1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * kexec_file for LoongArch
4 *
5 * Author: Youling Tang <tangyouling@kylinos.cn>
6 * Copyright (C) 2025 KylinSoft Corporation.
7 *
8 * Most code is derived from LoongArch 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/memblock.h>
17 #include <linux/slab.h>
18 #include <linux/string.h>
19 #include <linux/types.h>
20 #include <linux/vmalloc.h>
21 #include <asm/bootinfo.h>
22
23 const struct kexec_file_ops * const kexec_file_loaders[] = {
24 &kexec_efi_ops,
25 &kexec_elf_ops,
26 NULL
27 };
28
arch_kimage_file_post_load_cleanup(struct kimage * image)29 int arch_kimage_file_post_load_cleanup(struct kimage *image)
30 {
31 vfree(image->elf_headers);
32 image->elf_headers = NULL;
33 image->elf_headers_sz = 0;
34
35 return kexec_image_post_load_cleanup_default(image);
36 }
37
38 /* Add the "kexec_file" command line parameter to command line. */
cmdline_add_loader(unsigned long * cmdline_tmplen,char * modified_cmdline)39 static void cmdline_add_loader(unsigned long *cmdline_tmplen, char *modified_cmdline)
40 {
41 int loader_strlen;
42
43 loader_strlen = sprintf(modified_cmdline + (*cmdline_tmplen), "kexec_file ");
44 *cmdline_tmplen += loader_strlen;
45 }
46
47 /* Add the "initrd=start,size" command line parameter to command line. */
cmdline_add_initrd(struct kimage * image,unsigned long * cmdline_tmplen,char * modified_cmdline,unsigned long initrd)48 static void cmdline_add_initrd(struct kimage *image, unsigned long *cmdline_tmplen,
49 char *modified_cmdline, unsigned long initrd)
50 {
51 int initrd_strlen;
52
53 initrd_strlen = sprintf(modified_cmdline + (*cmdline_tmplen), "initrd=0x%lx,0x%lx ",
54 initrd, image->initrd_buf_len);
55 *cmdline_tmplen += initrd_strlen;
56 }
57
58 #ifdef CONFIG_CRASH_DUMP
59
prepare_elf_headers(void ** addr,unsigned long * sz)60 static int prepare_elf_headers(void **addr, unsigned long *sz)
61 {
62 int ret, nr_ranges;
63 uint64_t i;
64 phys_addr_t start, end;
65 struct crash_mem *cmem;
66
67 nr_ranges = 2; /* for exclusion of crashkernel region */
68 for_each_mem_range(i, &start, &end)
69 nr_ranges++;
70
71 cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL);
72 if (!cmem)
73 return -ENOMEM;
74
75 cmem->max_nr_ranges = nr_ranges;
76 cmem->nr_ranges = 0;
77 for_each_mem_range(i, &start, &end) {
78 cmem->ranges[cmem->nr_ranges].start = start;
79 cmem->ranges[cmem->nr_ranges].end = end - 1;
80 cmem->nr_ranges++;
81 }
82
83 /* Exclude crashkernel region */
84 ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
85 if (ret < 0)
86 goto out;
87
88 if (crashk_low_res.end) {
89 ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
90 if (ret < 0)
91 goto out;
92 }
93
94 ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
95
96 out:
97 kfree(cmem);
98 return ret;
99 }
100
101 /*
102 * Add the "mem=size@start" command line parameter to command line, indicating the
103 * memory region the new kernel can use to boot into.
104 */
cmdline_add_mem(unsigned long * cmdline_tmplen,char * modified_cmdline)105 static void cmdline_add_mem(unsigned long *cmdline_tmplen, char *modified_cmdline)
106 {
107 int mem_strlen = 0;
108
109 mem_strlen = sprintf(modified_cmdline + (*cmdline_tmplen), "mem=0x%llx@0x%llx ",
110 crashk_res.end - crashk_res.start + 1, crashk_res.start);
111 *cmdline_tmplen += mem_strlen;
112
113 if (crashk_low_res.end) {
114 mem_strlen = sprintf(modified_cmdline + (*cmdline_tmplen), "mem=0x%llx@0x%llx ",
115 crashk_low_res.end - crashk_low_res.start + 1, crashk_low_res.start);
116 *cmdline_tmplen += mem_strlen;
117 }
118 }
119
120 /* Add the "elfcorehdr=size@start" command line parameter to command line. */
cmdline_add_elfcorehdr(struct kimage * image,unsigned long * cmdline_tmplen,char * modified_cmdline,unsigned long elfcorehdr_sz)121 static void cmdline_add_elfcorehdr(struct kimage *image, unsigned long *cmdline_tmplen,
122 char *modified_cmdline, unsigned long elfcorehdr_sz)
123 {
124 int elfcorehdr_strlen = 0;
125
126 elfcorehdr_strlen = sprintf(modified_cmdline + (*cmdline_tmplen), "elfcorehdr=0x%lx@0x%lx ",
127 elfcorehdr_sz, image->elf_load_addr);
128 *cmdline_tmplen += elfcorehdr_strlen;
129 }
130
131 #endif
132
133 /*
134 * Try to add the initrd to the image. If it is not possible to find valid
135 * locations, this function will undo changes to the image and return non zero.
136 */
load_other_segments(struct kimage * image,unsigned long kernel_load_addr,unsigned long kernel_size,char * initrd,unsigned long initrd_len,char * cmdline,unsigned long cmdline_len)137 int load_other_segments(struct kimage *image,
138 unsigned long kernel_load_addr, unsigned long kernel_size,
139 char *initrd, unsigned long initrd_len, char *cmdline, unsigned long cmdline_len)
140 {
141 int ret = 0;
142 unsigned long cmdline_tmplen = 0;
143 unsigned long initrd_load_addr = 0;
144 unsigned long orig_segments = image->nr_segments;
145 char *modified_cmdline = NULL;
146 struct kexec_buf kbuf;
147
148 kbuf.image = image;
149 /* Don't allocate anything below the kernel */
150 kbuf.buf_min = kernel_load_addr + kernel_size;
151
152 modified_cmdline = kzalloc(COMMAND_LINE_SIZE, GFP_KERNEL);
153 if (!modified_cmdline)
154 return -EINVAL;
155
156 cmdline_add_loader(&cmdline_tmplen, modified_cmdline);
157 /* Ensure it's null terminated */
158 modified_cmdline[COMMAND_LINE_SIZE - 1] = '\0';
159
160 #ifdef CONFIG_CRASH_DUMP
161 /* Load elf core header */
162 if (image->type == KEXEC_TYPE_CRASH) {
163 void *headers;
164 unsigned long headers_sz;
165
166 ret = prepare_elf_headers(&headers, &headers_sz);
167 if (ret < 0) {
168 pr_err("Preparing elf core header failed\n");
169 goto out_err;
170 }
171
172 kbuf.buffer = headers;
173 kbuf.bufsz = headers_sz;
174 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
175 kbuf.memsz = headers_sz;
176 kbuf.buf_align = SZ_64K; /* largest supported page size */
177 kbuf.buf_max = ULONG_MAX;
178 kbuf.top_down = true;
179
180 ret = kexec_add_buffer(&kbuf);
181 if (ret < 0) {
182 vfree(headers);
183 goto out_err;
184 }
185 image->elf_headers = headers;
186 image->elf_load_addr = kbuf.mem;
187 image->elf_headers_sz = headers_sz;
188
189 kexec_dprintk("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
190 image->elf_load_addr, kbuf.bufsz, kbuf.memsz);
191
192 /* Add the mem=size@start parameter to the command line */
193 cmdline_add_mem(&cmdline_tmplen, modified_cmdline);
194
195 /* Add the elfcorehdr=size@start parameter to the command line */
196 cmdline_add_elfcorehdr(image, &cmdline_tmplen, modified_cmdline, headers_sz);
197 }
198 #endif
199
200 /* Load initrd */
201 if (initrd) {
202 kbuf.buffer = initrd;
203 kbuf.bufsz = initrd_len;
204 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
205 kbuf.memsz = initrd_len;
206 kbuf.buf_align = 0;
207 /* within 1GB-aligned window of up to 32GB in size */
208 kbuf.buf_max = round_down(kernel_load_addr, SZ_1G) + (unsigned long)SZ_1G * 32;
209 kbuf.top_down = false;
210
211 ret = kexec_add_buffer(&kbuf);
212 if (ret < 0)
213 goto out_err;
214 initrd_load_addr = kbuf.mem;
215
216 kexec_dprintk("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
217 initrd_load_addr, kbuf.bufsz, kbuf.memsz);
218
219 /* Add the initrd=start,size parameter to the command line */
220 cmdline_add_initrd(image, &cmdline_tmplen, modified_cmdline, initrd_load_addr);
221 }
222
223 if (cmdline_len + cmdline_tmplen > COMMAND_LINE_SIZE) {
224 pr_err("Appending command line exceeds COMMAND_LINE_SIZE\n");
225 ret = -EINVAL;
226 goto out_err;
227 }
228
229 memcpy(modified_cmdline + cmdline_tmplen, cmdline, cmdline_len);
230 cmdline = modified_cmdline;
231 image->arch.cmdline_ptr = (unsigned long)cmdline;
232
233 return 0;
234
235 out_err:
236 image->nr_segments = orig_segments;
237 kfree(modified_cmdline);
238 return ret;
239 }
240