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efi/libstub: Introduce ExitBootServices helper
[linux.git] / drivers / firmware / efi / libstub / fdt.c
CommitLineData
263b4a30
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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AB
13#include <linux/efi.h>
14#include <linux/libfdt.h>
15#include <asm/efi.h>
16
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AB
17#include "efistub.h"
18
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AB
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{
500899c2 27 int node, num_rsv;
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28 int status;
29 u32 fdt_val32;
30 u64 fdt_val64;
31
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RF
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
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MS
56 /*
57 * Delete all memory reserve map entries. When booting via UEFI,
58 * kernel will use the UEFI memory map to find reserved regions.
59 */
60 num_rsv = fdt_num_mem_rsv(fdt);
61 while (num_rsv-- > 0)
62 fdt_del_mem_rsv(fdt, num_rsv);
63
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RF
64 node = fdt_subnode_offset(fdt, 0, "chosen");
65 if (node < 0) {
66 node = fdt_add_subnode(fdt, 0, "chosen");
67 if (node < 0) {
68 status = node; /* node is error code when negative */
69 goto fdt_set_fail;
70 }
71 }
72
73 if ((cmdline_ptr != NULL) && (strlen(cmdline_ptr) > 0)) {
74 status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr,
75 strlen(cmdline_ptr) + 1);
76 if (status)
77 goto fdt_set_fail;
78 }
79
80 /* Set initrd address/end in device tree, if present */
81 if (initrd_size != 0) {
82 u64 initrd_image_end;
83 u64 initrd_image_start = cpu_to_fdt64(initrd_addr);
84
85 status = fdt_setprop(fdt, node, "linux,initrd-start",
86 &initrd_image_start, sizeof(u64));
87 if (status)
88 goto fdt_set_fail;
89 initrd_image_end = cpu_to_fdt64(initrd_addr + initrd_size);
90 status = fdt_setprop(fdt, node, "linux,initrd-end",
91 &initrd_image_end, sizeof(u64));
92 if (status)
93 goto fdt_set_fail;
94 }
95
96 /* Add FDT entries for EFI runtime services in chosen node. */
97 node = fdt_subnode_offset(fdt, 0, "chosen");
98 fdt_val64 = cpu_to_fdt64((u64)(unsigned long)sys_table);
99 status = fdt_setprop(fdt, node, "linux,uefi-system-table",
100 &fdt_val64, sizeof(fdt_val64));
101 if (status)
102 goto fdt_set_fail;
103
104 fdt_val64 = cpu_to_fdt64((u64)(unsigned long)memory_map);
105 status = fdt_setprop(fdt, node, "linux,uefi-mmap-start",
106 &fdt_val64, sizeof(fdt_val64));
107 if (status)
108 goto fdt_set_fail;
109
110 fdt_val32 = cpu_to_fdt32(map_size);
111 status = fdt_setprop(fdt, node, "linux,uefi-mmap-size",
112 &fdt_val32, sizeof(fdt_val32));
113 if (status)
114 goto fdt_set_fail;
115
116 fdt_val32 = cpu_to_fdt32(desc_size);
117 status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-size",
118 &fdt_val32, sizeof(fdt_val32));
119 if (status)
120 goto fdt_set_fail;
121
122 fdt_val32 = cpu_to_fdt32(desc_ver);
123 status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-ver",
124 &fdt_val32, sizeof(fdt_val32));
125 if (status)
126 goto fdt_set_fail;
127
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AB
128 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
129 efi_status_t efi_status;
130
131 efi_status = efi_get_random_bytes(sys_table, sizeof(fdt_val64),
132 (u8 *)&fdt_val64);
133 if (efi_status == EFI_SUCCESS) {
134 status = fdt_setprop(fdt, node, "kaslr-seed",
135 &fdt_val64, sizeof(fdt_val64));
136 if (status)
137 goto fdt_set_fail;
138 } else if (efi_status != EFI_NOT_FOUND) {
139 return efi_status;
140 }
141 }
263b4a30
RF
142 return EFI_SUCCESS;
143
144fdt_set_fail:
145 if (status == -FDT_ERR_NOSPACE)
146 return EFI_BUFFER_TOO_SMALL;
147
148 return EFI_LOAD_ERROR;
149}
150
151#ifndef EFI_FDT_ALIGN
152#define EFI_FDT_ALIGN EFI_PAGE_SIZE
153#endif
154
155/*
156 * Allocate memory for a new FDT, then add EFI, commandline, and
157 * initrd related fields to the FDT. This routine increases the
158 * FDT allocation size until the allocated memory is large
159 * enough. EFI allocations are in EFI_PAGE_SIZE granules,
160 * which are fixed at 4K bytes, so in most cases the first
161 * allocation should succeed.
162 * EFI boot services are exited at the end of this function.
163 * There must be no allocations between the get_memory_map()
164 * call and the exit_boot_services() call, so the exiting of
165 * boot services is very tightly tied to the creation of the FDT
166 * with the final memory map in it.
167 */
168
169efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
170 void *handle,
171 unsigned long *new_fdt_addr,
172 unsigned long max_addr,
173 u64 initrd_addr, u64 initrd_size,
174 char *cmdline_ptr,
175 unsigned long fdt_addr,
176 unsigned long fdt_size)
177{
dadb57ab 178 unsigned long map_size, desc_size, buff_size;
263b4a30
RF
179 u32 desc_ver;
180 unsigned long mmap_key;
f3cdfd23 181 efi_memory_desc_t *memory_map, *runtime_map;
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RF
182 unsigned long new_fdt_size;
183 efi_status_t status;
f3cdfd23 184 int runtime_entry_count = 0;
dadb57ab
JH
185 struct efi_boot_memmap map;
186
187 map.map = &runtime_map;
188 map.map_size = &map_size;
189 map.desc_size = &desc_size;
190 map.desc_ver = &desc_ver;
191 map.key_ptr = &mmap_key;
192 map.buff_size = &buff_size;
f3cdfd23
AB
193
194 /*
195 * Get a copy of the current memory map that we will use to prepare
196 * the input for SetVirtualAddressMap(). We don't have to worry about
197 * subsequent allocations adding entries, since they could not affect
198 * the number of EFI_MEMORY_RUNTIME regions.
199 */
dadb57ab 200 status = efi_get_memory_map(sys_table, &map);
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AB
201 if (status != EFI_SUCCESS) {
202 pr_efi_err(sys_table, "Unable to retrieve UEFI memory map.\n");
203 return status;
204 }
205
206 pr_efi(sys_table,
207 "Exiting boot services and installing virtual address map...\n");
263b4a30 208
dadb57ab 209 map.map = &memory_map;
263b4a30
RF
210 /*
211 * Estimate size of new FDT, and allocate memory for it. We
212 * will allocate a bigger buffer if this ends up being too
213 * small, so a rough guess is OK here.
214 */
215 new_fdt_size = fdt_size + EFI_PAGE_SIZE;
216 while (1) {
217 status = efi_high_alloc(sys_table, new_fdt_size, EFI_FDT_ALIGN,
218 new_fdt_addr, max_addr);
219 if (status != EFI_SUCCESS) {
220 pr_efi_err(sys_table, "Unable to allocate memory for new device tree.\n");
221 goto fail;
222 }
223
224 /*
225 * Now that we have done our final memory allocation (and free)
226 * we can get the memory map key needed for
227 * exit_boot_services().
228 */
dadb57ab 229 status = efi_get_memory_map(sys_table, &map);
263b4a30
RF
230 if (status != EFI_SUCCESS)
231 goto fail_free_new_fdt;
232
233 status = update_fdt(sys_table,
234 (void *)fdt_addr, fdt_size,
235 (void *)*new_fdt_addr, new_fdt_size,
236 cmdline_ptr, initrd_addr, initrd_size,
237 memory_map, map_size, desc_size, desc_ver);
238
239 /* Succeeding the first time is the expected case. */
240 if (status == EFI_SUCCESS)
241 break;
242
243 if (status == EFI_BUFFER_TOO_SMALL) {
244 /*
245 * We need to allocate more space for the new
246 * device tree, so free existing buffer that is
247 * too small. Also free memory map, as we will need
248 * to get new one that reflects the free/alloc we do
249 * on the device tree buffer.
250 */
251 efi_free(sys_table, new_fdt_size, *new_fdt_addr);
252 sys_table->boottime->free_pool(memory_map);
253 new_fdt_size += EFI_PAGE_SIZE;
254 } else {
e3d132d1 255 pr_efi_err(sys_table, "Unable to construct new device tree.\n");
263b4a30
RF
256 goto fail_free_mmap;
257 }
258 }
259
f3cdfd23
AB
260 /*
261 * Update the memory map with virtual addresses. The function will also
262 * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME
263 * entries so that we can pass it straight into SetVirtualAddressMap()
264 */
265 efi_get_virtmap(memory_map, map_size, desc_size, runtime_map,
266 &runtime_entry_count);
267
263b4a30
RF
268 /* Now we are ready to exit_boot_services.*/
269 status = sys_table->boottime->exit_boot_services(handle, mmap_key);
270
f3cdfd23
AB
271 if (status == EFI_SUCCESS) {
272 efi_set_virtual_address_map_t *svam;
263b4a30 273
f3cdfd23
AB
274 /* Install the new virtual address map */
275 svam = sys_table->runtime->set_virtual_address_map;
276 status = svam(runtime_entry_count * desc_size, desc_size,
277 desc_ver, runtime_map);
278
279 /*
280 * We are beyond the point of no return here, so if the call to
281 * SetVirtualAddressMap() failed, we need to signal that to the
282 * incoming kernel but proceed normally otherwise.
283 */
284 if (status != EFI_SUCCESS) {
285 int l;
286
287 /*
288 * Set the virtual address field of all
289 * EFI_MEMORY_RUNTIME entries to 0. This will signal
290 * the incoming kernel that no virtual translation has
291 * been installed.
292 */
293 for (l = 0; l < map_size; l += desc_size) {
294 efi_memory_desc_t *p = (void *)memory_map + l;
295
296 if (p->attribute & EFI_MEMORY_RUNTIME)
297 p->virt_addr = 0;
298 }
299 }
300 return EFI_SUCCESS;
301 }
263b4a30
RF
302
303 pr_efi_err(sys_table, "Exit boot services failed.\n");
304
305fail_free_mmap:
306 sys_table->boottime->free_pool(memory_map);
307
308fail_free_new_fdt:
309 efi_free(sys_table, new_fdt_size, *new_fdt_addr);
310
311fail:
f3cdfd23 312 sys_table->boottime->free_pool(runtime_map);
263b4a30
RF
313 return EFI_LOAD_ERROR;
314}
315
a643375f 316void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size)
263b4a30
RF
317{
318 efi_guid_t fdt_guid = DEVICE_TREE_GUID;
319 efi_config_table_t *tables;
320 void *fdt;
321 int i;
322
323 tables = (efi_config_table_t *) sys_table->tables;
324 fdt = NULL;
325
326 for (i = 0; i < sys_table->nr_tables; i++)
327 if (efi_guidcmp(tables[i].guid, fdt_guid) == 0) {
328 fdt = (void *) tables[i].table;
a643375f
AB
329 if (fdt_check_header(fdt) != 0) {
330 pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n");
331 return NULL;
332 }
333 *fdt_size = fdt_totalsize(fdt);
263b4a30
RF
334 break;
335 }
336
337 return fdt;
338}
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