1 /*
2 * tboot.c: main implementation of helper functions used by kernel for
3 * runtime support of Intel(R) Trusted Execution Technology
4 *
5 * Copyright (c) 2006-2009, Intel Corporation
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 */
21
22 #include <linux/dma_remapping.h>
23 #include <linux/init_task.h>
24 #include <linux/spinlock.h>
25 #include <linux/export.h>
26 #include <linux/delay.h>
27 #include <linux/sched.h>
28 #include <linux/init.h>
29 #include <linux/dmar.h>
30 #include <linux/cpu.h>
31 #include <linux/pfn.h>
32 #include <linux/mm.h>
33 #include <linux/tboot.h>
34 #include <linux/debugfs.h>
35
36 #include <asm/realmode.h>
37 #include <asm/processor.h>
38 #include <asm/bootparam.h>
39 #include <asm/pgtable.h>
40 #include <asm/pgalloc.h>
41 #include <asm/swiotlb.h>
42 #include <asm/fixmap.h>
43 #include <asm/proto.h>
44 #include <asm/setup.h>
45 #include <asm/e820/api.h>
46 #include <asm/io.h>
47
48 #include "../realmode/rm/wakeup.h"
49
50 /* Global pointer to shared data; NULL means no measured launch. */
51 struct tboot *tboot __read_mostly;
52 EXPORT_SYMBOL(tboot);
53
54 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
55 #define AP_WAIT_TIMEOUT 1
56
57 #undef pr_fmt
58 #define pr_fmt(fmt) "tboot: " fmt
59
60 static u8 tboot_uuid[16] __initdata = TBOOT_UUID;
61
tboot_probe(void)62 void __init tboot_probe(void)
63 {
64 /* Look for valid page-aligned address for shared page. */
65 if (!boot_params.tboot_addr)
66 return;
67 /*
68 * also verify that it is mapped as we expect it before calling
69 * set_fixmap(), to reduce chance of garbage value causing crash
70 */
71 if (!e820__mapped_any(boot_params.tboot_addr,
72 boot_params.tboot_addr, E820_TYPE_RESERVED)) {
73 pr_warning("non-0 tboot_addr but it is not of type E820_TYPE_RESERVED\n");
74 return;
75 }
76
77 /* Map and check for tboot UUID. */
78 set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
79 tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE);
80 if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
81 pr_warning("tboot at 0x%llx is invalid\n",
82 boot_params.tboot_addr);
83 tboot = NULL;
84 return;
85 }
86 if (tboot->version < 5) {
87 pr_warning("tboot version is invalid: %u\n", tboot->version);
88 tboot = NULL;
89 return;
90 }
91
92 pr_info("found shared page at phys addr 0x%llx:\n",
93 boot_params.tboot_addr);
94 pr_debug("version: %d\n", tboot->version);
95 pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
96 pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
97 pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
98 pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
99 }
100
101 static pgd_t *tboot_pg_dir;
102 static struct mm_struct tboot_mm = {
103 .mm_rb = RB_ROOT,
104 .pgd = swapper_pg_dir,
105 .mm_users = ATOMIC_INIT(2),
106 .mm_count = ATOMIC_INIT(1),
107 .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem),
108 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
109 .mmlist = LIST_HEAD_INIT(init_mm.mmlist),
110 };
111
switch_to_tboot_pt(void)112 static inline void switch_to_tboot_pt(void)
113 {
114 write_cr3(virt_to_phys(tboot_pg_dir));
115 }
116
map_tboot_page(unsigned long vaddr,unsigned long pfn,pgprot_t prot)117 static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
118 pgprot_t prot)
119 {
120 pgd_t *pgd;
121 p4d_t *p4d;
122 pud_t *pud;
123 pmd_t *pmd;
124 pte_t *pte;
125
126 pgd = pgd_offset(&tboot_mm, vaddr);
127 p4d = p4d_alloc(&tboot_mm, pgd, vaddr);
128 if (!p4d)
129 return -1;
130 pud = pud_alloc(&tboot_mm, p4d, vaddr);
131 if (!pud)
132 return -1;
133 pmd = pmd_alloc(&tboot_mm, pud, vaddr);
134 if (!pmd)
135 return -1;
136 pte = pte_alloc_map(&tboot_mm, pmd, vaddr);
137 if (!pte)
138 return -1;
139 set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
140 pte_unmap(pte);
141
142 /*
143 * PTI poisons low addresses in the kernel page tables in the
144 * name of making them unusable for userspace. To execute
145 * code at such a low address, the poison must be cleared.
146 *
147 * Note: 'pgd' actually gets set in p4d_alloc() _or_
148 * pud_alloc() depending on 4/5-level paging.
149 */
150 pgd->pgd &= ~_PAGE_NX;
151
152 return 0;
153 }
154
map_tboot_pages(unsigned long vaddr,unsigned long start_pfn,unsigned long nr)155 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
156 unsigned long nr)
157 {
158 /* Reuse the original kernel mapping */
159 tboot_pg_dir = pgd_alloc(&tboot_mm);
160 if (!tboot_pg_dir)
161 return -1;
162
163 for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
164 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
165 return -1;
166 }
167
168 return 0;
169 }
170
tboot_create_trampoline(void)171 static void tboot_create_trampoline(void)
172 {
173 u32 map_base, map_size;
174
175 /* Create identity map for tboot shutdown code. */
176 map_base = PFN_DOWN(tboot->tboot_base);
177 map_size = PFN_UP(tboot->tboot_size);
178 if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size))
179 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n",
180 map_base, map_size);
181 }
182
183 #ifdef CONFIG_ACPI_SLEEP
184
add_mac_region(phys_addr_t start,unsigned long size)185 static void add_mac_region(phys_addr_t start, unsigned long size)
186 {
187 struct tboot_mac_region *mr;
188 phys_addr_t end = start + size;
189
190 if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS)
191 panic("tboot: Too many MAC regions\n");
192
193 if (start && size) {
194 mr = &tboot->mac_regions[tboot->num_mac_regions++];
195 mr->start = round_down(start, PAGE_SIZE);
196 mr->size = round_up(end, PAGE_SIZE) - mr->start;
197 }
198 }
199
tboot_setup_sleep(void)200 static int tboot_setup_sleep(void)
201 {
202 int i;
203
204 tboot->num_mac_regions = 0;
205
206 for (i = 0; i < e820_table->nr_entries; i++) {
207 if ((e820_table->entries[i].type != E820_TYPE_RAM)
208 && (e820_table->entries[i].type != E820_TYPE_RESERVED_KERN))
209 continue;
210
211 add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size);
212 }
213
214 tboot->acpi_sinfo.kernel_s3_resume_vector =
215 real_mode_header->wakeup_start;
216
217 return 0;
218 }
219
220 #else /* no CONFIG_ACPI_SLEEP */
221
tboot_setup_sleep(void)222 static int tboot_setup_sleep(void)
223 {
224 /* S3 shutdown requested, but S3 not supported by the kernel... */
225 BUG();
226 return -1;
227 }
228
229 #endif
230
tboot_shutdown(u32 shutdown_type)231 void tboot_shutdown(u32 shutdown_type)
232 {
233 void (*shutdown)(void);
234
235 if (!tboot_enabled())
236 return;
237
238 /*
239 * if we're being called before the 1:1 mapping is set up then just
240 * return and let the normal shutdown happen; this should only be
241 * due to very early panic()
242 */
243 if (!tboot_pg_dir)
244 return;
245
246 /* if this is S3 then set regions to MAC */
247 if (shutdown_type == TB_SHUTDOWN_S3)
248 if (tboot_setup_sleep())
249 return;
250
251 tboot->shutdown_type = shutdown_type;
252
253 switch_to_tboot_pt();
254
255 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
256 shutdown();
257
258 /* should not reach here */
259 while (1)
260 halt();
261 }
262
tboot_copy_fadt(const struct acpi_table_fadt * fadt)263 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
264 {
265 #define TB_COPY_GAS(tbg, g) \
266 tbg.space_id = g.space_id; \
267 tbg.bit_width = g.bit_width; \
268 tbg.bit_offset = g.bit_offset; \
269 tbg.access_width = g.access_width; \
270 tbg.address = g.address;
271
272 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
273 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
274 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
275 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);
276
277 /*
278 * We need phys addr of waking vector, but can't use virt_to_phys() on
279 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
280 * addr.
281 */
282 tboot->acpi_sinfo.wakeup_vector = fadt->facs +
283 offsetof(struct acpi_table_facs, firmware_waking_vector);
284 }
285
tboot_sleep(u8 sleep_state,u32 pm1a_control,u32 pm1b_control)286 static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
287 {
288 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
289 /* S0,1,2: */ -1, -1, -1,
290 /* S3: */ TB_SHUTDOWN_S3,
291 /* S4: */ TB_SHUTDOWN_S4,
292 /* S5: */ TB_SHUTDOWN_S5 };
293
294 if (!tboot_enabled())
295 return 0;
296
297 tboot_copy_fadt(&acpi_gbl_FADT);
298 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
299 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
300 /* we always use the 32b wakeup vector */
301 tboot->acpi_sinfo.vector_width = 32;
302
303 if (sleep_state >= ACPI_S_STATE_COUNT ||
304 acpi_shutdown_map[sleep_state] == -1) {
305 pr_warning("unsupported sleep state 0x%x\n", sleep_state);
306 return -1;
307 }
308
309 tboot_shutdown(acpi_shutdown_map[sleep_state]);
310 return 0;
311 }
312
tboot_extended_sleep(u8 sleep_state,u32 val_a,u32 val_b)313 static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b)
314 {
315 if (!tboot_enabled())
316 return 0;
317
318 pr_warning("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)");
319 return -ENODEV;
320 }
321
322 static atomic_t ap_wfs_count;
323
tboot_wait_for_aps(int num_aps)324 static int tboot_wait_for_aps(int num_aps)
325 {
326 unsigned long timeout;
327
328 timeout = AP_WAIT_TIMEOUT*HZ;
329 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
330 timeout) {
331 mdelay(1);
332 timeout--;
333 }
334
335 if (timeout)
336 pr_warning("tboot wait for APs timeout\n");
337
338 return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps);
339 }
340
tboot_dying_cpu(unsigned int cpu)341 static int tboot_dying_cpu(unsigned int cpu)
342 {
343 atomic_inc(&ap_wfs_count);
344 if (num_online_cpus() == 1) {
345 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
346 return -EBUSY;
347 }
348 return 0;
349 }
350
351 #ifdef CONFIG_DEBUG_FS
352
353 #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \
354 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 }
355
356 #define TBOOT_SERIAL_LOG_ADDR 0x60000
357 #define TBOOT_SERIAL_LOG_SIZE 0x08000
358 #define LOG_MAX_SIZE_OFF 16
359 #define LOG_BUF_OFF 24
360
361 static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID;
362
tboot_log_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)363 static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos)
364 {
365 void __iomem *log_base;
366 u8 log_uuid[16];
367 u32 max_size;
368 void *kbuf;
369 int ret = -EFAULT;
370
371 log_base = ioremap_nocache(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE);
372 if (!log_base)
373 return ret;
374
375 memcpy_fromio(log_uuid, log_base, sizeof(log_uuid));
376 if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid)))
377 goto err_iounmap;
378
379 max_size = readl(log_base + LOG_MAX_SIZE_OFF);
380 if (*ppos >= max_size) {
381 ret = 0;
382 goto err_iounmap;
383 }
384
385 if (*ppos + count > max_size)
386 count = max_size - *ppos;
387
388 kbuf = kmalloc(count, GFP_KERNEL);
389 if (!kbuf) {
390 ret = -ENOMEM;
391 goto err_iounmap;
392 }
393
394 memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count);
395 if (copy_to_user(user_buf, kbuf, count))
396 goto err_kfree;
397
398 *ppos += count;
399
400 ret = count;
401
402 err_kfree:
403 kfree(kbuf);
404
405 err_iounmap:
406 iounmap(log_base);
407
408 return ret;
409 }
410
411 static const struct file_operations tboot_log_fops = {
412 .read = tboot_log_read,
413 .llseek = default_llseek,
414 };
415
416 #endif /* CONFIG_DEBUG_FS */
417
tboot_late_init(void)418 static __init int tboot_late_init(void)
419 {
420 if (!tboot_enabled())
421 return 0;
422
423 tboot_create_trampoline();
424
425 atomic_set(&ap_wfs_count, 0);
426 cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL,
427 tboot_dying_cpu);
428 #ifdef CONFIG_DEBUG_FS
429 debugfs_create_file("tboot_log", S_IRUSR,
430 arch_debugfs_dir, NULL, &tboot_log_fops);
431 #endif
432
433 acpi_os_set_prepare_sleep(&tboot_sleep);
434 acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep);
435 return 0;
436 }
437
438 late_initcall(tboot_late_init);
439
440 /*
441 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
442 */
443
444 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000
445 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000
446
447 /* # pages for each config regs space - used by fixmap */
448 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \
449 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
450
451 /* offsets from pub/priv config space */
452 #define TXTCR_HEAP_BASE 0x0300
453 #define TXTCR_HEAP_SIZE 0x0308
454
455 #define SHA1_SIZE 20
456
457 struct sha1_hash {
458 u8 hash[SHA1_SIZE];
459 };
460
461 struct sinit_mle_data {
462 u32 version; /* currently 6 */
463 struct sha1_hash bios_acm_id;
464 u32 edx_senter_flags;
465 u64 mseg_valid;
466 struct sha1_hash sinit_hash;
467 struct sha1_hash mle_hash;
468 struct sha1_hash stm_hash;
469 struct sha1_hash lcp_policy_hash;
470 u32 lcp_policy_control;
471 u32 rlp_wakeup_addr;
472 u32 reserved;
473 u32 num_mdrs;
474 u32 mdrs_off;
475 u32 num_vtd_dmars;
476 u32 vtd_dmars_off;
477 } __packed;
478
tboot_get_dmar_table(struct acpi_table_header * dmar_tbl)479 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
480 {
481 void *heap_base, *heap_ptr, *config;
482
483 if (!tboot_enabled())
484 return dmar_tbl;
485
486 /*
487 * ACPI tables may not be DMA protected by tboot, so use DMAR copy
488 * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
489 */
490
491 /* map config space in order to get heap addr */
492 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
493 PAGE_SIZE);
494 if (!config)
495 return NULL;
496
497 /* now map TXT heap */
498 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
499 *(u64 *)(config + TXTCR_HEAP_SIZE));
500 iounmap(config);
501 if (!heap_base)
502 return NULL;
503
504 /* walk heap to SinitMleData */
505 /* skip BiosData */
506 heap_ptr = heap_base + *(u64 *)heap_base;
507 /* skip OsMleData */
508 heap_ptr += *(u64 *)heap_ptr;
509 /* skip OsSinitData */
510 heap_ptr += *(u64 *)heap_ptr;
511 /* now points to SinitMleDataSize; set to SinitMleData */
512 heap_ptr += sizeof(u64);
513 /* get addr of DMAR table */
514 dmar_tbl = (struct acpi_table_header *)(heap_ptr +
515 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
516 sizeof(u64));
517
518 /* don't unmap heap because dmar.c needs access to this */
519
520 return dmar_tbl;
521 }
522
tboot_force_iommu(void)523 int tboot_force_iommu(void)
524 {
525 if (!tboot_enabled())
526 return 0;
527
528 if (intel_iommu_tboot_noforce)
529 return 1;
530
531 if (no_iommu || swiotlb || dmar_disabled)
532 pr_warning("Forcing Intel-IOMMU to enabled\n");
533
534 dmar_disabled = 0;
535 #ifdef CONFIG_SWIOTLB
536 swiotlb = 0;
537 #endif
538 no_iommu = 0;
539
540 return 1;
541 }
542
