xref: /openbmc/linux/drivers/xen/efi.c (revision ecefa105)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * EFI support for Xen.
4  *
5  * Copyright (C) 1999 VA Linux Systems
6  * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
7  * Copyright (C) 1999-2002 Hewlett-Packard Co.
8  *	David Mosberger-Tang <davidm@hpl.hp.com>
9  *	Stephane Eranian <eranian@hpl.hp.com>
10  * Copyright (C) 2005-2008 Intel Co.
11  *	Fenghua Yu <fenghua.yu@intel.com>
12  *	Bibo Mao <bibo.mao@intel.com>
13  *	Chandramouli Narayanan <mouli@linux.intel.com>
14  *	Huang Ying <ying.huang@intel.com>
15  * Copyright (C) 2011 Novell Co.
16  *	Jan Beulich <JBeulich@suse.com>
17  * Copyright (C) 2011-2012 Oracle Co.
18  *	Liang Tang <liang.tang@oracle.com>
19  * Copyright (c) 2014 Oracle Co., Daniel Kiper
20  */
21 
22 #include <linux/bug.h>
23 #include <linux/efi.h>
24 #include <linux/init.h>
25 #include <linux/string.h>
26 
27 #include <xen/interface/xen.h>
28 #include <xen/interface/platform.h>
29 #include <xen/page.h>
30 #include <xen/xen.h>
31 #include <xen/xen-ops.h>
32 
33 #include <asm/page.h>
34 
35 #include <asm/xen/hypercall.h>
36 
37 #define INIT_EFI_OP(name) \
38 	{.cmd = XENPF_efi_runtime_call, \
39 	 .u.efi_runtime_call.function = XEN_EFI_##name, \
40 	 .u.efi_runtime_call.misc = 0}
41 
42 #define efi_data(op)	(op.u.efi_runtime_call)
43 
44 static efi_status_t xen_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
45 {
46 	struct xen_platform_op op = INIT_EFI_OP(get_time);
47 
48 	if (HYPERVISOR_platform_op(&op) < 0)
49 		return EFI_UNSUPPORTED;
50 
51 	if (tm) {
52 		BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.get_time.time));
53 		memcpy(tm, &efi_data(op).u.get_time.time, sizeof(*tm));
54 	}
55 
56 	if (tc) {
57 		tc->resolution = efi_data(op).u.get_time.resolution;
58 		tc->accuracy = efi_data(op).u.get_time.accuracy;
59 		tc->sets_to_zero = !!(efi_data(op).misc &
60 				      XEN_EFI_GET_TIME_SET_CLEARS_NS);
61 	}
62 
63 	return efi_data(op).status;
64 }
65 
66 static efi_status_t xen_efi_set_time(efi_time_t *tm)
67 {
68 	struct xen_platform_op op = INIT_EFI_OP(set_time);
69 
70 	BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.set_time));
71 	memcpy(&efi_data(op).u.set_time, tm, sizeof(*tm));
72 
73 	if (HYPERVISOR_platform_op(&op) < 0)
74 		return EFI_UNSUPPORTED;
75 
76 	return efi_data(op).status;
77 }
78 
79 static efi_status_t xen_efi_get_wakeup_time(efi_bool_t *enabled,
80 					    efi_bool_t *pending,
81 					    efi_time_t *tm)
82 {
83 	struct xen_platform_op op = INIT_EFI_OP(get_wakeup_time);
84 
85 	if (HYPERVISOR_platform_op(&op) < 0)
86 		return EFI_UNSUPPORTED;
87 
88 	if (tm) {
89 		BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.get_wakeup_time));
90 		memcpy(tm, &efi_data(op).u.get_wakeup_time, sizeof(*tm));
91 	}
92 
93 	if (enabled)
94 		*enabled = !!(efi_data(op).misc & XEN_EFI_GET_WAKEUP_TIME_ENABLED);
95 
96 	if (pending)
97 		*pending = !!(efi_data(op).misc & XEN_EFI_GET_WAKEUP_TIME_PENDING);
98 
99 	return efi_data(op).status;
100 }
101 
102 static efi_status_t xen_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
103 {
104 	struct xen_platform_op op = INIT_EFI_OP(set_wakeup_time);
105 
106 	BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.set_wakeup_time));
107 	if (enabled)
108 		efi_data(op).misc = XEN_EFI_SET_WAKEUP_TIME_ENABLE;
109 	if (tm)
110 		memcpy(&efi_data(op).u.set_wakeup_time, tm, sizeof(*tm));
111 	else
112 		efi_data(op).misc |= XEN_EFI_SET_WAKEUP_TIME_ENABLE_ONLY;
113 
114 	if (HYPERVISOR_platform_op(&op) < 0)
115 		return EFI_UNSUPPORTED;
116 
117 	return efi_data(op).status;
118 }
119 
120 static efi_status_t xen_efi_get_variable(efi_char16_t *name, efi_guid_t *vendor,
121 					 u32 *attr, unsigned long *data_size,
122 					 void *data)
123 {
124 	struct xen_platform_op op = INIT_EFI_OP(get_variable);
125 
126 	set_xen_guest_handle(efi_data(op).u.get_variable.name, name);
127 	BUILD_BUG_ON(sizeof(*vendor) !=
128 		     sizeof(efi_data(op).u.get_variable.vendor_guid));
129 	memcpy(&efi_data(op).u.get_variable.vendor_guid, vendor, sizeof(*vendor));
130 	efi_data(op).u.get_variable.size = *data_size;
131 	set_xen_guest_handle(efi_data(op).u.get_variable.data, data);
132 
133 	if (HYPERVISOR_platform_op(&op) < 0)
134 		return EFI_UNSUPPORTED;
135 
136 	*data_size = efi_data(op).u.get_variable.size;
137 	if (attr)
138 		*attr = efi_data(op).misc;
139 
140 	return efi_data(op).status;
141 }
142 
143 static efi_status_t xen_efi_get_next_variable(unsigned long *name_size,
144 					      efi_char16_t *name,
145 					      efi_guid_t *vendor)
146 {
147 	struct xen_platform_op op = INIT_EFI_OP(get_next_variable_name);
148 
149 	efi_data(op).u.get_next_variable_name.size = *name_size;
150 	set_xen_guest_handle(efi_data(op).u.get_next_variable_name.name, name);
151 	BUILD_BUG_ON(sizeof(*vendor) !=
152 		     sizeof(efi_data(op).u.get_next_variable_name.vendor_guid));
153 	memcpy(&efi_data(op).u.get_next_variable_name.vendor_guid, vendor,
154 	       sizeof(*vendor));
155 
156 	if (HYPERVISOR_platform_op(&op) < 0)
157 		return EFI_UNSUPPORTED;
158 
159 	*name_size = efi_data(op).u.get_next_variable_name.size;
160 	memcpy(vendor, &efi_data(op).u.get_next_variable_name.vendor_guid,
161 	       sizeof(*vendor));
162 
163 	return efi_data(op).status;
164 }
165 
166 static efi_status_t xen_efi_set_variable(efi_char16_t *name, efi_guid_t *vendor,
167 					 u32 attr, unsigned long data_size,
168 					 void *data)
169 {
170 	struct xen_platform_op op = INIT_EFI_OP(set_variable);
171 
172 	set_xen_guest_handle(efi_data(op).u.set_variable.name, name);
173 	efi_data(op).misc = attr;
174 	BUILD_BUG_ON(sizeof(*vendor) !=
175 		     sizeof(efi_data(op).u.set_variable.vendor_guid));
176 	memcpy(&efi_data(op).u.set_variable.vendor_guid, vendor, sizeof(*vendor));
177 	efi_data(op).u.set_variable.size = data_size;
178 	set_xen_guest_handle(efi_data(op).u.set_variable.data, data);
179 
180 	if (HYPERVISOR_platform_op(&op) < 0)
181 		return EFI_UNSUPPORTED;
182 
183 	return efi_data(op).status;
184 }
185 
186 static efi_status_t xen_efi_query_variable_info(u32 attr, u64 *storage_space,
187 						u64 *remaining_space,
188 						u64 *max_variable_size)
189 {
190 	struct xen_platform_op op = INIT_EFI_OP(query_variable_info);
191 
192 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
193 		return EFI_UNSUPPORTED;
194 
195 	efi_data(op).u.query_variable_info.attr = attr;
196 
197 	if (HYPERVISOR_platform_op(&op) < 0)
198 		return EFI_UNSUPPORTED;
199 
200 	*storage_space = efi_data(op).u.query_variable_info.max_store_size;
201 	*remaining_space = efi_data(op).u.query_variable_info.remain_store_size;
202 	*max_variable_size = efi_data(op).u.query_variable_info.max_size;
203 
204 	return efi_data(op).status;
205 }
206 
207 static efi_status_t xen_efi_get_next_high_mono_count(u32 *count)
208 {
209 	struct xen_platform_op op = INIT_EFI_OP(get_next_high_monotonic_count);
210 
211 	if (HYPERVISOR_platform_op(&op) < 0)
212 		return EFI_UNSUPPORTED;
213 
214 	*count = efi_data(op).misc;
215 
216 	return efi_data(op).status;
217 }
218 
219 static efi_status_t xen_efi_update_capsule(efi_capsule_header_t **capsules,
220 				unsigned long count, unsigned long sg_list)
221 {
222 	struct xen_platform_op op = INIT_EFI_OP(update_capsule);
223 
224 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
225 		return EFI_UNSUPPORTED;
226 
227 	set_xen_guest_handle(efi_data(op).u.update_capsule.capsule_header_array,
228 			     capsules);
229 	efi_data(op).u.update_capsule.capsule_count = count;
230 	efi_data(op).u.update_capsule.sg_list = sg_list;
231 
232 	if (HYPERVISOR_platform_op(&op) < 0)
233 		return EFI_UNSUPPORTED;
234 
235 	return efi_data(op).status;
236 }
237 
238 static efi_status_t xen_efi_query_capsule_caps(efi_capsule_header_t **capsules,
239 			unsigned long count, u64 *max_size, int *reset_type)
240 {
241 	struct xen_platform_op op = INIT_EFI_OP(query_capsule_capabilities);
242 
243 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
244 		return EFI_UNSUPPORTED;
245 
246 	set_xen_guest_handle(efi_data(op).u.query_capsule_capabilities.capsule_header_array,
247 					capsules);
248 	efi_data(op).u.query_capsule_capabilities.capsule_count = count;
249 
250 	if (HYPERVISOR_platform_op(&op) < 0)
251 		return EFI_UNSUPPORTED;
252 
253 	*max_size = efi_data(op).u.query_capsule_capabilities.max_capsule_size;
254 	*reset_type = efi_data(op).u.query_capsule_capabilities.reset_type;
255 
256 	return efi_data(op).status;
257 }
258 
259 static void xen_efi_reset_system(int reset_type, efi_status_t status,
260 				 unsigned long data_size, efi_char16_t *data)
261 {
262 	switch (reset_type) {
263 	case EFI_RESET_COLD:
264 	case EFI_RESET_WARM:
265 		xen_reboot(SHUTDOWN_reboot);
266 		break;
267 	case EFI_RESET_SHUTDOWN:
268 		xen_reboot(SHUTDOWN_poweroff);
269 		break;
270 	default:
271 		BUG();
272 	}
273 }
274 
275 /*
276  * Set XEN EFI runtime services function pointers. Other fields of struct efi,
277  * e.g. efi.systab, will be set like normal EFI.
278  */
279 void __init xen_efi_runtime_setup(void)
280 {
281 	efi.get_time			= xen_efi_get_time;
282 	efi.set_time			= xen_efi_set_time;
283 	efi.get_wakeup_time		= xen_efi_get_wakeup_time;
284 	efi.set_wakeup_time		= xen_efi_set_wakeup_time;
285 	efi.get_variable		= xen_efi_get_variable;
286 	efi.get_next_variable		= xen_efi_get_next_variable;
287 	efi.set_variable		= xen_efi_set_variable;
288 	efi.set_variable_nonblocking	= xen_efi_set_variable;
289 	efi.query_variable_info		= xen_efi_query_variable_info;
290 	efi.query_variable_info_nonblocking = xen_efi_query_variable_info;
291 	efi.update_capsule		= xen_efi_update_capsule;
292 	efi.query_capsule_caps		= xen_efi_query_capsule_caps;
293 	efi.get_next_high_mono_count	= xen_efi_get_next_high_mono_count;
294 	efi.reset_system		= xen_efi_reset_system;
295 }
296 
297 int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
298 {
299 	static_assert(XEN_PAGE_SHIFT == EFI_PAGE_SHIFT,
300 	              "Mismatch between EFI_PAGE_SHIFT and XEN_PAGE_SHIFT");
301 	struct xen_platform_op op;
302 	union xenpf_efi_info *info = &op.u.firmware_info.u.efi_info;
303 	int rc;
304 
305 	if (!efi_enabled(EFI_PARAVIRT) || efi_enabled(EFI_MEMMAP))
306 		return __efi_mem_desc_lookup(phys_addr, out_md);
307 	phys_addr &= ~(u64)(EFI_PAGE_SIZE - 1);
308 	op = (struct xen_platform_op) {
309 		.cmd = XENPF_firmware_info,
310 		.u.firmware_info = {
311 			.type = XEN_FW_EFI_INFO,
312 			.index = XEN_FW_EFI_MEM_INFO,
313 			.u.efi_info.mem.addr = phys_addr,
314 			.u.efi_info.mem.size = U64_MAX - phys_addr,
315 		},
316 	};
317 
318 	rc = HYPERVISOR_platform_op(&op);
319 	if (rc) {
320 		pr_warn("Failed to lookup header 0x%llx in Xen memory map: error %d\n",
321 		        phys_addr, rc);
322 	}
323 
324 	out_md->phys_addr	= info->mem.addr;
325 	out_md->num_pages	= info->mem.size >> EFI_PAGE_SHIFT;
326 	out_md->type    	= info->mem.type;
327 	out_md->attribute	= info->mem.attr;
328 
329 	return 0;
330 }
331 
332 bool __init xen_efi_config_table_is_usable(const efi_guid_t *guid,
333                                            unsigned long table)
334 {
335 	efi_memory_desc_t md;
336 	int rc;
337 
338 	if (!efi_enabled(EFI_PARAVIRT))
339 		return true;
340 
341 	rc = efi_mem_desc_lookup(table, &md);
342 	if (rc)
343 		return false;
344 
345 	switch (md.type) {
346 	case EFI_RUNTIME_SERVICES_CODE:
347 	case EFI_RUNTIME_SERVICES_DATA:
348 	case EFI_ACPI_RECLAIM_MEMORY:
349 	case EFI_ACPI_MEMORY_NVS:
350 	case EFI_RESERVED_TYPE:
351 		return true;
352 	default:
353 		return false;
354 	}
355 }
356