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(ioapic: apic);
22 apic_op.reg = reg;
23 ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, arg: &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: &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

source code of linux/arch/x86/xen/apic.c