1// SPDX-License-Identifier: GPL-2.0
2#define BOOT_CTYPE_H
3#include "misc.h"
4#include "error.h"
5#include "../string.h"
6#include "efi.h"
7
8#include <asm/bootparam.h>
9
10#include <linux/numa.h>
11
12/*
13 * Longest parameter of 'acpi=' is 'copy_dsdt', plus an extra '\0'
14 * for termination.
15 */
16#define MAX_ACPI_ARG_LENGTH 10
17
18/*
19 * Immovable memory regions representation. Max amount of memory regions is
20 * MAX_NUMNODES*2.
21 */
22struct mem_vector immovable_mem[MAX_NUMNODES*2];
23
24static acpi_physical_address
25__efi_get_rsdp_addr(unsigned long cfg_tbl_pa, unsigned int cfg_tbl_len)
26{
27#ifdef CONFIG_EFI
28 unsigned long rsdp_addr;
29 int ret;
30
31 /*
32 * Search EFI system tables for RSDP. Preferred is ACPI_20_TABLE_GUID to
33 * ACPI_TABLE_GUID because it has more features.
34 */
35 rsdp_addr = efi_find_vendor_table(bp: boot_params_ptr, cfg_tbl_pa, cfg_tbl_len,
36 ACPI_20_TABLE_GUID);
37 if (rsdp_addr)
38 return (acpi_physical_address)rsdp_addr;
39
40 /* No ACPI_20_TABLE_GUID found, fallback to ACPI_TABLE_GUID. */
41 rsdp_addr = efi_find_vendor_table(bp: boot_params_ptr, cfg_tbl_pa, cfg_tbl_len,
42 ACPI_TABLE_GUID);
43 if (rsdp_addr)
44 return (acpi_physical_address)rsdp_addr;
45
46 debug_putstr("Error getting RSDP address.\n");
47#endif
48 return 0;
49}
50
51static acpi_physical_address efi_get_rsdp_addr(void)
52{
53#ifdef CONFIG_EFI
54 unsigned long cfg_tbl_pa = 0;
55 unsigned int cfg_tbl_len;
56 unsigned long systab_pa;
57 unsigned int nr_tables;
58 enum efi_type et;
59 int ret;
60
61 et = efi_get_type(bp: boot_params_ptr);
62 if (et == EFI_TYPE_NONE)
63 return 0;
64
65 systab_pa = efi_get_system_table(bp: boot_params_ptr);
66 if (!systab_pa)
67 error(m: "EFI support advertised, but unable to locate system table.");
68
69 ret = efi_get_conf_table(bp: boot_params_ptr, cfg_tbl_pa: &cfg_tbl_pa, cfg_tbl_len: &cfg_tbl_len);
70 if (ret || !cfg_tbl_pa)
71 error(m: "EFI config table not found.");
72
73 return __efi_get_rsdp_addr(cfg_tbl_pa, cfg_tbl_len);
74#else
75 return 0;
76#endif
77}
78
79static u8 compute_checksum(u8 *buffer, u32 length)
80{
81 u8 *end = buffer + length;
82 u8 sum = 0;
83
84 while (buffer < end)
85 sum += *(buffer++);
86
87 return sum;
88}
89
90/* Search a block of memory for the RSDP signature. */
91static u8 *scan_mem_for_rsdp(u8 *start, u32 length)
92{
93 struct acpi_table_rsdp *rsdp;
94 u8 *address, *end;
95
96 end = start + length;
97
98 /* Search from given start address for the requested length */
99 for (address = start; address < end; address += ACPI_RSDP_SCAN_STEP) {
100 /*
101 * Both RSDP signature and checksum must be correct.
102 * Note: Sometimes there exists more than one RSDP in memory;
103 * the valid RSDP has a valid checksum, all others have an
104 * invalid checksum.
105 */
106 rsdp = (struct acpi_table_rsdp *)address;
107
108 /* BAD Signature */
109 if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature))
110 continue;
111
112 /* Check the standard checksum */
113 if (compute_checksum(buffer: (u8 *)rsdp, ACPI_RSDP_CHECKSUM_LENGTH))
114 continue;
115
116 /* Check extended checksum if table version >= 2 */
117 if ((rsdp->revision >= 2) &&
118 (compute_checksum(buffer: (u8 *)rsdp, ACPI_RSDP_XCHECKSUM_LENGTH)))
119 continue;
120
121 /* Signature and checksum valid, we have found a real RSDP */
122 return address;
123 }
124 return NULL;
125}
126
127/* Search RSDP address in EBDA. */
128static acpi_physical_address bios_get_rsdp_addr(void)
129{
130 unsigned long address;
131 u8 *rsdp;
132
133 /* Get the location of the Extended BIOS Data Area (EBDA) */
134 address = *(u16 *)ACPI_EBDA_PTR_LOCATION;
135 address <<= 4;
136
137 /*
138 * Search EBDA paragraphs (EBDA is required to be a minimum of
139 * 1K length)
140 */
141 if (address > 0x400) {
142 rsdp = scan_mem_for_rsdp(start: (u8 *)address, ACPI_EBDA_WINDOW_SIZE);
143 if (rsdp)
144 return (acpi_physical_address)(unsigned long)rsdp;
145 }
146
147 /* Search upper memory: 16-byte boundaries in E0000h-FFFFFh */
148 rsdp = scan_mem_for_rsdp(start: (u8 *) ACPI_HI_RSDP_WINDOW_BASE,
149 ACPI_HI_RSDP_WINDOW_SIZE);
150 if (rsdp)
151 return (acpi_physical_address)(unsigned long)rsdp;
152
153 return 0;
154}
155
156/* Return RSDP address on success, otherwise 0. */
157acpi_physical_address get_rsdp_addr(void)
158{
159 acpi_physical_address pa;
160
161 pa = boot_params_ptr->acpi_rsdp_addr;
162
163 if (!pa)
164 pa = efi_get_rsdp_addr();
165
166 if (!pa)
167 pa = bios_get_rsdp_addr();
168
169 return pa;
170}
171
172#if defined(CONFIG_RANDOMIZE_BASE) && defined(CONFIG_MEMORY_HOTREMOVE)
173/*
174 * Max length of 64-bit hex address string is 19, prefix "0x" + 16 hex
175 * digits, and '\0' for termination.
176 */
177#define MAX_ADDR_LEN 19
178
179static unsigned long get_cmdline_acpi_rsdp(void)
180{
181 unsigned long addr = 0;
182
183#ifdef CONFIG_KEXEC_CORE
184 char val[MAX_ADDR_LEN] = { };
185 int ret;
186
187 ret = cmdline_find_option(option: "acpi_rsdp", buffer: val, MAX_ADDR_LEN);
188 if (ret < 0)
189 return 0;
190
191 if (boot_kstrtoul(s: val, base: 16, res: &addr))
192 return 0;
193#endif
194 return addr;
195}
196
197/* Compute SRAT address from RSDP. */
198static unsigned long get_acpi_srat_table(void)
199{
200 unsigned long root_table, acpi_table;
201 struct acpi_table_header *header;
202 struct acpi_table_rsdp *rsdp;
203 u32 num_entries, size, len;
204 char arg[10];
205 u8 *entry;
206
207 /*
208 * Check whether we were given an RSDP on the command line. We don't
209 * stash this in boot params because the kernel itself may have
210 * different ideas about whether to trust a command-line parameter.
211 */
212 rsdp = (struct acpi_table_rsdp *)get_cmdline_acpi_rsdp();
213 if (!rsdp)
214 rsdp = (struct acpi_table_rsdp *)(long)
215 boot_params_ptr->acpi_rsdp_addr;
216
217 if (!rsdp)
218 return 0;
219
220 /* Get ACPI root table from RSDP.*/
221 if (!(cmdline_find_option(option: "acpi", buffer: arg, bufsize: sizeof(arg)) == 4 &&
222 !strncmp(cs: arg, ct: "rsdt", count: 4)) &&
223 rsdp->xsdt_physical_address &&
224 rsdp->revision > 1) {
225 root_table = rsdp->xsdt_physical_address;
226 size = ACPI_XSDT_ENTRY_SIZE;
227 } else {
228 root_table = rsdp->rsdt_physical_address;
229 size = ACPI_RSDT_ENTRY_SIZE;
230 }
231
232 if (!root_table)
233 return 0;
234
235 header = (struct acpi_table_header *)root_table;
236 len = header->length;
237 if (len < sizeof(struct acpi_table_header) + size)
238 return 0;
239
240 num_entries = (len - sizeof(struct acpi_table_header)) / size;
241 entry = (u8 *)(root_table + sizeof(struct acpi_table_header));
242
243 while (num_entries--) {
244 if (size == ACPI_RSDT_ENTRY_SIZE)
245 acpi_table = *(u32 *)entry;
246 else
247 acpi_table = *(u64 *)entry;
248
249 if (acpi_table) {
250 header = (struct acpi_table_header *)acpi_table;
251
252 if (ACPI_COMPARE_NAMESEG(header->signature, ACPI_SIG_SRAT))
253 return acpi_table;
254 }
255 entry += size;
256 }
257 return 0;
258}
259
260/**
261 * count_immovable_mem_regions - Parse SRAT and cache the immovable
262 * memory regions into the immovable_mem array.
263 *
264 * Return the number of immovable memory regions on success, 0 on failure:
265 *
266 * - Too many immovable memory regions
267 * - ACPI off or no SRAT found
268 * - No immovable memory region found.
269 */
270int count_immovable_mem_regions(void)
271{
272 unsigned long table_addr, table_end, table;
273 struct acpi_subtable_header *sub_table;
274 struct acpi_table_header *table_header;
275 char arg[MAX_ACPI_ARG_LENGTH];
276 int num = 0;
277
278 if (cmdline_find_option(option: "acpi", buffer: arg, bufsize: sizeof(arg)) == 3 &&
279 !strncmp(cs: arg, ct: "off", count: 3))
280 return 0;
281
282 table_addr = get_acpi_srat_table();
283 if (!table_addr)
284 return 0;
285
286 table_header = (struct acpi_table_header *)table_addr;
287 table_end = table_addr + table_header->length;
288 table = table_addr + sizeof(struct acpi_table_srat);
289
290 while (table + sizeof(struct acpi_subtable_header) < table_end) {
291
292 sub_table = (struct acpi_subtable_header *)table;
293 if (!sub_table->length) {
294 debug_putstr("Invalid zero length SRAT subtable.\n");
295 return 0;
296 }
297
298 if (sub_table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) {
299 struct acpi_srat_mem_affinity *ma;
300
301 ma = (struct acpi_srat_mem_affinity *)sub_table;
302 if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) && ma->length) {
303 immovable_mem[num].start = ma->base_address;
304 immovable_mem[num].size = ma->length;
305 num++;
306 }
307
308 if (num >= MAX_NUMNODES*2) {
309 debug_putstr("Too many immovable memory regions, aborting.\n");
310 return 0;
311 }
312 }
313 table += sub_table->length;
314 }
315 return num;
316}
317#endif /* CONFIG_RANDOMIZE_BASE && CONFIG_MEMORY_HOTREMOVE */
318

source code of linux/arch/x86/boot/compressed/acpi.c