[PATCH 09/11] x86/ioapic: Add OF bindings for IO-APIC

From: Sebastian Andrzej Siewior
Date: Tue Feb 22 2011 - 15:08:36 EST


ioapic_xlate provides a translation from the information in device tree
to ioapic related informations. This includes
- obtaining hw irq which is the vector number "=> pin number + gsi"
- obtaining type (level/edge/..)
- programming this information into ioapic

ioapic_add_ofnode adds an irq_domain based on informations from the device
tree. This information (irq_domain) is required in order to map a device to
its proper interrupt controller.

Cc: devicetree-discuss@xxxxxxxxxxxxxxxx
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Dirk Brandewie <dirk.brandewie@xxxxxxxxx>
---
arch/x86/include/asm/io_apic.h | 7 +++
arch/x86/include/asm/prom.h | 2 +
arch/x86/kernel/apic/io_apic.c | 99 ++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/devicetree.c | 13 +++++
arch/x86/kernel/irqinit.c | 6 ++
5 files changed, 127 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index f327d38..fe88a73 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -177,6 +177,13 @@ struct mp_ioapic_gsi{
u32 gsi_base;
u32 gsi_end;
};
+#ifdef CONFIG_OF
+struct mp_of_ioapic {
+ struct device_node *node;
+};
+extern struct mp_of_ioapic mp_of_ioapic[MAX_IO_APICS];
+void __init ioapic_add_ofnode(struct device_node *np);
+#endif
extern struct mp_ioapic_gsi mp_gsi_routing[];
extern u32 gsi_top;
int mp_find_ioapic(u32 gsi);
diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
index 3e441b3..98b9a73 100644
--- a/arch/x86/include/asm/prom.h
+++ b/arch/x86/include/asm/prom.h
@@ -26,6 +26,7 @@
extern int of_ioapic;
extern u64 initial_dtb;
extern void add_dtb(u64 data);
+extern void x86_add_irq_domains(void);
void x86_dtb_find_config(void);
void x86_dtb_get_config(unsigned int unused);
void add_interrupt_host(struct irq_domain *ih);
@@ -43,6 +44,7 @@ static inline struct device_node *pci_bus_to_OF_node(struct pci_bus *bus)

#else
static inline void add_dtb(u64 data) { }
+static inline void x86_add_irq_domains(void) { }
static inline void x86_of_pci_init(void) { }
#define x86_dtb_find_config x86_init_noop
#define x86_dtb_get_config x86_init_uint_noop
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index ca9e2a3..c172452 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -43,6 +43,7 @@
#include <linux/bootmem.h>
#include <linux/dmar.h>
#include <linux/hpet.h>
+#include <linux/of_address.h>

#include <asm/idle.h>
#include <asm/io.h>
@@ -60,6 +61,7 @@
#include <asm/irq_remapping.h>
#include <asm/hpet.h>
#include <asm/hw_irq.h>
+#include <asm/irq_controller.h>

#include <asm/apic.h>

@@ -88,6 +90,10 @@ int nr_ioapics;
/* IO APIC gsi routing info */
struct mp_ioapic_gsi mp_gsi_routing[MAX_IO_APICS];

+#ifdef CONFIG_OF
+/* OF -> IO APIC lookup */
+struct mp_of_ioapic mp_of_ioapic[MAX_IO_APICS];
+#endif
/* The one past the highest gsi number used */
u32 gsi_top;

@@ -4083,6 +4089,99 @@ void __init mp_register_ioapic(int id, u32 address, u32 gsi_base)
nr_ioapics++;
}

+#ifdef CONFIG_OF
+static int ioapic_xlate(struct irq_domain *id, const u32 *intspec, u32 intsize,
+ u32 *out_hwirq, u32 *out_type)
+{
+ u32 line;
+ u32 idx;
+ u32 type;
+ u32 trigger;
+ u32 polarity;
+ struct irq_cfg *cfg;
+ struct irq_desc *desc;
+
+ if (intsize < 1)
+ return -EINVAL;
+
+ line = *intspec;
+ idx = (u32) id->priv;
+ *out_hwirq = line + mp_gsi_routing[idx].gsi_base;
+ if (intsize > 1) {
+ intspec++;
+ type = *intspec;
+ switch (type) {
+ case 0:
+ *out_type = IRQ_TYPE_EDGE_RISING;
+ trigger = IOAPIC_EDGE;
+ polarity = 1;
+ break;
+ case 1:
+ *out_type = IRQ_TYPE_LEVEL_LOW;
+ trigger = IOAPIC_LEVEL;
+ polarity = 0;
+ break;
+ case 2:
+ *out_type = IRQ_TYPE_LEVEL_HIGH;
+ trigger = IOAPIC_LEVEL;
+ polarity = 1;
+ break;
+ case 3:
+ *out_type = IRQ_TYPE_EDGE_FALLING;
+ trigger = IOAPIC_EDGE;
+ polarity = 0;
+ break;
+ default:
+ *out_type = IRQ_TYPE_NONE;
+ trigger = IOAPIC_AUTO;
+ polarity = 0;
+ break;
+ };
+ } else {
+ *out_type = IRQ_TYPE_NONE;
+ trigger = IOAPIC_AUTO;
+ polarity = 0;
+ }
+ /* And now tell the IO APIC to make the line ready */
+ desc = irq_to_desc_alloc_node(*out_hwirq, 0);
+ cfg = irq_cfg(*out_hwirq);
+ add_pin_to_irq_node(cfg, 0, idx, line);
+ /* make it edge by default, settype will update it */
+ setup_ioapic_irq(idx, line, *out_hwirq, cfg, trigger, polarity);
+ return 0;
+}
+
+void __init ioapic_add_ofnode(struct device_node *np)
+{
+ int i;
+ int ret;
+ struct resource r;
+
+ ret = of_address_to_resource(np, 0, &r);
+ if (ret) {
+ printk(KERN_ERR "Failed to obtain address for %s\n",
+ np->full_name);
+ return;
+ }
+
+ for (i = 0; i < nr_ioapics; i++) {
+ if (r.start == mp_ioapics[i].apicaddr) {
+ struct irq_domain *id;
+
+ mp_of_ioapic[i].node = np;
+ id = kzalloc(sizeof(*id), GFP_KERNEL);
+ BUG_ON(!id);
+ id->controller = np;
+ id->xlate = ioapic_xlate;
+ id->priv = (void *)i;
+ add_interrupt_host(id);
+ return;
+ }
+ }
+ printk(KERN_ERR "IOxAPIC at %s is not registered.\n", np->full_name);
+}
+#endif
+
/* Enable IOAPIC early just for system timer */
void __init pre_init_apic_IRQ0(void)
{
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 179833f..62d0072 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -322,3 +322,16 @@ void __init x86_dtb_get_config(unsigned int unused)
dtb_setup_hpet();
dtb_apic_setup();
}
+
+void __init x86_add_irq_domains(void)
+{
+ struct device_node *dp;
+
+ if (!initial_boot_params)
+ return;
+
+ for_each_node_with_property(dp, "interrupt-controller") {
+ if (of_device_is_compatible(dp, "intel,ce4100-ioapic"))
+ ioapic_add_ofnode(dp);
+ }
+}
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index 4cadf86..9f76f89 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -119,6 +119,12 @@ void __init init_IRQ(void)
int i;

/*
+ * We probably need a better place for this, but it works for
+ * now ...
+ */
+ x86_add_irq_domains();
+
+ /*
* On cpu 0, Assign IRQ0_VECTOR..IRQ15_VECTOR's to IRQ 0..15.
* If these IRQ's are handled by legacy interrupt-controllers like PIC,
* then this configuration will likely be static after the boot. If
--
1.7.4

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