irqchip/gic-v5: Drop has_gcie_v3_compat from gic_kvm_info

The presence of FEAT_GCIE_LEGACY is now handled as a CPU
feature. Therefore, drop the check and flag from the GIC driver and
gic_kvm_info as it is no longer required or used by KVM.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: Sticklyman1936

drivers/irqchip/irq-gic-v5.c

@@ -1062,16 +1062,9 @@ static void gicv5_set_cpuif_idbits(void)
 #ifdef CONFIG_KVM
 static struct gic_kvm_info gic_v5_kvm_info __initdata;
 
-static bool __init gicv5_cpuif_has_gcie_legacy(void)
-{
-	u64 idr0 = read_sysreg_s(SYS_ICC_IDR0_EL1);
-	return !!FIELD_GET(ICC_IDR0_EL1_GCIE_LEGACY, idr0);
-}
-
 static void __init gic_of_setup_kvm_info(struct device_node *node)
 {
 	gic_v5_kvm_info.type = GIC_V5;
-	gic_v5_kvm_info.has_gcie_v3_compat = gicv5_cpuif_has_gcie_legacy();
 
 	/* GIC Virtual CPU interface maintenance interrupt */
 	gic_v5_kvm_info.no_maint_irq_mask = false;

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

@@ -36,8 +36,6 @@ struct gic_kvm_info {
 	bool		has_v4_1;
 	/* Deactivation impared, subpar stuff */
 	bool		no_hw_deactivation;
-	/* v3 compat support (GICv5 hosts, only) */
-	bool		has_gcie_v3_compat;
 };
 
 #ifdef CONFIG_KVM