xref: /openbmc/linux/arch/x86/kernel/jailhouse.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Jailhouse paravirt_ops implementation
4  *
5  * Copyright (c) Siemens AG, 2015-2017
6  *
7  * Authors:
8  *  Jan Kiszka <jan.kiszka@siemens.com>
9  */
10 
11 #include <linux/acpi_pmtmr.h>
12 #include <linux/kernel.h>
13 #include <linux/reboot.h>
14 #include <asm/apic.h>
15 #include <asm/cpu.h>
16 #include <asm/hypervisor.h>
17 #include <asm/i8259.h>
18 #include <asm/irqdomain.h>
19 #include <asm/pci_x86.h>
20 #include <asm/reboot.h>
21 #include <asm/setup.h>
22 #include <asm/jailhouse_para.h>
23 
24 static __initdata struct jailhouse_setup_data setup_data;
25 static unsigned int precalibrated_tsc_khz;
26 
27 static uint32_t jailhouse_cpuid_base(void)
28 {
29 	if (boot_cpu_data.cpuid_level < 0 ||
30 	    !boot_cpu_has(X86_FEATURE_HYPERVISOR))
31 		return 0;
32 
33 	return hypervisor_cpuid_base("Jailhouse\0\0\0", 0);
34 }
35 
36 static uint32_t __init jailhouse_detect(void)
37 {
38 	return jailhouse_cpuid_base();
39 }
40 
41 static void jailhouse_get_wallclock(struct timespec64 *now)
42 {
43 	memset(now, 0, sizeof(*now));
44 }
45 
46 static void __init jailhouse_timer_init(void)
47 {
48 	lapic_timer_period = setup_data.apic_khz * (1000 / HZ);
49 }
50 
51 static unsigned long jailhouse_get_tsc(void)
52 {
53 	return precalibrated_tsc_khz;
54 }
55 
56 static void __init jailhouse_x2apic_init(void)
57 {
58 #ifdef CONFIG_X86_X2APIC
59 	if (!x2apic_enabled())
60 		return;
61 	/*
62 	 * We do not have access to IR inside Jailhouse non-root cells.  So
63 	 * we have to run in physical mode.
64 	 */
65 	x2apic_phys = 1;
66 	/*
67 	 * This will trigger the switch to apic_x2apic_phys.  Empty OEM IDs
68 	 * ensure that only this APIC driver picks up the call.
69 	 */
70 	default_acpi_madt_oem_check("", "");
71 #endif
72 }
73 
74 static void __init jailhouse_get_smp_config(unsigned int early)
75 {
76 	struct ioapic_domain_cfg ioapic_cfg = {
77 		.type = IOAPIC_DOMAIN_STRICT,
78 		.ops = &mp_ioapic_irqdomain_ops,
79 	};
80 	struct mpc_intsrc mp_irq = {
81 		.type = MP_INTSRC,
82 		.irqtype = mp_INT,
83 		.irqflag = MP_IRQPOL_ACTIVE_HIGH | MP_IRQTRIG_EDGE,
84 	};
85 	unsigned int cpu;
86 
87 	jailhouse_x2apic_init();
88 
89 	register_lapic_address(0xfee00000);
90 
91 	for (cpu = 0; cpu < setup_data.num_cpus; cpu++) {
92 		generic_processor_info(setup_data.cpu_ids[cpu],
93 				       boot_cpu_apic_version);
94 	}
95 
96 	smp_found_config = 1;
97 
98 	if (setup_data.standard_ioapic) {
99 		mp_register_ioapic(0, 0xfec00000, gsi_top, &ioapic_cfg);
100 
101 		/* Register 1:1 mapping for legacy UART IRQs 3 and 4 */
102 		mp_irq.srcbusirq = mp_irq.dstirq = 3;
103 		mp_save_irq(&mp_irq);
104 
105 		mp_irq.srcbusirq = mp_irq.dstirq = 4;
106 		mp_save_irq(&mp_irq);
107 	}
108 }
109 
110 static void jailhouse_no_restart(void)
111 {
112 	pr_notice("Jailhouse: Restart not supported, halting\n");
113 	machine_halt();
114 }
115 
116 static int __init jailhouse_pci_arch_init(void)
117 {
118 	pci_direct_init(1);
119 
120 	/*
121 	 * There are no bridges on the virtual PCI root bus under Jailhouse,
122 	 * thus no other way to discover all devices than a full scan.
123 	 * Respect any overrides via the command line, though.
124 	 */
125 	if (pcibios_last_bus < 0)
126 		pcibios_last_bus = 0xff;
127 
128 #ifdef CONFIG_PCI_MMCONFIG
129 	if (setup_data.pci_mmconfig_base) {
130 		pci_mmconfig_add(0, 0, pcibios_last_bus,
131 				 setup_data.pci_mmconfig_base);
132 		pci_mmcfg_arch_init();
133 	}
134 #endif
135 
136 	return 0;
137 }
138 
139 static void __init jailhouse_init_platform(void)
140 {
141 	u64 pa_data = boot_params.hdr.setup_data;
142 	struct setup_data header;
143 	void *mapping;
144 
145 	x86_init.irqs.pre_vector_init	= x86_init_noop;
146 	x86_init.timers.timer_init	= jailhouse_timer_init;
147 	x86_init.mpparse.get_smp_config	= jailhouse_get_smp_config;
148 	x86_init.pci.arch_init		= jailhouse_pci_arch_init;
149 
150 	x86_platform.calibrate_cpu	= jailhouse_get_tsc;
151 	x86_platform.calibrate_tsc	= jailhouse_get_tsc;
152 	x86_platform.get_wallclock	= jailhouse_get_wallclock;
153 	x86_platform.legacy.rtc		= 0;
154 	x86_platform.legacy.warm_reset	= 0;
155 	x86_platform.legacy.i8042	= X86_LEGACY_I8042_PLATFORM_ABSENT;
156 
157 	legacy_pic			= &null_legacy_pic;
158 
159 	machine_ops.emergency_restart	= jailhouse_no_restart;
160 
161 	while (pa_data) {
162 		mapping = early_memremap(pa_data, sizeof(header));
163 		memcpy(&header, mapping, sizeof(header));
164 		early_memunmap(mapping, sizeof(header));
165 
166 		if (header.type == SETUP_JAILHOUSE &&
167 		    header.len >= sizeof(setup_data)) {
168 			pa_data += offsetof(struct setup_data, data);
169 
170 			mapping = early_memremap(pa_data, sizeof(setup_data));
171 			memcpy(&setup_data, mapping, sizeof(setup_data));
172 			early_memunmap(mapping, sizeof(setup_data));
173 
174 			break;
175 		}
176 
177 		pa_data = header.next;
178 	}
179 
180 	if (!pa_data)
181 		panic("Jailhouse: No valid setup data found");
182 
183 	if (setup_data.compatible_version > JAILHOUSE_SETUP_REQUIRED_VERSION)
184 		panic("Jailhouse: Unsupported setup data structure");
185 
186 	pmtmr_ioport = setup_data.pm_timer_address;
187 	pr_debug("Jailhouse: PM-Timer IO Port: %#x\n", pmtmr_ioport);
188 
189 	precalibrated_tsc_khz = setup_data.tsc_khz;
190 	setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
191 
192 	pci_probe = 0;
193 
194 	/*
195 	 * Avoid that the kernel complains about missing ACPI tables - there
196 	 * are none in a non-root cell.
197 	 */
198 	disable_acpi();
199 }
200 
201 bool jailhouse_paravirt(void)
202 {
203 	return jailhouse_cpuid_base() != 0;
204 }
205 
206 static bool __init jailhouse_x2apic_available(void)
207 {
208 	/*
209 	 * The x2APIC is only available if the root cell enabled it. Jailhouse
210 	 * does not support switching between xAPIC and x2APIC.
211 	 */
212 	return x2apic_enabled();
213 }
214 
215 const struct hypervisor_x86 x86_hyper_jailhouse __refconst = {
216 	.name			= "Jailhouse",
217 	.detect			= jailhouse_detect,
218 	.init.init_platform	= jailhouse_init_platform,
219 	.init.x2apic_available	= jailhouse_x2apic_available,
220 	.ignore_nopv		= true,
221 };
222