1// SPDX-License-Identifier: GPL-2.0
2#include <linux/init.h>
3#include <linux/thread_info.h>
4
5#include <asm/x86_init.h>
6#include <asm/apic.h>
7#include <asm/io_apic.h>
8#include <asm/xen/hypercall.h>
9
10#include <xen/xen.h>
11#include <xen/interface/physdev.h>
12#include "xen-ops.h"
13#include "pmu.h"
14#include "smp.h"
15
16static unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
17{
18	struct physdev_apic apic_op;
19	int ret;
20
21	apic_op.apic_physbase = mpc_ioapic_addr(apic);
22	apic_op.reg = reg;
23	ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
24	if (!ret)
25		return apic_op.value;
26
27	/* fallback to return an emulated IO_APIC values */
28	if (reg == 0x1)
29		return 0x00170020;
30	else if (reg == 0x0)
31		return apic << 24;
32
33	return 0xfd;
34}
35
36static u32 xen_get_apic_id(u32 x)
37{
38	return ((x)>>24) & 0xFFu;
39}
40
41static u32 xen_apic_read(u32 reg)
42{
43	struct xen_platform_op op = {
44		.cmd = XENPF_get_cpuinfo,
45		.interface_version = XENPF_INTERFACE_VERSION,
46	};
47	int ret, cpu;
48
49	if (reg == APIC_LVR)
50		return 0x14;
51	if (reg != APIC_ID)
52		return 0;
53
54	cpu = smp_processor_id();
55	if (!xen_initial_domain())
56		return cpu ? cpuid_to_apicid[cpu] << 24 : 0;
57
58	op.u.pcpu_info.xen_cpuid = cpu;
59
60	ret = HYPERVISOR_platform_op(&op);
61	if (ret)
62		op.u.pcpu_info.apic_id = BAD_APICID;
63
64	return op.u.pcpu_info.apic_id << 24;
65}
66
67static void xen_apic_write(u32 reg, u32 val)
68{
69	if (reg == APIC_LVTPC) {
70		(void)pmu_apic_update(reg);
71		return;
72	}
73
74	/* Warn to see if there's any stray references */
75	WARN(1,"register: %x, value: %x\n", reg, val);
76}
77
78static void xen_apic_eoi(void)
79{
80	WARN_ON_ONCE(1);
81}
82
83static u64 xen_apic_icr_read(void)
84{
85	return 0;
86}
87
88static void xen_apic_icr_write(u32 low, u32 id)
89{
90	/* Warn to see if there's any stray references */
91	WARN_ON(1);
92}
93
94static int xen_apic_probe_pv(void)
95{
96	if (xen_pv_domain())
97		return 1;
98
99	return 0;
100}
101
102static int xen_madt_oem_check(char *oem_id, char *oem_table_id)
103{
104	return xen_pv_domain();
105}
106
107static u32 xen_cpu_present_to_apicid(int cpu)
108{
109	if (cpu_present(cpu))
110		return cpu_data(cpu).topo.apicid;
111	else
112		return BAD_APICID;
113}
114
115static struct apic xen_pv_apic __ro_after_init = {
116	.name				= "Xen PV",
117	.probe				= xen_apic_probe_pv,
118	.acpi_madt_oem_check		= xen_madt_oem_check,
119
120	/* .delivery_mode and .dest_mode_logical not used by XENPV */
121
122	.disable_esr			= 0,
123
124	.cpu_present_to_apicid		= xen_cpu_present_to_apicid,
125
126	.max_apic_id			= UINT_MAX,
127	.get_apic_id			= xen_get_apic_id,
128
129	.calc_dest_apicid		= apic_flat_calc_apicid,
130
131#ifdef CONFIG_SMP
132	.send_IPI_mask			= xen_send_IPI_mask,
133	.send_IPI_mask_allbutself	= xen_send_IPI_mask_allbutself,
134	.send_IPI_allbutself		= xen_send_IPI_allbutself,
135	.send_IPI_all			= xen_send_IPI_all,
136	.send_IPI_self			= xen_send_IPI_self,
137#endif
138	.read				= xen_apic_read,
139	.write				= xen_apic_write,
140	.eoi				= xen_apic_eoi,
141
142	.icr_read			= xen_apic_icr_read,
143	.icr_write			= xen_apic_icr_write,
144};
145apic_driver(xen_pv_apic);
146
147void __init xen_init_apic(void)
148{
149	x86_apic_ops.io_apic_read = xen_io_apic_read;
150}
151