1 // SPDX-License-Identifier: GPL-2.0
7 #include <linux/numa.h>
12 * Longest parameter of 'acpi=' is 'copy_dsdt', plus an extra '\0'
15 #define MAX_ACPI_ARG_LENGTH 10
18 * Immovable memory regions representation. Max amount of memory regions is
21 struct mem_vector immovable_mem
[MAX_NUMNODES
*2];
24 * Search EFI system tables for RSDP. If both ACPI_20_TABLE_GUID and
25 * ACPI_TABLE_GUID are found, take the former, which has more features.
27 static acpi_physical_address
28 __efi_get_rsdp_addr(unsigned long config_tables
, unsigned int nr_tables
,
31 acpi_physical_address rsdp_addr
= 0;
36 /* Get EFI tables from systab. */
37 for (i
= 0; i
< nr_tables
; i
++) {
38 acpi_physical_address table
;
42 efi_config_table_64_t
*tbl
= (efi_config_table_64_t
*)config_tables
+ i
;
47 if (!IS_ENABLED(CONFIG_X86_64
) && table
>> 32) {
48 debug_putstr("Error getting RSDP address: EFI config table located above 4GB.\n");
52 efi_config_table_32_t
*tbl
= (efi_config_table_32_t
*)config_tables
+ i
;
58 if (!(efi_guidcmp(guid
, ACPI_TABLE_GUID
)))
60 else if (!(efi_guidcmp(guid
, ACPI_20_TABLE_GUID
)))
67 /* EFI/kexec support is 64-bit only. */
69 static struct efi_setup_data
*get_kexec_setup_data_addr(void)
71 struct setup_data
*data
;
74 pa_data
= boot_params
->hdr
.setup_data
;
76 data
= (struct setup_data
*)pa_data
;
77 if (data
->type
== SETUP_EFI
)
78 return (struct efi_setup_data
*)(pa_data
+ sizeof(struct setup_data
));
85 static acpi_physical_address
kexec_get_rsdp_addr(void)
87 efi_system_table_64_t
*systab
;
88 struct efi_setup_data
*esd
;
92 esd
= (struct efi_setup_data
*)get_kexec_setup_data_addr();
97 debug_putstr("Wrong kexec SETUP_EFI data.\n");
101 ei
= &boot_params
->efi_info
;
102 sig
= (char *)&ei
->efi_loader_signature
;
103 if (strncmp(sig
, EFI64_LOADER_SIGNATURE
, 4)) {
104 debug_putstr("Wrong kexec EFI loader signature.\n");
108 /* Get systab from boot params. */
109 systab
= (efi_system_table_64_t
*) (ei
->efi_systab
| ((__u64
)ei
->efi_systab_hi
<< 32));
111 error("EFI system table not found in kexec boot_params.");
113 return __efi_get_rsdp_addr((unsigned long)esd
->tables
, systab
->nr_tables
, true);
116 static acpi_physical_address
kexec_get_rsdp_addr(void) { return 0; }
117 #endif /* CONFIG_X86_64 */
119 static acpi_physical_address
efi_get_rsdp_addr(void)
122 unsigned long systab
, config_tables
;
123 unsigned int nr_tables
;
128 ei
= &boot_params
->efi_info
;
129 sig
= (char *)&ei
->efi_loader_signature
;
131 if (!strncmp(sig
, EFI64_LOADER_SIGNATURE
, 4)) {
133 } else if (!strncmp(sig
, EFI32_LOADER_SIGNATURE
, 4)) {
136 debug_putstr("Wrong EFI loader signature.\n");
140 /* Get systab from boot params. */
142 systab
= ei
->efi_systab
| ((__u64
)ei
->efi_systab_hi
<< 32);
144 if (ei
->efi_systab_hi
|| ei
->efi_memmap_hi
) {
145 debug_putstr("Error getting RSDP address: EFI system table located above 4GB.\n");
148 systab
= ei
->efi_systab
;
151 error("EFI system table not found.");
153 /* Handle EFI bitness properly */
155 efi_system_table_64_t
*stbl
= (efi_system_table_64_t
*)systab
;
157 config_tables
= stbl
->tables
;
158 nr_tables
= stbl
->nr_tables
;
160 efi_system_table_32_t
*stbl
= (efi_system_table_32_t
*)systab
;
162 config_tables
= stbl
->tables
;
163 nr_tables
= stbl
->nr_tables
;
167 error("EFI config tables not found.");
169 return __efi_get_rsdp_addr(config_tables
, nr_tables
, efi_64
);
175 static u8
compute_checksum(u8
*buffer
, u32 length
)
177 u8
*end
= buffer
+ length
;
186 /* Search a block of memory for the RSDP signature. */
187 static u8
*scan_mem_for_rsdp(u8
*start
, u32 length
)
189 struct acpi_table_rsdp
*rsdp
;
192 end
= start
+ length
;
194 /* Search from given start address for the requested length */
195 for (address
= start
; address
< end
; address
+= ACPI_RSDP_SCAN_STEP
) {
197 * Both RSDP signature and checksum must be correct.
198 * Note: Sometimes there exists more than one RSDP in memory;
199 * the valid RSDP has a valid checksum, all others have an
202 rsdp
= (struct acpi_table_rsdp
*)address
;
205 if (!ACPI_VALIDATE_RSDP_SIG(rsdp
->signature
))
208 /* Check the standard checksum */
209 if (compute_checksum((u8
*)rsdp
, ACPI_RSDP_CHECKSUM_LENGTH
))
212 /* Check extended checksum if table version >= 2 */
213 if ((rsdp
->revision
>= 2) &&
214 (compute_checksum((u8
*)rsdp
, ACPI_RSDP_XCHECKSUM_LENGTH
)))
217 /* Signature and checksum valid, we have found a real RSDP */
223 /* Search RSDP address in EBDA. */
224 static acpi_physical_address
bios_get_rsdp_addr(void)
226 unsigned long address
;
229 /* Get the location of the Extended BIOS Data Area (EBDA) */
230 address
= *(u16
*)ACPI_EBDA_PTR_LOCATION
;
234 * Search EBDA paragraphs (EBDA is required to be a minimum of
237 if (address
> 0x400) {
238 rsdp
= scan_mem_for_rsdp((u8
*)address
, ACPI_EBDA_WINDOW_SIZE
);
240 return (acpi_physical_address
)(unsigned long)rsdp
;
243 /* Search upper memory: 16-byte boundaries in E0000h-FFFFFh */
244 rsdp
= scan_mem_for_rsdp((u8
*) ACPI_HI_RSDP_WINDOW_BASE
,
245 ACPI_HI_RSDP_WINDOW_SIZE
);
247 return (acpi_physical_address
)(unsigned long)rsdp
;
252 /* Return RSDP address on success, otherwise 0. */
253 acpi_physical_address
get_rsdp_addr(void)
255 acpi_physical_address pa
;
257 pa
= boot_params
->acpi_rsdp_addr
;
260 * Try to get EFI data from setup_data. This can happen when we're a
261 * kexec'ed kernel and kexec(1) has passed all the required EFI info to
265 pa
= kexec_get_rsdp_addr();
268 pa
= efi_get_rsdp_addr();
271 pa
= bios_get_rsdp_addr();
276 #if defined(CONFIG_RANDOMIZE_BASE) && defined(CONFIG_MEMORY_HOTREMOVE)
278 * Max length of 64-bit hex address string is 19, prefix "0x" + 16 hex
279 * digits, and '\0' for termination.
281 #define MAX_ADDR_LEN 19
283 static unsigned long get_cmdline_acpi_rsdp(void)
285 unsigned long addr
= 0;
288 char val
[MAX_ADDR_LEN
] = { };
291 ret
= cmdline_find_option("acpi_rsdp", val
, MAX_ADDR_LEN
);
295 if (boot_kstrtoul(val
, 16, &addr
))
301 /* Compute SRAT address from RSDP. */
302 static unsigned long get_acpi_srat_table(void)
304 unsigned long root_table
, acpi_table
;
305 struct acpi_table_header
*header
;
306 struct acpi_table_rsdp
*rsdp
;
307 u32 num_entries
, size
, len
;
312 * Check whether we were given an RSDP on the command line. We don't
313 * stash this in boot params because the kernel itself may have
314 * different ideas about whether to trust a command-line parameter.
316 rsdp
= (struct acpi_table_rsdp
*)get_cmdline_acpi_rsdp();
318 rsdp
= (struct acpi_table_rsdp
*)(long)
319 boot_params
->acpi_rsdp_addr
;
324 /* Get ACPI root table from RSDP.*/
325 if (!(cmdline_find_option("acpi", arg
, sizeof(arg
)) == 4 &&
326 !strncmp(arg
, "rsdt", 4)) &&
327 rsdp
->xsdt_physical_address
&&
328 rsdp
->revision
> 1) {
329 root_table
= rsdp
->xsdt_physical_address
;
330 size
= ACPI_XSDT_ENTRY_SIZE
;
332 root_table
= rsdp
->rsdt_physical_address
;
333 size
= ACPI_RSDT_ENTRY_SIZE
;
339 header
= (struct acpi_table_header
*)root_table
;
340 len
= header
->length
;
341 if (len
< sizeof(struct acpi_table_header
) + size
)
344 num_entries
= (len
- sizeof(struct acpi_table_header
)) / size
;
345 entry
= (u8
*)(root_table
+ sizeof(struct acpi_table_header
));
347 while (num_entries
--) {
348 if (size
== ACPI_RSDT_ENTRY_SIZE
)
349 acpi_table
= *(u32
*)entry
;
351 acpi_table
= *(u64
*)entry
;
354 header
= (struct acpi_table_header
*)acpi_table
;
356 if (ACPI_COMPARE_NAMESEG(header
->signature
, ACPI_SIG_SRAT
))
365 * count_immovable_mem_regions - Parse SRAT and cache the immovable
366 * memory regions into the immovable_mem array.
368 * Return the number of immovable memory regions on success, 0 on failure:
370 * - Too many immovable memory regions
371 * - ACPI off or no SRAT found
372 * - No immovable memory region found.
374 int count_immovable_mem_regions(void)
376 unsigned long table_addr
, table_end
, table
;
377 struct acpi_subtable_header
*sub_table
;
378 struct acpi_table_header
*table_header
;
379 char arg
[MAX_ACPI_ARG_LENGTH
];
382 if (cmdline_find_option("acpi", arg
, sizeof(arg
)) == 3 &&
383 !strncmp(arg
, "off", 3))
386 table_addr
= get_acpi_srat_table();
390 table_header
= (struct acpi_table_header
*)table_addr
;
391 table_end
= table_addr
+ table_header
->length
;
392 table
= table_addr
+ sizeof(struct acpi_table_srat
);
394 while (table
+ sizeof(struct acpi_subtable_header
) < table_end
) {
396 sub_table
= (struct acpi_subtable_header
*)table
;
397 if (!sub_table
->length
) {
398 debug_putstr("Invalid zero length SRAT subtable.\n");
402 if (sub_table
->type
== ACPI_SRAT_TYPE_MEMORY_AFFINITY
) {
403 struct acpi_srat_mem_affinity
*ma
;
405 ma
= (struct acpi_srat_mem_affinity
*)sub_table
;
406 if (!(ma
->flags
& ACPI_SRAT_MEM_HOT_PLUGGABLE
) && ma
->length
) {
407 immovable_mem
[num
].start
= ma
->base_address
;
408 immovable_mem
[num
].size
= ma
->length
;
412 if (num
>= MAX_NUMNODES
*2) {
413 debug_putstr("Too many immovable memory regions, aborting.\n");
417 table
+= sub_table
->length
;
421 #endif /* CONFIG_RANDOMIZE_BASE && CONFIG_MEMORY_HOTREMOVE */