xref: /openbmc/linux/arch/x86/xen/apic.c (revision bb0eb050)
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 "pmu.h"
11 #include "smp.h"
12 
13 static unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
14 {
15 	struct physdev_apic apic_op;
16 	int ret;
17 
18 	apic_op.apic_physbase = mpc_ioapic_addr(apic);
19 	apic_op.reg = reg;
20 	ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
21 	if (!ret)
22 		return apic_op.value;
23 
24 	/* fallback to return an emulated IO_APIC values */
25 	if (reg == 0x1)
26 		return 0x00170020;
27 	else if (reg == 0x0)
28 		return apic << 24;
29 
30 	return 0xfd;
31 }
32 
33 static unsigned long xen_set_apic_id(unsigned int x)
34 {
35 	WARN_ON(1);
36 	return x;
37 }
38 
39 static unsigned int xen_get_apic_id(unsigned long x)
40 {
41 	return ((x)>>24) & 0xFFu;
42 }
43 
44 static u32 xen_apic_read(u32 reg)
45 {
46 	struct xen_platform_op op = {
47 		.cmd = XENPF_get_cpuinfo,
48 		.interface_version = XENPF_INTERFACE_VERSION,
49 		.u.pcpu_info.xen_cpuid = 0,
50 	};
51 	int ret = 0;
52 
53 	/* Shouldn't need this as APIC is turned off for PV, and we only
54 	 * get called on the bootup processor. But just in case. */
55 	if (!xen_initial_domain() || smp_processor_id())
56 		return 0;
57 
58 	if (reg == APIC_LVR)
59 		return 0x10;
60 #ifdef CONFIG_X86_32
61 	if (reg == APIC_LDR)
62 		return SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
63 #endif
64 	if (reg != APIC_ID)
65 		return 0;
66 
67 	ret = HYPERVISOR_platform_op(&op);
68 	if (ret)
69 		op.u.pcpu_info.apic_id = BAD_APICID;
70 
71 	return op.u.pcpu_info.apic_id << 24;
72 }
73 
74 static void xen_apic_write(u32 reg, u32 val)
75 {
76 	if (reg == APIC_LVTPC) {
77 		(void)pmu_apic_update(reg);
78 		return;
79 	}
80 
81 	/* Warn to see if there's any stray references */
82 	WARN(1,"register: %x, value: %x\n", reg, val);
83 }
84 
85 static u64 xen_apic_icr_read(void)
86 {
87 	return 0;
88 }
89 
90 static void xen_apic_icr_write(u32 low, u32 id)
91 {
92 	/* Warn to see if there's any stray references */
93 	WARN_ON(1);
94 }
95 
96 static u32 xen_safe_apic_wait_icr_idle(void)
97 {
98         return 0;
99 }
100 
101 static int xen_apic_probe_pv(void)
102 {
103 	if (xen_pv_domain())
104 		return 1;
105 
106 	return 0;
107 }
108 
109 static int xen_madt_oem_check(char *oem_id, char *oem_table_id)
110 {
111 	return xen_pv_domain();
112 }
113 
114 static int xen_id_always_valid(int apicid)
115 {
116 	return 1;
117 }
118 
119 static int xen_id_always_registered(void)
120 {
121 	return 1;
122 }
123 
124 static int xen_phys_pkg_id(int initial_apic_id, int index_msb)
125 {
126 	return initial_apic_id >> index_msb;
127 }
128 
129 #ifdef CONFIG_X86_32
130 static int xen_x86_32_early_logical_apicid(int cpu)
131 {
132 	/* Match with APIC_LDR read. Otherwise setup_local_APIC complains. */
133 	return 1 << cpu;
134 }
135 #endif
136 
137 static void xen_noop(void)
138 {
139 }
140 
141 static void xen_silent_inquire(int apicid)
142 {
143 }
144 
145 static int xen_cpu_present_to_apicid(int cpu)
146 {
147 	if (cpu_present(cpu))
148 		return cpu_data(cpu).apicid;
149 	else
150 		return BAD_APICID;
151 }
152 
153 static struct apic xen_pv_apic = {
154 	.name 				= "Xen PV",
155 	.probe 				= xen_apic_probe_pv,
156 	.acpi_madt_oem_check		= xen_madt_oem_check,
157 	.apic_id_valid 			= xen_id_always_valid,
158 	.apic_id_registered 		= xen_id_always_registered,
159 
160 	/* .irq_delivery_mode - used in native_compose_msi_msg only */
161 	/* .irq_dest_mode     - used in native_compose_msi_msg only */
162 
163 	.target_cpus			= default_target_cpus,
164 	.disable_esr			= 0,
165 	/* .dest_logical      -  default_send_IPI_ use it but we use our own. */
166 	.check_apicid_used		= default_check_apicid_used, /* Used on 32-bit */
167 
168 	.vector_allocation_domain	= flat_vector_allocation_domain,
169 	.init_apic_ldr			= xen_noop, /* setup_local_APIC calls it */
170 
171 	.ioapic_phys_id_map		= default_ioapic_phys_id_map, /* Used on 32-bit */
172 	.setup_apic_routing		= NULL,
173 	.cpu_present_to_apicid		= xen_cpu_present_to_apicid,
174 	.apicid_to_cpu_present		= physid_set_mask_of_physid, /* Used on 32-bit */
175 	.check_phys_apicid_present	= default_check_phys_apicid_present, /* smp_sanity_check needs it */
176 	.phys_pkg_id			= xen_phys_pkg_id, /* detect_ht */
177 
178 	.get_apic_id 			= xen_get_apic_id,
179 	.set_apic_id 			= xen_set_apic_id, /* Can be NULL on 32-bit. */
180 
181 	.cpu_mask_to_apicid_and		= flat_cpu_mask_to_apicid_and,
182 
183 #ifdef CONFIG_SMP
184 	.send_IPI_mask 			= xen_send_IPI_mask,
185 	.send_IPI_mask_allbutself 	= xen_send_IPI_mask_allbutself,
186 	.send_IPI_allbutself 		= xen_send_IPI_allbutself,
187 	.send_IPI_all 			= xen_send_IPI_all,
188 	.send_IPI_self 			= xen_send_IPI_self,
189 #endif
190 	/* .wait_for_init_deassert- used  by AP bootup - smp_callin which we don't use */
191 	.inquire_remote_apic		= xen_silent_inquire,
192 
193 	.read				= xen_apic_read,
194 	.write				= xen_apic_write,
195 	.eoi_write			= xen_apic_write,
196 
197 	.icr_read 			= xen_apic_icr_read,
198 	.icr_write 			= xen_apic_icr_write,
199 	.wait_icr_idle 			= xen_noop,
200 	.safe_wait_icr_idle 		= xen_safe_apic_wait_icr_idle,
201 
202 #ifdef CONFIG_X86_32
203 	/* generic_processor_info and setup_local_APIC. */
204 	.x86_32_early_logical_apicid	= xen_x86_32_early_logical_apicid,
205 #endif
206 };
207 
208 static void __init xen_apic_check(void)
209 {
210 	if (apic == &xen_pv_apic)
211 		return;
212 
213 	pr_info("Switched APIC routing from %s to %s.\n", apic->name,
214 		xen_pv_apic.name);
215 	apic = &xen_pv_apic;
216 }
217 void __init xen_init_apic(void)
218 {
219 	x86_io_apic_ops.read = xen_io_apic_read;
220 	/* On PV guests the APIC CPUID bit is disabled so none of the
221 	 * routines end up executing. */
222 	if (!xen_initial_domain())
223 		apic = &xen_pv_apic;
224 
225 	x86_platform.apic_post_init = xen_apic_check;
226 }
227 apic_driver(xen_pv_apic);
228