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
35 #include <asm/trampoline.h>
36 #include <asm/processor.h>
37 #include <asm/bootparam.h>
38 #include <asm/pgtable.h>
39 #include <asm/pgalloc.h>
40 #include <asm/swiotlb.h>
41 #include <asm/fixmap.h>
42 #include <asm/proto.h>
43 #include <asm/setup.h>
44 #include <asm/e820.h>
45 #include <asm/io.h>
46
47 #include "acpi/realmode/wakeup.h"
48
49 /* Global pointer to shared data; NULL means no measured launch. */
50 struct tboot *tboot __read_mostly;
51 EXPORT_SYMBOL(tboot);
52
53 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
54 #define AP_WAIT_TIMEOUT 1
55
56 #undef pr_fmt
57 #define pr_fmt(fmt) "tboot: " fmt
58
59 static u8 tboot_uuid[16] __initdata = TBOOT_UUID;
60
tboot_probe(void)61 void __init tboot_probe(void)
62 {
63 /* Look for valid page-aligned address for shared page. */
64 if (!boot_params.tboot_addr)
65 return;
66 /*
67 * also verify that it is mapped as we expect it before calling
68 * set_fixmap(), to reduce chance of garbage value causing crash
69 */
70 if (!e820_any_mapped(boot_params.tboot_addr,
71 boot_params.tboot_addr, E820_RESERVED)) {
72 pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n");
73 return;
74 }
75
76 /* only a natively booted kernel should be using TXT */
77 if (paravirt_enabled()) {
78 pr_warning("non-0 tboot_addr but pv_ops is enabled\n");
79 return;
80 }
81
82 /* Map and check for tboot UUID. */
83 set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
84 tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE);
85 if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
86 pr_warning("tboot at 0x%llx is invalid\n",
87 boot_params.tboot_addr);
88 tboot = NULL;
89 return;
90 }
91 if (tboot->version < 5) {
92 pr_warning("tboot version is invalid: %u\n", tboot->version);
93 tboot = NULL;
94 return;
95 }
96
97 pr_info("found shared page at phys addr 0x%llx:\n",
98 boot_params.tboot_addr);
99 pr_debug("version: %d\n", tboot->version);
100 pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
101 pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
102 pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
103 pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
104 }
105
106 static pgd_t *tboot_pg_dir;
107 static struct mm_struct tboot_mm = {
108 .mm_rb = RB_ROOT,
109 .pgd = swapper_pg_dir,
110 .mm_users = ATOMIC_INIT(2),
111 .mm_count = ATOMIC_INIT(1),
112 .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem),
113 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
114 .mmlist = LIST_HEAD_INIT(init_mm.mmlist),
115 };
116
switch_to_tboot_pt(void)117 static inline void switch_to_tboot_pt(void)
118 {
119 write_cr3(virt_to_phys(tboot_pg_dir));
120 }
121
map_tboot_page(unsigned long vaddr,unsigned long pfn,pgprot_t prot)122 static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
123 pgprot_t prot)
124 {
125 pgd_t *pgd;
126 pud_t *pud;
127 pmd_t *pmd;
128 pte_t *pte;
129
130 pgd = pgd_offset(&tboot_mm, vaddr);
131 pud = pud_alloc(&tboot_mm, pgd, vaddr);
132 if (!pud)
133 return -1;
134 pmd = pmd_alloc(&tboot_mm, pud, vaddr);
135 if (!pmd)
136 return -1;
137 pte = pte_alloc_map(&tboot_mm, NULL, pmd, vaddr);
138 if (!pte)
139 return -1;
140 set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
141 pte_unmap(pte);
142 return 0;
143 }
144
map_tboot_pages(unsigned long vaddr,unsigned long start_pfn,unsigned long nr)145 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
146 unsigned long nr)
147 {
148 /* Reuse the original kernel mapping */
149 tboot_pg_dir = pgd_alloc(&tboot_mm);
150 if (!tboot_pg_dir)
151 return -1;
152
153 for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
154 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
155 return -1;
156 }
157
158 return 0;
159 }
160
tboot_create_trampoline(void)161 static void tboot_create_trampoline(void)
162 {
163 u32 map_base, map_size;
164
165 /* Create identity map for tboot shutdown code. */
166 map_base = PFN_DOWN(tboot->tboot_base);
167 map_size = PFN_UP(tboot->tboot_size);
168 if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size))
169 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n",
170 map_base, map_size);
171 }
172
173 #ifdef CONFIG_ACPI_SLEEP
174
add_mac_region(phys_addr_t start,unsigned long size)175 static void add_mac_region(phys_addr_t start, unsigned long size)
176 {
177 struct tboot_mac_region *mr;
178 phys_addr_t end = start + size;
179
180 if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS)
181 panic("tboot: Too many MAC regions\n");
182
183 if (start && size) {
184 mr = &tboot->mac_regions[tboot->num_mac_regions++];
185 mr->start = round_down(start, PAGE_SIZE);
186 mr->size = round_up(end, PAGE_SIZE) - mr->start;
187 }
188 }
189
tboot_setup_sleep(void)190 static int tboot_setup_sleep(void)
191 {
192 int i;
193
194 tboot->num_mac_regions = 0;
195
196 for (i = 0; i < e820.nr_map; i++) {
197 if ((e820.map[i].type != E820_RAM)
198 && (e820.map[i].type != E820_RESERVED_KERN))
199 continue;
200
201 add_mac_region(e820.map[i].addr, e820.map[i].size);
202 }
203
204 tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
205
206 return 0;
207 }
208
209 #else /* no CONFIG_ACPI_SLEEP */
210
tboot_setup_sleep(void)211 static int tboot_setup_sleep(void)
212 {
213 /* S3 shutdown requested, but S3 not supported by the kernel... */
214 BUG();
215 return -1;
216 }
217
218 #endif
219
tboot_shutdown(u32 shutdown_type)220 void tboot_shutdown(u32 shutdown_type)
221 {
222 void (*shutdown)(void);
223
224 if (!tboot_enabled())
225 return;
226
227 /*
228 * if we're being called before the 1:1 mapping is set up then just
229 * return and let the normal shutdown happen; this should only be
230 * due to very early panic()
231 */
232 if (!tboot_pg_dir)
233 return;
234
235 /* if this is S3 then set regions to MAC */
236 if (shutdown_type == TB_SHUTDOWN_S3)
237 if (tboot_setup_sleep())
238 return;
239
240 tboot->shutdown_type = shutdown_type;
241
242 switch_to_tboot_pt();
243
244 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
245 shutdown();
246
247 /* should not reach here */
248 while (1)
249 halt();
250 }
251
tboot_copy_fadt(const struct acpi_table_fadt * fadt)252 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
253 {
254 #define TB_COPY_GAS(tbg, g) \
255 tbg.space_id = g.space_id; \
256 tbg.bit_width = g.bit_width; \
257 tbg.bit_offset = g.bit_offset; \
258 tbg.access_width = g.access_width; \
259 tbg.address = g.address;
260
261 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
262 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
263 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
264 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);
265
266 /*
267 * We need phys addr of waking vector, but can't use virt_to_phys() on
268 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
269 * addr.
270 */
271 tboot->acpi_sinfo.wakeup_vector = fadt->facs +
272 offsetof(struct acpi_table_facs, firmware_waking_vector);
273 }
274
tboot_sleep(u8 sleep_state,u32 pm1a_control,u32 pm1b_control)275 static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
276 {
277 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
278 /* S0,1,2: */ -1, -1, -1,
279 /* S3: */ TB_SHUTDOWN_S3,
280 /* S4: */ TB_SHUTDOWN_S4,
281 /* S5: */ TB_SHUTDOWN_S5 };
282
283 if (!tboot_enabled())
284 return 0;
285
286 tboot_copy_fadt(&acpi_gbl_FADT);
287 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
288 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
289 /* we always use the 32b wakeup vector */
290 tboot->acpi_sinfo.vector_width = 32;
291
292 if (sleep_state >= ACPI_S_STATE_COUNT ||
293 acpi_shutdown_map[sleep_state] == -1) {
294 pr_warning("unsupported sleep state 0x%x\n", sleep_state);
295 return -1;
296 }
297
298 tboot_shutdown(acpi_shutdown_map[sleep_state]);
299 return 0;
300 }
301
302 static atomic_t ap_wfs_count;
303
tboot_wait_for_aps(int num_aps)304 static int tboot_wait_for_aps(int num_aps)
305 {
306 unsigned long timeout;
307
308 timeout = AP_WAIT_TIMEOUT*HZ;
309 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
310 timeout) {
311 mdelay(1);
312 timeout--;
313 }
314
315 if (timeout)
316 pr_warning("tboot wait for APs timeout\n");
317
318 return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps);
319 }
320
tboot_cpu_callback(struct notifier_block * nfb,unsigned long action,void * hcpu)321 static int __cpuinit tboot_cpu_callback(struct notifier_block *nfb,
322 unsigned long action, void *hcpu)
323 {
324 switch (action) {
325 case CPU_DYING:
326 atomic_inc(&ap_wfs_count);
327 if (num_online_cpus() == 1)
328 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
329 return NOTIFY_BAD;
330 break;
331 }
332 return NOTIFY_OK;
333 }
334
335 static struct notifier_block tboot_cpu_notifier __cpuinitdata =
336 {
337 .notifier_call = tboot_cpu_callback,
338 };
339
tboot_late_init(void)340 static __init int tboot_late_init(void)
341 {
342 if (!tboot_enabled())
343 return 0;
344
345 tboot_create_trampoline();
346
347 atomic_set(&ap_wfs_count, 0);
348 register_hotcpu_notifier(&tboot_cpu_notifier);
349
350 acpi_os_set_prepare_sleep(&tboot_sleep);
351 return 0;
352 }
353
354 late_initcall(tboot_late_init);
355
356 /*
357 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
358 */
359
360 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000
361 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000
362
363 /* # pages for each config regs space - used by fixmap */
364 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \
365 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
366
367 /* offsets from pub/priv config space */
368 #define TXTCR_HEAP_BASE 0x0300
369 #define TXTCR_HEAP_SIZE 0x0308
370
371 #define SHA1_SIZE 20
372
373 struct sha1_hash {
374 u8 hash[SHA1_SIZE];
375 };
376
377 struct sinit_mle_data {
378 u32 version; /* currently 6 */
379 struct sha1_hash bios_acm_id;
380 u32 edx_senter_flags;
381 u64 mseg_valid;
382 struct sha1_hash sinit_hash;
383 struct sha1_hash mle_hash;
384 struct sha1_hash stm_hash;
385 struct sha1_hash lcp_policy_hash;
386 u32 lcp_policy_control;
387 u32 rlp_wakeup_addr;
388 u32 reserved;
389 u32 num_mdrs;
390 u32 mdrs_off;
391 u32 num_vtd_dmars;
392 u32 vtd_dmars_off;
393 } __packed;
394
tboot_get_dmar_table(struct acpi_table_header * dmar_tbl)395 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
396 {
397 void *heap_base, *heap_ptr, *config;
398
399 if (!tboot_enabled())
400 return dmar_tbl;
401
402 /*
403 * ACPI tables may not be DMA protected by tboot, so use DMAR copy
404 * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
405 */
406
407 /* map config space in order to get heap addr */
408 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
409 PAGE_SIZE);
410 if (!config)
411 return NULL;
412
413 /* now map TXT heap */
414 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
415 *(u64 *)(config + TXTCR_HEAP_SIZE));
416 iounmap(config);
417 if (!heap_base)
418 return NULL;
419
420 /* walk heap to SinitMleData */
421 /* skip BiosData */
422 heap_ptr = heap_base + *(u64 *)heap_base;
423 /* skip OsMleData */
424 heap_ptr += *(u64 *)heap_ptr;
425 /* skip OsSinitData */
426 heap_ptr += *(u64 *)heap_ptr;
427 /* now points to SinitMleDataSize; set to SinitMleData */
428 heap_ptr += sizeof(u64);
429 /* get addr of DMAR table */
430 dmar_tbl = (struct acpi_table_header *)(heap_ptr +
431 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
432 sizeof(u64));
433
434 /* don't unmap heap because dmar.c needs access to this */
435
436 return dmar_tbl;
437 }
438
tboot_force_iommu(void)439 int tboot_force_iommu(void)
440 {
441 if (!tboot_enabled())
442 return 0;
443
444 if (no_iommu || swiotlb || dmar_disabled)
445 pr_warning("Forcing Intel-IOMMU to enabled\n");
446
447 dmar_disabled = 0;
448 #ifdef CONFIG_SWIOTLB
449 swiotlb = 0;
450 #endif
451 no_iommu = 0;
452
453 return 1;
454 }
455