KVM: ARM: vgic: split GICv2 backend from the main vgic code

Brutally hack the innocent vgic code, and move the GICv2 specific code
to its own file, using vgic_ops and vgic_params as a way to pass
information between the two blocks.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

arch/arm/kvm/Makefile

@@ -21,4 +21,5 @@ obj-y += kvm-arm.o init.o interrupts.o
 obj-y += arm.o handle_exit.o guest.o mmu.o emulate.o reset.o
 obj-y += coproc.o coproc_a15.o coproc_a7.o mmio.o psci.o perf.o
 obj-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic.o
+obj-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic-v2.o
 obj-$(CONFIG_KVM_ARM_TIMER) += $(KVM)/arm/arch_timer.o

arch/arm64/kvm/Makefile

@@ -19,5 +19,5 @@ kvm-$(CONFIG_KVM_ARM_HOST) += emulate.o inject_fault.o regmap.o
 kvm-$(CONFIG_KVM_ARM_HOST) += hyp.o hyp-init.o handle_exit.o
 kvm-$(CONFIG_KVM_ARM_HOST) += guest.o reset.o sys_regs.o sys_regs_generic_v8.o
 
-kvm-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic.o
+kvm-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic.o $(KVM)/arm/vgic-v2.o
 kvm-$(CONFIG_KVM_ARM_TIMER) += $(KVM)/arm/arch_timer.o

include/kvm/arm_vgic.h

@@ -32,7 +32,8 @@
 #define VGIC_NR_PRIVATE_IRQS	(VGIC_NR_SGIS + VGIC_NR_PPIS)
 #define VGIC_NR_SHARED_IRQS	(VGIC_NR_IRQS - VGIC_NR_PRIVATE_IRQS)
 #define VGIC_MAX_CPUS		KVM_MAX_VCPUS
-#define VGIC_MAX_LRS		(1 << 6)
+
+#define VGIC_V2_MAX_LRS		(1 << 6)
 
 /* Sanity checks... */
 #if (VGIC_MAX_CPUS > 8)
@@ -162,7 +163,7 @@ struct vgic_v2_cpu_if {
 	u32		vgic_eisr[2];	/* Saved only */
 	u32		vgic_elrsr[2];	/* Saved only */
 	u32		vgic_apr;
-	u32		vgic_lr[VGIC_MAX_LRS];
+	u32		vgic_lr[VGIC_V2_MAX_LRS];
 };
 
 struct vgic_cpu {
@@ -175,7 +176,7 @@ struct vgic_cpu {
 	DECLARE_BITMAP(	pending_shared, VGIC_NR_SHARED_IRQS);
 
 	/* Bitmap of used/free list registers */
-	DECLARE_BITMAP(	lr_used, VGIC_MAX_LRS);
+	DECLARE_BITMAP(	lr_used, VGIC_V2_MAX_LRS);
 
 	/* Number of list registers on this CPU */
 	int		nr_lr;
@@ -214,6 +215,10 @@ bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
 #define irqchip_in_kernel(k)	(!!((k)->arch.vgic.vctrl_base))
 #define vgic_initialized(k)	((k)->arch.vgic.ready)
 
+int vgic_v2_probe(struct device_node *vgic_node,
+		  const struct vgic_ops **ops,
+		  const struct vgic_params **params);
+
 #else
 static inline int kvm_vgic_hyp_init(void)
 {

virt/kvm/arm/vgic-v2.c

+/*
+ * Copyright (C) 2012,2013 ARM Limited, All Rights Reserved.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/cpu.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#include <linux/irqchip/arm-gic.h>
+
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_mmu.h>
+
+static struct vgic_lr vgic_v2_get_lr(const struct kvm_vcpu *vcpu, int lr)
+{
+	struct vgic_lr lr_desc;
+	u32 val = vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr];
+
+	lr_desc.irq	= val & GICH_LR_VIRTUALID;
+	if (lr_desc.irq <= 15)
+		lr_desc.source	= (val >> GICH_LR_PHYSID_CPUID_SHIFT) & 0x7;
+	else
+		lr_desc.source = 0;
+	lr_desc.state	= 0;
+
+	if (val & GICH_LR_PENDING_BIT)
+		lr_desc.state |= LR_STATE_PENDING;
+	if (val & GICH_LR_ACTIVE_BIT)
+		lr_desc.state |= LR_STATE_ACTIVE;
+	if (val & GICH_LR_EOI)
+		lr_desc.state |= LR_EOI_INT;
+
+	return lr_desc;
+}
+
+static void vgic_v2_set_lr(struct kvm_vcpu *vcpu, int lr,
+			   struct vgic_lr lr_desc)
+{
+	u32 lr_val = (lr_desc.source << GICH_LR_PHYSID_CPUID_SHIFT) | lr_desc.irq;
+
+	if (lr_desc.state & LR_STATE_PENDING)
+		lr_val |= GICH_LR_PENDING_BIT;
+	if (lr_desc.state & LR_STATE_ACTIVE)
+		lr_val |= GICH_LR_ACTIVE_BIT;
+	if (lr_desc.state & LR_EOI_INT)
+		lr_val |= GICH_LR_EOI;
+
+	vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = lr_val;
+}
+
+static void vgic_v2_sync_lr_elrsr(struct kvm_vcpu *vcpu, int lr,
+				  struct vgic_lr lr_desc)
+{
+	if (!(lr_desc.state & LR_STATE_MASK))
+		set_bit(lr, (unsigned long *)vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr);
+}
+
+static u64 vgic_v2_get_elrsr(const struct kvm_vcpu *vcpu)
+{
+	u64 val;
+
+#if BITS_PER_LONG == 64
+	val  = vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr[1];
+	val <<= 32;
+	val |= vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr[0];
+#else
+	val = *(u64 *)vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr;
+#endif
+	return val;
+}
+
+static u64 vgic_v2_get_eisr(const struct kvm_vcpu *vcpu)
+{
+	u64 val;
+
+#if BITS_PER_LONG == 64
+	val  = vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr[1];
+	val <<= 32;
+	val |= vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr[0];
+#else
+	val = *(u64 *)vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr;
+#endif
+	return val;
+}
+
+static u32 vgic_v2_get_interrupt_status(const struct kvm_vcpu *vcpu)
+{
+	u32 misr = vcpu->arch.vgic_cpu.vgic_v2.vgic_misr;
+	u32 ret = 0;
+
+	if (misr & GICH_MISR_EOI)
+		ret |= INT_STATUS_EOI;
+	if (misr & GICH_MISR_U)
+		ret |= INT_STATUS_UNDERFLOW;
+
+	return ret;
+}
+
+static void vgic_v2_enable_underflow(struct kvm_vcpu *vcpu)
+{
+	vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr |= GICH_HCR_UIE;
+}
+
+static void vgic_v2_disable_underflow(struct kvm_vcpu *vcpu)
+{
+	vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr &= ~GICH_HCR_UIE;
+}
+
+static void vgic_v2_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
+{
+	u32 vmcr = vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr;
+
+	vmcrp->ctlr = (vmcr & GICH_VMCR_CTRL_MASK) >> GICH_VMCR_CTRL_SHIFT;
+	vmcrp->abpr = (vmcr & GICH_VMCR_ALIAS_BINPOINT_MASK) >> GICH_VMCR_ALIAS_BINPOINT_SHIFT;
+	vmcrp->bpr  = (vmcr & GICH_VMCR_BINPOINT_MASK) >> GICH_VMCR_BINPOINT_SHIFT;
+	vmcrp->pmr  = (vmcr & GICH_VMCR_PRIMASK_MASK) >> GICH_VMCR_PRIMASK_SHIFT;
+}
+
+static void vgic_v2_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
+{
+	u32 vmcr;
+
+	vmcr  = (vmcrp->ctlr << GICH_VMCR_CTRL_SHIFT) & GICH_VMCR_CTRL_MASK;
+	vmcr |= (vmcrp->abpr << GICH_VMCR_ALIAS_BINPOINT_SHIFT) & GICH_VMCR_ALIAS_BINPOINT_MASK;
+	vmcr |= (vmcrp->bpr << GICH_VMCR_BINPOINT_SHIFT) & GICH_VMCR_BINPOINT_MASK;
+	vmcr |= (vmcrp->pmr << GICH_VMCR_PRIMASK_SHIFT) & GICH_VMCR_PRIMASK_MASK;
+
+	vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr = vmcr;
+}
+
+static void vgic_v2_enable(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * By forcing VMCR to zero, the GIC will restore the binary
+	 * points to their reset values. Anything else resets to zero
+	 * anyway.
+	 */
+	vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr = 0;
+
+	/* Get the show on the road... */
+	vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr = GICH_HCR_EN;
+}
+
+static const struct vgic_ops vgic_v2_ops = {
+	.get_lr			= vgic_v2_get_lr,
+	.set_lr			= vgic_v2_set_lr,
+	.sync_lr_elrsr		= vgic_v2_sync_lr_elrsr,
+	.get_elrsr		= vgic_v2_get_elrsr,
+	.get_eisr		= vgic_v2_get_eisr,
+	.get_interrupt_status	= vgic_v2_get_interrupt_status,
+	.enable_underflow	= vgic_v2_enable_underflow,
+	.disable_underflow	= vgic_v2_disable_underflow,
+	.get_vmcr		= vgic_v2_get_vmcr,
+	.set_vmcr		= vgic_v2_set_vmcr,
+	.enable			= vgic_v2_enable,
+};
+
+static struct vgic_params vgic_v2_params;
+
+/**
+ * vgic_v2_probe - probe for a GICv2 compatible interrupt controller in DT
+ * @node:	pointer to the DT node
+ * @ops: 	address of a pointer to the GICv2 operations
+ * @params:	address of a pointer to HW-specific parameters
+ *
+ * Returns 0 if a GICv2 has been found, with the low level operations
+ * in *ops and the HW parameters in *params. Returns an error code
+ * otherwise.
+ */
+int vgic_v2_probe(struct device_node *vgic_node,
+		  const struct vgic_ops **ops,
+		  const struct vgic_params **params)
+{
+	int ret;
+	struct resource vctrl_res;
+	struct resource vcpu_res;
+	struct vgic_params *vgic = &vgic_v2_params;
+
+	vgic->maint_irq = irq_of_parse_and_map(vgic_node, 0);
+	if (!vgic->maint_irq) {
+		kvm_err("error getting vgic maintenance irq from DT\n");
+		ret = -ENXIO;
+		goto out;
+	}
+
+	ret = of_address_to_resource(vgic_node, 2, &vctrl_res);
+	if (ret) {
+		kvm_err("Cannot obtain GICH resource\n");
+		goto out;
+	}
+
+	vgic->vctrl_base = of_iomap(vgic_node, 2);
+	if (!vgic->vctrl_base) {
+		kvm_err("Cannot ioremap GICH\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	vgic->nr_lr = readl_relaxed(vgic->vctrl_base + GICH_VTR);
+	vgic->nr_lr = (vgic->nr_lr & 0x3f) + 1;
+
+	ret = create_hyp_io_mappings(vgic->vctrl_base,
+				     vgic->vctrl_base + resource_size(&vctrl_res),
+				     vctrl_res.start);
+	if (ret) {
+		kvm_err("Cannot map VCTRL into hyp\n");
+		goto out_unmap;
+	}
+
+	if (of_address_to_resource(vgic_node, 3, &vcpu_res)) {
+		kvm_err("Cannot obtain GICV resource\n");
+		ret = -ENXIO;
+		goto out_unmap;
+	}
+	vgic->vcpu_base = vcpu_res.start;
+
+	kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
+		 vctrl_res.start, vgic->maint_irq);
+
+	*ops = &vgic_v2_ops;
+	*params = vgic;
+	goto out;
+
+out_unmap:
+	iounmap(vgic->vctrl_base);
+out:
+	of_node_put(vgic_node);
+	return ret;
+}