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/swiotlb.h>
28 #include <asm/fixmap.h>
29 #include <asm/proto.h>
30 #include <asm/setup.h>
31 #include <asm/e820/api.h>
34 #include "../realmode/rm/wakeup.h"
36 /* Global pointer to shared data; NULL means no measured launch. */
37 static struct tboot
*tboot __read_mostly
;
39 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
40 #define AP_WAIT_TIMEOUT 1
43 #define pr_fmt(fmt) "tboot: " fmt
45 static u8 tboot_uuid
[16] __initdata
= TBOOT_UUID
;
47 bool tboot_enabled(void)
52 /* noinline to prevent gcc from warning about dereferencing constant fixaddr */
53 static noinline __init
bool check_tboot_version(void)
55 if (memcmp(&tboot_uuid
, &tboot
->uuid
, sizeof(tboot
->uuid
))) {
56 pr_warn("tboot at 0x%llx is invalid\n", boot_params
.tboot_addr
);
60 if (tboot
->version
< 5) {
61 pr_warn("tboot version is invalid: %u\n", tboot
->version
);
65 pr_info("found shared page at phys addr 0x%llx:\n",
66 boot_params
.tboot_addr
);
67 pr_debug("version: %d\n", tboot
->version
);
68 pr_debug("log_addr: 0x%08x\n", tboot
->log_addr
);
69 pr_debug("shutdown_entry: 0x%x\n", tboot
->shutdown_entry
);
70 pr_debug("tboot_base: 0x%08x\n", tboot
->tboot_base
);
71 pr_debug("tboot_size: 0x%x\n", tboot
->tboot_size
);
76 void __init
tboot_probe(void)
78 /* Look for valid page-aligned address for shared page. */
79 if (!boot_params
.tboot_addr
)
82 * also verify that it is mapped as we expect it before calling
83 * set_fixmap(), to reduce chance of garbage value causing crash
85 if (!e820__mapped_any(boot_params
.tboot_addr
,
86 boot_params
.tboot_addr
, E820_TYPE_RESERVED
)) {
87 pr_warn("non-0 tboot_addr but it is not of type E820_TYPE_RESERVED\n");
91 /* Map and check for tboot UUID. */
92 set_fixmap(FIX_TBOOT_BASE
, boot_params
.tboot_addr
);
93 tboot
= (void *)fix_to_virt(FIX_TBOOT_BASE
);
94 if (!check_tboot_version())
98 static pgd_t
*tboot_pg_dir
;
99 static struct mm_struct tboot_mm
= {
101 .pgd
= swapper_pg_dir
,
102 .mm_users
= ATOMIC_INIT(2),
103 .mm_count
= ATOMIC_INIT(1),
104 .write_protect_seq
= SEQCNT_ZERO(tboot_mm
.write_protect_seq
),
105 MMAP_LOCK_INITIALIZER(init_mm
)
106 .page_table_lock
= __SPIN_LOCK_UNLOCKED(init_mm
.page_table_lock
),
107 .mmlist
= LIST_HEAD_INIT(init_mm
.mmlist
),
110 static inline void switch_to_tboot_pt(void)
112 write_cr3(virt_to_phys(tboot_pg_dir
));
115 static int map_tboot_page(unsigned long vaddr
, unsigned long pfn
,
124 pgd
= pgd_offset(&tboot_mm
, vaddr
);
125 p4d
= p4d_alloc(&tboot_mm
, pgd
, vaddr
);
128 pud
= pud_alloc(&tboot_mm
, p4d
, vaddr
);
131 pmd
= pmd_alloc(&tboot_mm
, pud
, vaddr
);
134 pte
= pte_alloc_map(&tboot_mm
, pmd
, vaddr
);
137 set_pte_at(&tboot_mm
, vaddr
, pte
, pfn_pte(pfn
, prot
));
141 * PTI poisons low addresses in the kernel page tables in the
142 * name of making them unusable for userspace. To execute
143 * code at such a low address, the poison must be cleared.
145 * Note: 'pgd' actually gets set in p4d_alloc() _or_
146 * pud_alloc() depending on 4/5-level paging.
148 pgd
->pgd
&= ~_PAGE_NX
;
153 static int map_tboot_pages(unsigned long vaddr
, unsigned long start_pfn
,
156 /* Reuse the original kernel mapping */
157 tboot_pg_dir
= pgd_alloc(&tboot_mm
);
161 for (; nr
> 0; nr
--, vaddr
+= PAGE_SIZE
, start_pfn
++) {
162 if (map_tboot_page(vaddr
, start_pfn
, PAGE_KERNEL_EXEC
))
169 static void tboot_create_trampoline(void)
171 u32 map_base
, map_size
;
173 /* Create identity map for tboot shutdown code. */
174 map_base
= PFN_DOWN(tboot
->tboot_base
);
175 map_size
= PFN_UP(tboot
->tboot_size
);
176 if (map_tboot_pages(map_base
<< PAGE_SHIFT
, map_base
, map_size
))
177 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n",
181 #ifdef CONFIG_ACPI_SLEEP
183 static void add_mac_region(phys_addr_t start
, unsigned long size
)
185 struct tboot_mac_region
*mr
;
186 phys_addr_t end
= start
+ size
;
188 if (tboot
->num_mac_regions
>= MAX_TB_MAC_REGIONS
)
189 panic("tboot: Too many MAC regions\n");
192 mr
= &tboot
->mac_regions
[tboot
->num_mac_regions
++];
193 mr
->start
= round_down(start
, PAGE_SIZE
);
194 mr
->size
= round_up(end
, PAGE_SIZE
) - mr
->start
;
198 static int tboot_setup_sleep(void)
202 tboot
->num_mac_regions
= 0;
204 for (i
= 0; i
< e820_table
->nr_entries
; i
++) {
205 if ((e820_table
->entries
[i
].type
!= E820_TYPE_RAM
)
206 && (e820_table
->entries
[i
].type
!= E820_TYPE_RESERVED_KERN
))
209 add_mac_region(e820_table
->entries
[i
].addr
, e820_table
->entries
[i
].size
);
212 tboot
->acpi_sinfo
.kernel_s3_resume_vector
=
213 real_mode_header
->wakeup_start
;
218 #else /* no CONFIG_ACPI_SLEEP */
220 static int tboot_setup_sleep(void)
222 /* S3 shutdown requested, but S3 not supported by the kernel... */
229 void tboot_shutdown(u32 shutdown_type
)
231 void (*shutdown
)(void);
233 if (!tboot_enabled())
237 * if we're being called before the 1:1 mapping is set up then just
238 * return and let the normal shutdown happen; this should only be
239 * due to very early panic()
244 /* if this is S3 then set regions to MAC */
245 if (shutdown_type
== TB_SHUTDOWN_S3
)
246 if (tboot_setup_sleep())
249 tboot
->shutdown_type
= shutdown_type
;
251 switch_to_tboot_pt();
253 shutdown
= (void(*)(void))(unsigned long)tboot
->shutdown_entry
;
256 /* should not reach here */
261 static void tboot_copy_fadt(const struct acpi_table_fadt
*fadt
)
263 #define TB_COPY_GAS(tbg, g) \
264 tbg.space_id = g.space_id; \
265 tbg.bit_width = g.bit_width; \
266 tbg.bit_offset = g.bit_offset; \
267 tbg.access_width = g.access_width; \
268 tbg.address = g.address;
270 TB_COPY_GAS(tboot
->acpi_sinfo
.pm1a_cnt_blk
, fadt
->xpm1a_control_block
);
271 TB_COPY_GAS(tboot
->acpi_sinfo
.pm1b_cnt_blk
, fadt
->xpm1b_control_block
);
272 TB_COPY_GAS(tboot
->acpi_sinfo
.pm1a_evt_blk
, fadt
->xpm1a_event_block
);
273 TB_COPY_GAS(tboot
->acpi_sinfo
.pm1b_evt_blk
, fadt
->xpm1b_event_block
);
276 * We need phys addr of waking vector, but can't use virt_to_phys() on
277 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
280 tboot
->acpi_sinfo
.wakeup_vector
= fadt
->facs
+
281 offsetof(struct acpi_table_facs
, firmware_waking_vector
);
284 static int tboot_sleep(u8 sleep_state
, u32 pm1a_control
, u32 pm1b_control
)
286 static u32 acpi_shutdown_map
[ACPI_S_STATE_COUNT
] = {
287 /* S0,1,2: */ -1, -1, -1,
288 /* S3: */ TB_SHUTDOWN_S3
,
289 /* S4: */ TB_SHUTDOWN_S4
,
290 /* S5: */ TB_SHUTDOWN_S5
};
292 if (!tboot_enabled())
295 tboot_copy_fadt(&acpi_gbl_FADT
);
296 tboot
->acpi_sinfo
.pm1a_cnt_val
= pm1a_control
;
297 tboot
->acpi_sinfo
.pm1b_cnt_val
= pm1b_control
;
298 /* we always use the 32b wakeup vector */
299 tboot
->acpi_sinfo
.vector_width
= 32;
301 if (sleep_state
>= ACPI_S_STATE_COUNT
||
302 acpi_shutdown_map
[sleep_state
] == -1) {
303 pr_warn("unsupported sleep state 0x%x\n", sleep_state
);
307 tboot_shutdown(acpi_shutdown_map
[sleep_state
]);
311 static int tboot_extended_sleep(u8 sleep_state
, u32 val_a
, u32 val_b
)
313 if (!tboot_enabled())
316 pr_warn("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)");
320 static atomic_t ap_wfs_count
;
322 static int tboot_wait_for_aps(int num_aps
)
324 unsigned long timeout
;
326 timeout
= AP_WAIT_TIMEOUT
*HZ
;
327 while (atomic_read((atomic_t
*)&tboot
->num_in_wfs
) != num_aps
&&
334 pr_warn("tboot wait for APs timeout\n");
336 return !(atomic_read((atomic_t
*)&tboot
->num_in_wfs
) == num_aps
);
339 static int tboot_dying_cpu(unsigned int cpu
)
341 atomic_inc(&ap_wfs_count
);
342 if (num_online_cpus() == 1) {
343 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count
)))
349 #ifdef CONFIG_DEBUG_FS
351 #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \
352 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 }
354 #define TBOOT_SERIAL_LOG_ADDR 0x60000
355 #define TBOOT_SERIAL_LOG_SIZE 0x08000
356 #define LOG_MAX_SIZE_OFF 16
357 #define LOG_BUF_OFF 24
359 static uint8_t tboot_log_uuid
[16] = TBOOT_LOG_UUID
;
361 static ssize_t
tboot_log_read(struct file
*file
, char __user
*user_buf
, size_t count
, loff_t
*ppos
)
363 void __iomem
*log_base
;
369 log_base
= ioremap(TBOOT_SERIAL_LOG_ADDR
, TBOOT_SERIAL_LOG_SIZE
);
373 memcpy_fromio(log_uuid
, log_base
, sizeof(log_uuid
));
374 if (memcmp(&tboot_log_uuid
, log_uuid
, sizeof(log_uuid
)))
377 max_size
= readl(log_base
+ LOG_MAX_SIZE_OFF
);
378 if (*ppos
>= max_size
) {
383 if (*ppos
+ count
> max_size
)
384 count
= max_size
- *ppos
;
386 kbuf
= kmalloc(count
, GFP_KERNEL
);
392 memcpy_fromio(kbuf
, log_base
+ LOG_BUF_OFF
+ *ppos
, count
);
393 if (copy_to_user(user_buf
, kbuf
, count
))
409 static const struct file_operations tboot_log_fops
= {
410 .read
= tboot_log_read
,
411 .llseek
= default_llseek
,
414 #endif /* CONFIG_DEBUG_FS */
416 static __init
int tboot_late_init(void)
418 if (!tboot_enabled())
421 tboot_create_trampoline();
423 atomic_set(&ap_wfs_count
, 0);
424 cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING
, "x86/tboot:dying", NULL
,
426 #ifdef CONFIG_DEBUG_FS
427 debugfs_create_file("tboot_log", S_IRUSR
,
428 arch_debugfs_dir
, NULL
, &tboot_log_fops
);
431 acpi_os_set_prepare_sleep(&tboot_sleep
);
432 acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep
);
436 late_initcall(tboot_late_init
);
439 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
442 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000
443 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000
445 /* # pages for each config regs space - used by fixmap */
446 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \
447 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
449 /* offsets from pub/priv config space */
450 #define TXTCR_HEAP_BASE 0x0300
451 #define TXTCR_HEAP_SIZE 0x0308
459 struct sinit_mle_data
{
460 u32 version
; /* currently 6 */
461 struct sha1_hash bios_acm_id
;
462 u32 edx_senter_flags
;
464 struct sha1_hash sinit_hash
;
465 struct sha1_hash mle_hash
;
466 struct sha1_hash stm_hash
;
467 struct sha1_hash lcp_policy_hash
;
468 u32 lcp_policy_control
;
477 struct acpi_table_header
*tboot_get_dmar_table(struct acpi_table_header
*dmar_tbl
)
479 void *heap_base
, *heap_ptr
, *config
;
481 if (!tboot_enabled())
485 * ACPI tables may not be DMA protected by tboot, so use DMAR copy
486 * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
489 /* map config space in order to get heap addr */
490 config
= ioremap(TXT_PUB_CONFIG_REGS_BASE
, NR_TXT_CONFIG_PAGES
*
495 /* now map TXT heap */
496 heap_base
= ioremap(*(u64
*)(config
+ TXTCR_HEAP_BASE
),
497 *(u64
*)(config
+ TXTCR_HEAP_SIZE
));
502 /* walk heap to SinitMleData */
504 heap_ptr
= heap_base
+ *(u64
*)heap_base
;
506 heap_ptr
+= *(u64
*)heap_ptr
;
507 /* skip OsSinitData */
508 heap_ptr
+= *(u64
*)heap_ptr
;
509 /* now points to SinitMleDataSize; set to SinitMleData */
510 heap_ptr
+= sizeof(u64
);
511 /* get addr of DMAR table */
512 dmar_tbl
= (struct acpi_table_header
*)(heap_ptr
+
513 ((struct sinit_mle_data
*)heap_ptr
)->vtd_dmars_off
-
516 /* don't unmap heap because dmar.c needs access to this */
521 int tboot_force_iommu(void)
523 if (!tboot_enabled())
526 if (no_iommu
|| dmar_disabled
)
527 pr_warn("Forcing Intel-IOMMU to enabled\n");