1 // SPDX-License-Identifier: GPL-2.0-only
3 * tboot.c: main implementation of helper functions used by kernel for
4 * runtime support of Intel(R) Trusted Execution Technology
6 * Copyright (c) 2006-2009, Intel Corporation
9 #include <linux/intel-iommu.h>
10 #include <linux/init_task.h>
11 #include <linux/spinlock.h>
12 #include <linux/export.h>
13 #include <linux/delay.h>
14 #include <linux/sched.h>
15 #include <linux/init.h>
16 #include <linux/dmar.h>
17 #include <linux/cpu.h>
18 #include <linux/pfn.h>
20 #include <linux/tboot.h>
21 #include <linux/debugfs.h>
23 #include <asm/realmode.h>
24 #include <asm/processor.h>
25 #include <asm/bootparam.h>
26 #include <asm/pgalloc.h>
27 #include <asm/fixmap.h>
28 #include <asm/proto.h>
29 #include <asm/setup.h>
30 #include <asm/e820/api.h>
33 #include "../realmode/rm/wakeup.h"
35 /* Global pointer to shared data; NULL means no measured launch. */
36 static struct tboot *tboot __read_mostly;
38 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
39 #define AP_WAIT_TIMEOUT 1
42 #define pr_fmt(fmt) "tboot: " fmt
44 static u8 tboot_uuid[16] __initdata = TBOOT_UUID;
46 bool tboot_enabled(void)
51 /* noinline to prevent gcc from warning about dereferencing constant fixaddr */
52 static noinline __init bool check_tboot_version(void)
54 if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
55 pr_warn("tboot at 0x%llx is invalid\n", boot_params.tboot_addr);
59 if (tboot->version < 5) {
60 pr_warn("tboot version is invalid: %u\n", tboot->version);
64 pr_info("found shared page at phys addr 0x%llx:\n",
65 boot_params.tboot_addr);
66 pr_debug("version: %d\n", tboot->version);
67 pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
68 pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
69 pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
70 pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
75 void __init tboot_probe(void)
77 /* Look for valid page-aligned address for shared page. */
78 if (!boot_params.tboot_addr)
81 * also verify that it is mapped as we expect it before calling
82 * set_fixmap(), to reduce chance of garbage value causing crash
84 if (!e820__mapped_any(boot_params.tboot_addr,
85 boot_params.tboot_addr, E820_TYPE_RESERVED)) {
86 pr_warn("non-0 tboot_addr but it is not of type E820_TYPE_RESERVED\n");
90 /* Map and check for tboot UUID. */
91 set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
92 tboot = (void *)fix_to_virt(FIX_TBOOT_BASE);
93 if (!check_tboot_version())
97 static pgd_t *tboot_pg_dir;
98 static struct mm_struct tboot_mm = {
100 .pgd = swapper_pg_dir,
101 .mm_users = ATOMIC_INIT(2),
102 .mm_count = ATOMIC_INIT(1),
103 .write_protect_seq = SEQCNT_ZERO(tboot_mm.write_protect_seq),
104 MMAP_LOCK_INITIALIZER(init_mm)
105 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
106 .mmlist = LIST_HEAD_INIT(init_mm.mmlist),
109 static inline void switch_to_tboot_pt(void)
111 write_cr3(virt_to_phys(tboot_pg_dir));
114 static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
123 pgd = pgd_offset(&tboot_mm, vaddr);
124 p4d = p4d_alloc(&tboot_mm, pgd, vaddr);
127 pud = pud_alloc(&tboot_mm, p4d, vaddr);
130 pmd = pmd_alloc(&tboot_mm, pud, vaddr);
133 pte = pte_alloc_map(&tboot_mm, pmd, vaddr);
136 set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
140 * PTI poisons low addresses in the kernel page tables in the
141 * name of making them unusable for userspace. To execute
142 * code at such a low address, the poison must be cleared.
144 * Note: 'pgd' actually gets set in p4d_alloc() _or_
145 * pud_alloc() depending on 4/5-level paging.
147 pgd->pgd &= ~_PAGE_NX;
152 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
155 /* Reuse the original kernel mapping */
156 tboot_pg_dir = pgd_alloc(&tboot_mm);
160 for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
161 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
168 static void tboot_create_trampoline(void)
170 u32 map_base, map_size;
172 /* Create identity map for tboot shutdown code. */
173 map_base = PFN_DOWN(tboot->tboot_base);
174 map_size = PFN_UP(tboot->tboot_size);
175 if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size))
176 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n",
180 #ifdef CONFIG_ACPI_SLEEP
182 static void add_mac_region(phys_addr_t start, unsigned long size)
184 struct tboot_mac_region *mr;
185 phys_addr_t end = start + size;
187 if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS)
188 panic("tboot: Too many MAC regions\n");
191 mr = &tboot->mac_regions[tboot->num_mac_regions++];
192 mr->start = round_down(start, PAGE_SIZE);
193 mr->size = round_up(end, PAGE_SIZE) - mr->start;
197 static int tboot_setup_sleep(void)
201 tboot->num_mac_regions = 0;
203 for (i = 0; i < e820_table->nr_entries; i++) {
204 if ((e820_table->entries[i].type != E820_TYPE_RAM)
205 && (e820_table->entries[i].type != E820_TYPE_RESERVED_KERN))
208 add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size);
211 tboot->acpi_sinfo.kernel_s3_resume_vector =
212 real_mode_header->wakeup_start;
217 #else /* no CONFIG_ACPI_SLEEP */
219 static int tboot_setup_sleep(void)
221 /* S3 shutdown requested, but S3 not supported by the kernel... */
228 void tboot_shutdown(u32 shutdown_type)
230 void (*shutdown)(void);
232 if (!tboot_enabled())
236 * if we're being called before the 1:1 mapping is set up then just
237 * return and let the normal shutdown happen; this should only be
238 * due to very early panic()
243 /* if this is S3 then set regions to MAC */
244 if (shutdown_type == TB_SHUTDOWN_S3)
245 if (tboot_setup_sleep())
248 tboot->shutdown_type = shutdown_type;
250 switch_to_tboot_pt();
252 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
255 /* should not reach here */
260 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
262 #define TB_COPY_GAS(tbg, g) \
263 tbg.space_id = g.space_id; \
264 tbg.bit_width = g.bit_width; \
265 tbg.bit_offset = g.bit_offset; \
266 tbg.access_width = g.access_width; \
267 tbg.address = g.address;
269 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
270 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
271 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
272 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);
275 * We need phys addr of waking vector, but can't use virt_to_phys() on
276 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
279 tboot->acpi_sinfo.wakeup_vector = fadt->facs +
280 offsetof(struct acpi_table_facs, firmware_waking_vector);
283 static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
285 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
286 /* S0,1,2: */ -1, -1, -1,
287 /* S3: */ TB_SHUTDOWN_S3,
288 /* S4: */ TB_SHUTDOWN_S4,
289 /* S5: */ TB_SHUTDOWN_S5 };
291 if (!tboot_enabled())
294 tboot_copy_fadt(&acpi_gbl_FADT);
295 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
296 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
297 /* we always use the 32b wakeup vector */
298 tboot->acpi_sinfo.vector_width = 32;
300 if (sleep_state >= ACPI_S_STATE_COUNT ||
301 acpi_shutdown_map[sleep_state] == -1) {
302 pr_warn("unsupported sleep state 0x%x\n", sleep_state);
306 tboot_shutdown(acpi_shutdown_map[sleep_state]);
310 static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b)
312 if (!tboot_enabled())
315 pr_warn("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)");
319 static atomic_t ap_wfs_count;
321 static int tboot_wait_for_aps(int num_aps)
323 unsigned long timeout;
325 timeout = AP_WAIT_TIMEOUT*HZ;
326 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
333 pr_warn("tboot wait for APs timeout\n");
335 return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps);
338 static int tboot_dying_cpu(unsigned int cpu)
340 atomic_inc(&ap_wfs_count);
341 if (num_online_cpus() == 1) {
342 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
348 #ifdef CONFIG_DEBUG_FS
350 #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \
351 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 }
353 #define TBOOT_SERIAL_LOG_ADDR 0x60000
354 #define TBOOT_SERIAL_LOG_SIZE 0x08000
355 #define LOG_MAX_SIZE_OFF 16
356 #define LOG_BUF_OFF 24
358 static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID;
360 static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos)
362 void __iomem *log_base;
368 log_base = ioremap(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE);
372 memcpy_fromio(log_uuid, log_base, sizeof(log_uuid));
373 if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid)))
376 max_size = readl(log_base + LOG_MAX_SIZE_OFF);
377 if (*ppos >= max_size) {
382 if (*ppos + count > max_size)
383 count = max_size - *ppos;
385 kbuf = kmalloc(count, GFP_KERNEL);
391 memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count);
392 if (copy_to_user(user_buf, kbuf, count))
408 static const struct file_operations tboot_log_fops = {
409 .read = tboot_log_read,
410 .llseek = default_llseek,
413 #endif /* CONFIG_DEBUG_FS */
415 static __init int tboot_late_init(void)
417 if (!tboot_enabled())
420 tboot_create_trampoline();
422 atomic_set(&ap_wfs_count, 0);
423 cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL,
425 #ifdef CONFIG_DEBUG_FS
426 debugfs_create_file("tboot_log", S_IRUSR,
427 arch_debugfs_dir, NULL, &tboot_log_fops);
430 acpi_os_set_prepare_sleep(&tboot_sleep);
431 acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep);
435 late_initcall(tboot_late_init);
438 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
441 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000
442 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000
444 /* # pages for each config regs space - used by fixmap */
445 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \
446 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
448 /* offsets from pub/priv config space */
449 #define TXTCR_HEAP_BASE 0x0300
450 #define TXTCR_HEAP_SIZE 0x0308
458 struct sinit_mle_data {
459 u32 version; /* currently 6 */
460 struct sha1_hash bios_acm_id;
461 u32 edx_senter_flags;
463 struct sha1_hash sinit_hash;
464 struct sha1_hash mle_hash;
465 struct sha1_hash stm_hash;
466 struct sha1_hash lcp_policy_hash;
467 u32 lcp_policy_control;
476 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
478 void *heap_base, *heap_ptr, *config;
480 if (!tboot_enabled())
484 * ACPI tables may not be DMA protected by tboot, so use DMAR copy
485 * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
488 /* map config space in order to get heap addr */
489 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
494 /* now map TXT heap */
495 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
496 *(u64 *)(config + TXTCR_HEAP_SIZE));
501 /* walk heap to SinitMleData */
503 heap_ptr = heap_base + *(u64 *)heap_base;
505 heap_ptr += *(u64 *)heap_ptr;
506 /* skip OsSinitData */
507 heap_ptr += *(u64 *)heap_ptr;
508 /* now points to SinitMleDataSize; set to SinitMleData */
509 heap_ptr += sizeof(u64);
510 /* get addr of DMAR table */
511 dmar_tbl = (struct acpi_table_header *)(heap_ptr +
512 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
515 /* don't unmap heap because dmar.c needs access to this */
520 int tboot_force_iommu(void)
522 if (!tboot_enabled())
525 if (no_iommu || dmar_disabled)
526 pr_warn("Forcing Intel-IOMMU to enabled\n");