xref: /openbmc/linux/arch/x86/xen/apic.c (revision 4bce6fce)
1 #include <linux/init.h>
2 
3 #include <asm/x86_init.h>
4 #include <asm/apic.h>
5 #include <asm/xen/hypercall.h>
6 
7 #include <xen/xen.h>
8 #include <xen/interface/physdev.h>
9 #include "xen-ops.h"
10 #include "smp.h"
11 
12 static unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
13 {
14 	struct physdev_apic apic_op;
15 	int ret;
16 
17 	apic_op.apic_physbase = mpc_ioapic_addr(apic);
18 	apic_op.reg = reg;
19 	ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
20 	if (!ret)
21 		return apic_op.value;
22 
23 	/* fallback to return an emulated IO_APIC values */
24 	if (reg == 0x1)
25 		return 0x00170020;
26 	else if (reg == 0x0)
27 		return apic << 24;
28 
29 	return 0xfd;
30 }
31 
32 static unsigned long xen_set_apic_id(unsigned int x)
33 {
34 	WARN_ON(1);
35 	return x;
36 }
37 
38 static unsigned int xen_get_apic_id(unsigned long x)
39 {
40 	return ((x)>>24) & 0xFFu;
41 }
42 
43 static u32 xen_apic_read(u32 reg)
44 {
45 	struct xen_platform_op op = {
46 		.cmd = XENPF_get_cpuinfo,
47 		.interface_version = XENPF_INTERFACE_VERSION,
48 		.u.pcpu_info.xen_cpuid = 0,
49 	};
50 	int ret = 0;
51 
52 	/* Shouldn't need this as APIC is turned off for PV, and we only
53 	 * get called on the bootup processor. But just in case. */
54 	if (!xen_initial_domain() || smp_processor_id())
55 		return 0;
56 
57 	if (reg == APIC_LVR)
58 		return 0x10;
59 #ifdef CONFIG_X86_32
60 	if (reg == APIC_LDR)
61 		return SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
62 #endif
63 	if (reg != APIC_ID)
64 		return 0;
65 
66 	ret = HYPERVISOR_dom0_op(&op);
67 	if (ret)
68 		return 0;
69 
70 	return op.u.pcpu_info.apic_id << 24;
71 }
72 
73 static void xen_apic_write(u32 reg, u32 val)
74 {
75 	/* Warn to see if there's any stray references */
76 	WARN(1,"register: %x, value: %x\n", reg, val);
77 }
78 
79 static u64 xen_apic_icr_read(void)
80 {
81 	return 0;
82 }
83 
84 static void xen_apic_icr_write(u32 low, u32 id)
85 {
86 	/* Warn to see if there's any stray references */
87 	WARN_ON(1);
88 }
89 
90 static u32 xen_safe_apic_wait_icr_idle(void)
91 {
92         return 0;
93 }
94 
95 static int xen_apic_probe_pv(void)
96 {
97 	if (xen_pv_domain())
98 		return 1;
99 
100 	return 0;
101 }
102 
103 static int xen_madt_oem_check(char *oem_id, char *oem_table_id)
104 {
105 	return xen_pv_domain();
106 }
107 
108 static int xen_id_always_valid(int apicid)
109 {
110 	return 1;
111 }
112 
113 static int xen_id_always_registered(void)
114 {
115 	return 1;
116 }
117 
118 static int xen_phys_pkg_id(int initial_apic_id, int index_msb)
119 {
120 	return initial_apic_id >> index_msb;
121 }
122 
123 #ifdef CONFIG_X86_32
124 static int xen_x86_32_early_logical_apicid(int cpu)
125 {
126 	/* Match with APIC_LDR read. Otherwise setup_local_APIC complains. */
127 	return 1 << cpu;
128 }
129 #endif
130 
131 static void xen_noop(void)
132 {
133 }
134 
135 static void xen_silent_inquire(int apicid)
136 {
137 }
138 
139 static struct apic xen_pv_apic = {
140 	.name 				= "Xen PV",
141 	.probe 				= xen_apic_probe_pv,
142 	.acpi_madt_oem_check		= xen_madt_oem_check,
143 	.apic_id_valid 			= xen_id_always_valid,
144 	.apic_id_registered 		= xen_id_always_registered,
145 
146 	/* .irq_delivery_mode - used in native_compose_msi_msg only */
147 	/* .irq_dest_mode     - used in native_compose_msi_msg only */
148 
149 	.target_cpus			= default_target_cpus,
150 	.disable_esr			= 0,
151 	/* .dest_logical      -  default_send_IPI_ use it but we use our own. */
152 	.check_apicid_used		= default_check_apicid_used, /* Used on 32-bit */
153 
154 	.vector_allocation_domain	= flat_vector_allocation_domain,
155 	.init_apic_ldr			= xen_noop, /* setup_local_APIC calls it */
156 
157 	.ioapic_phys_id_map		= default_ioapic_phys_id_map, /* Used on 32-bit */
158 	.setup_apic_routing		= NULL,
159 	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
160 	.apicid_to_cpu_present		= physid_set_mask_of_physid, /* Used on 32-bit */
161 	.check_phys_apicid_present	= default_check_phys_apicid_present, /* smp_sanity_check needs it */
162 	.phys_pkg_id			= xen_phys_pkg_id, /* detect_ht */
163 
164 	.get_apic_id 			= xen_get_apic_id,
165 	.set_apic_id 			= xen_set_apic_id, /* Can be NULL on 32-bit. */
166 	.apic_id_mask			= 0xFF << 24, /* Used by verify_local_APIC. Match with what xen_get_apic_id does. */
167 
168 	.cpu_mask_to_apicid_and		= flat_cpu_mask_to_apicid_and,
169 
170 #ifdef CONFIG_SMP
171 	.send_IPI_mask 			= xen_send_IPI_mask,
172 	.send_IPI_mask_allbutself 	= xen_send_IPI_mask_allbutself,
173 	.send_IPI_allbutself 		= xen_send_IPI_allbutself,
174 	.send_IPI_all 			= xen_send_IPI_all,
175 	.send_IPI_self 			= xen_send_IPI_self,
176 #endif
177 	/* .wait_for_init_deassert- used  by AP bootup - smp_callin which we don't use */
178 	.inquire_remote_apic		= xen_silent_inquire,
179 
180 	.read				= xen_apic_read,
181 	.write				= xen_apic_write,
182 	.eoi_write			= xen_apic_write,
183 
184 	.icr_read 			= xen_apic_icr_read,
185 	.icr_write 			= xen_apic_icr_write,
186 	.wait_icr_idle 			= xen_noop,
187 	.safe_wait_icr_idle 		= xen_safe_apic_wait_icr_idle,
188 
189 #ifdef CONFIG_X86_32
190 	/* generic_processor_info and setup_local_APIC. */
191 	.x86_32_early_logical_apicid	= xen_x86_32_early_logical_apicid,
192 #endif
193 };
194 
195 static void __init xen_apic_check(void)
196 {
197 	if (apic == &xen_pv_apic)
198 		return;
199 
200 	pr_info("Switched APIC routing from %s to %s.\n", apic->name,
201 		xen_pv_apic.name);
202 	apic = &xen_pv_apic;
203 }
204 void __init xen_init_apic(void)
205 {
206 	x86_io_apic_ops.read = xen_io_apic_read;
207 	/* On PV guests the APIC CPUID bit is disabled so none of the
208 	 * routines end up executing. */
209 	if (!xen_initial_domain())
210 		apic = &xen_pv_apic;
211 
212 	x86_platform.apic_post_init = xen_apic_check;
213 }
214 apic_driver(xen_pv_apic);
215