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_set_apic_id(u32 x)
37{
38 WARN_ON(1);
39 return x;
40}
41
42static u32 xen_get_apic_id(u32 x)
43{
44 return ((x)>>24) & 0xFFu;
45}
46
47static u32 xen_apic_read(u32 reg)
48{
49 struct xen_platform_op op = {
50 .cmd = XENPF_get_cpuinfo,
51 .interface_version = XENPF_INTERFACE_VERSION,
52 .u.pcpu_info.xen_cpuid = 0,
53 };
54 int ret;
55
56 /* Shouldn't need this as APIC is turned off for PV, and we only
57 * get called on the bootup processor. But just in case. */
58 if (!xen_initial_domain() || smp_processor_id())
59 return 0;
60
61 if (reg == APIC_LVR)
62 return 0x14;
63 if (reg != APIC_ID)
64 return 0;
65
66 ret = HYPERVISOR_platform_op(op: &op);
67 if (ret)
68 op.u.pcpu_info.apic_id = BAD_APICID;
69
70 return op.u.pcpu_info.apic_id << 24;
71}
72
73static void xen_apic_write(u32 reg, u32 val)
74{
75 if (reg == APIC_LVTPC) {
76 (void)pmu_apic_update(reg);
77 return;
78 }
79
80 /* Warn to see if there's any stray references */
81 WARN(1,"register: %x, value: %x\n", reg, val);
82}
83
84static void xen_apic_eoi(void)
85{
86 WARN_ON_ONCE(1);
87}
88
89static u64 xen_apic_icr_read(void)
90{
91 return 0;
92}
93
94static void xen_apic_icr_write(u32 low, u32 id)
95{
96 /* Warn to see if there's any stray references */
97 WARN_ON(1);
98}
99
100static int xen_apic_probe_pv(void)
101{
102 if (xen_pv_domain())
103 return 1;
104
105 return 0;
106}
107
108static int xen_madt_oem_check(char *oem_id, char *oem_table_id)
109{
110 return xen_pv_domain();
111}
112
113static u32 xen_phys_pkg_id(u32 initial_apic_id, int index_msb)
114{
115 return initial_apic_id >> index_msb;
116}
117
118static u32 xen_cpu_present_to_apicid(int cpu)
119{
120 if (cpu_present(cpu))
121 return cpu_data(cpu).topo.apicid;
122 else
123 return BAD_APICID;
124}
125
126static struct apic xen_pv_apic __ro_after_init = {
127 .name = "Xen PV",
128 .probe = xen_apic_probe_pv,
129 .acpi_madt_oem_check = xen_madt_oem_check,
130
131 /* .delivery_mode and .dest_mode_logical not used by XENPV */
132
133 .disable_esr = 0,
134
135 .cpu_present_to_apicid = xen_cpu_present_to_apicid,
136 .phys_pkg_id = xen_phys_pkg_id, /* detect_ht */
137
138 .max_apic_id = UINT_MAX,
139 .get_apic_id = xen_get_apic_id,
140 .set_apic_id = xen_set_apic_id,
141
142 .calc_dest_apicid = apic_flat_calc_apicid,
143
144#ifdef CONFIG_SMP
145 .send_IPI_mask = xen_send_IPI_mask,
146 .send_IPI_mask_allbutself = xen_send_IPI_mask_allbutself,
147 .send_IPI_allbutself = xen_send_IPI_allbutself,
148 .send_IPI_all = xen_send_IPI_all,
149 .send_IPI_self = xen_send_IPI_self,
150#endif
151 .read = xen_apic_read,
152 .write = xen_apic_write,
153 .eoi = xen_apic_eoi,
154
155 .icr_read = xen_apic_icr_read,
156 .icr_write = xen_apic_icr_write,
157};
158apic_driver(xen_pv_apic);
159
160void __init xen_init_apic(void)
161{
162 x86_apic_ops.io_apic_read = xen_io_apic_read;
163}
164

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