1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * tboot.c: main implementation of helper functions used by kernel for |
4 | * runtime support of Intel(R) Trusted Execution Technology |
5 | * |
6 | * Copyright (c) 2006-2009, Intel Corporation |
7 | */ |
8 | |
9 | #include <linux/init_task.h> |
10 | #include <linux/spinlock.h> |
11 | #include <linux/export.h> |
12 | #include <linux/delay.h> |
13 | #include <linux/sched.h> |
14 | #include <linux/init.h> |
15 | #include <linux/dmar.h> |
16 | #include <linux/cpu.h> |
17 | #include <linux/pfn.h> |
18 | #include <linux/mm.h> |
19 | #include <linux/tboot.h> |
20 | #include <linux/debugfs.h> |
21 | |
22 | #include <asm/realmode.h> |
23 | #include <asm/processor.h> |
24 | #include <asm/bootparam.h> |
25 | #include <asm/pgalloc.h> |
26 | #include <asm/fixmap.h> |
27 | #include <asm/proto.h> |
28 | #include <asm/setup.h> |
29 | #include <asm/e820/api.h> |
30 | #include <asm/io.h> |
31 | |
32 | #include "../realmode/rm/wakeup.h" |
33 | |
34 | /* Global pointer to shared data; NULL means no measured launch. */ |
35 | static struct tboot *tboot __read_mostly; |
36 | |
37 | /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */ |
38 | #define AP_WAIT_TIMEOUT 1 |
39 | |
40 | #undef pr_fmt |
41 | #define pr_fmt(fmt) "tboot: " fmt |
42 | |
43 | static u8 tboot_uuid[16] __initdata = TBOOT_UUID; |
44 | |
45 | bool tboot_enabled(void) |
46 | { |
47 | return tboot != NULL; |
48 | } |
49 | |
50 | /* noinline to prevent gcc from warning about dereferencing constant fixaddr */ |
51 | static noinline __init bool check_tboot_version(void) |
52 | { |
53 | if (memcmp(p: &tboot_uuid, q: &tboot->uuid, size: sizeof(tboot->uuid))) { |
54 | pr_warn("tboot at 0x%llx is invalid\n" , boot_params.tboot_addr); |
55 | return false; |
56 | } |
57 | |
58 | if (tboot->version < 5) { |
59 | pr_warn("tboot version is invalid: %u\n" , tboot->version); |
60 | return false; |
61 | } |
62 | |
63 | pr_info("found shared page at phys addr 0x%llx:\n" , |
64 | boot_params.tboot_addr); |
65 | pr_debug("version: %d\n" , tboot->version); |
66 | pr_debug("log_addr: 0x%08x\n" , tboot->log_addr); |
67 | pr_debug("shutdown_entry: 0x%x\n" , tboot->shutdown_entry); |
68 | pr_debug("tboot_base: 0x%08x\n" , tboot->tboot_base); |
69 | pr_debug("tboot_size: 0x%x\n" , tboot->tboot_size); |
70 | |
71 | return true; |
72 | } |
73 | |
74 | void __init tboot_probe(void) |
75 | { |
76 | /* Look for valid page-aligned address for shared page. */ |
77 | if (!boot_params.tboot_addr) |
78 | return; |
79 | /* |
80 | * also verify that it is mapped as we expect it before calling |
81 | * set_fixmap(), to reduce chance of garbage value causing crash |
82 | */ |
83 | if (!e820__mapped_any(start: boot_params.tboot_addr, |
84 | end: boot_params.tboot_addr, type: E820_TYPE_RESERVED)) { |
85 | pr_warn("non-0 tboot_addr but it is not of type E820_TYPE_RESERVED\n" ); |
86 | return; |
87 | } |
88 | |
89 | /* Map and check for tboot UUID. */ |
90 | set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr); |
91 | tboot = (void *)fix_to_virt(idx: FIX_TBOOT_BASE); |
92 | if (!check_tboot_version()) |
93 | tboot = NULL; |
94 | } |
95 | |
96 | static pgd_t *tboot_pg_dir; |
97 | static struct mm_struct tboot_mm = { |
98 | .mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, tboot_mm.mmap_lock), |
99 | .pgd = swapper_pg_dir, |
100 | .mm_users = ATOMIC_INIT(2), |
101 | .mm_count = ATOMIC_INIT(1), |
102 | .write_protect_seq = SEQCNT_ZERO(tboot_mm.write_protect_seq), |
103 | MMAP_LOCK_INITIALIZER(init_mm) |
104 | .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), |
105 | .mmlist = LIST_HEAD_INIT(init_mm.mmlist), |
106 | }; |
107 | |
108 | static inline void switch_to_tboot_pt(void) |
109 | { |
110 | write_cr3(virt_to_phys(address: tboot_pg_dir)); |
111 | } |
112 | |
113 | static int map_tboot_page(unsigned long vaddr, unsigned long pfn, |
114 | pgprot_t prot) |
115 | { |
116 | pgd_t *pgd; |
117 | p4d_t *p4d; |
118 | pud_t *pud; |
119 | pmd_t *pmd; |
120 | pte_t *pte; |
121 | |
122 | pgd = pgd_offset(&tboot_mm, vaddr); |
123 | p4d = p4d_alloc(mm: &tboot_mm, pgd, address: vaddr); |
124 | if (!p4d) |
125 | return -1; |
126 | pud = pud_alloc(mm: &tboot_mm, p4d, address: vaddr); |
127 | if (!pud) |
128 | return -1; |
129 | pmd = pmd_alloc(mm: &tboot_mm, pud, address: vaddr); |
130 | if (!pmd) |
131 | return -1; |
132 | pte = pte_alloc_map(&tboot_mm, pmd, vaddr); |
133 | if (!pte) |
134 | return -1; |
135 | set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); |
136 | pte_unmap(pte); |
137 | |
138 | /* |
139 | * PTI poisons low addresses in the kernel page tables in the |
140 | * name of making them unusable for userspace. To execute |
141 | * code at such a low address, the poison must be cleared. |
142 | * |
143 | * Note: 'pgd' actually gets set in p4d_alloc() _or_ |
144 | * pud_alloc() depending on 4/5-level paging. |
145 | */ |
146 | pgd->pgd &= ~_PAGE_NX; |
147 | |
148 | return 0; |
149 | } |
150 | |
151 | static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, |
152 | unsigned long nr) |
153 | { |
154 | /* Reuse the original kernel mapping */ |
155 | tboot_pg_dir = pgd_alloc(&tboot_mm); |
156 | if (!tboot_pg_dir) |
157 | return -1; |
158 | |
159 | for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { |
160 | if (map_tboot_page(vaddr, pfn: start_pfn, PAGE_KERNEL_EXEC)) |
161 | return -1; |
162 | } |
163 | |
164 | return 0; |
165 | } |
166 | |
167 | static void tboot_create_trampoline(void) |
168 | { |
169 | u32 map_base, map_size; |
170 | |
171 | /* Create identity map for tboot shutdown code. */ |
172 | map_base = PFN_DOWN(tboot->tboot_base); |
173 | map_size = PFN_UP(tboot->tboot_size); |
174 | if (map_tboot_pages(vaddr: map_base << PAGE_SHIFT, start_pfn: map_base, nr: map_size)) |
175 | panic(fmt: "tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n" , |
176 | map_base, map_size); |
177 | } |
178 | |
179 | #ifdef CONFIG_ACPI_SLEEP |
180 | |
181 | static void add_mac_region(phys_addr_t start, unsigned long size) |
182 | { |
183 | struct tboot_mac_region *mr; |
184 | phys_addr_t end = start + size; |
185 | |
186 | if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS) |
187 | panic(fmt: "tboot: Too many MAC regions\n" ); |
188 | |
189 | if (start && size) { |
190 | mr = &tboot->mac_regions[tboot->num_mac_regions++]; |
191 | mr->start = round_down(start, PAGE_SIZE); |
192 | mr->size = round_up(end, PAGE_SIZE) - mr->start; |
193 | } |
194 | } |
195 | |
196 | static int tboot_setup_sleep(void) |
197 | { |
198 | int i; |
199 | |
200 | tboot->num_mac_regions = 0; |
201 | |
202 | for (i = 0; i < e820_table->nr_entries; i++) { |
203 | if ((e820_table->entries[i].type != E820_TYPE_RAM) |
204 | && (e820_table->entries[i].type != E820_TYPE_RESERVED_KERN)) |
205 | continue; |
206 | |
207 | add_mac_region(start: e820_table->entries[i].addr, size: e820_table->entries[i].size); |
208 | } |
209 | |
210 | tboot->acpi_sinfo.kernel_s3_resume_vector = |
211 | real_mode_header->wakeup_start; |
212 | |
213 | return 0; |
214 | } |
215 | |
216 | #else /* no CONFIG_ACPI_SLEEP */ |
217 | |
218 | static int tboot_setup_sleep(void) |
219 | { |
220 | /* S3 shutdown requested, but S3 not supported by the kernel... */ |
221 | BUG(); |
222 | return -1; |
223 | } |
224 | |
225 | #endif |
226 | |
227 | void tboot_shutdown(u32 shutdown_type) |
228 | { |
229 | void (*shutdown)(void); |
230 | |
231 | if (!tboot_enabled()) |
232 | return; |
233 | |
234 | /* |
235 | * if we're being called before the 1:1 mapping is set up then just |
236 | * return and let the normal shutdown happen; this should only be |
237 | * due to very early panic() |
238 | */ |
239 | if (!tboot_pg_dir) |
240 | return; |
241 | |
242 | /* if this is S3 then set regions to MAC */ |
243 | if (shutdown_type == TB_SHUTDOWN_S3) |
244 | if (tboot_setup_sleep()) |
245 | return; |
246 | |
247 | tboot->shutdown_type = shutdown_type; |
248 | |
249 | switch_to_tboot_pt(); |
250 | |
251 | shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; |
252 | shutdown(); |
253 | |
254 | /* should not reach here */ |
255 | while (1) |
256 | halt(); |
257 | } |
258 | |
259 | static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) |
260 | { |
261 | #define TB_COPY_GAS(tbg, g) \ |
262 | tbg.space_id = g.space_id; \ |
263 | tbg.bit_width = g.bit_width; \ |
264 | tbg.bit_offset = g.bit_offset; \ |
265 | tbg.access_width = g.access_width; \ |
266 | tbg.address = g.address; |
267 | |
268 | TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); |
269 | TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); |
270 | TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); |
271 | TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); |
272 | |
273 | /* |
274 | * We need phys addr of waking vector, but can't use virt_to_phys() on |
275 | * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys |
276 | * addr. |
277 | */ |
278 | tboot->acpi_sinfo.wakeup_vector = fadt->facs + |
279 | offsetof(struct acpi_table_facs, firmware_waking_vector); |
280 | } |
281 | |
282 | static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) |
283 | { |
284 | static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { |
285 | /* S0,1,2: */ -1, -1, -1, |
286 | /* S3: */ TB_SHUTDOWN_S3, |
287 | /* S4: */ TB_SHUTDOWN_S4, |
288 | /* S5: */ TB_SHUTDOWN_S5 }; |
289 | |
290 | if (!tboot_enabled()) |
291 | return 0; |
292 | |
293 | tboot_copy_fadt(fadt: &acpi_gbl_FADT); |
294 | tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; |
295 | tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; |
296 | /* we always use the 32b wakeup vector */ |
297 | tboot->acpi_sinfo.vector_width = 32; |
298 | |
299 | if (sleep_state >= ACPI_S_STATE_COUNT || |
300 | acpi_shutdown_map[sleep_state] == -1) { |
301 | pr_warn("unsupported sleep state 0x%x\n" , sleep_state); |
302 | return -1; |
303 | } |
304 | |
305 | tboot_shutdown(shutdown_type: acpi_shutdown_map[sleep_state]); |
306 | return 0; |
307 | } |
308 | |
309 | static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b) |
310 | { |
311 | if (!tboot_enabled()) |
312 | return 0; |
313 | |
314 | pr_warn("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)" ); |
315 | return -ENODEV; |
316 | } |
317 | |
318 | static atomic_t ap_wfs_count; |
319 | |
320 | static int tboot_wait_for_aps(int num_aps) |
321 | { |
322 | unsigned long timeout; |
323 | |
324 | timeout = AP_WAIT_TIMEOUT*HZ; |
325 | while (atomic_read(v: (atomic_t *)&tboot->num_in_wfs) != num_aps && |
326 | timeout) { |
327 | mdelay(1); |
328 | timeout--; |
329 | } |
330 | |
331 | if (timeout) |
332 | pr_warn("tboot wait for APs timeout\n" ); |
333 | |
334 | return !(atomic_read(v: (atomic_t *)&tboot->num_in_wfs) == num_aps); |
335 | } |
336 | |
337 | static int tboot_dying_cpu(unsigned int cpu) |
338 | { |
339 | atomic_inc(v: &ap_wfs_count); |
340 | if (num_online_cpus() == 1) { |
341 | if (tboot_wait_for_aps(num_aps: atomic_read(v: &ap_wfs_count))) |
342 | return -EBUSY; |
343 | } |
344 | return 0; |
345 | } |
346 | |
347 | #ifdef CONFIG_DEBUG_FS |
348 | |
349 | #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ |
350 | 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } |
351 | |
352 | #define TBOOT_SERIAL_LOG_ADDR 0x60000 |
353 | #define TBOOT_SERIAL_LOG_SIZE 0x08000 |
354 | #define LOG_MAX_SIZE_OFF 16 |
355 | #define LOG_BUF_OFF 24 |
356 | |
357 | static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; |
358 | |
359 | static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) |
360 | { |
361 | void __iomem *log_base; |
362 | u8 log_uuid[16]; |
363 | u32 max_size; |
364 | void *kbuf; |
365 | int ret = -EFAULT; |
366 | |
367 | log_base = ioremap(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); |
368 | if (!log_base) |
369 | return ret; |
370 | |
371 | memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); |
372 | if (memcmp(p: &tboot_log_uuid, q: log_uuid, size: sizeof(log_uuid))) |
373 | goto err_iounmap; |
374 | |
375 | max_size = readl(addr: log_base + LOG_MAX_SIZE_OFF); |
376 | if (*ppos >= max_size) { |
377 | ret = 0; |
378 | goto err_iounmap; |
379 | } |
380 | |
381 | if (*ppos + count > max_size) |
382 | count = max_size - *ppos; |
383 | |
384 | kbuf = kmalloc(size: count, GFP_KERNEL); |
385 | if (!kbuf) { |
386 | ret = -ENOMEM; |
387 | goto err_iounmap; |
388 | } |
389 | |
390 | memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); |
391 | if (copy_to_user(to: user_buf, from: kbuf, n: count)) |
392 | goto err_kfree; |
393 | |
394 | *ppos += count; |
395 | |
396 | ret = count; |
397 | |
398 | err_kfree: |
399 | kfree(objp: kbuf); |
400 | |
401 | err_iounmap: |
402 | iounmap(addr: log_base); |
403 | |
404 | return ret; |
405 | } |
406 | |
407 | static const struct file_operations tboot_log_fops = { |
408 | .read = tboot_log_read, |
409 | .llseek = default_llseek, |
410 | }; |
411 | |
412 | #endif /* CONFIG_DEBUG_FS */ |
413 | |
414 | static __init int tboot_late_init(void) |
415 | { |
416 | if (!tboot_enabled()) |
417 | return 0; |
418 | |
419 | tboot_create_trampoline(); |
420 | |
421 | atomic_set(v: &ap_wfs_count, i: 0); |
422 | cpuhp_setup_state(state: CPUHP_AP_X86_TBOOT_DYING, name: "x86/tboot:dying" , NULL, |
423 | teardown: tboot_dying_cpu); |
424 | #ifdef CONFIG_DEBUG_FS |
425 | debugfs_create_file(name: "tboot_log" , S_IRUSR, |
426 | parent: arch_debugfs_dir, NULL, fops: &tboot_log_fops); |
427 | #endif |
428 | |
429 | acpi_os_set_prepare_sleep(func: &tboot_sleep); |
430 | acpi_os_set_prepare_extended_sleep(func: &tboot_extended_sleep); |
431 | return 0; |
432 | } |
433 | |
434 | late_initcall(tboot_late_init); |
435 | |
436 | /* |
437 | * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) |
438 | */ |
439 | |
440 | #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 |
441 | #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 |
442 | |
443 | /* # pages for each config regs space - used by fixmap */ |
444 | #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ |
445 | TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) |
446 | |
447 | /* offsets from pub/priv config space */ |
448 | #define TXTCR_HEAP_BASE 0x0300 |
449 | #define TXTCR_HEAP_SIZE 0x0308 |
450 | |
451 | #define SHA1_SIZE 20 |
452 | |
453 | struct sha1_hash { |
454 | u8 hash[SHA1_SIZE]; |
455 | }; |
456 | |
457 | struct sinit_mle_data { |
458 | u32 version; /* currently 6 */ |
459 | struct sha1_hash bios_acm_id; |
460 | u32 edx_senter_flags; |
461 | u64 mseg_valid; |
462 | struct sha1_hash sinit_hash; |
463 | struct sha1_hash mle_hash; |
464 | struct sha1_hash stm_hash; |
465 | struct sha1_hash lcp_policy_hash; |
466 | u32 lcp_policy_control; |
467 | u32 rlp_wakeup_addr; |
468 | u32 reserved; |
469 | u32 num_mdrs; |
470 | u32 mdrs_off; |
471 | u32 num_vtd_dmars; |
472 | u32 vtd_dmars_off; |
473 | } __packed; |
474 | |
475 | struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) |
476 | { |
477 | void *heap_base, *heap_ptr, *config; |
478 | |
479 | if (!tboot_enabled()) |
480 | return dmar_tbl; |
481 | |
482 | /* |
483 | * ACPI tables may not be DMA protected by tboot, so use DMAR copy |
484 | * SINIT saved in SinitMleData in TXT heap (which is DMA protected) |
485 | */ |
486 | |
487 | /* map config space in order to get heap addr */ |
488 | config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * |
489 | PAGE_SIZE); |
490 | if (!config) |
491 | return NULL; |
492 | |
493 | /* now map TXT heap */ |
494 | heap_base = ioremap(offset: *(u64 *)(config + TXTCR_HEAP_BASE), |
495 | size: *(u64 *)(config + TXTCR_HEAP_SIZE)); |
496 | iounmap(addr: config); |
497 | if (!heap_base) |
498 | return NULL; |
499 | |
500 | /* walk heap to SinitMleData */ |
501 | /* skip BiosData */ |
502 | heap_ptr = heap_base + *(u64 *)heap_base; |
503 | /* skip OsMleData */ |
504 | heap_ptr += *(u64 *)heap_ptr; |
505 | /* skip OsSinitData */ |
506 | heap_ptr += *(u64 *)heap_ptr; |
507 | /* now points to SinitMleDataSize; set to SinitMleData */ |
508 | heap_ptr += sizeof(u64); |
509 | /* get addr of DMAR table */ |
510 | dmar_tbl = (struct acpi_table_header *)(heap_ptr + |
511 | ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - |
512 | sizeof(u64)); |
513 | |
514 | /* don't unmap heap because dmar.c needs access to this */ |
515 | |
516 | return dmar_tbl; |
517 | } |
518 | |