1/*
2 * Copyright (C) 2012,2013 ARM Limited, All Rights Reserved.
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16 */
17
18#include <linux/cpu.h>
19#include <linux/kvm.h>
20#include <linux/kvm_host.h>
21#include <linux/interrupt.h>
22#include <linux/io.h>
23#include <linux/of.h>
24#include <linux/of_address.h>
25#include <linux/of_irq.h>
26
27#include <linux/irqchip/arm-gic.h>
28
29#include <asm/kvm_emulate.h>
30#include <asm/kvm_arm.h>
31#include <asm/kvm_mmu.h>
32
33static struct vgic_lr vgic_v2_get_lr(const struct kvm_vcpu *vcpu, int lr)
34{
35	struct vgic_lr lr_desc;
36	u32 val = vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr];
37
38	lr_desc.irq	= val & GICH_LR_VIRTUALID;
39	if (lr_desc.irq <= 15)
40		lr_desc.source	= (val >> GICH_LR_PHYSID_CPUID_SHIFT) & 0x7;
41	else
42		lr_desc.source = 0;
43	lr_desc.state	= 0;
44
45	if (val & GICH_LR_PENDING_BIT)
46		lr_desc.state |= LR_STATE_PENDING;
47	if (val & GICH_LR_ACTIVE_BIT)
48		lr_desc.state |= LR_STATE_ACTIVE;
49	if (val & GICH_LR_EOI)
50		lr_desc.state |= LR_EOI_INT;
51
52	return lr_desc;
53}
54
55static void vgic_v2_set_lr(struct kvm_vcpu *vcpu, int lr,
56			   struct vgic_lr lr_desc)
57{
58	u32 lr_val = (lr_desc.source << GICH_LR_PHYSID_CPUID_SHIFT) | lr_desc.irq;
59
60	if (lr_desc.state & LR_STATE_PENDING)
61		lr_val |= GICH_LR_PENDING_BIT;
62	if (lr_desc.state & LR_STATE_ACTIVE)
63		lr_val |= GICH_LR_ACTIVE_BIT;
64	if (lr_desc.state & LR_EOI_INT)
65		lr_val |= GICH_LR_EOI;
66
67	vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = lr_val;
68}
69
70static void vgic_v2_sync_lr_elrsr(struct kvm_vcpu *vcpu, int lr,
71				  struct vgic_lr lr_desc)
72{
73	if (!(lr_desc.state & LR_STATE_MASK))
74		vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr |= (1ULL << lr);
75	else
76		vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr &= ~(1ULL << lr);
77}
78
79static u64 vgic_v2_get_elrsr(const struct kvm_vcpu *vcpu)
80{
81	return vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr;
82}
83
84static u64 vgic_v2_get_eisr(const struct kvm_vcpu *vcpu)
85{
86	return vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr;
87}
88
89static void vgic_v2_clear_eisr(struct kvm_vcpu *vcpu)
90{
91	vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr = 0;
92}
93
94static u32 vgic_v2_get_interrupt_status(const struct kvm_vcpu *vcpu)
95{
96	u32 misr = vcpu->arch.vgic_cpu.vgic_v2.vgic_misr;
97	u32 ret = 0;
98
99	if (misr & GICH_MISR_EOI)
100		ret |= INT_STATUS_EOI;
101	if (misr & GICH_MISR_U)
102		ret |= INT_STATUS_UNDERFLOW;
103
104	return ret;
105}
106
107static void vgic_v2_enable_underflow(struct kvm_vcpu *vcpu)
108{
109	vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr |= GICH_HCR_UIE;
110}
111
112static void vgic_v2_disable_underflow(struct kvm_vcpu *vcpu)
113{
114	vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr &= ~GICH_HCR_UIE;
115}
116
117static void vgic_v2_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
118{
119	u32 vmcr = vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr;
120
121	vmcrp->ctlr = (vmcr & GICH_VMCR_CTRL_MASK) >> GICH_VMCR_CTRL_SHIFT;
122	vmcrp->abpr = (vmcr & GICH_VMCR_ALIAS_BINPOINT_MASK) >> GICH_VMCR_ALIAS_BINPOINT_SHIFT;
123	vmcrp->bpr  = (vmcr & GICH_VMCR_BINPOINT_MASK) >> GICH_VMCR_BINPOINT_SHIFT;
124	vmcrp->pmr  = (vmcr & GICH_VMCR_PRIMASK_MASK) >> GICH_VMCR_PRIMASK_SHIFT;
125}
126
127static void vgic_v2_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
128{
129	u32 vmcr;
130
131	vmcr  = (vmcrp->ctlr << GICH_VMCR_CTRL_SHIFT) & GICH_VMCR_CTRL_MASK;
132	vmcr |= (vmcrp->abpr << GICH_VMCR_ALIAS_BINPOINT_SHIFT) & GICH_VMCR_ALIAS_BINPOINT_MASK;
133	vmcr |= (vmcrp->bpr << GICH_VMCR_BINPOINT_SHIFT) & GICH_VMCR_BINPOINT_MASK;
134	vmcr |= (vmcrp->pmr << GICH_VMCR_PRIMASK_SHIFT) & GICH_VMCR_PRIMASK_MASK;
135
136	vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr = vmcr;
137}
138
139static void vgic_v2_enable(struct kvm_vcpu *vcpu)
140{
141	/*
142	 * By forcing VMCR to zero, the GIC will restore the binary
143	 * points to their reset values. Anything else resets to zero
144	 * anyway.
145	 */
146	vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr = 0;
147
148	/* Get the show on the road... */
149	vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr = GICH_HCR_EN;
150}
151
152static const struct vgic_ops vgic_v2_ops = {
153	.get_lr			= vgic_v2_get_lr,
154	.set_lr			= vgic_v2_set_lr,
155	.sync_lr_elrsr		= vgic_v2_sync_lr_elrsr,
156	.get_elrsr		= vgic_v2_get_elrsr,
157	.get_eisr		= vgic_v2_get_eisr,
158	.clear_eisr		= vgic_v2_clear_eisr,
159	.get_interrupt_status	= vgic_v2_get_interrupt_status,
160	.enable_underflow	= vgic_v2_enable_underflow,
161	.disable_underflow	= vgic_v2_disable_underflow,
162	.get_vmcr		= vgic_v2_get_vmcr,
163	.set_vmcr		= vgic_v2_set_vmcr,
164	.enable			= vgic_v2_enable,
165};
166
167static struct vgic_params vgic_v2_params;
168
169/**
170 * vgic_v2_probe - probe for a GICv2 compatible interrupt controller in DT
171 * @node:	pointer to the DT node
172 * @ops: 	address of a pointer to the GICv2 operations
173 * @params:	address of a pointer to HW-specific parameters
174 *
175 * Returns 0 if a GICv2 has been found, with the low level operations
176 * in *ops and the HW parameters in *params. Returns an error code
177 * otherwise.
178 */
179int vgic_v2_probe(struct device_node *vgic_node,
180		  const struct vgic_ops **ops,
181		  const struct vgic_params **params)
182{
183	int ret;
184	struct resource vctrl_res;
185	struct resource vcpu_res;
186	struct vgic_params *vgic = &vgic_v2_params;
187
188	vgic->maint_irq = irq_of_parse_and_map(vgic_node, 0);
189	if (!vgic->maint_irq) {
190		kvm_err("error getting vgic maintenance irq from DT\n");
191		ret = -ENXIO;
192		goto out;
193	}
194
195	ret = of_address_to_resource(vgic_node, 2, &vctrl_res);
196	if (ret) {
197		kvm_err("Cannot obtain GICH resource\n");
198		goto out;
199	}
200
201	vgic->vctrl_base = of_iomap(vgic_node, 2);
202	if (!vgic->vctrl_base) {
203		kvm_err("Cannot ioremap GICH\n");
204		ret = -ENOMEM;
205		goto out;
206	}
207
208	vgic->nr_lr = readl_relaxed(vgic->vctrl_base + GICH_VTR);
209	vgic->nr_lr = (vgic->nr_lr & 0x3f) + 1;
210
211	ret = create_hyp_io_mappings(vgic->vctrl_base,
212				     vgic->vctrl_base + resource_size(&vctrl_res),
213				     vctrl_res.start);
214	if (ret) {
215		kvm_err("Cannot map VCTRL into hyp\n");
216		goto out_unmap;
217	}
218
219	if (of_address_to_resource(vgic_node, 3, &vcpu_res)) {
220		kvm_err("Cannot obtain GICV resource\n");
221		ret = -ENXIO;
222		goto out_unmap;
223	}
224
225	if (!PAGE_ALIGNED(vcpu_res.start)) {
226		kvm_err("GICV physical address 0x%llx not page aligned\n",
227			(unsigned long long)vcpu_res.start);
228		ret = -ENXIO;
229		goto out_unmap;
230	}
231
232	if (!PAGE_ALIGNED(resource_size(&vcpu_res))) {
233		kvm_err("GICV size 0x%llx not a multiple of page size 0x%lx\n",
234			(unsigned long long)resource_size(&vcpu_res),
235			PAGE_SIZE);
236		ret = -ENXIO;
237		goto out_unmap;
238	}
239
240	vgic->can_emulate_gicv2 = true;
241	kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
242
243	vgic->vcpu_base = vcpu_res.start;
244
245	kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
246		 vctrl_res.start, vgic->maint_irq);
247
248	vgic->type = VGIC_V2;
249	vgic->max_gic_vcpus = VGIC_V2_MAX_CPUS;
250	*ops = &vgic_v2_ops;
251	*params = vgic;
252	goto out;
253
254out_unmap:
255	iounmap(vgic->vctrl_base);
256out:
257	of_node_put(vgic_node);
258	return ret;
259}
260