET + (irq & ~3);
73 unsigned int shift = (irq % 4) * 8;
74 u32 val;
75
76 val = readl(reg) & ~(0xff << shift);
77 val |= 1 << (cpu + shift);
78 writel(val, reg);
79}
80
81static struct irqchip gic_chip = {
82 .ack = gic_ack_irq,
83 .mask = gic_mask_irq,
84 .unmask = gic_unmask_irq,
85#ifdef CONFIG_SMP
86 .set_cpu = gic_set_cpu,
87#endif
88};
89
90void __init gic_dist_init(void __iomem *base)
91{
92 unsigned int max_irq, i;
93 u32 cpumask = 1 << smp_processor_id();
94
95 cpumask |= cpumask << 8;
96 cpumask |= cpumask << 16;
97
98 gic_dist_base = base;
99
100 writel(0, base + GIC_DIST_CTRL);
101
102 /*
103 * Find out how many interrupts are supported.
104 */
105 max_irq = readl(base + GIC_DIST_CTR) & 0x1f;
106 max_irq = (max_irq + 1) * 32;
107
108 /*
109 * The GIC only supports up to 1020 interrupt sources.
110 * Limit this to either the architected maximum, or the
111 * platform maximum.
112 */
113 if (max_irq > max(1020, NR_IRQS))
114 max_irq = max(1020, NR_IRQS);
115
116 /*
117 * Set all global interrupts to be level triggered, active low.
118 */
119 for (i = 32; i < max_irq; i += 16)
120 writel(0, base + GIC_DIST_CONFIG + i * 4 / 16);
121
122 /*
123 * Set all global interrupts to this CPU only.
124 */
125 for (i = 32; i < max_irq; i += 4)
126 writel(cpumask, base + GIC_DIST_TARGET + i * 4 / 4);
127
128 /*
129 * Set priority on all interrupts.
130 */
131 for (i = 0; i < max_irq; i += 4)
132 writel(0xa0a0a0a0, base + GIC_DIST_PRI + i * 4 / 4);
133
134 /*
135 * Disable all interrupts.
136 */
137 for (i = 0; i < max_irq; i += 32)
138 writel(0xffffffff, base + GIC_DIST_ENABLE_CLEAR + i * 4 / 32);
139
140 /*
141 * Setup the Linux IRQ subsystem.
142 */
143 for (i = 29; i < max_irq; i++) {
144 set_irq_chip(i, &gic_chip);
145 set_irq_handler(i, do_level_IRQ);
146 set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
147 }
148
149 writel(1, base + GIC_DIST_CTRL);
150}
151
152void __cpuinit gic_cpu_init(void __iomem *base)
153{
154 gic_cpu_base = base;
155 writel(0xf0, base + GIC_CPU_PRIMASK);
156 writel(1, base + GIC_CPU_CTRL);
157}
158
159#ifdef CONFIG_SMP
160void gic_raise_softirq(cpumask_t cpumask, unsigned int irq)
161{
162 unsigned long map = *cpus_addr(cpumask);
163
164 writel(map << 16 | irq, gic_dist_base + GIC_DIST_SOFTINT);
165}
166#endif