aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel/tboot.c
blob: 6410744ac5cb7249544fb9424853b0e88f28679f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
/*
 * tboot.c: main implementation of helper functions used by kernel for
 *          runtime support of Intel(R) Trusted Execution Technology
 *
 * Copyright (c) 2006-2009, Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include <linux/dma_remapping.h>
#include <linux/init_task.h>
#include <linux/spinlock.h>
#include <linux/export.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/dmar.h>
#include <linux/cpu.h>
#include <linux/pfn.h>
#include <linux/mm.h>
#include <linux/tboot.h>

#include <asm/trampoline.h>
#include <asm/processor.h>
#include <asm/bootparam.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/swiotlb.h>
#include <asm/fixmap.h>
#include <asm/proto.h>
#include <asm/setup.h>
#include <asm/e820.h>
#include <asm/io.h>

#include "acpi/realmode/wakeup.h"

/* Global pointer to shared data; NULL means no measured launch. */
struct tboot *tboot __read_mostly;
EXPORT_SYMBOL(tboot);

/* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
#define AP_WAIT_TIMEOUT		1

#undef pr_fmt
#define pr_fmt(fmt)	"tboot: " fmt

static u8 tboot_uuid[16] __initdata = TBOOT_UUID;

void __init tboot_probe(void)
{
	/* Look for valid page-aligned address for shared page. */
	if (!boot_params.tboot_addr)
		return;
	/*
	 * also verify that it is mapped as we expect it before calling
	 * set_fixmap(), to reduce chance of garbage value causing crash
	 */
	if (!e820_any_mapped(boot_params.tboot_addr,
			     boot_params.tboot_addr, E820_RESERVED)) {
		pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n");
		return;
	}

	/* only a natively booted kernel should be using TXT */
	if (paravirt_enabled()) {
		pr_warning("non-0 tboot_addr but pv_ops is enabled\n");
		return;
	}

	/* Map and check for tboot UUID. */
	set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
	tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE);
	if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
		pr_warning("tboot at 0x%llx is invalid\n",
			   boot_params.tboot_addr);
		tboot = NULL;
		return;
	}
	if (tboot->version < 5) {
		pr_warning("tboot version is invalid: %u\n", tboot->version);
		tboot = NULL;
		return;
	}

	pr_info("found shared page at phys addr 0x%llx:\n",
		boot_params.tboot_addr);
	pr_debug("version: %d\n", tboot->version);
	pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
	pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
	pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
	pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
}

static pgd_t *tboot_pg_dir;
static struct mm_struct tboot_mm = {
	.mm_rb          = RB_ROOT,
	.pgd            = swapper_pg_dir,
	.mm_users       = ATOMIC_INIT(2),
	.mm_count       = ATOMIC_INIT(1),
	.mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
	.page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
	.mmlist         = LIST_HEAD_INIT(init_mm.mmlist),
};

static inline void switch_to_tboot_pt(void)
{
	write_cr3(virt_to_phys(tboot_pg_dir));
}

static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
			  pgprot_t prot)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;

	pgd = pgd_offset(&tboot_mm, vaddr);
	pud = pud_alloc(&tboot_mm, pgd, vaddr);
	if (!pud)
		return -1;
	pmd = pmd_alloc(&tboot_mm, pud, vaddr);
	if (!pmd)
		return -1;
	pte = pte_alloc_map(&tboot_mm, NULL, pmd, vaddr);
	if (!pte)
		return -1;
	set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
	pte_unmap(pte);
	return 0;
}

static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
			   unsigned long nr)
{
	/* Reuse the original kernel mapping */
	tboot_pg_dir = pgd_alloc(&tboot_mm);
	if (!tboot_pg_dir)
		return -1;

	for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
		if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
			return -1;
	}

	return 0;
}

static void tboot_create_trampoline(void)
{
	u32 map_base, map_size;

	/* Create identity map for tboot shutdown code. */
	map_base = PFN_DOWN(tboot->tboot_base);
	map_size = PFN_UP(tboot->tboot_size);
	if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size))
		panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n",
		      map_base, map_size);
}

#ifdef CONFIG_ACPI_SLEEP

static void add_mac_region(phys_addr_t start, unsigned long size)
{
	struct tboot_mac_region *mr;
	phys_addr_t end = start + size;

	if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS)
		panic("tboot: Too many MAC regions\n");

	if (start && size) {
		mr = &tboot->mac_regions[tboot->num_mac_regions++];
		mr->start = round_down(start, PAGE_SIZE);
		mr->size  = round_up(end, PAGE_SIZE) - mr->start;
	}
}

static int tboot_setup_sleep(void)
{
	int i;

	tboot->num_mac_regions = 0;

	for (i = 0; i < e820.nr_map; i++) {
		if ((e820.map[i].type != E820_RAM)
		 && (e820.map[i].type != E820_RESERVED_KERN))
			continue;

		add_mac_region(e820.map[i].addr, e820.map[i].size);
	}

	tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;

	return 0;
}

#else /* no CONFIG_ACPI_SLEEP */

static int tboot_setup_sleep(void)
{
	/* S3 shutdown requested, but S3 not supported by the kernel... */
	BUG();
	return -1;
}

#endif

void tboot_shutdown(u32 shutdown_type)
{
	void (*shutdown)(void);

	if (!tboot_enabled())
		return;

	/*
	 * if we're being called before the 1:1 mapping is set up then just
	 * return and let the normal shutdown happen; this should only be
	 * due to very early panic()
	 */
	if (!tboot_pg_dir)
		return;

	/* if this is S3 then set regions to MAC */
	if (shutdown_type == TB_SHUTDOWN_S3)
		if (tboot_setup_sleep())
			return;

	tboot->shutdown_type = shutdown_type;

	switch_to_tboot_pt();

	shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
	shutdown();

	/* should not reach here */
	while (1)
		halt();
}

static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
{
#define TB_COPY_GAS(tbg, g)			\
	tbg.space_id     = g.space_id;		\
	tbg.bit_width    = g.bit_width;		\
	tbg.bit_offset   = g.bit_offset;	\
	tbg.access_width = g.access_width;	\
	tbg.address      = g.address;

	TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
	TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
	TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
	TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);

	/*
	 * We need phys addr of waking vector, but can't use virt_to_phys() on
	 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
	 * addr.
	 */
	tboot->acpi_sinfo.wakeup_vector = fadt->facs +
		offsetof(struct acpi_table_facs, firmware_waking_vector);
}

static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
{
	static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
		/* S0,1,2: */ -1, -1, -1,
		/* S3: */ TB_SHUTDOWN_S3,
		/* S4: */ TB_SHUTDOWN_S4,
		/* S5: */ TB_SHUTDOWN_S5 };

	if (!tboot_enabled())
		return 0;

	tboot_copy_fadt(&acpi_gbl_FADT);
	tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
	tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
	/* we always use the 32b wakeup vector */
	tboot->acpi_sinfo.vector_width = 32;

	if (sleep_state >= ACPI_S_STATE_COUNT ||
	    acpi_shutdown_map[sleep_state] == -1) {
		pr_warning("unsupported sleep state 0x%x\n", sleep_state);
		return -1;
	}

	tboot_shutdown(acpi_shutdown_map[sleep_state]);
	return 0;
}

static atomic_t ap_wfs_count;

static int tboot_wait_for_aps(int num_aps)
{
	unsigned long timeout;

	timeout = AP_WAIT_TIMEOUT*HZ;
	while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
	       timeout) {
		mdelay(1);
		timeout--;
	}

	if (timeout)
		pr_warning("tboot wait for APs timeout\n");

	return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps);
}

static int __cpuinit tboot_cpu_callback(struct notifier_block *nfb,
			unsigned long action, void *hcpu)
{
	switch (action) {
	case CPU_DYING:
		atomic_inc(&ap_wfs_count);
		if (num_online_cpus() == 1)
			if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
				return NOTIFY_BAD;
		break;
	}
	return NOTIFY_OK;
}

static struct notifier_block tboot_cpu_notifier __cpuinitdata =
{
	.notifier_call = tboot_cpu_callback,
};

static __init int tboot_late_init(void)
{
	if (!tboot_enabled())
		return 0;

	tboot_create_trampoline();

	atomic_set(&ap_wfs_count, 0);
	register_hotcpu_notifier(&tboot_cpu_notifier);

	acpi_os_set_prepare_sleep(&tboot_sleep);
	return 0;
}

late_initcall(tboot_late_init);

/*
 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
 */

#define TXT_PUB_CONFIG_REGS_BASE       0xfed30000
#define TXT_PRIV_CONFIG_REGS_BASE      0xfed20000

/* # pages for each config regs space - used by fixmap */
#define NR_TXT_CONFIG_PAGES     ((TXT_PUB_CONFIG_REGS_BASE -                \
				  TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)

/* offsets from pub/priv config space */
#define TXTCR_HEAP_BASE             0x0300
#define TXTCR_HEAP_SIZE             0x0308

#define SHA1_SIZE      20

struct sha1_hash {
	u8 hash[SHA1_SIZE];
};

struct sinit_mle_data {
	u32               version;             /* currently 6 */
	struct sha1_hash  bios_acm_id;
	u32               edx_senter_flags;
	u64               mseg_valid;
	struct sha1_hash  sinit_hash;
	struct sha1_hash  mle_hash;
	struct sha1_hash  stm_hash;
	struct sha1_hash  lcp_policy_hash;
	u32               lcp_policy_control;
	u32               rlp_wakeup_addr;
	u32               reserved;
	u32               num_mdrs;
	u32               mdrs_off;
	u32               num_vtd_dmars;
	u32               vtd_dmars_off;
} __packed;

struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
{
	void *heap_base, *heap_ptr, *config;

	if (!tboot_enabled())
		return dmar_tbl;

	/*
	 * ACPI tables may not be DMA protected by tboot, so use DMAR copy
	 * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
	 */

	/* map config space in order to get heap addr */
	config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
			 PAGE_SIZE);
	if (!config)
		return NULL;

	/* now map TXT heap */
	heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
			    *(u64 *)(config + TXTCR_HEAP_SIZE));
	iounmap(config);
	if (!heap_base)
		return NULL;

	/* walk heap to SinitMleData */
	/* skip BiosData */
	heap_ptr = heap_base + *(u64 *)heap_base;
	/* skip OsMleData */
	heap_ptr += *(u64 *)heap_ptr;
	/* skip OsSinitData */
	heap_ptr += *(u64 *)heap_ptr;
	/* now points to SinitMleDataSize; set to SinitMleData */
	heap_ptr += sizeof(u64);
	/* get addr of DMAR table */
	dmar_tbl = (struct acpi_table_header *)(heap_ptr +
		   ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
		   sizeof(u64));

	/* don't unmap heap because dmar.c needs access to this */

	return dmar_tbl;
}

int tboot_force_iommu(void)
{
	if (!tboot_enabled())
		return 0;

	if (no_iommu || swiotlb || dmar_disabled)
		pr_warning("Forcing Intel-IOMMU to enabled\n");

	dmar_disabled = 0;
#ifdef CONFIG_SWIOTLB
	swiotlb = 0;
#endif
	no_iommu = 0;

	return 1;
}