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.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. */
51struct tboot *tboot __read_mostly;
52EXPORT_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
60static u8 tboot_uuid[16] __initdata = TBOOT_UUID;
61
62void __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_any_mapped(boot_params.tboot_addr,
72			     boot_params.tboot_addr, E820_RESERVED)) {
73		pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n");
74		return;
75	}
76
77	/* only a natively booted kernel should be using TXT */
78	if (paravirt_enabled()) {
79		pr_warning("non-0 tboot_addr but pv_ops is enabled\n");
80		return;
81	}
82
83	/* Map and check for tboot UUID. */
84	set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
85	tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE);
86	if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
87		pr_warning("tboot at 0x%llx is invalid\n",
88			   boot_params.tboot_addr);
89		tboot = NULL;
90		return;
91	}
92	if (tboot->version < 5) {
93		pr_warning("tboot version is invalid: %u\n", tboot->version);
94		tboot = NULL;
95		return;
96	}
97
98	pr_info("found shared page at phys addr 0x%llx:\n",
99		boot_params.tboot_addr);
100	pr_debug("version: %d\n", tboot->version);
101	pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
102	pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
103	pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
104	pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
105}
106
107static pgd_t *tboot_pg_dir;
108static struct mm_struct tboot_mm = {
109	.mm_rb          = RB_ROOT,
110	.pgd            = swapper_pg_dir,
111	.mm_users       = ATOMIC_INIT(2),
112	.mm_count       = ATOMIC_INIT(1),
113	.mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
114	.page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
115	.mmlist         = LIST_HEAD_INIT(init_mm.mmlist),
116};
117
118static inline void switch_to_tboot_pt(void)
119{
120	write_cr3(virt_to_phys(tboot_pg_dir));
121}
122
123static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
124			  pgprot_t prot)
125{
126	pgd_t *pgd;
127	pud_t *pud;
128	pmd_t *pmd;
129	pte_t *pte;
130
131	pgd = pgd_offset(&tboot_mm, vaddr);
132	pud = pud_alloc(&tboot_mm, pgd, vaddr);
133	if (!pud)
134		return -1;
135	pmd = pmd_alloc(&tboot_mm, pud, vaddr);
136	if (!pmd)
137		return -1;
138	pte = pte_alloc_map(&tboot_mm, NULL, pmd, vaddr);
139	if (!pte)
140		return -1;
141	set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
142	pte_unmap(pte);
143	return 0;
144}
145
146static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
147			   unsigned long nr)
148{
149	/* Reuse the original kernel mapping */
150	tboot_pg_dir = pgd_alloc(&tboot_mm);
151	if (!tboot_pg_dir)
152		return -1;
153
154	for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
155		if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
156			return -1;
157	}
158
159	return 0;
160}
161
162static void tboot_create_trampoline(void)
163{
164	u32 map_base, map_size;
165
166	/* Create identity map for tboot shutdown code. */
167	map_base = PFN_DOWN(tboot->tboot_base);
168	map_size = PFN_UP(tboot->tboot_size);
169	if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size))
170		panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n",
171		      map_base, map_size);
172}
173
174#ifdef CONFIG_ACPI_SLEEP
175
176static void add_mac_region(phys_addr_t start, unsigned long size)
177{
178	struct tboot_mac_region *mr;
179	phys_addr_t end = start + size;
180
181	if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS)
182		panic("tboot: Too many MAC regions\n");
183
184	if (start && size) {
185		mr = &tboot->mac_regions[tboot->num_mac_regions++];
186		mr->start = round_down(start, PAGE_SIZE);
187		mr->size  = round_up(end, PAGE_SIZE) - mr->start;
188	}
189}
190
191static int tboot_setup_sleep(void)
192{
193	int i;
194
195	tboot->num_mac_regions = 0;
196
197	for (i = 0; i < e820.nr_map; i++) {
198		if ((e820.map[i].type != E820_RAM)
199		 && (e820.map[i].type != E820_RESERVED_KERN))
200			continue;
201
202		add_mac_region(e820.map[i].addr, e820.map[i].size);
203	}
204
205	tboot->acpi_sinfo.kernel_s3_resume_vector =
206		real_mode_header->wakeup_start;
207
208	return 0;
209}
210
211#else /* no CONFIG_ACPI_SLEEP */
212
213static int tboot_setup_sleep(void)
214{
215	/* S3 shutdown requested, but S3 not supported by the kernel... */
216	BUG();
217	return -1;
218}
219
220#endif
221
222void tboot_shutdown(u32 shutdown_type)
223{
224	void (*shutdown)(void);
225
226	if (!tboot_enabled())
227		return;
228
229	/*
230	 * if we're being called before the 1:1 mapping is set up then just
231	 * return and let the normal shutdown happen; this should only be
232	 * due to very early panic()
233	 */
234	if (!tboot_pg_dir)
235		return;
236
237	/* if this is S3 then set regions to MAC */
238	if (shutdown_type == TB_SHUTDOWN_S3)
239		if (tboot_setup_sleep())
240			return;
241
242	tboot->shutdown_type = shutdown_type;
243
244	switch_to_tboot_pt();
245
246	shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
247	shutdown();
248
249	/* should not reach here */
250	while (1)
251		halt();
252}
253
254static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
255{
256#define TB_COPY_GAS(tbg, g)			\
257	tbg.space_id     = g.space_id;		\
258	tbg.bit_width    = g.bit_width;		\
259	tbg.bit_offset   = g.bit_offset;	\
260	tbg.access_width = g.access_width;	\
261	tbg.address      = g.address;
262
263	TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
264	TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
265	TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
266	TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);
267
268	/*
269	 * We need phys addr of waking vector, but can't use virt_to_phys() on
270	 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
271	 * addr.
272	 */
273	tboot->acpi_sinfo.wakeup_vector = fadt->facs +
274		offsetof(struct acpi_table_facs, firmware_waking_vector);
275}
276
277static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
278{
279	static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
280		/* S0,1,2: */ -1, -1, -1,
281		/* S3: */ TB_SHUTDOWN_S3,
282		/* S4: */ TB_SHUTDOWN_S4,
283		/* S5: */ TB_SHUTDOWN_S5 };
284
285	if (!tboot_enabled())
286		return 0;
287
288	tboot_copy_fadt(&acpi_gbl_FADT);
289	tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
290	tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
291	/* we always use the 32b wakeup vector */
292	tboot->acpi_sinfo.vector_width = 32;
293
294	if (sleep_state >= ACPI_S_STATE_COUNT ||
295	    acpi_shutdown_map[sleep_state] == -1) {
296		pr_warning("unsupported sleep state 0x%x\n", sleep_state);
297		return -1;
298	}
299
300	tboot_shutdown(acpi_shutdown_map[sleep_state]);
301	return 0;
302}
303
304static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b)
305{
306	if (!tboot_enabled())
307		return 0;
308
309	pr_warning("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)");
310	return -ENODEV;
311}
312
313static atomic_t ap_wfs_count;
314
315static int tboot_wait_for_aps(int num_aps)
316{
317	unsigned long timeout;
318
319	timeout = AP_WAIT_TIMEOUT*HZ;
320	while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
321	       timeout) {
322		mdelay(1);
323		timeout--;
324	}
325
326	if (timeout)
327		pr_warning("tboot wait for APs timeout\n");
328
329	return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps);
330}
331
332static int tboot_cpu_callback(struct notifier_block *nfb, unsigned long action,
333			      void *hcpu)
334{
335	switch (action) {
336	case CPU_DYING:
337		atomic_inc(&ap_wfs_count);
338		if (num_online_cpus() == 1)
339			if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
340				return NOTIFY_BAD;
341		break;
342	}
343	return NOTIFY_OK;
344}
345
346static struct notifier_block tboot_cpu_notifier =
347{
348	.notifier_call = tboot_cpu_callback,
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
361static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID;
362
363static 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
402err_kfree:
403	kfree(kbuf);
404
405err_iounmap:
406	iounmap(log_base);
407
408	return ret;
409}
410
411static const struct file_operations tboot_log_fops = {
412	.read	= tboot_log_read,
413	.llseek	= default_llseek,
414};
415
416#endif /* CONFIG_DEBUG_FS */
417
418static __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	register_hotcpu_notifier(&tboot_cpu_notifier);
427
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
438late_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
457struct sha1_hash {
458	u8 hash[SHA1_SIZE];
459};
460
461struct 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
479struct 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
523int tboot_force_iommu(void)
524{
525	if (!tboot_enabled())
526		return 0;
527
528	if (no_iommu || swiotlb || dmar_disabled)
529		pr_warning("Forcing Intel-IOMMU to enabled\n");
530
531	dmar_disabled = 0;
532#ifdef CONFIG_SWIOTLB
533	swiotlb = 0;
534#endif
535	no_iommu = 0;
536
537	return 1;
538}
539