xref: /openbmc/linux/arch/x86/kernel/jailhouse.c (revision 63705da3)
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 <linux/serial_8250.h>
15 #include <asm/apic.h>
16 #include <asm/io_apic.h>
17 #include <asm/acpi.h>
18 #include <asm/cpu.h>
19 #include <asm/hypervisor.h>
20 #include <asm/i8259.h>
21 #include <asm/irqdomain.h>
22 #include <asm/pci_x86.h>
23 #include <asm/reboot.h>
24 #include <asm/setup.h>
25 #include <asm/jailhouse_para.h>
26 
27 static struct jailhouse_setup_data setup_data;
28 #define SETUP_DATA_V1_LEN	(sizeof(setup_data.hdr) + sizeof(setup_data.v1))
29 #define SETUP_DATA_V2_LEN	(SETUP_DATA_V1_LEN + sizeof(setup_data.v2))
30 
31 static unsigned int precalibrated_tsc_khz;
32 
33 static void jailhouse_setup_irq(unsigned int irq)
34 {
35 	struct mpc_intsrc mp_irq = {
36 		.type		= MP_INTSRC,
37 		.irqtype	= mp_INT,
38 		.irqflag	= MP_IRQPOL_ACTIVE_HIGH | MP_IRQTRIG_EDGE,
39 		.srcbusirq	= irq,
40 		.dstirq		= irq,
41 	};
42 	mp_save_irq(&mp_irq);
43 }
44 
45 static uint32_t jailhouse_cpuid_base(void)
46 {
47 	if (boot_cpu_data.cpuid_level < 0 ||
48 	    !boot_cpu_has(X86_FEATURE_HYPERVISOR))
49 		return 0;
50 
51 	return hypervisor_cpuid_base("Jailhouse\0\0\0", 0);
52 }
53 
54 static uint32_t __init jailhouse_detect(void)
55 {
56 	return jailhouse_cpuid_base();
57 }
58 
59 static void jailhouse_get_wallclock(struct timespec64 *now)
60 {
61 	memset(now, 0, sizeof(*now));
62 }
63 
64 static void __init jailhouse_timer_init(void)
65 {
66 	lapic_timer_period = setup_data.v1.apic_khz * (1000 / HZ);
67 }
68 
69 static unsigned long jailhouse_get_tsc(void)
70 {
71 	return precalibrated_tsc_khz;
72 }
73 
74 static void __init jailhouse_x2apic_init(void)
75 {
76 #ifdef CONFIG_X86_X2APIC
77 	if (!x2apic_enabled())
78 		return;
79 	/*
80 	 * We do not have access to IR inside Jailhouse non-root cells.  So
81 	 * we have to run in physical mode.
82 	 */
83 	x2apic_phys = 1;
84 	/*
85 	 * This will trigger the switch to apic_x2apic_phys.  Empty OEM IDs
86 	 * ensure that only this APIC driver picks up the call.
87 	 */
88 	default_acpi_madt_oem_check("", "");
89 #endif
90 }
91 
92 static void __init jailhouse_get_smp_config(unsigned int early)
93 {
94 	struct ioapic_domain_cfg ioapic_cfg = {
95 		.type = IOAPIC_DOMAIN_STRICT,
96 		.ops = &mp_ioapic_irqdomain_ops,
97 	};
98 	unsigned int cpu;
99 
100 	jailhouse_x2apic_init();
101 
102 	register_lapic_address(0xfee00000);
103 
104 	for (cpu = 0; cpu < setup_data.v1.num_cpus; cpu++) {
105 		generic_processor_info(setup_data.v1.cpu_ids[cpu],
106 				       boot_cpu_apic_version);
107 	}
108 
109 	smp_found_config = 1;
110 
111 	if (setup_data.v1.standard_ioapic) {
112 		mp_register_ioapic(0, 0xfec00000, gsi_top, &ioapic_cfg);
113 
114 		if (IS_ENABLED(CONFIG_SERIAL_8250) &&
115 		    setup_data.hdr.version < 2) {
116 			/* Register 1:1 mapping for legacy UART IRQs 3 and 4 */
117 			jailhouse_setup_irq(3);
118 			jailhouse_setup_irq(4);
119 		}
120 	}
121 }
122 
123 static void jailhouse_no_restart(void)
124 {
125 	pr_notice("Jailhouse: Restart not supported, halting\n");
126 	machine_halt();
127 }
128 
129 static int __init jailhouse_pci_arch_init(void)
130 {
131 	pci_direct_init(1);
132 
133 	/*
134 	 * There are no bridges on the virtual PCI root bus under Jailhouse,
135 	 * thus no other way to discover all devices than a full scan.
136 	 * Respect any overrides via the command line, though.
137 	 */
138 	if (pcibios_last_bus < 0)
139 		pcibios_last_bus = 0xff;
140 
141 #ifdef CONFIG_PCI_MMCONFIG
142 	if (setup_data.v1.pci_mmconfig_base) {
143 		pci_mmconfig_add(0, 0, pcibios_last_bus,
144 				 setup_data.v1.pci_mmconfig_base);
145 		pci_mmcfg_arch_init();
146 	}
147 #endif
148 
149 	return 0;
150 }
151 
152 #ifdef CONFIG_SERIAL_8250
153 static inline bool jailhouse_uart_enabled(unsigned int uart_nr)
154 {
155 	return setup_data.v2.flags & BIT(uart_nr);
156 }
157 
158 static void jailhouse_serial_fixup(int port, struct uart_port *up,
159 				   u32 *capabilities)
160 {
161 	static const u16 pcuart_base[] = {0x3f8, 0x2f8, 0x3e8, 0x2e8};
162 	unsigned int n;
163 
164 	for (n = 0; n < ARRAY_SIZE(pcuart_base); n++) {
165 		if (pcuart_base[n] != up->iobase)
166 			continue;
167 
168 		if (jailhouse_uart_enabled(n)) {
169 			pr_info("Enabling UART%u (port 0x%lx)\n", n,
170 				up->iobase);
171 			jailhouse_setup_irq(up->irq);
172 		} else {
173 			/* Deactivate UART if access isn't allowed */
174 			up->iobase = 0;
175 		}
176 		break;
177 	}
178 }
179 
180 static void __init jailhouse_serial_workaround(void)
181 {
182 	/*
183 	 * There are flags inside setup_data that indicate availability of
184 	 * platform UARTs since setup data version 2.
185 	 *
186 	 * In case of version 1, we don't know which UARTs belong Linux. In
187 	 * this case, unconditionally register 1:1 mapping for legacy UART IRQs
188 	 * 3 and 4.
189 	 */
190 	if (setup_data.hdr.version > 1)
191 		serial8250_set_isa_configurator(jailhouse_serial_fixup);
192 }
193 #else /* !CONFIG_SERIAL_8250 */
194 static inline void jailhouse_serial_workaround(void)
195 {
196 }
197 #endif /* CONFIG_SERIAL_8250 */
198 
199 static void __init jailhouse_init_platform(void)
200 {
201 	u64 pa_data = boot_params.hdr.setup_data;
202 	unsigned long setup_data_len;
203 	struct setup_data header;
204 	void *mapping;
205 
206 	x86_init.irqs.pre_vector_init	= x86_init_noop;
207 	x86_init.timers.timer_init	= jailhouse_timer_init;
208 	x86_init.mpparse.get_smp_config	= jailhouse_get_smp_config;
209 	x86_init.pci.arch_init		= jailhouse_pci_arch_init;
210 
211 	x86_platform.calibrate_cpu	= jailhouse_get_tsc;
212 	x86_platform.calibrate_tsc	= jailhouse_get_tsc;
213 	x86_platform.get_wallclock	= jailhouse_get_wallclock;
214 	x86_platform.legacy.rtc		= 0;
215 	x86_platform.legacy.warm_reset	= 0;
216 	x86_platform.legacy.i8042	= X86_LEGACY_I8042_PLATFORM_ABSENT;
217 
218 	legacy_pic			= &null_legacy_pic;
219 
220 	machine_ops.emergency_restart	= jailhouse_no_restart;
221 
222 	while (pa_data) {
223 		mapping = early_memremap(pa_data, sizeof(header));
224 		memcpy(&header, mapping, sizeof(header));
225 		early_memunmap(mapping, sizeof(header));
226 
227 		if (header.type == SETUP_JAILHOUSE)
228 			break;
229 
230 		pa_data = header.next;
231 	}
232 
233 	if (!pa_data)
234 		panic("Jailhouse: No valid setup data found");
235 
236 	/* setup data must at least contain the header */
237 	if (header.len < sizeof(setup_data.hdr))
238 		goto unsupported;
239 
240 	pa_data += offsetof(struct setup_data, data);
241 	setup_data_len = min_t(unsigned long, sizeof(setup_data),
242 			       (unsigned long)header.len);
243 	mapping = early_memremap(pa_data, setup_data_len);
244 	memcpy(&setup_data, mapping, setup_data_len);
245 	early_memunmap(mapping, setup_data_len);
246 
247 	if (setup_data.hdr.version == 0 ||
248 	    setup_data.hdr.compatible_version !=
249 		JAILHOUSE_SETUP_REQUIRED_VERSION ||
250 	    (setup_data.hdr.version == 1 && header.len < SETUP_DATA_V1_LEN) ||
251 	    (setup_data.hdr.version >= 2 && header.len < SETUP_DATA_V2_LEN))
252 		goto unsupported;
253 
254 	pmtmr_ioport = setup_data.v1.pm_timer_address;
255 	pr_debug("Jailhouse: PM-Timer IO Port: %#x\n", pmtmr_ioport);
256 
257 	precalibrated_tsc_khz = setup_data.v1.tsc_khz;
258 	setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
259 
260 	pci_probe = 0;
261 
262 	/*
263 	 * Avoid that the kernel complains about missing ACPI tables - there
264 	 * are none in a non-root cell.
265 	 */
266 	disable_acpi();
267 
268 	jailhouse_serial_workaround();
269 	return;
270 
271 unsupported:
272 	panic("Jailhouse: Unsupported setup data structure");
273 }
274 
275 bool jailhouse_paravirt(void)
276 {
277 	return jailhouse_cpuid_base() != 0;
278 }
279 
280 static bool __init jailhouse_x2apic_available(void)
281 {
282 	/*
283 	 * The x2APIC is only available if the root cell enabled it. Jailhouse
284 	 * does not support switching between xAPIC and x2APIC.
285 	 */
286 	return x2apic_enabled();
287 }
288 
289 const struct hypervisor_x86 x86_hyper_jailhouse __refconst = {
290 	.name			= "Jailhouse",
291 	.detect			= jailhouse_detect,
292 	.init.init_platform	= jailhouse_init_platform,
293 	.init.x2apic_available	= jailhouse_x2apic_available,
294 	.ignore_nopv		= true,
295 };
296