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Commit | Line | Data |
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3c7f2550 MS |
1 | /* |
2 | * EFI stub implementation that is shared by arm and arm64 architectures. | |
3 | * This should be #included by the EFI stub implementation files. | |
4 | * | |
5 | * Copyright (C) 2013,2014 Linaro Limited | |
6 | * Roy Franz <roy.franz@linaro.org | |
7 | * Copyright (C) 2013 Red Hat, Inc. | |
8 | * Mark Salter <msalter@redhat.com> | |
9 | * | |
10 | * This file is part of the Linux kernel, and is made available under the | |
11 | * terms of the GNU General Public License version 2. | |
12 | * | |
13 | */ | |
14 | ||
bd669475 | 15 | #include <linux/efi.h> |
0ce3cc00 | 16 | #include <linux/sort.h> |
bd669475 AB |
17 | #include <asm/efi.h> |
18 | ||
19 | #include "efistub.h" | |
20 | ||
e69176d6 AB |
21 | /* |
22 | * This is the base address at which to start allocating virtual memory ranges | |
23 | * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use | |
24 | * any allocation we choose, and eliminate the risk of a conflict after kexec. | |
25 | * The value chosen is the largest non-zero power of 2 suitable for this purpose | |
26 | * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can | |
27 | * be mapped efficiently. | |
28 | * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split, | |
29 | * map everything below 1 GB. (512 MB is a reasonable upper bound for the | |
30 | * entire footprint of the UEFI runtime services memory regions) | |
31 | */ | |
32 | #define EFI_RT_VIRTUAL_BASE SZ_512M | |
33 | #define EFI_RT_VIRTUAL_SIZE SZ_512M | |
34 | ||
197decef | 35 | #ifdef CONFIG_ARM64 |
363524d2 | 36 | # define EFI_RT_VIRTUAL_LIMIT DEFAULT_MAP_WINDOW_64 |
197decef AB |
37 | #else |
38 | # define EFI_RT_VIRTUAL_LIMIT TASK_SIZE | |
39 | #endif | |
40 | ||
e69176d6 AB |
41 | static u64 virtmap_base = EFI_RT_VIRTUAL_BASE; |
42 | ||
bd669475 | 43 | void efi_char16_printk(efi_system_table_t *sys_table_arg, |
3c7f2550 MS |
44 | efi_char16_t *str) |
45 | { | |
46 | struct efi_simple_text_output_protocol *out; | |
47 | ||
48 | out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out; | |
49 | out->output_string(out, str); | |
50 | } | |
51 | ||
f0827e18 AB |
52 | static struct screen_info *setup_graphics(efi_system_table_t *sys_table_arg) |
53 | { | |
54 | efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; | |
55 | efi_status_t status; | |
56 | unsigned long size; | |
57 | void **gop_handle = NULL; | |
58 | struct screen_info *si = NULL; | |
59 | ||
60 | size = 0; | |
61 | status = efi_call_early(locate_handle, EFI_LOCATE_BY_PROTOCOL, | |
62 | &gop_proto, NULL, &size, gop_handle); | |
63 | if (status == EFI_BUFFER_TOO_SMALL) { | |
64 | si = alloc_screen_info(sys_table_arg); | |
65 | if (!si) | |
66 | return NULL; | |
67 | efi_setup_gop(sys_table_arg, si, &gop_proto, size); | |
68 | } | |
69 | return si; | |
70 | } | |
3c7f2550 | 71 | |
b844470f AB |
72 | void install_memreserve_table(efi_system_table_t *sys_table_arg) |
73 | { | |
74 | struct linux_efi_memreserve *rsv; | |
75 | efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID; | |
76 | efi_status_t status; | |
77 | ||
78 | status = efi_call_early(allocate_pool, EFI_LOADER_DATA, sizeof(*rsv), | |
79 | (void **)&rsv); | |
80 | if (status != EFI_SUCCESS) { | |
81 | pr_efi_err(sys_table_arg, "Failed to allocate memreserve entry!\n"); | |
82 | return; | |
83 | } | |
84 | ||
85 | rsv->next = 0; | |
b844470f | 86 | rsv->size = 0; |
5f0b0ecf | 87 | atomic_set(&rsv->count, 0); |
b844470f AB |
88 | |
89 | status = efi_call_early(install_configuration_table, | |
90 | &memreserve_table_guid, | |
91 | rsv); | |
92 | if (status != EFI_SUCCESS) | |
93 | pr_efi_err(sys_table_arg, "Failed to install memreserve config table!\n"); | |
94 | } | |
95 | ||
96 | ||
3c7f2550 MS |
97 | /* |
98 | * This function handles the architcture specific differences between arm and | |
99 | * arm64 regarding where the kernel image must be loaded and any memory that | |
100 | * must be reserved. On failure it is required to free all | |
101 | * all allocations it has made. | |
102 | */ | |
bd669475 AB |
103 | efi_status_t handle_kernel_image(efi_system_table_t *sys_table, |
104 | unsigned long *image_addr, | |
105 | unsigned long *image_size, | |
106 | unsigned long *reserve_addr, | |
107 | unsigned long *reserve_size, | |
108 | unsigned long dram_base, | |
109 | efi_loaded_image_t *image); | |
3c7f2550 MS |
110 | /* |
111 | * EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint | |
112 | * that is described in the PE/COFF header. Most of the code is the same | |
113 | * for both archictectures, with the arch-specific code provided in the | |
114 | * handle_kernel_image() function. | |
115 | */ | |
ddeeefe2 | 116 | unsigned long efi_entry(void *handle, efi_system_table_t *sys_table, |
3c7f2550 MS |
117 | unsigned long *image_addr) |
118 | { | |
119 | efi_loaded_image_t *image; | |
120 | efi_status_t status; | |
121 | unsigned long image_size = 0; | |
122 | unsigned long dram_base; | |
123 | /* addr/point and size pairs for memory management*/ | |
124 | unsigned long initrd_addr; | |
125 | u64 initrd_size = 0; | |
345c736e | 126 | unsigned long fdt_addr = 0; /* Original DTB */ |
a643375f | 127 | unsigned long fdt_size = 0; |
3c7f2550 MS |
128 | char *cmdline_ptr = NULL; |
129 | int cmdline_size = 0; | |
130 | unsigned long new_fdt_addr; | |
131 | efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID; | |
132 | unsigned long reserve_addr = 0; | |
133 | unsigned long reserve_size = 0; | |
de8cb458 | 134 | enum efi_secureboot_mode secure_boot; |
f0827e18 | 135 | struct screen_info *si; |
3c7f2550 MS |
136 | |
137 | /* Check if we were booted by the EFI firmware */ | |
138 | if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) | |
139 | goto fail; | |
140 | ||
b9d6769b AB |
141 | status = check_platform_features(sys_table); |
142 | if (status != EFI_SUCCESS) | |
143 | goto fail; | |
144 | ||
3c7f2550 MS |
145 | /* |
146 | * Get a handle to the loaded image protocol. This is used to get | |
147 | * information about the running image, such as size and the command | |
148 | * line. | |
149 | */ | |
150 | status = sys_table->boottime->handle_protocol(handle, | |
151 | &loaded_image_proto, (void *)&image); | |
152 | if (status != EFI_SUCCESS) { | |
153 | pr_efi_err(sys_table, "Failed to get loaded image protocol\n"); | |
154 | goto fail; | |
155 | } | |
156 | ||
157 | dram_base = get_dram_base(sys_table); | |
158 | if (dram_base == EFI_ERROR) { | |
159 | pr_efi_err(sys_table, "Failed to find DRAM base\n"); | |
160 | goto fail; | |
161 | } | |
3c7f2550 MS |
162 | |
163 | /* | |
164 | * Get the command line from EFI, using the LOADED_IMAGE | |
165 | * protocol. We are going to copy the command line into the | |
166 | * device tree, so this can be allocated anywhere. | |
167 | */ | |
168 | cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size); | |
169 | if (!cmdline_ptr) { | |
170 | pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n"); | |
2b5fe07a AB |
171 | goto fail; |
172 | } | |
173 | ||
eeff7d63 AB |
174 | if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) || |
175 | IS_ENABLED(CONFIG_CMDLINE_FORCE) || | |
176 | cmdline_size == 0) | |
177 | efi_parse_options(CONFIG_CMDLINE); | |
178 | ||
179 | if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0) | |
180 | efi_parse_options(cmdline_ptr); | |
181 | ||
182 | pr_efi(sys_table, "Booting Linux Kernel...\n"); | |
183 | ||
f0827e18 AB |
184 | si = setup_graphics(sys_table); |
185 | ||
2b5fe07a AB |
186 | status = handle_kernel_image(sys_table, image_addr, &image_size, |
187 | &reserve_addr, | |
188 | &reserve_size, | |
189 | dram_base, image); | |
190 | if (status != EFI_SUCCESS) { | |
191 | pr_efi_err(sys_table, "Failed to relocate kernel\n"); | |
192 | goto fail_free_cmdline; | |
3c7f2550 MS |
193 | } |
194 | ||
ccc829ba MG |
195 | /* Ask the firmware to clear memory on unclean shutdown */ |
196 | efi_enable_reset_attack_mitigation(sys_table); | |
197 | ||
73a64925 | 198 | secure_boot = efi_get_secureboot(sys_table); |
73a64925 | 199 | |
345c736e | 200 | /* |
de8cb458 DH |
201 | * Unauthenticated device tree data is a security hazard, so ignore |
202 | * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure | |
203 | * boot is enabled if we can't determine its state. | |
345c736e | 204 | */ |
3d7ee348 AB |
205 | if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) || |
206 | secure_boot != efi_secureboot_mode_disabled) { | |
207 | if (strstr(cmdline_ptr, "dtb=")) | |
208 | pr_efi(sys_table, "Ignoring DTB from command line.\n"); | |
345c736e | 209 | } else { |
3c7f2550 MS |
210 | status = handle_cmdline_files(sys_table, image, cmdline_ptr, |
211 | "dtb=", | |
a643375f | 212 | ~0UL, &fdt_addr, &fdt_size); |
3c7f2550 MS |
213 | |
214 | if (status != EFI_SUCCESS) { | |
215 | pr_efi_err(sys_table, "Failed to load device tree!\n"); | |
2b5fe07a | 216 | goto fail_free_image; |
3c7f2550 MS |
217 | } |
218 | } | |
0bcaa904 MR |
219 | |
220 | if (fdt_addr) { | |
221 | pr_efi(sys_table, "Using DTB from command line\n"); | |
222 | } else { | |
345c736e | 223 | /* Look for a device tree configuration table entry. */ |
a643375f | 224 | fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size); |
0bcaa904 MR |
225 | if (fdt_addr) |
226 | pr_efi(sys_table, "Using DTB from configuration table\n"); | |
227 | } | |
228 | ||
229 | if (!fdt_addr) | |
230 | pr_efi(sys_table, "Generating empty DTB\n"); | |
3c7f2550 | 231 | |
138728dd AB |
232 | status = handle_cmdline_files(sys_table, image, cmdline_ptr, "initrd=", |
233 | efi_get_max_initrd_addr(dram_base, | |
234 | *image_addr), | |
3c7f2550 MS |
235 | (unsigned long *)&initrd_addr, |
236 | (unsigned long *)&initrd_size); | |
237 | if (status != EFI_SUCCESS) | |
238 | pr_efi_err(sys_table, "Failed initrd from command line!\n"); | |
239 | ||
568bc4e8 AB |
240 | efi_random_get_seed(sys_table); |
241 | ||
38fb6652 AB |
242 | /* hibernation expects the runtime regions to stay in the same place */ |
243 | if (!IS_ENABLED(CONFIG_HIBERNATION) && !nokaslr()) { | |
e69176d6 AB |
244 | /* |
245 | * Randomize the base of the UEFI runtime services region. | |
246 | * Preserve the 2 MB alignment of the region by taking a | |
247 | * shift of 21 bit positions into account when scaling | |
248 | * the headroom value using a 32-bit random value. | |
249 | */ | |
197decef AB |
250 | static const u64 headroom = EFI_RT_VIRTUAL_LIMIT - |
251 | EFI_RT_VIRTUAL_BASE - | |
252 | EFI_RT_VIRTUAL_SIZE; | |
e69176d6 AB |
253 | u32 rnd; |
254 | ||
255 | status = efi_get_random_bytes(sys_table, sizeof(rnd), | |
256 | (u8 *)&rnd); | |
257 | if (status == EFI_SUCCESS) { | |
258 | virtmap_base = EFI_RT_VIRTUAL_BASE + | |
259 | (((headroom >> 21) * rnd) >> (32 - 21)); | |
260 | } | |
261 | } | |
262 | ||
b844470f AB |
263 | install_memreserve_table(sys_table); |
264 | ||
3c7f2550 MS |
265 | new_fdt_addr = fdt_addr; |
266 | status = allocate_new_fdt_and_exit_boot(sys_table, handle, | |
138728dd | 267 | &new_fdt_addr, efi_get_max_fdt_addr(dram_base), |
3c7f2550 MS |
268 | initrd_addr, initrd_size, cmdline_ptr, |
269 | fdt_addr, fdt_size); | |
270 | ||
271 | /* | |
272 | * If all went well, we need to return the FDT address to the | |
273 | * calling function so it can be passed to kernel as part of | |
274 | * the kernel boot protocol. | |
275 | */ | |
276 | if (status == EFI_SUCCESS) | |
277 | return new_fdt_addr; | |
278 | ||
279 | pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n"); | |
280 | ||
281 | efi_free(sys_table, initrd_size, initrd_addr); | |
282 | efi_free(sys_table, fdt_size, fdt_addr); | |
283 | ||
3c7f2550 MS |
284 | fail_free_image: |
285 | efi_free(sys_table, image_size, *image_addr); | |
286 | efi_free(sys_table, reserve_size, reserve_addr); | |
2b5fe07a | 287 | fail_free_cmdline: |
f0827e18 | 288 | free_screen_info(sys_table, si); |
2b5fe07a | 289 | efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr); |
3c7f2550 MS |
290 | fail: |
291 | return EFI_ERROR; | |
292 | } | |
f3cdfd23 | 293 | |
0ce3cc00 AB |
294 | static int cmp_mem_desc(const void *l, const void *r) |
295 | { | |
296 | const efi_memory_desc_t *left = l, *right = r; | |
297 | ||
298 | return (left->phys_addr > right->phys_addr) ? 1 : -1; | |
299 | } | |
300 | ||
301 | /* | |
302 | * Returns whether region @left ends exactly where region @right starts, | |
303 | * or false if either argument is NULL. | |
304 | */ | |
305 | static bool regions_are_adjacent(efi_memory_desc_t *left, | |
306 | efi_memory_desc_t *right) | |
307 | { | |
308 | u64 left_end; | |
309 | ||
310 | if (left == NULL || right == NULL) | |
311 | return false; | |
312 | ||
313 | left_end = left->phys_addr + left->num_pages * EFI_PAGE_SIZE; | |
314 | ||
315 | return left_end == right->phys_addr; | |
316 | } | |
317 | ||
318 | /* | |
319 | * Returns whether region @left and region @right have compatible memory type | |
320 | * mapping attributes, and are both EFI_MEMORY_RUNTIME regions. | |
321 | */ | |
322 | static bool regions_have_compatible_memory_type_attrs(efi_memory_desc_t *left, | |
323 | efi_memory_desc_t *right) | |
324 | { | |
325 | static const u64 mem_type_mask = EFI_MEMORY_WB | EFI_MEMORY_WT | | |
326 | EFI_MEMORY_WC | EFI_MEMORY_UC | | |
327 | EFI_MEMORY_RUNTIME; | |
328 | ||
329 | return ((left->attribute ^ right->attribute) & mem_type_mask) == 0; | |
330 | } | |
331 | ||
f3cdfd23 AB |
332 | /* |
333 | * efi_get_virtmap() - create a virtual mapping for the EFI memory map | |
334 | * | |
335 | * This function populates the virt_addr fields of all memory region descriptors | |
336 | * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors | |
337 | * are also copied to @runtime_map, and their total count is returned in @count. | |
338 | */ | |
339 | void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, | |
340 | unsigned long desc_size, efi_memory_desc_t *runtime_map, | |
341 | int *count) | |
342 | { | |
e69176d6 | 343 | u64 efi_virt_base = virtmap_base; |
0ce3cc00 | 344 | efi_memory_desc_t *in, *prev = NULL, *out = runtime_map; |
f3cdfd23 AB |
345 | int l; |
346 | ||
0ce3cc00 AB |
347 | /* |
348 | * To work around potential issues with the Properties Table feature | |
349 | * introduced in UEFI 2.5, which may split PE/COFF executable images | |
350 | * in memory into several RuntimeServicesCode and RuntimeServicesData | |
351 | * regions, we need to preserve the relative offsets between adjacent | |
352 | * EFI_MEMORY_RUNTIME regions with the same memory type attributes. | |
353 | * The easiest way to find adjacent regions is to sort the memory map | |
354 | * before traversing it. | |
355 | */ | |
29f9007b AB |
356 | if (IS_ENABLED(CONFIG_ARM64)) |
357 | sort(memory_map, map_size / desc_size, desc_size, cmp_mem_desc, | |
358 | NULL); | |
0ce3cc00 AB |
359 | |
360 | for (l = 0; l < map_size; l += desc_size, prev = in) { | |
f3cdfd23 AB |
361 | u64 paddr, size; |
362 | ||
0ce3cc00 | 363 | in = (void *)memory_map + l; |
f3cdfd23 AB |
364 | if (!(in->attribute & EFI_MEMORY_RUNTIME)) |
365 | continue; | |
366 | ||
0ce3cc00 AB |
367 | paddr = in->phys_addr; |
368 | size = in->num_pages * EFI_PAGE_SIZE; | |
369 | ||
f3cdfd23 AB |
370 | /* |
371 | * Make the mapping compatible with 64k pages: this allows | |
372 | * a 4k page size kernel to kexec a 64k page size kernel and | |
373 | * vice versa. | |
374 | */ | |
29f9007b AB |
375 | if ((IS_ENABLED(CONFIG_ARM64) && |
376 | !regions_are_adjacent(prev, in)) || | |
0ce3cc00 AB |
377 | !regions_have_compatible_memory_type_attrs(prev, in)) { |
378 | ||
379 | paddr = round_down(in->phys_addr, SZ_64K); | |
380 | size += in->phys_addr - paddr; | |
381 | ||
382 | /* | |
383 | * Avoid wasting memory on PTEs by choosing a virtual | |
384 | * base that is compatible with section mappings if this | |
385 | * region has the appropriate size and physical | |
386 | * alignment. (Sections are 2 MB on 4k granule kernels) | |
387 | */ | |
388 | if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M) | |
389 | efi_virt_base = round_up(efi_virt_base, SZ_2M); | |
390 | else | |
391 | efi_virt_base = round_up(efi_virt_base, SZ_64K); | |
392 | } | |
f3cdfd23 AB |
393 | |
394 | in->virt_addr = efi_virt_base + in->phys_addr - paddr; | |
395 | efi_virt_base += size; | |
396 | ||
397 | memcpy(out, in, desc_size); | |
398 | out = (void *)out + desc_size; | |
399 | ++*count; | |
400 | } | |
401 | } |