xref: /openbmc/linux/arch/x86/kernel/jailhouse.c (revision 9a6b55ac)
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/cpu.h>
17 #include <asm/hypervisor.h>
18 #include <asm/i8259.h>
19 #include <asm/irqdomain.h>
20 #include <asm/pci_x86.h>
21 #include <asm/reboot.h>
22 #include <asm/setup.h>
23 #include <asm/jailhouse_para.h>
24 
25 static struct jailhouse_setup_data setup_data;
26 #define SETUP_DATA_V1_LEN	(sizeof(setup_data.hdr) + sizeof(setup_data.v1))
27 #define SETUP_DATA_V2_LEN	(SETUP_DATA_V1_LEN + sizeof(setup_data.v2))
28 
29 static unsigned int precalibrated_tsc_khz;
30 
31 static void jailhouse_setup_irq(unsigned int irq)
32 {
33 	struct mpc_intsrc mp_irq = {
34 		.type		= MP_INTSRC,
35 		.irqtype	= mp_INT,
36 		.irqflag	= MP_IRQPOL_ACTIVE_HIGH | MP_IRQTRIG_EDGE,
37 		.srcbusirq	= irq,
38 		.dstirq		= irq,
39 	};
40 	mp_save_irq(&mp_irq);
41 }
42 
43 static uint32_t jailhouse_cpuid_base(void)
44 {
45 	if (boot_cpu_data.cpuid_level < 0 ||
46 	    !boot_cpu_has(X86_FEATURE_HYPERVISOR))
47 		return 0;
48 
49 	return hypervisor_cpuid_base("Jailhouse\0\0\0", 0);
50 }
51 
52 static uint32_t __init jailhouse_detect(void)
53 {
54 	return jailhouse_cpuid_base();
55 }
56 
57 static void jailhouse_get_wallclock(struct timespec64 *now)
58 {
59 	memset(now, 0, sizeof(*now));
60 }
61 
62 static void __init jailhouse_timer_init(void)
63 {
64 	lapic_timer_period = setup_data.v1.apic_khz * (1000 / HZ);
65 }
66 
67 static unsigned long jailhouse_get_tsc(void)
68 {
69 	return precalibrated_tsc_khz;
70 }
71 
72 static void __init jailhouse_x2apic_init(void)
73 {
74 #ifdef CONFIG_X86_X2APIC
75 	if (!x2apic_enabled())
76 		return;
77 	/*
78 	 * We do not have access to IR inside Jailhouse non-root cells.  So
79 	 * we have to run in physical mode.
80 	 */
81 	x2apic_phys = 1;
82 	/*
83 	 * This will trigger the switch to apic_x2apic_phys.  Empty OEM IDs
84 	 * ensure that only this APIC driver picks up the call.
85 	 */
86 	default_acpi_madt_oem_check("", "");
87 #endif
88 }
89 
90 static void __init jailhouse_get_smp_config(unsigned int early)
91 {
92 	struct ioapic_domain_cfg ioapic_cfg = {
93 		.type = IOAPIC_DOMAIN_STRICT,
94 		.ops = &mp_ioapic_irqdomain_ops,
95 	};
96 	unsigned int cpu;
97 
98 	jailhouse_x2apic_init();
99 
100 	register_lapic_address(0xfee00000);
101 
102 	for (cpu = 0; cpu < setup_data.v1.num_cpus; cpu++) {
103 		generic_processor_info(setup_data.v1.cpu_ids[cpu],
104 				       boot_cpu_apic_version);
105 	}
106 
107 	smp_found_config = 1;
108 
109 	if (setup_data.v1.standard_ioapic) {
110 		mp_register_ioapic(0, 0xfec00000, gsi_top, &ioapic_cfg);
111 
112 		if (IS_ENABLED(CONFIG_SERIAL_8250) &&
113 		    setup_data.hdr.version < 2) {
114 			/* Register 1:1 mapping for legacy UART IRQs 3 and 4 */
115 			jailhouse_setup_irq(3);
116 			jailhouse_setup_irq(4);
117 		}
118 	}
119 }
120 
121 static void jailhouse_no_restart(void)
122 {
123 	pr_notice("Jailhouse: Restart not supported, halting\n");
124 	machine_halt();
125 }
126 
127 static int __init jailhouse_pci_arch_init(void)
128 {
129 	pci_direct_init(1);
130 
131 	/*
132 	 * There are no bridges on the virtual PCI root bus under Jailhouse,
133 	 * thus no other way to discover all devices than a full scan.
134 	 * Respect any overrides via the command line, though.
135 	 */
136 	if (pcibios_last_bus < 0)
137 		pcibios_last_bus = 0xff;
138 
139 #ifdef CONFIG_PCI_MMCONFIG
140 	if (setup_data.v1.pci_mmconfig_base) {
141 		pci_mmconfig_add(0, 0, pcibios_last_bus,
142 				 setup_data.v1.pci_mmconfig_base);
143 		pci_mmcfg_arch_init();
144 	}
145 #endif
146 
147 	return 0;
148 }
149 
150 #ifdef CONFIG_SERIAL_8250
151 static inline bool jailhouse_uart_enabled(unsigned int uart_nr)
152 {
153 	return setup_data.v2.flags & BIT(uart_nr);
154 }
155 
156 static void jailhouse_serial_fixup(int port, struct uart_port *up,
157 				   u32 *capabilities)
158 {
159 	static const u16 pcuart_base[] = {0x3f8, 0x2f8, 0x3e8, 0x2e8};
160 	unsigned int n;
161 
162 	for (n = 0; n < ARRAY_SIZE(pcuart_base); n++) {
163 		if (pcuart_base[n] != up->iobase)
164 			continue;
165 
166 		if (jailhouse_uart_enabled(n)) {
167 			pr_info("Enabling UART%u (port 0x%lx)\n", n,
168 				up->iobase);
169 			jailhouse_setup_irq(up->irq);
170 		} else {
171 			/* Deactivate UART if access isn't allowed */
172 			up->iobase = 0;
173 		}
174 		break;
175 	}
176 }
177 
178 static void __init jailhouse_serial_workaround(void)
179 {
180 	/*
181 	 * There are flags inside setup_data that indicate availability of
182 	 * platform UARTs since setup data version 2.
183 	 *
184 	 * In case of version 1, we don't know which UARTs belong Linux. In
185 	 * this case, unconditionally register 1:1 mapping for legacy UART IRQs
186 	 * 3 and 4.
187 	 */
188 	if (setup_data.hdr.version > 1)
189 		serial8250_set_isa_configurator(jailhouse_serial_fixup);
190 }
191 #else /* !CONFIG_SERIAL_8250 */
192 static inline void jailhouse_serial_workaround(void)
193 {
194 }
195 #endif /* CONFIG_SERIAL_8250 */
196 
197 static void __init jailhouse_init_platform(void)
198 {
199 	u64 pa_data = boot_params.hdr.setup_data;
200 	unsigned long setup_data_len;
201 	struct setup_data header;
202 	void *mapping;
203 
204 	x86_init.irqs.pre_vector_init	= x86_init_noop;
205 	x86_init.timers.timer_init	= jailhouse_timer_init;
206 	x86_init.mpparse.get_smp_config	= jailhouse_get_smp_config;
207 	x86_init.pci.arch_init		= jailhouse_pci_arch_init;
208 
209 	x86_platform.calibrate_cpu	= jailhouse_get_tsc;
210 	x86_platform.calibrate_tsc	= jailhouse_get_tsc;
211 	x86_platform.get_wallclock	= jailhouse_get_wallclock;
212 	x86_platform.legacy.rtc		= 0;
213 	x86_platform.legacy.warm_reset	= 0;
214 	x86_platform.legacy.i8042	= X86_LEGACY_I8042_PLATFORM_ABSENT;
215 
216 	legacy_pic			= &null_legacy_pic;
217 
218 	machine_ops.emergency_restart	= jailhouse_no_restart;
219 
220 	while (pa_data) {
221 		mapping = early_memremap(pa_data, sizeof(header));
222 		memcpy(&header, mapping, sizeof(header));
223 		early_memunmap(mapping, sizeof(header));
224 
225 		if (header.type == SETUP_JAILHOUSE)
226 			break;
227 
228 		pa_data = header.next;
229 	}
230 
231 	if (!pa_data)
232 		panic("Jailhouse: No valid setup data found");
233 
234 	/* setup data must at least contain the header */
235 	if (header.len < sizeof(setup_data.hdr))
236 		goto unsupported;
237 
238 	pa_data += offsetof(struct setup_data, data);
239 	setup_data_len = min_t(unsigned long, sizeof(setup_data),
240 			       (unsigned long)header.len);
241 	mapping = early_memremap(pa_data, setup_data_len);
242 	memcpy(&setup_data, mapping, setup_data_len);
243 	early_memunmap(mapping, setup_data_len);
244 
245 	if (setup_data.hdr.version == 0 ||
246 	    setup_data.hdr.compatible_version !=
247 		JAILHOUSE_SETUP_REQUIRED_VERSION ||
248 	    (setup_data.hdr.version == 1 && header.len < SETUP_DATA_V1_LEN) ||
249 	    (setup_data.hdr.version >= 2 && header.len < SETUP_DATA_V2_LEN))
250 		goto unsupported;
251 
252 	pmtmr_ioport = setup_data.v1.pm_timer_address;
253 	pr_debug("Jailhouse: PM-Timer IO Port: %#x\n", pmtmr_ioport);
254 
255 	precalibrated_tsc_khz = setup_data.v1.tsc_khz;
256 	setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
257 
258 	pci_probe = 0;
259 
260 	/*
261 	 * Avoid that the kernel complains about missing ACPI tables - there
262 	 * are none in a non-root cell.
263 	 */
264 	disable_acpi();
265 
266 	jailhouse_serial_workaround();
267 	return;
268 
269 unsupported:
270 	panic("Jailhouse: Unsupported setup data structure");
271 }
272 
273 bool jailhouse_paravirt(void)
274 {
275 	return jailhouse_cpuid_base() != 0;
276 }
277 
278 static bool __init jailhouse_x2apic_available(void)
279 {
280 	/*
281 	 * The x2APIC is only available if the root cell enabled it. Jailhouse
282 	 * does not support switching between xAPIC and x2APIC.
283 	 */
284 	return x2apic_enabled();
285 }
286 
287 const struct hypervisor_x86 x86_hyper_jailhouse __refconst = {
288 	.name			= "Jailhouse",
289 	.detect			= jailhouse_detect,
290 	.init.init_platform	= jailhouse_init_platform,
291 	.init.x2apic_available	= jailhouse_x2apic_available,
292 	.ignore_nopv		= true,
293 };
294