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
 25const struct kexec_file_ops * const kexec_file_loaders[] = {
 26	&kexec_image_ops,
 27	NULL
 28};
 29
 30int 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
 43static int prepare_elf_headers(void **addr, unsigned long *sz)
 44{
 45	struct crash_mem *cmem;
 46	unsigned int nr_ranges;
 47	int ret;
 48	u64 i;
 49	phys_addr_t start, end;
 50
 51	nr_ranges = 2; /* for exclusion of crashkernel region */
 52	for_each_mem_range(i, &start, &end)
 53		nr_ranges++;
 54
 55	cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL);
 56	if (!cmem)
 57		return -ENOMEM;
 58
 59	cmem->max_nr_ranges = nr_ranges;
 60	cmem->nr_ranges = 0;
 61	for_each_mem_range(i, &start, &end) {
 62		cmem->ranges[cmem->nr_ranges].start = start;
 63		cmem->ranges[cmem->nr_ranges].end = end - 1;
 64		cmem->nr_ranges++;
 65	}
 66
 67	/* Exclude crashkernel region */
 68	ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
 69	if (ret)
 70		goto out;
 71
 72	if (crashk_low_res.end) {
 73		ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
 74		if (ret)
 75			goto out;
 76	}
 77
 78	ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
 79
 80out:
 81	kfree(cmem);
 82	return ret;
 83}
 84#endif
 85
 86/*
 87 * Tries to add the initrd and DTB to the image. If it is not possible to find
 88 * valid locations, this function will undo changes to the image and return non
 89 * zero.
 90 */
 91int load_other_segments(struct kimage *image,
 92			unsigned long kernel_load_addr,
 93			unsigned long kernel_size,
 94			char *initrd, unsigned long initrd_len,
 95			char *cmdline)
 96{
 97	struct kexec_buf kbuf;
 98	void *dtb = NULL;
 99	unsigned long initrd_load_addr = 0, dtb_len,
100		      orig_segments = image->nr_segments;
101	int ret = 0;
102
103	kbuf.image = image;
104	/* not allocate anything below the kernel */
105	kbuf.buf_min = kernel_load_addr + kernel_size;
106
107#ifdef CONFIG_CRASH_DUMP
108	/* load elf core header */
109	void *headers;
110	unsigned long headers_sz;
111	if (image->type == KEXEC_TYPE_CRASH) {
112		ret = prepare_elf_headers(&headers, &headers_sz);
113		if (ret) {
114			pr_err("Preparing elf core header failed\n");
115			goto out_err;
116		}
117
118		kbuf.buffer = headers;
119		kbuf.bufsz = headers_sz;
120		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
121		kbuf.memsz = headers_sz;
122		kbuf.buf_align = SZ_64K; /* largest supported page size */
123		kbuf.buf_max = ULONG_MAX;
124		kbuf.top_down = true;
125
126		ret = kexec_add_buffer(&kbuf);
127		if (ret) {
128			vfree(headers);
129			goto out_err;
130		}
131		image->elf_headers = headers;
132		image->elf_load_addr = kbuf.mem;
133		image->elf_headers_sz = headers_sz;
134
135		kexec_dprintk("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
136			      image->elf_load_addr, kbuf.bufsz, kbuf.memsz);
137	}
138#endif
139
140	/* load initrd */
141	if (initrd) {
142		kbuf.buffer = initrd;
143		kbuf.bufsz = initrd_len;
144		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
145		kbuf.memsz = initrd_len;
146		kbuf.buf_align = 0;
147		/* within 1GB-aligned window of up to 32GB in size */
148		kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
149						+ (unsigned long)SZ_1G * 32;
150		kbuf.top_down = false;
151
152		ret = kexec_add_buffer(&kbuf);
153		if (ret)
154			goto out_err;
155		initrd_load_addr = kbuf.mem;
156
157		kexec_dprintk("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
158			      initrd_load_addr, kbuf.bufsz, kbuf.memsz);
159	}
160
161	/* load dtb */
162	dtb = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
163					   initrd_len, cmdline, 0);
164	if (!dtb) {
165		pr_err("Preparing for new dtb failed\n");
166		ret = -EINVAL;
167		goto out_err;
168	}
169
170	/* trim it */
171	fdt_pack(dtb);
172	dtb_len = fdt_totalsize(dtb);
173	kbuf.buffer = dtb;
174	kbuf.bufsz = dtb_len;
175	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
176	kbuf.memsz = dtb_len;
177	/* not across 2MB boundary */
178	kbuf.buf_align = SZ_2M;
179	kbuf.buf_max = ULONG_MAX;
180	kbuf.top_down = true;
181
182	ret = kexec_add_buffer(&kbuf);
183	if (ret)
184		goto out_err;
185	image->arch.dtb = dtb;
186	image->arch.dtb_mem = kbuf.mem;
187
188	kexec_dprintk("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
189		      kbuf.mem, kbuf.bufsz, kbuf.memsz);
190
191	return 0;
192
193out_err:
194	image->nr_segments = orig_segments;
195	kvfree(dtb);
196	return ret;
197}