xref: /kernel/linux/linux-6.6/arch/x86/xen/apic.c (revision 62306a36)
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_set_apic_id(unsigned int x)
37{
38	WARN_ON(1);
39	return x;
40}
41
42static unsigned int xen_get_apic_id(unsigned long 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);
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 int xen_phys_pkg_id(int initial_apic_id, int index_msb)
114{
115	return initial_apic_id >> index_msb;
116}
117
118static int xen_cpu_present_to_apicid(int cpu)
119{
120	if (cpu_present(cpu))
121		return cpu_data(cpu).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