1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Author: Erik Kaneda <erik.kaneda@intel.com> |
4 | * Copyright 2020 Intel Corporation |
5 | * |
6 | * prmt.c |
7 | * |
8 | * Each PRM service is an executable that is run in a restricted environment |
9 | * that is invoked by writing to the PlatformRtMechanism OperationRegion from |
10 | * AML bytecode. |
11 | * |
12 | * init_prmt initializes the Platform Runtime Mechanism (PRM) services by |
13 | * processing data in the PRMT as well as registering an ACPI OperationRegion |
14 | * handler for the PlatformRtMechanism subtype. |
15 | * |
16 | */ |
17 | #include <linux/kernel.h> |
18 | #include <linux/efi.h> |
19 | #include <linux/acpi.h> |
20 | #include <linux/prmt.h> |
21 | #include <asm/efi.h> |
22 | |
23 | #pragma pack(1) |
24 | struct prm_mmio_addr_range { |
25 | u64 phys_addr; |
26 | u64 virt_addr; |
27 | u32 length; |
28 | }; |
29 | |
30 | struct prm_mmio_info { |
31 | u64 mmio_count; |
32 | struct prm_mmio_addr_range addr_ranges[]; |
33 | }; |
34 | |
35 | struct prm_buffer { |
36 | u8 prm_status; |
37 | u64 efi_status; |
38 | u8 prm_cmd; |
39 | guid_t handler_guid; |
40 | }; |
41 | |
42 | struct prm_context_buffer { |
43 | char signature[ACPI_NAMESEG_SIZE]; |
44 | u16 revision; |
45 | u16 reserved; |
46 | guid_t identifier; |
47 | u64 static_data_buffer; |
48 | struct prm_mmio_info *mmio_ranges; |
49 | }; |
50 | #pragma pack() |
51 | |
52 | static LIST_HEAD(prm_module_list); |
53 | |
54 | struct prm_handler_info { |
55 | guid_t guid; |
56 | efi_status_t (__efiapi *handler_addr)(u64, void *); |
57 | u64 static_data_buffer_addr; |
58 | u64 acpi_param_buffer_addr; |
59 | |
60 | struct list_head handler_list; |
61 | }; |
62 | |
63 | struct prm_module_info { |
64 | guid_t guid; |
65 | u16 major_rev; |
66 | u16 minor_rev; |
67 | u16 handler_count; |
68 | struct prm_mmio_info *mmio_info; |
69 | bool updatable; |
70 | |
71 | struct list_head module_list; |
72 | struct prm_handler_info handlers[] __counted_by(handler_count); |
73 | }; |
74 | |
75 | static u64 efi_pa_va_lookup(u64 pa) |
76 | { |
77 | efi_memory_desc_t *md; |
78 | u64 pa_offset = pa & ~PAGE_MASK; |
79 | u64 page = pa & PAGE_MASK; |
80 | |
81 | for_each_efi_memory_desc(md) { |
82 | if (md->phys_addr < pa && pa < md->phys_addr + PAGE_SIZE * md->num_pages) |
83 | return pa_offset + md->virt_addr + page - md->phys_addr; |
84 | } |
85 | |
86 | return 0; |
87 | } |
88 | |
89 | #define get_first_handler(a) ((struct acpi_prmt_handler_info *) ((char *) (a) + a->handler_info_offset)) |
90 | #define get_next_handler(a) ((struct acpi_prmt_handler_info *) (sizeof(struct acpi_prmt_handler_info) + (char *) a)) |
91 | |
92 | static int __init |
93 | acpi_parse_prmt(union acpi_subtable_headers *, const unsigned long end) |
94 | { |
95 | struct acpi_prmt_module_info *module_info; |
96 | struct acpi_prmt_handler_info *handler_info; |
97 | struct prm_handler_info *th; |
98 | struct prm_module_info *tm; |
99 | u64 *mmio_count; |
100 | u64 cur_handler = 0; |
101 | u32 module_info_size = 0; |
102 | u64 mmio_range_size = 0; |
103 | void *temp_mmio; |
104 | |
105 | module_info = (struct acpi_prmt_module_info *) header; |
106 | module_info_size = struct_size(tm, handlers, module_info->handler_info_count); |
107 | tm = kmalloc(size: module_info_size, GFP_KERNEL); |
108 | if (!tm) |
109 | goto parse_prmt_out1; |
110 | |
111 | guid_copy(dst: &tm->guid, src: (guid_t *) module_info->module_guid); |
112 | tm->major_rev = module_info->major_rev; |
113 | tm->minor_rev = module_info->minor_rev; |
114 | tm->handler_count = module_info->handler_info_count; |
115 | tm->updatable = true; |
116 | |
117 | if (module_info->mmio_list_pointer) { |
118 | /* |
119 | * Each module is associated with a list of addr |
120 | * ranges that it can use during the service |
121 | */ |
122 | mmio_count = (u64 *) memremap(offset: module_info->mmio_list_pointer, size: 8, flags: MEMREMAP_WB); |
123 | if (!mmio_count) |
124 | goto parse_prmt_out2; |
125 | |
126 | mmio_range_size = struct_size(tm->mmio_info, addr_ranges, *mmio_count); |
127 | tm->mmio_info = kmalloc(size: mmio_range_size, GFP_KERNEL); |
128 | if (!tm->mmio_info) |
129 | goto parse_prmt_out3; |
130 | |
131 | temp_mmio = memremap(offset: module_info->mmio_list_pointer, size: mmio_range_size, flags: MEMREMAP_WB); |
132 | if (!temp_mmio) |
133 | goto parse_prmt_out4; |
134 | memmove(tm->mmio_info, temp_mmio, mmio_range_size); |
135 | } else { |
136 | tm->mmio_info = kmalloc(size: sizeof(*tm->mmio_info), GFP_KERNEL); |
137 | if (!tm->mmio_info) |
138 | goto parse_prmt_out2; |
139 | |
140 | tm->mmio_info->mmio_count = 0; |
141 | } |
142 | |
143 | INIT_LIST_HEAD(list: &tm->module_list); |
144 | list_add(new: &tm->module_list, head: &prm_module_list); |
145 | |
146 | handler_info = get_first_handler(module_info); |
147 | do { |
148 | th = &tm->handlers[cur_handler]; |
149 | |
150 | guid_copy(dst: &th->guid, src: (guid_t *)handler_info->handler_guid); |
151 | th->handler_addr = (void *)efi_pa_va_lookup(pa: handler_info->handler_address); |
152 | th->static_data_buffer_addr = efi_pa_va_lookup(pa: handler_info->static_data_buffer_address); |
153 | th->acpi_param_buffer_addr = efi_pa_va_lookup(pa: handler_info->acpi_param_buffer_address); |
154 | } while (++cur_handler < tm->handler_count && (handler_info = get_next_handler(handler_info))); |
155 | |
156 | return 0; |
157 | |
158 | parse_prmt_out4: |
159 | kfree(objp: tm->mmio_info); |
160 | parse_prmt_out3: |
161 | memunmap(addr: mmio_count); |
162 | parse_prmt_out2: |
163 | kfree(objp: tm); |
164 | parse_prmt_out1: |
165 | return -ENOMEM; |
166 | } |
167 | |
168 | #define GET_MODULE 0 |
169 | #define GET_HANDLER 1 |
170 | |
171 | static void *find_guid_info(const guid_t *guid, u8 mode) |
172 | { |
173 | struct prm_handler_info *cur_handler; |
174 | struct prm_module_info *cur_module; |
175 | int i = 0; |
176 | |
177 | list_for_each_entry(cur_module, &prm_module_list, module_list) { |
178 | for (i = 0; i < cur_module->handler_count; ++i) { |
179 | cur_handler = &cur_module->handlers[i]; |
180 | if (guid_equal(u1: guid, u2: &cur_handler->guid)) { |
181 | if (mode == GET_MODULE) |
182 | return (void *)cur_module; |
183 | else |
184 | return (void *)cur_handler; |
185 | } |
186 | } |
187 | } |
188 | |
189 | return NULL; |
190 | } |
191 | |
192 | static struct prm_module_info *find_prm_module(const guid_t *guid) |
193 | { |
194 | return (struct prm_module_info *)find_guid_info(guid, GET_MODULE); |
195 | } |
196 | |
197 | static struct prm_handler_info *find_prm_handler(const guid_t *guid) |
198 | { |
199 | return (struct prm_handler_info *) find_guid_info(guid, GET_HANDLER); |
200 | } |
201 | |
202 | /* In-coming PRM commands */ |
203 | |
204 | #define PRM_CMD_RUN_SERVICE 0 |
205 | #define PRM_CMD_START_TRANSACTION 1 |
206 | #define PRM_CMD_END_TRANSACTION 2 |
207 | |
208 | /* statuses that can be passed back to ASL */ |
209 | |
210 | #define PRM_HANDLER_SUCCESS 0 |
211 | #define PRM_HANDLER_ERROR 1 |
212 | #define INVALID_PRM_COMMAND 2 |
213 | #define PRM_HANDLER_GUID_NOT_FOUND 3 |
214 | #define UPDATE_LOCK_ALREADY_HELD 4 |
215 | #define UPDATE_UNLOCK_WITHOUT_LOCK 5 |
216 | |
217 | /* |
218 | * This is the PlatformRtMechanism opregion space handler. |
219 | * @function: indicates the read/write. In fact as the PlatformRtMechanism |
220 | * message is driven by command, only write is meaningful. |
221 | * |
222 | * @addr : not used |
223 | * @bits : not used. |
224 | * @value : it is an in/out parameter. It points to the PRM message buffer. |
225 | * @handler_context: not used |
226 | */ |
227 | static acpi_status acpi_platformrt_space_handler(u32 function, |
228 | acpi_physical_address addr, |
229 | u32 bits, acpi_integer *value, |
230 | void *handler_context, |
231 | void *region_context) |
232 | { |
233 | struct prm_buffer *buffer = ACPI_CAST_PTR(struct prm_buffer, value); |
234 | struct prm_handler_info *handler; |
235 | struct prm_module_info *module; |
236 | efi_status_t status; |
237 | struct prm_context_buffer context; |
238 | |
239 | if (!efi_enabled(EFI_RUNTIME_SERVICES)) { |
240 | pr_err_ratelimited("PRM: EFI runtime services no longer available\n" ); |
241 | return AE_NO_HANDLER; |
242 | } |
243 | |
244 | /* |
245 | * The returned acpi_status will always be AE_OK. Error values will be |
246 | * saved in the first byte of the PRM message buffer to be used by ASL. |
247 | */ |
248 | switch (buffer->prm_cmd) { |
249 | case PRM_CMD_RUN_SERVICE: |
250 | |
251 | handler = find_prm_handler(guid: &buffer->handler_guid); |
252 | module = find_prm_module(guid: &buffer->handler_guid); |
253 | if (!handler || !module) |
254 | goto invalid_guid; |
255 | |
256 | ACPI_COPY_NAMESEG(context.signature, "PRMC" ); |
257 | context.revision = 0x0; |
258 | context.reserved = 0x0; |
259 | context.identifier = handler->guid; |
260 | context.static_data_buffer = handler->static_data_buffer_addr; |
261 | context.mmio_ranges = module->mmio_info; |
262 | |
263 | status = efi_call_acpi_prm_handler(handler_addr: handler->handler_addr, |
264 | param_buffer_addr: handler->acpi_param_buffer_addr, |
265 | context: &context); |
266 | if (status == EFI_SUCCESS) { |
267 | buffer->prm_status = PRM_HANDLER_SUCCESS; |
268 | } else { |
269 | buffer->prm_status = PRM_HANDLER_ERROR; |
270 | buffer->efi_status = status; |
271 | } |
272 | break; |
273 | |
274 | case PRM_CMD_START_TRANSACTION: |
275 | |
276 | module = find_prm_module(guid: &buffer->handler_guid); |
277 | if (!module) |
278 | goto invalid_guid; |
279 | |
280 | if (module->updatable) |
281 | module->updatable = false; |
282 | else |
283 | buffer->prm_status = UPDATE_LOCK_ALREADY_HELD; |
284 | break; |
285 | |
286 | case PRM_CMD_END_TRANSACTION: |
287 | |
288 | module = find_prm_module(guid: &buffer->handler_guid); |
289 | if (!module) |
290 | goto invalid_guid; |
291 | |
292 | if (module->updatable) |
293 | buffer->prm_status = UPDATE_UNLOCK_WITHOUT_LOCK; |
294 | else |
295 | module->updatable = true; |
296 | break; |
297 | |
298 | default: |
299 | |
300 | buffer->prm_status = INVALID_PRM_COMMAND; |
301 | break; |
302 | } |
303 | |
304 | return AE_OK; |
305 | |
306 | invalid_guid: |
307 | buffer->prm_status = PRM_HANDLER_GUID_NOT_FOUND; |
308 | return AE_OK; |
309 | } |
310 | |
311 | void __init init_prmt(void) |
312 | { |
313 | struct acpi_table_header *tbl; |
314 | acpi_status status; |
315 | int mc; |
316 | |
317 | status = acpi_get_table(ACPI_SIG_PRMT, instance: 0, out_table: &tbl); |
318 | if (ACPI_FAILURE(status)) |
319 | return; |
320 | |
321 | mc = acpi_table_parse_entries(ACPI_SIG_PRMT, table_size: sizeof(struct acpi_table_prmt) + |
322 | sizeof (struct acpi_table_prmt_header), |
323 | entry_id: 0, handler: acpi_parse_prmt, max_entries: 0); |
324 | acpi_put_table(table: tbl); |
325 | /* |
326 | * Return immediately if PRMT table is not present or no PRM module found. |
327 | */ |
328 | if (mc <= 0) |
329 | return; |
330 | |
331 | pr_info("PRM: found %u modules\n" , mc); |
332 | |
333 | if (!efi_enabled(EFI_RUNTIME_SERVICES)) { |
334 | pr_err("PRM: EFI runtime services unavailable\n" ); |
335 | return; |
336 | } |
337 | |
338 | status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT, |
339 | ACPI_ADR_SPACE_PLATFORM_RT, |
340 | handler: &acpi_platformrt_space_handler, |
341 | NULL, NULL); |
342 | if (ACPI_FAILURE(status)) |
343 | pr_alert("PRM: OperationRegion handler could not be installed\n" ); |
344 | } |
345 | |