irqchip/gic: Split vGIC probing information from the GIC code

The vGIC advertising code is unsurprisingly very much tied to
the GIC implementations. However, we are about to extend the
support to lesser implementations.

Let's dissociate the vgic registration from the GIC code and
move it into KVM, where it makes a bit more sense. This also
allows us to mark the gic_kvm_info structures as __initdata.
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

arch/arm64/kvm/vgic/vgic-init.c

@@ -482,6 +482,16 @@ static irqreturn_t vgic_maintenance_handler(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static struct gic_kvm_info *gic_kvm_info;
+
+void __init vgic_set_kvm_info(const struct gic_kvm_info *info)
+{
+	BUG_ON(gic_kvm_info != NULL);
+	gic_kvm_info = kmalloc(sizeof(*info), GFP_KERNEL);
+	if (gic_kvm_info)
+		*gic_kvm_info = *info;
+}
+
 /**
  * kvm_vgic_init_cpu_hardware - initialize the GIC VE hardware
  *
@@ -509,10 +519,8 @@ void kvm_vgic_init_cpu_hardware(void)
  */
 int kvm_vgic_hyp_init(void)
 {
-	const struct gic_kvm_info *gic_kvm_info;
 	int ret;
 
-	gic_kvm_info = gic_get_kvm_info();
 	if (!gic_kvm_info)
 		return -ENODEV;
 
@@ -536,10 +544,14 @@ int kvm_vgic_hyp_init(void)
 		ret = -ENODEV;
 	}
 
+	kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
+
+	kfree(gic_kvm_info);
+	gic_kvm_info = NULL;
+
 	if (ret)
 		return ret;
 
-	kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
 	ret = request_percpu_irq(kvm_vgic_global_state.maint_irq,
 				 vgic_maintenance_handler,
 				 "vgic", kvm_get_running_vcpus());

drivers/irqchip/irq-gic-common.c

@@ -12,19 +12,6 @@
 
 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
 
-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)
-{
-	BUG_ON(gic_kvm_info != NULL);
-	gic_kvm_info = info;
-}
-
 void gic_enable_of_quirks(const struct device_node *np,
 			  const struct gic_quirk *quirks, void *data)
 {

drivers/irqchip/irq-gic-common.h

@@ -28,6 +28,4 @@ void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
 void gic_enable_of_quirks(const struct device_node *np,
 			  const struct gic_quirk *quirks, void *data);
 
-void gic_set_kvm_info(const struct gic_kvm_info *info);
-
 #endif /* _IRQ_GIC_COMMON_H */

drivers/irqchip/irq-gic-v3.c

@@ -103,7 +103,7 @@ EXPORT_SYMBOL(gic_nonsecure_priorities);
 /* ppi_nmi_refs[n] == number of cpus having ppi[n + 16] set as NMI */
 static refcount_t *ppi_nmi_refs;
 
-static struct gic_kvm_info gic_v3_kvm_info;
+static struct gic_kvm_info gic_v3_kvm_info __initdata;
 static DEFINE_PER_CPU(bool, has_rss);
 
 #define MPIDR_RS(mpidr)			(((mpidr) & 0xF0UL) >> 4)
@@ -1852,7 +1852,7 @@ static void __init gic_of_setup_kvm_info(struct device_node *node)
 
 	gic_v3_kvm_info.has_v4 = gic_data.rdists.has_vlpis;
 	gic_v3_kvm_info.has_v4_1 = gic_data.rdists.has_rvpeid;
-	gic_set_kvm_info(&gic_v3_kvm_info);
+	vgic_set_kvm_info(&gic_v3_kvm_info);
 }
 
 static int __init gic_of_init(struct device_node *node, struct device_node *parent)
@@ -2168,7 +2168,7 @@ static void __init gic_acpi_setup_kvm_info(void)
 
 	gic_v3_kvm_info.has_v4 = gic_data.rdists.has_vlpis;
 	gic_v3_kvm_info.has_v4_1 = gic_data.rdists.has_rvpeid;
-	gic_set_kvm_info(&gic_v3_kvm_info);
+	vgic_set_kvm_info(&gic_v3_kvm_info);
 }
 
 static int __init

drivers/irqchip/irq-gic.c

@@ -119,7 +119,7 @@ static DEFINE_STATIC_KEY_TRUE(supports_deactivate_key);
 
 static struct gic_chip_data gic_data[CONFIG_ARM_GIC_MAX_NR] __read_mostly;
 
-static struct gic_kvm_info gic_v2_kvm_info;
+static struct gic_kvm_info gic_v2_kvm_info __initdata;
 
 static DEFINE_PER_CPU(u32, sgi_intid);
 
@@ -1451,7 +1451,7 @@ static void __init gic_of_setup_kvm_info(struct device_node *node)
 		return;
 
 	if (static_branch_likely(&supports_deactivate_key))
-		gic_set_kvm_info(&gic_v2_kvm_info);
+		vgic_set_kvm_info(&gic_v2_kvm_info);
 }
 
 int __init
@@ -1618,7 +1618,7 @@ static void __init gic_acpi_setup_kvm_info(void)
 
 	gic_v2_kvm_info.maint_irq = irq;
 
-	gic_set_kvm_info(&gic_v2_kvm_info);
+	vgic_set_kvm_info(&gic_v2_kvm_info);
 }
 
 static int __init gic_v2_acpi_init(union acpi_subtable_headers *header,

include/linux/irqchip/arm-gic-common.h

@@ -7,8 +7,7 @@
 #ifndef __LINUX_IRQCHIP_ARM_GIC_COMMON_H
 #define __LINUX_IRQCHIP_ARM_GIC_COMMON_H
 
-#include <linux/types.h>
-#include <linux/ioport.h>
+#include <linux/irqchip/arm-vgic-info.h>
 
 #define GICD_INT_DEF_PRI		0xa0
 #define GICD_INT_DEF_PRI_X4		((GICD_INT_DEF_PRI << 24) |\
@@ -16,28 +15,6 @@
 					(GICD_INT_DEF_PRI << 8) |\
 					GICD_INT_DEF_PRI)
 
-enum gic_type {
-	GIC_V2,
-	GIC_V3,
-};
-
-struct gic_kvm_info {
-	/* GIC type */
-	enum gic_type	type;
-	/* Virtual CPU interface */
-	struct resource vcpu;
-	/* Interrupt number */
-	unsigned int	maint_irq;
-	/* Virtual control interface */
-	struct resource vctrl;
-	/* vlpi support */
-	bool		has_v4;
-	/* rvpeid support */
-	bool		has_v4_1;
-};
-
-const struct gic_kvm_info *gic_get_kvm_info(void);
-
 struct irq_domain;
 struct fwnode_handle;
 int gicv2m_init(struct fwnode_handle *parent_handle,

include/linux/irqchip/arm-vgic-info.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * include/linux/irqchip/arm-vgic-info.h
+ *
+ * Copyright (C) 2016 ARM Limited, All Rights Reserved.
+ */
+#ifndef __LINUX_IRQCHIP_ARM_VGIC_INFO_H
+#define __LINUX_IRQCHIP_ARM_VGIC_INFO_H
+
+#include <linux/types.h>
+#include <linux/ioport.h>
+
+enum gic_type {
+	/* Full GICv2 */
+	GIC_V2,
+	/* Full GICv3, optionally with v2 compat */
+	GIC_V3,
+};
+
+struct gic_kvm_info {
+	/* GIC type */
+	enum gic_type	type;
+	/* Virtual CPU interface */
+	struct resource vcpu;
+	/* Interrupt number */
+	unsigned int	maint_irq;
+	/* Virtual control interface */
+	struct resource vctrl;
+	/* vlpi support */
+	bool		has_v4;
+	/* rvpeid support */
+	bool		has_v4_1;
+};
+
+#ifdef CONFIG_KVM
+void vgic_set_kvm_info(const struct gic_kvm_info *info);
+#else
+static inline void vgic_set_kvm_info(const struct gic_kvm_info *info) {}
+#endif
+
+#endif