xref: /linux/arch/arm64/kernel/machine_kexec_file.c (revision 59e6295fac26b8e85c1ea859cdd89fa1e47519d7)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * kexec_file for arm64
4  *
5  * Copyright (C) 2018 Linaro Limited
6  * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
7  *
8  * Most code is derived from arm64 port of kexec-tools
9  */
10 
11 #define pr_fmt(fmt) "kexec_file: " fmt
12 
13 #include <linux/ioport.h>
14 #include <linux/kernel.h>
15 #include <linux/kexec.h>
16 #include <linux/libfdt.h>
17 #include <linux/memblock.h>
18 #include <linux/of.h>
19 #include <linux/of_fdt.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
22 #include <linux/types.h>
23 #include <linux/vmalloc.h>
24 
25 const struct kexec_file_ops * const kexec_file_loaders[] = {
26 	&kexec_image_ops,
27 	NULL
28 };
29 
30 int arch_kimage_file_post_load_cleanup(struct kimage *image)
31 {
32 	kvfree(image->arch.dtb);
33 	image->arch.dtb = NULL;
34 
35 	vfree(image->elf_headers);
36 	image->elf_headers = NULL;
37 	image->elf_headers_sz = 0;
38 
39 	return kexec_image_post_load_cleanup_default(image);
40 }
41 
42 #ifdef CONFIG_CRASH_DUMP
43 unsigned int arch_get_system_nr_ranges(void)
44 {
45 	unsigned int nr_ranges = 2 + crashk_cma_cnt; /* for exclusion of crashkernel region */
46 	phys_addr_t start, end;
47 	u64 i;
48 
49 	for_each_mem_range(i, &start, &end)
50 		nr_ranges++;
51 
52 	return nr_ranges;
53 }
54 
55 int arch_crash_populate_cmem(struct crash_mem *cmem)
56 {
57 	phys_addr_t start, end;
58 	u64 i;
59 
60 	for_each_mem_range(i, &start, &end) {
61 		cmem->ranges[cmem->nr_ranges].start = start;
62 		cmem->ranges[cmem->nr_ranges].end = end - 1;
63 		cmem->nr_ranges++;
64 	}
65 
66 	return 0;
67 }
68 #endif
69 
70 /*
71  * Tries to add the initrd and DTB to the image. If it is not possible to find
72  * valid locations, this function will undo changes to the image and return non
73  * zero.
74  */
75 int load_other_segments(struct kimage *image,
76 			unsigned long kernel_load_addr,
77 			unsigned long kernel_size,
78 			char *initrd, unsigned long initrd_len,
79 			char *cmdline)
80 {
81 	struct kexec_buf kbuf = {};
82 	void *dtb = NULL;
83 	unsigned long initrd_load_addr = 0, dtb_len,
84 		      orig_segments = image->nr_segments;
85 	int ret = 0;
86 
87 	kbuf.image = image;
88 	/* not allocate anything below the kernel */
89 	kbuf.buf_min = kernel_load_addr + kernel_size;
90 
91 #ifdef CONFIG_CRASH_DUMP
92 	/* load elf core header */
93 	void *headers;
94 	unsigned long headers_sz;
95 	if (image->type == KEXEC_TYPE_CRASH) {
96 		ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
97 		if (ret) {
98 			pr_err("Preparing elf core header failed\n");
99 			goto out_err;
100 		}
101 
102 		kbuf.buffer = headers;
103 		kbuf.bufsz = headers_sz;
104 		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
105 		kbuf.memsz = headers_sz;
106 		kbuf.buf_align = SZ_64K; /* largest supported page size */
107 		kbuf.buf_max = ULONG_MAX;
108 		kbuf.top_down = true;
109 
110 		ret = kexec_add_buffer(&kbuf);
111 		if (ret) {
112 			vfree(headers);
113 			goto out_err;
114 		}
115 		image->elf_headers = headers;
116 		image->elf_load_addr = kbuf.mem;
117 		image->elf_headers_sz = headers_sz;
118 
119 		kexec_dprintk("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
120 			      image->elf_load_addr, kbuf.bufsz, kbuf.memsz);
121 
122 		ret = crash_load_dm_crypt_keys(image);
123 		if (ret)
124 			goto out_err;
125 	}
126 #endif
127 
128 	/* load initrd */
129 	if (initrd) {
130 		kbuf.buffer = initrd;
131 		kbuf.bufsz = initrd_len;
132 		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
133 		kbuf.memsz = initrd_len;
134 		kbuf.buf_align = 0;
135 		/* within 1GB-aligned window of up to 32GB in size */
136 		kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
137 						+ (unsigned long)SZ_1G * 32;
138 		kbuf.top_down = false;
139 
140 		ret = kexec_add_buffer(&kbuf);
141 		if (ret)
142 			goto out_err;
143 		initrd_load_addr = kbuf.mem;
144 
145 		kexec_dprintk("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
146 			      initrd_load_addr, kbuf.bufsz, kbuf.memsz);
147 	}
148 
149 	/* load dtb */
150 	dtb = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
151 					   initrd_len, cmdline, 0);
152 	if (!dtb) {
153 		pr_err("Preparing for new dtb failed\n");
154 		ret = -EINVAL;
155 		goto out_err;
156 	}
157 
158 	/* trim it */
159 	fdt_pack(dtb);
160 	dtb_len = fdt_totalsize(dtb);
161 	kbuf.buffer = dtb;
162 	kbuf.bufsz = dtb_len;
163 	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
164 	kbuf.memsz = dtb_len;
165 	/* not across 2MB boundary */
166 	kbuf.buf_align = SZ_2M;
167 	kbuf.buf_max = ULONG_MAX;
168 	kbuf.top_down = true;
169 
170 	ret = kexec_add_buffer(&kbuf);
171 	if (ret)
172 		goto out_err;
173 	image->arch.dtb = dtb;
174 	image->arch.dtb_mem = kbuf.mem;
175 
176 	kexec_dprintk("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
177 		      kbuf.mem, kbuf.bufsz, kbuf.memsz);
178 
179 	return 0;
180 
181 out_err:
182 	image->nr_segments = orig_segments;
183 	kvfree(dtb);
184 	return ret;
185 }
186