arm64: efi: invoke EFI_RNG_PROTOCOL to supply KASLR randomness
[linux-2.6-block.git] / drivers / firmware / efi / libstub / fdt.c
CommitLineData
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RF
1/*
2 * FDT related Helper functions used by the EFI stub on multiple
3 * architectures. This should be #included by the EFI stub
4 * implementation files.
5 *
6 * Copyright 2013 Linaro Limited; author Roy Franz
7 *
8 * This file is part of the Linux kernel, and is made available
9 * under the terms of the GNU General Public License version 2.
10 *
11 */
12
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13#include <linux/efi.h>
14#include <linux/libfdt.h>
15#include <asm/efi.h>
16
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17#include "efistub.h"
18
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19efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
20 unsigned long orig_fdt_size,
21 void *fdt, int new_fdt_size, char *cmdline_ptr,
22 u64 initrd_addr, u64 initrd_size,
23 efi_memory_desc_t *memory_map,
24 unsigned long map_size, unsigned long desc_size,
25 u32 desc_ver)
263b4a30 26{
0ceac9e0 27 int node, prev, num_rsv;
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28 int status;
29 u32 fdt_val32;
30 u64 fdt_val64;
31
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32 /* Do some checks on provided FDT, if it exists*/
33 if (orig_fdt) {
34 if (fdt_check_header(orig_fdt)) {
35 pr_efi_err(sys_table, "Device Tree header not valid!\n");
36 return EFI_LOAD_ERROR;
37 }
38 /*
39 * We don't get the size of the FDT if we get if from a
40 * configuration table.
41 */
42 if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) {
43 pr_efi_err(sys_table, "Truncated device tree! foo!\n");
44 return EFI_LOAD_ERROR;
45 }
46 }
47
48 if (orig_fdt)
49 status = fdt_open_into(orig_fdt, fdt, new_fdt_size);
50 else
51 status = fdt_create_empty_tree(fdt, new_fdt_size);
52
53 if (status != 0)
54 goto fdt_set_fail;
55
56 /*
57 * Delete any memory nodes present. We must delete nodes which
58 * early_init_dt_scan_memory may try to use.
59 */
60 prev = 0;
61 for (;;) {
6fb8cc82 62 const char *type;
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63 int len;
64
65 node = fdt_next_node(fdt, prev, NULL);
66 if (node < 0)
67 break;
68
69 type = fdt_getprop(fdt, node, "device_type", &len);
70 if (type && strncmp(type, "memory", len) == 0) {
71 fdt_del_node(fdt, node);
72 continue;
73 }
74
75 prev = node;
76 }
77
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78 /*
79 * Delete all memory reserve map entries. When booting via UEFI,
80 * kernel will use the UEFI memory map to find reserved regions.
81 */
82 num_rsv = fdt_num_mem_rsv(fdt);
83 while (num_rsv-- > 0)
84 fdt_del_mem_rsv(fdt, num_rsv);
85
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86 node = fdt_subnode_offset(fdt, 0, "chosen");
87 if (node < 0) {
88 node = fdt_add_subnode(fdt, 0, "chosen");
89 if (node < 0) {
90 status = node; /* node is error code when negative */
91 goto fdt_set_fail;
92 }
93 }
94
95 if ((cmdline_ptr != NULL) && (strlen(cmdline_ptr) > 0)) {
96 status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr,
97 strlen(cmdline_ptr) + 1);
98 if (status)
99 goto fdt_set_fail;
100 }
101
102 /* Set initrd address/end in device tree, if present */
103 if (initrd_size != 0) {
104 u64 initrd_image_end;
105 u64 initrd_image_start = cpu_to_fdt64(initrd_addr);
106
107 status = fdt_setprop(fdt, node, "linux,initrd-start",
108 &initrd_image_start, sizeof(u64));
109 if (status)
110 goto fdt_set_fail;
111 initrd_image_end = cpu_to_fdt64(initrd_addr + initrd_size);
112 status = fdt_setprop(fdt, node, "linux,initrd-end",
113 &initrd_image_end, sizeof(u64));
114 if (status)
115 goto fdt_set_fail;
116 }
117
118 /* Add FDT entries for EFI runtime services in chosen node. */
119 node = fdt_subnode_offset(fdt, 0, "chosen");
120 fdt_val64 = cpu_to_fdt64((u64)(unsigned long)sys_table);
121 status = fdt_setprop(fdt, node, "linux,uefi-system-table",
122 &fdt_val64, sizeof(fdt_val64));
123 if (status)
124 goto fdt_set_fail;
125
126 fdt_val64 = cpu_to_fdt64((u64)(unsigned long)memory_map);
127 status = fdt_setprop(fdt, node, "linux,uefi-mmap-start",
128 &fdt_val64, sizeof(fdt_val64));
129 if (status)
130 goto fdt_set_fail;
131
132 fdt_val32 = cpu_to_fdt32(map_size);
133 status = fdt_setprop(fdt, node, "linux,uefi-mmap-size",
134 &fdt_val32, sizeof(fdt_val32));
135 if (status)
136 goto fdt_set_fail;
137
138 fdt_val32 = cpu_to_fdt32(desc_size);
139 status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-size",
140 &fdt_val32, sizeof(fdt_val32));
141 if (status)
142 goto fdt_set_fail;
143
144 fdt_val32 = cpu_to_fdt32(desc_ver);
145 status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-ver",
146 &fdt_val32, sizeof(fdt_val32));
147 if (status)
148 goto fdt_set_fail;
149
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150 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
151 efi_status_t efi_status;
152
153 efi_status = efi_get_random_bytes(sys_table, sizeof(fdt_val64),
154 (u8 *)&fdt_val64);
155 if (efi_status == EFI_SUCCESS) {
156 status = fdt_setprop(fdt, node, "kaslr-seed",
157 &fdt_val64, sizeof(fdt_val64));
158 if (status)
159 goto fdt_set_fail;
160 } else if (efi_status != EFI_NOT_FOUND) {
161 return efi_status;
162 }
163 }
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RF
164 return EFI_SUCCESS;
165
166fdt_set_fail:
167 if (status == -FDT_ERR_NOSPACE)
168 return EFI_BUFFER_TOO_SMALL;
169
170 return EFI_LOAD_ERROR;
171}
172
173#ifndef EFI_FDT_ALIGN
174#define EFI_FDT_ALIGN EFI_PAGE_SIZE
175#endif
176
177/*
178 * Allocate memory for a new FDT, then add EFI, commandline, and
179 * initrd related fields to the FDT. This routine increases the
180 * FDT allocation size until the allocated memory is large
181 * enough. EFI allocations are in EFI_PAGE_SIZE granules,
182 * which are fixed at 4K bytes, so in most cases the first
183 * allocation should succeed.
184 * EFI boot services are exited at the end of this function.
185 * There must be no allocations between the get_memory_map()
186 * call and the exit_boot_services() call, so the exiting of
187 * boot services is very tightly tied to the creation of the FDT
188 * with the final memory map in it.
189 */
190
191efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
192 void *handle,
193 unsigned long *new_fdt_addr,
194 unsigned long max_addr,
195 u64 initrd_addr, u64 initrd_size,
196 char *cmdline_ptr,
197 unsigned long fdt_addr,
198 unsigned long fdt_size)
199{
200 unsigned long map_size, desc_size;
201 u32 desc_ver;
202 unsigned long mmap_key;
f3cdfd23 203 efi_memory_desc_t *memory_map, *runtime_map;
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204 unsigned long new_fdt_size;
205 efi_status_t status;
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AB
206 int runtime_entry_count = 0;
207
208 /*
209 * Get a copy of the current memory map that we will use to prepare
210 * the input for SetVirtualAddressMap(). We don't have to worry about
211 * subsequent allocations adding entries, since they could not affect
212 * the number of EFI_MEMORY_RUNTIME regions.
213 */
214 status = efi_get_memory_map(sys_table, &runtime_map, &map_size,
215 &desc_size, &desc_ver, &mmap_key);
216 if (status != EFI_SUCCESS) {
217 pr_efi_err(sys_table, "Unable to retrieve UEFI memory map.\n");
218 return status;
219 }
220
221 pr_efi(sys_table,
222 "Exiting boot services and installing virtual address map...\n");
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RF
223
224 /*
225 * Estimate size of new FDT, and allocate memory for it. We
226 * will allocate a bigger buffer if this ends up being too
227 * small, so a rough guess is OK here.
228 */
229 new_fdt_size = fdt_size + EFI_PAGE_SIZE;
230 while (1) {
231 status = efi_high_alloc(sys_table, new_fdt_size, EFI_FDT_ALIGN,
232 new_fdt_addr, max_addr);
233 if (status != EFI_SUCCESS) {
234 pr_efi_err(sys_table, "Unable to allocate memory for new device tree.\n");
235 goto fail;
236 }
237
238 /*
239 * Now that we have done our final memory allocation (and free)
240 * we can get the memory map key needed for
241 * exit_boot_services().
242 */
243 status = efi_get_memory_map(sys_table, &memory_map, &map_size,
244 &desc_size, &desc_ver, &mmap_key);
245 if (status != EFI_SUCCESS)
246 goto fail_free_new_fdt;
247
248 status = update_fdt(sys_table,
249 (void *)fdt_addr, fdt_size,
250 (void *)*new_fdt_addr, new_fdt_size,
251 cmdline_ptr, initrd_addr, initrd_size,
252 memory_map, map_size, desc_size, desc_ver);
253
254 /* Succeeding the first time is the expected case. */
255 if (status == EFI_SUCCESS)
256 break;
257
258 if (status == EFI_BUFFER_TOO_SMALL) {
259 /*
260 * We need to allocate more space for the new
261 * device tree, so free existing buffer that is
262 * too small. Also free memory map, as we will need
263 * to get new one that reflects the free/alloc we do
264 * on the device tree buffer.
265 */
266 efi_free(sys_table, new_fdt_size, *new_fdt_addr);
267 sys_table->boottime->free_pool(memory_map);
268 new_fdt_size += EFI_PAGE_SIZE;
269 } else {
e3d132d1 270 pr_efi_err(sys_table, "Unable to construct new device tree.\n");
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RF
271 goto fail_free_mmap;
272 }
273 }
274
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AB
275 /*
276 * Update the memory map with virtual addresses. The function will also
277 * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME
278 * entries so that we can pass it straight into SetVirtualAddressMap()
279 */
280 efi_get_virtmap(memory_map, map_size, desc_size, runtime_map,
281 &runtime_entry_count);
282
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283 /* Now we are ready to exit_boot_services.*/
284 status = sys_table->boottime->exit_boot_services(handle, mmap_key);
285
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286 if (status == EFI_SUCCESS) {
287 efi_set_virtual_address_map_t *svam;
263b4a30 288
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289 /* Install the new virtual address map */
290 svam = sys_table->runtime->set_virtual_address_map;
291 status = svam(runtime_entry_count * desc_size, desc_size,
292 desc_ver, runtime_map);
293
294 /*
295 * We are beyond the point of no return here, so if the call to
296 * SetVirtualAddressMap() failed, we need to signal that to the
297 * incoming kernel but proceed normally otherwise.
298 */
299 if (status != EFI_SUCCESS) {
300 int l;
301
302 /*
303 * Set the virtual address field of all
304 * EFI_MEMORY_RUNTIME entries to 0. This will signal
305 * the incoming kernel that no virtual translation has
306 * been installed.
307 */
308 for (l = 0; l < map_size; l += desc_size) {
309 efi_memory_desc_t *p = (void *)memory_map + l;
310
311 if (p->attribute & EFI_MEMORY_RUNTIME)
312 p->virt_addr = 0;
313 }
314 }
315 return EFI_SUCCESS;
316 }
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317
318 pr_efi_err(sys_table, "Exit boot services failed.\n");
319
320fail_free_mmap:
321 sys_table->boottime->free_pool(memory_map);
322
323fail_free_new_fdt:
324 efi_free(sys_table, new_fdt_size, *new_fdt_addr);
325
326fail:
f3cdfd23 327 sys_table->boottime->free_pool(runtime_map);
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328 return EFI_LOAD_ERROR;
329}
330
a643375f 331void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size)
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332{
333 efi_guid_t fdt_guid = DEVICE_TREE_GUID;
334 efi_config_table_t *tables;
335 void *fdt;
336 int i;
337
338 tables = (efi_config_table_t *) sys_table->tables;
339 fdt = NULL;
340
341 for (i = 0; i < sys_table->nr_tables; i++)
342 if (efi_guidcmp(tables[i].guid, fdt_guid) == 0) {
343 fdt = (void *) tables[i].table;
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AB
344 if (fdt_check_header(fdt) != 0) {
345 pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n");
346 return NULL;
347 }
348 *fdt_size = fdt_totalsize(fdt);
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349 break;
350 }
351
352 return fdt;
353}