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 static int prepare_elf_headers(void **addr, unsigned long *sz)
43 {
44 	struct crash_mem *cmem;
45 	unsigned int nr_ranges;
46 	int ret;
47 	u64 i;
48 	phys_addr_t start, end;
49 
50 	nr_ranges = 1; /* for exclusion of crashkernel region */
51 	for_each_mem_range(i, &start, &end)
52 		nr_ranges++;
53 
54 	cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL);
55 	if (!cmem)
56 		return -ENOMEM;
57 
58 	cmem->max_nr_ranges = nr_ranges;
59 	cmem->nr_ranges = 0;
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 	/* Exclude crashkernel region */
67 	ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
68 
69 	if (!ret)
70 		ret =  crash_prepare_elf64_headers(cmem, true, addr, sz);
71 
72 	kfree(cmem);
73 	return ret;
74 }
75 
76 /*
77  * Tries to add the initrd and DTB to the image. If it is not possible to find
78  * valid locations, this function will undo changes to the image and return non
79  * zero.
80  */
81 int load_other_segments(struct kimage *image,
82 			unsigned long kernel_load_addr,
83 			unsigned long kernel_size,
84 			char *initrd, unsigned long initrd_len,
85 			char *cmdline)
86 {
87 	struct kexec_buf kbuf;
88 	void *headers, *dtb = NULL;
89 	unsigned long headers_sz, initrd_load_addr = 0, dtb_len,
90 		      orig_segments = image->nr_segments;
91 	int ret = 0;
92 
93 	kbuf.image = image;
94 	/* not allocate anything below the kernel */
95 	kbuf.buf_min = kernel_load_addr + kernel_size;
96 
97 	/* load elf core header */
98 	if (image->type == KEXEC_TYPE_CRASH) {
99 		ret = prepare_elf_headers(&headers, &headers_sz);
100 		if (ret) {
101 			pr_err("Preparing elf core header failed\n");
102 			goto out_err;
103 		}
104 
105 		kbuf.buffer = headers;
106 		kbuf.bufsz = headers_sz;
107 		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
108 		kbuf.memsz = headers_sz;
109 		kbuf.buf_align = SZ_64K; /* largest supported page size */
110 		kbuf.buf_max = ULONG_MAX;
111 		kbuf.top_down = true;
112 
113 		ret = kexec_add_buffer(&kbuf);
114 		if (ret) {
115 			vfree(headers);
116 			goto out_err;
117 		}
118 		image->elf_headers = headers;
119 		image->elf_load_addr = kbuf.mem;
120 		image->elf_headers_sz = headers_sz;
121 
122 		pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
123 			 image->elf_load_addr, kbuf.bufsz, kbuf.memsz);
124 	}
125 
126 	/* load initrd */
127 	if (initrd) {
128 		kbuf.buffer = initrd;
129 		kbuf.bufsz = initrd_len;
130 		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
131 		kbuf.memsz = initrd_len;
132 		kbuf.buf_align = 0;
133 		/* within 1GB-aligned window of up to 32GB in size */
134 		kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
135 						+ (unsigned long)SZ_1G * 32;
136 		kbuf.top_down = false;
137 
138 		ret = kexec_add_buffer(&kbuf);
139 		if (ret)
140 			goto out_err;
141 		initrd_load_addr = kbuf.mem;
142 
143 		pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
144 				initrd_load_addr, kbuf.bufsz, kbuf.memsz);
145 	}
146 
147 	/* load dtb */
148 	dtb = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
149 					   initrd_len, cmdline, 0);
150 	if (!dtb) {
151 		pr_err("Preparing for new dtb failed\n");
152 		ret = -EINVAL;
153 		goto out_err;
154 	}
155 
156 	/* trim it */
157 	fdt_pack(dtb);
158 	dtb_len = fdt_totalsize(dtb);
159 	kbuf.buffer = dtb;
160 	kbuf.bufsz = dtb_len;
161 	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
162 	kbuf.memsz = dtb_len;
163 	/* not across 2MB boundary */
164 	kbuf.buf_align = SZ_2M;
165 	kbuf.buf_max = ULONG_MAX;
166 	kbuf.top_down = true;
167 
168 	ret = kexec_add_buffer(&kbuf);
169 	if (ret)
170 		goto out_err;
171 	image->arch.dtb = dtb;
172 	image->arch.dtb_mem = kbuf.mem;
173 
174 	pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
175 			kbuf.mem, kbuf.bufsz, kbuf.memsz);
176 
177 	return 0;
178 
179 out_err:
180 	image->nr_segments = orig_segments;
181 	kvfree(dtb);
182 	return ret;
183 }
184