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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org>
4 */
5#include <linux/efi.h>
6#include <asm/efi.h>
7
8#include "efistub.h"
9
10static efi_guid_t cpu_state_guid = LINUX_EFI_ARM_CPU_STATE_TABLE_GUID;
11
12struct efi_arm_entry_state *efi_entry_state;
13
14static void get_cpu_state(u32 *cpsr, u32 *sctlr)
15{
16 asm("mrs %0, cpsr" : "=r"(*cpsr));
17 if ((*cpsr & MODE_MASK) == HYP_MODE)
18 asm("mrc p15, 4, %0, c1, c0, 0" : "=r"(*sctlr));
19 else
20 asm("mrc p15, 0, %0, c1, c0, 0" : "=r"(*sctlr));
21}
22
23efi_status_t check_platform_features(void)
24{
25 efi_status_t status;
26 u32 cpsr, sctlr;
27 int block;
28
29 get_cpu_state(&cpsr, &sctlr);
30
31 efi_info("Entering in %s mode with MMU %sabled\n",
32 ((cpsr & MODE_MASK) == HYP_MODE) ? "HYP" : "SVC",
33 (sctlr & 1) ? "en" : "dis");
34
35 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
36 sizeof(*efi_entry_state),
37 (void **)&efi_entry_state);
38 if (status != EFI_SUCCESS) {
39 efi_err("allocate_pool() failed\n");
40 return status;
41 }
42
43 efi_entry_state->cpsr_before_ebs = cpsr;
44 efi_entry_state->sctlr_before_ebs = sctlr;
45
46 status = efi_bs_call(install_configuration_table, &cpu_state_guid,
47 efi_entry_state);
48 if (status != EFI_SUCCESS) {
49 efi_err("install_configuration_table() failed\n");
50 goto free_state;
51 }
52
53 /* non-LPAE kernels can run anywhere */
54 if (!IS_ENABLED(CONFIG_ARM_LPAE))
55 return EFI_SUCCESS;
56
57 /* LPAE kernels need compatible hardware */
58 block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
59 if (block < 5) {
60 efi_err("This LPAE kernel is not supported by your CPU\n");
61 status = EFI_UNSUPPORTED;
62 goto drop_table;
63 }
64 return EFI_SUCCESS;
65
66drop_table:
67 efi_bs_call(install_configuration_table, &cpu_state_guid, NULL);
68free_state:
69 efi_bs_call(free_pool, efi_entry_state);
70 return status;
71}
72
73void efi_handle_post_ebs_state(void)
74{
75 get_cpu_state(&efi_entry_state->cpsr_after_ebs,
76 &efi_entry_state->sctlr_after_ebs);
77}
78
79efi_status_t handle_kernel_image(unsigned long *image_addr,
80 unsigned long *image_size,
81 unsigned long *reserve_addr,
82 unsigned long *reserve_size,
83 efi_loaded_image_t *image,
84 efi_handle_t image_handle)
85{
86 const int slack = TEXT_OFFSET - 5 * PAGE_SIZE;
87 int alloc_size = MAX_UNCOMP_KERNEL_SIZE + EFI_PHYS_ALIGN;
88 unsigned long alloc_base, kernel_base;
89 efi_status_t status;
90
91 /*
92 * Allocate space for the decompressed kernel as low as possible.
93 * The region should be 16 MiB aligned, but the first 'slack' bytes
94 * are not used by Linux, so we allow those to be occupied by the
95 * firmware.
96 */
97 status = efi_low_alloc_above(alloc_size, EFI_PAGE_SIZE, &alloc_base, 0x0);
98 if (status != EFI_SUCCESS) {
99 efi_err("Unable to allocate memory for uncompressed kernel.\n");
100 return status;
101 }
102
103 if ((alloc_base % EFI_PHYS_ALIGN) > slack) {
104 /*
105 * More than 'slack' bytes are already occupied at the base of
106 * the allocation, so we need to advance to the next 16 MiB block.
107 */
108 kernel_base = round_up(alloc_base, EFI_PHYS_ALIGN);
109 efi_info("Free memory starts at 0x%lx, setting kernel_base to 0x%lx\n",
110 alloc_base, kernel_base);
111 } else {
112 kernel_base = round_down(alloc_base, EFI_PHYS_ALIGN);
113 }
114
115 *reserve_addr = kernel_base + slack;
116 *reserve_size = MAX_UNCOMP_KERNEL_SIZE;
117
118 /* now free the parts that we will not use */
119 if (*reserve_addr > alloc_base) {
120 efi_bs_call(free_pages, alloc_base,
121 (*reserve_addr - alloc_base) / EFI_PAGE_SIZE);
122 alloc_size -= *reserve_addr - alloc_base;
123 }
124 efi_bs_call(free_pages, *reserve_addr + MAX_UNCOMP_KERNEL_SIZE,
125 (alloc_size - MAX_UNCOMP_KERNEL_SIZE) / EFI_PAGE_SIZE);
126
127 *image_addr = kernel_base + TEXT_OFFSET;
128 *image_size = 0;
129
130 efi_debug("image addr == 0x%lx, reserve_addr == 0x%lx\n",
131 *image_addr, *reserve_addr);
132
133 return EFI_SUCCESS;
134}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org>
4 */
5#include <linux/efi.h>
6#include <asm/efi.h>
7
8#include "efistub.h"
9
10static efi_guid_t cpu_state_guid = LINUX_EFI_ARM_CPU_STATE_TABLE_GUID;
11
12struct efi_arm_entry_state *efi_entry_state;
13
14static void get_cpu_state(u32 *cpsr, u32 *sctlr)
15{
16 asm("mrs %0, cpsr" : "=r"(*cpsr));
17 if ((*cpsr & MODE_MASK) == HYP_MODE)
18 asm("mrc p15, 4, %0, c1, c0, 0" : "=r"(*sctlr));
19 else
20 asm("mrc p15, 0, %0, c1, c0, 0" : "=r"(*sctlr));
21}
22
23efi_status_t check_platform_features(void)
24{
25 efi_status_t status;
26 u32 cpsr, sctlr;
27 int block;
28
29 get_cpu_state(&cpsr, &sctlr);
30
31 efi_info("Entering in %s mode with MMU %sabled\n",
32 ((cpsr & MODE_MASK) == HYP_MODE) ? "HYP" : "SVC",
33 (sctlr & 1) ? "en" : "dis");
34
35 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
36 sizeof(*efi_entry_state),
37 (void **)&efi_entry_state);
38 if (status != EFI_SUCCESS) {
39 efi_err("allocate_pool() failed\n");
40 return status;
41 }
42
43 efi_entry_state->cpsr_before_ebs = cpsr;
44 efi_entry_state->sctlr_before_ebs = sctlr;
45
46 status = efi_bs_call(install_configuration_table, &cpu_state_guid,
47 efi_entry_state);
48 if (status != EFI_SUCCESS) {
49 efi_err("install_configuration_table() failed\n");
50 goto free_state;
51 }
52
53 /* non-LPAE kernels can run anywhere */
54 if (!IS_ENABLED(CONFIG_ARM_LPAE))
55 return EFI_SUCCESS;
56
57 /* LPAE kernels need compatible hardware */
58 block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
59 if (block < 5) {
60 efi_err("This LPAE kernel is not supported by your CPU\n");
61 status = EFI_UNSUPPORTED;
62 goto drop_table;
63 }
64 return EFI_SUCCESS;
65
66drop_table:
67 efi_bs_call(install_configuration_table, &cpu_state_guid, NULL);
68free_state:
69 efi_bs_call(free_pool, efi_entry_state);
70 return status;
71}
72
73void efi_handle_post_ebs_state(void)
74{
75 get_cpu_state(&efi_entry_state->cpsr_after_ebs,
76 &efi_entry_state->sctlr_after_ebs);
77}
78
79static efi_guid_t screen_info_guid = LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID;
80
81struct screen_info *alloc_screen_info(void)
82{
83 struct screen_info *si;
84 efi_status_t status;
85
86 /*
87 * Unlike on arm64, where we can directly fill out the screen_info
88 * structure from the stub, we need to allocate a buffer to hold
89 * its contents while we hand over to the kernel proper from the
90 * decompressor.
91 */
92 status = efi_bs_call(allocate_pool, EFI_RUNTIME_SERVICES_DATA,
93 sizeof(*si), (void **)&si);
94
95 if (status != EFI_SUCCESS)
96 return NULL;
97
98 status = efi_bs_call(install_configuration_table,
99 &screen_info_guid, si);
100 if (status == EFI_SUCCESS)
101 return si;
102
103 efi_bs_call(free_pool, si);
104 return NULL;
105}
106
107void free_screen_info(struct screen_info *si)
108{
109 if (!si)
110 return;
111
112 efi_bs_call(install_configuration_table, &screen_info_guid, NULL);
113 efi_bs_call(free_pool, si);
114}
115
116static efi_status_t reserve_kernel_base(unsigned long dram_base,
117 unsigned long *reserve_addr,
118 unsigned long *reserve_size)
119{
120 efi_physical_addr_t alloc_addr;
121 efi_memory_desc_t *memory_map;
122 unsigned long nr_pages, map_size, desc_size, buff_size;
123 efi_status_t status;
124 unsigned long l;
125
126 struct efi_boot_memmap map = {
127 .map = &memory_map,
128 .map_size = &map_size,
129 .desc_size = &desc_size,
130 .desc_ver = NULL,
131 .key_ptr = NULL,
132 .buff_size = &buff_size,
133 };
134
135 /*
136 * Reserve memory for the uncompressed kernel image. This is
137 * all that prevents any future allocations from conflicting
138 * with the kernel. Since we can't tell from the compressed
139 * image how much DRAM the kernel actually uses (due to BSS
140 * size uncertainty) we allocate the maximum possible size.
141 * Do this very early, as prints can cause memory allocations
142 * that may conflict with this.
143 */
144 alloc_addr = dram_base + MAX_UNCOMP_KERNEL_SIZE;
145 nr_pages = MAX_UNCOMP_KERNEL_SIZE / EFI_PAGE_SIZE;
146 status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS,
147 EFI_BOOT_SERVICES_DATA, nr_pages, &alloc_addr);
148 if (status == EFI_SUCCESS) {
149 if (alloc_addr == dram_base) {
150 *reserve_addr = alloc_addr;
151 *reserve_size = MAX_UNCOMP_KERNEL_SIZE;
152 return EFI_SUCCESS;
153 }
154 /*
155 * If we end up here, the allocation succeeded but starts below
156 * dram_base. This can only occur if the real base of DRAM is
157 * not a multiple of 128 MB, in which case dram_base will have
158 * been rounded up. Since this implies that a part of the region
159 * was already occupied, we need to fall through to the code
160 * below to ensure that the existing allocations don't conflict.
161 * For this reason, we use EFI_BOOT_SERVICES_DATA above and not
162 * EFI_LOADER_DATA, which we wouldn't able to distinguish from
163 * allocations that we want to disallow.
164 */
165 }
166
167 /*
168 * If the allocation above failed, we may still be able to proceed:
169 * if the only allocations in the region are of types that will be
170 * released to the OS after ExitBootServices(), the decompressor can
171 * safely overwrite them.
172 */
173 status = efi_get_memory_map(&map);
174 if (status != EFI_SUCCESS) {
175 efi_err("reserve_kernel_base(): Unable to retrieve memory map.\n");
176 return status;
177 }
178
179 for (l = 0; l < map_size; l += desc_size) {
180 efi_memory_desc_t *desc;
181 u64 start, end;
182
183 desc = (void *)memory_map + l;
184 start = desc->phys_addr;
185 end = start + desc->num_pages * EFI_PAGE_SIZE;
186
187 /* Skip if entry does not intersect with region */
188 if (start >= dram_base + MAX_UNCOMP_KERNEL_SIZE ||
189 end <= dram_base)
190 continue;
191
192 switch (desc->type) {
193 case EFI_BOOT_SERVICES_CODE:
194 case EFI_BOOT_SERVICES_DATA:
195 /* Ignore types that are released to the OS anyway */
196 continue;
197
198 case EFI_CONVENTIONAL_MEMORY:
199 /* Skip soft reserved conventional memory */
200 if (efi_soft_reserve_enabled() &&
201 (desc->attribute & EFI_MEMORY_SP))
202 continue;
203
204 /*
205 * Reserve the intersection between this entry and the
206 * region.
207 */
208 start = max(start, (u64)dram_base);
209 end = min(end, (u64)dram_base + MAX_UNCOMP_KERNEL_SIZE);
210
211 status = efi_bs_call(allocate_pages,
212 EFI_ALLOCATE_ADDRESS,
213 EFI_LOADER_DATA,
214 (end - start) / EFI_PAGE_SIZE,
215 &start);
216 if (status != EFI_SUCCESS) {
217 efi_err("reserve_kernel_base(): alloc failed.\n");
218 goto out;
219 }
220 break;
221
222 case EFI_LOADER_CODE:
223 case EFI_LOADER_DATA:
224 /*
225 * These regions may be released and reallocated for
226 * another purpose (including EFI_RUNTIME_SERVICE_DATA)
227 * at any time during the execution of the OS loader,
228 * so we cannot consider them as safe.
229 */
230 default:
231 /*
232 * Treat any other allocation in the region as unsafe */
233 status = EFI_OUT_OF_RESOURCES;
234 goto out;
235 }
236 }
237
238 status = EFI_SUCCESS;
239out:
240 efi_bs_call(free_pool, memory_map);
241 return status;
242}
243
244efi_status_t handle_kernel_image(unsigned long *image_addr,
245 unsigned long *image_size,
246 unsigned long *reserve_addr,
247 unsigned long *reserve_size,
248 unsigned long dram_base,
249 efi_loaded_image_t *image)
250{
251 unsigned long kernel_base;
252 efi_status_t status;
253
254 /* use a 16 MiB aligned base for the decompressed kernel */
255 kernel_base = round_up(dram_base, SZ_16M) + TEXT_OFFSET;
256
257 /*
258 * Note that some platforms (notably, the Raspberry Pi 2) put
259 * spin-tables and other pieces of firmware at the base of RAM,
260 * abusing the fact that the window of TEXT_OFFSET bytes at the
261 * base of the kernel image is only partially used at the moment.
262 * (Up to 5 pages are used for the swapper page tables)
263 */
264 status = reserve_kernel_base(kernel_base - 5 * PAGE_SIZE, reserve_addr,
265 reserve_size);
266 if (status != EFI_SUCCESS) {
267 efi_err("Unable to allocate memory for uncompressed kernel.\n");
268 return status;
269 }
270
271 *image_addr = kernel_base;
272 *image_size = 0;
273 return EFI_SUCCESS;
274}