xref: /kernel/linux/linux-5.10/arch/x86/xen/apic.c (revision 8c2ecf20)
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 = 0;
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 u64 xen_apic_icr_read(void)
85{
86	return 0;
87}
88
89static void xen_apic_icr_write(u32 low, u32 id)
90{
91	/* Warn to see if there's any stray references */
92	WARN_ON(1);
93}
94
95static u32 xen_safe_apic_wait_icr_idle(void)
96{
97        return 0;
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_id_always_valid(u32 apicid)
114{
115	return 1;
116}
117
118static int xen_id_always_registered(void)
119{
120	return 1;
121}
122
123static int xen_phys_pkg_id(int initial_apic_id, int index_msb)
124{
125	return initial_apic_id >> index_msb;
126}
127
128static void xen_noop(void)
129{
130}
131
132static void xen_silent_inquire(int apicid)
133{
134}
135
136static int xen_cpu_present_to_apicid(int cpu)
137{
138	if (cpu_present(cpu))
139		return cpu_data(cpu).apicid;
140	else
141		return BAD_APICID;
142}
143
144static struct apic xen_pv_apic = {
145	.name 				= "Xen PV",
146	.probe 				= xen_apic_probe_pv,
147	.acpi_madt_oem_check		= xen_madt_oem_check,
148	.apic_id_valid 			= xen_id_always_valid,
149	.apic_id_registered 		= xen_id_always_registered,
150
151	/* .irq_delivery_mode - used in native_compose_msi_msg only */
152	/* .irq_dest_mode     - used in native_compose_msi_msg only */
153
154	.disable_esr			= 0,
155	/* .dest_logical      -  default_send_IPI_ use it but we use our own. */
156	.check_apicid_used		= default_check_apicid_used, /* Used on 32-bit */
157
158	.init_apic_ldr			= xen_noop, /* setup_local_APIC calls it */
159
160	.ioapic_phys_id_map		= default_ioapic_phys_id_map, /* Used on 32-bit */
161	.setup_apic_routing		= NULL,
162	.cpu_present_to_apicid		= xen_cpu_present_to_apicid,
163	.apicid_to_cpu_present		= physid_set_mask_of_physid, /* Used on 32-bit */
164	.check_phys_apicid_present	= default_check_phys_apicid_present, /* smp_sanity_check needs it */
165	.phys_pkg_id			= xen_phys_pkg_id, /* detect_ht */
166
167	.get_apic_id 			= xen_get_apic_id,
168	.set_apic_id 			= xen_set_apic_id, /* Can be NULL on 32-bit. */
169
170	.calc_dest_apicid		= apic_flat_calc_apicid,
171
172#ifdef CONFIG_SMP
173	.send_IPI_mask 			= xen_send_IPI_mask,
174	.send_IPI_mask_allbutself 	= xen_send_IPI_mask_allbutself,
175	.send_IPI_allbutself 		= xen_send_IPI_allbutself,
176	.send_IPI_all 			= xen_send_IPI_all,
177	.send_IPI_self 			= xen_send_IPI_self,
178#endif
179	/* .wait_for_init_deassert- used  by AP bootup - smp_callin which we don't use */
180	.inquire_remote_apic		= xen_silent_inquire,
181
182	.read				= xen_apic_read,
183	.write				= xen_apic_write,
184	.eoi_write			= xen_apic_write,
185
186	.icr_read 			= xen_apic_icr_read,
187	.icr_write 			= xen_apic_icr_write,
188	.wait_icr_idle 			= xen_noop,
189	.safe_wait_icr_idle 		= xen_safe_apic_wait_icr_idle,
190};
191
192static void __init xen_apic_check(void)
193{
194	if (apic == &xen_pv_apic)
195		return;
196
197	pr_info("Switched APIC routing from %s to %s.\n", apic->name,
198		xen_pv_apic.name);
199	apic = &xen_pv_apic;
200}
201void __init xen_init_apic(void)
202{
203	x86_apic_ops.io_apic_read = xen_io_apic_read;
204	/* On PV guests the APIC CPUID bit is disabled so none of the
205	 * routines end up executing. */
206	if (!xen_initial_domain())
207		apic = &xen_pv_apic;
208
209	x86_platform.apic_post_init = xen_apic_check;
210}
211apic_driver(xen_pv_apic);
212