[PATCH 3/5] irqchip/gic-v2: Parse and export virtual GIC information

For now, the firmware tables are parsed 2 times: once in the GIC
drivers, the other timer when initializing the vGIC. It means code
duplication and make more tedious to add the support for another
firmware table (like ACPI).

Introduce a new structure and set of helpers to get/set the virtual GIC
information. Also fill up the structure for GICv2.

Signed-off-by: Julien Grall <redacted>
---

Cc: Thomas Gleixner <redacted>
Cc: Jason Cooper <redacted>
Cc: Marc Zyngier <redacted>

 drivers/irqchip/irq-gic-common.c       | 13 ++++++
 drivers/irqchip/irq-gic-common.h       |  3 ++
 drivers/irqchip/irq-gic.c              | 78 +++++++++++++++++++++++++++++++++-
 include/linux/irqchip/arm-gic-common.h | 34 +++++++++++++++
 4 files changed, 127 insertions(+), 1 deletion(-)
 create mode 100644 include/linux/irqchip/arm-gic-common.h

diff --git a/drivers/irqchip/irq-gic-common.c b/drivers/irqchip/irq-gic-common.c
index f174ce0..704caf4 100644
--- a/drivers/irqchip/irq-gic-common.c
+++ b/drivers/irqchip/irq-gic-common.c

@@ -21,6 +21,19 @@
 
 #include "irq-gic-common.h"
 
+static const struct gic_kvm_info *gic_kvm_info;
+
+const struct gic_kvm_info *gic_get_kvm_info(void)
+{
+	return gic_kvm_info;
+}
+
+void gic_set_kvm_info(const struct gic_kvm_info *info)
+{
+	WARN(gic_kvm_info != NULL, "gic_kvm_info already set\n");
+	gic_kvm_info = info;
+}
+
 void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
 		void *data)
 {

diff --git a/drivers/irqchip/irq-gic-common.h b/drivers/irqchip/irq-gic-common.h
index fff697d..205e5fd 100644
--- a/drivers/irqchip/irq-gic-common.h
+++ b/drivers/irqchip/irq-gic-common.h

@@ -19,6 +19,7 @@
 
 #include <linux/of.h>
 #include <linux/irqdomain.h>
+#include <linux/irqchip/arm-gic-common.h>
 
 struct gic_quirk {
 	const char *desc;

@@ -35,4 +36,6 @@ void gic_cpu_config(void __iomem *base, void (*sync_access)(void));
 void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
 		void *data);
 
+void gic_set_kvm_info(const struct gic_kvm_info *info);
+
 #endif /* _IRQ_GIC_COMMON_H */

diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 911758c..d3a09a4 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c

@@ -102,6 +102,8 @@ static struct static_key supports_deactivate = STATIC_KEY_INIT_TRUE;
 
 static struct gic_chip_data gic_data[CONFIG_ARM_GIC_MAX_NR] __read_mostly;
 
+static struct gic_kvm_info gic_v2_kvm_info;
+
 #ifdef CONFIG_GIC_NON_BANKED
 static void __iomem *gic_get_percpu_base(union gic_base *base)
 {

@@ -1190,6 +1192,44 @@ static bool gic_check_eoimode(struct device_node *node, void __iomem **base)
 	return true;
 }
 
+static void __init gic_of_setup_kvm_info(struct device_node *node)
+{
+	int ret;
+	struct resource r;
+	unsigned int irq;
+
+	gic_v2_kvm_info.type = GIC_V2;
+
+	irq = irq_of_parse_and_map(node, 0);
+	if (!irq)
+		gic_v2_kvm_info.maint_irq = -1;
+	else
+		gic_v2_kvm_info.maint_irq = irq;
+
+	ret = of_address_to_resource(node, 2, &r);
+	if (!ret) {
+		gic_v2_kvm_info.vctrl_base = r.start;
+		gic_v2_kvm_info.vctrl_size = resource_size(&r);
+	}
+
+	ret = of_address_to_resource(node, 3, &r);
+	if (!ret) {
+		if (!PAGE_ALIGNED(r.start))
+			pr_warn("GICV physical address 0x%llx not page aligned\n",
+				(unsigned long long)r.start);
+		else if (!PAGE_ALIGNED(resource_size(&r)))
+			pr_warn("GICV size 0x%llx not a multiple of page size 0x%lx\n",
+				(unsigned long long)resource_size(&r),
+				PAGE_SIZE);
+		else {
+			gic_v2_kvm_info.vcpu_base = r.start;
+			gic_v2_kvm_info.vcpu_size = resource_size(&r);
+		}
+	}
+
+	gic_set_kvm_info(&gic_v2_kvm_info);
+}
+
 int __init
 gic_of_init(struct device_node *node, struct device_node *parent)
 {

@@ -1219,8 +1259,10 @@ gic_of_init(struct device_node *node, struct device_node *parent)
 
 	__gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset,
 			 &node->fwnode);
-	if (!gic_cnt)
+	if (!gic_cnt) {
 		gic_init_physaddr(node);
+		gic_of_setup_kvm_info(node);
+	}
 
 	if (parent) {
 		irq = irq_of_parse_and_map(node, 0);

@@ -1247,6 +1289,32 @@ IRQCHIP_DECLARE(pl390, "arm,pl390", gic_of_init);
 
 #ifdef CONFIG_ACPI
 static phys_addr_t cpu_phy_base __initdata;
+static struct
+{
+	u32 maint_irq;
+	int maint_irq_mode;
+	phys_addr_t vctrl_base;
+	phys_addr_t vcpu_base;
+} acpi_data __initdata;
+
+static void __init gic_acpi_setup_kvm_info(void)
+{
+	gic_v2_kvm_info.type = GIC_V2;
+
+	gic_v2_kvm_info.maint_irq = acpi_register_gsi(NULL,
+						      acpi_data.maint_irq,
+						      acpi_data.maint_irq_mode,
+						      ACPI_ACTIVE_HIGH);
+	gic_v2_kvm_info.vctrl_base = acpi_data.vctrl_base;
+	if (gic_v2_kvm_info.vctrl_base)
+		gic_v2_kvm_info.vctrl_size = SZ_8K;
+
+	gic_v2_kvm_info.vcpu_base = acpi_data.vcpu_base;
+	if (gic_v2_kvm_info.vcpu_base)
+		gic_v2_kvm_info.vcpu_size = SZ_8K;