1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Remote Processor Framework ELF loader
4 *
5 * Copyright (C) 2011 Texas Instruments, Inc.
6 * Copyright (C) 2011 Google, Inc.
7 *
8 * Ohad Ben-Cohen <ohad@wizery.com>
9 * Brian Swetland <swetland@google.com>
10 * Mark Grosen <mgrosen@ti.com>
11 * Fernando Guzman Lugo <fernando.lugo@ti.com>
12 * Suman Anna <s-anna@ti.com>
13 * Robert Tivy <rtivy@ti.com>
14 * Armando Uribe De Leon <x0095078@ti.com>
15 * Sjur Br��ndeland <sjur.brandeland@stericsson.com>
16 */
17
18#define pr_fmt(fmt)    "%s: " fmt, __func__
19
20#include <linux/module.h>
21#include <linux/firmware.h>
22#include <linux/remoteproc.h>
23#include <linux/elf.h>
24
25#include "remoteproc_internal.h"
26#include "remoteproc_elf_helpers.h"
27
28/**
29 * rproc_elf_sanity_check() - Sanity Check for ELF32/ELF64 firmware image
30 * @rproc: the remote processor handle
31 * @fw: the ELF firmware image
32 *
33 * Make sure this fw image is sane (ie a correct ELF32/ELF64 file).
34 *
35 * Return: 0 on success and -EINVAL upon any failure
36 */
37int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)
38{
39	const char *name = rproc->firmware;
40	struct device *dev = &rproc->dev;
41	/*
42	 * ELF files are beginning with the same structure. Thus, to simplify
43	 * header parsing, we can use the elf32_hdr one for both elf64 and
44	 * elf32.
45	 */
46	struct elf32_hdr *ehdr;
47	u32 elf_shdr_get_size;
48	u64 phoff, shoff;
49	char class;
50	u16 phnum;
51
52	if (!fw) {
53		dev_err(dev, "failed to load %s\n", name);
54		return -EINVAL;
55	}
56
57	if (fw->size < sizeof(struct elf32_hdr)) {
58		dev_err(dev, "Image is too small\n");
59		return -EINVAL;
60	}
61
62	ehdr = (struct elf32_hdr *)fw->data;
63
64	if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
65		dev_err(dev, "Image is corrupted (bad magic)\n");
66		return -EINVAL;
67	}
68
69	class = ehdr->e_ident[EI_CLASS];
70	if (class != ELFCLASS32 && class != ELFCLASS64) {
71		dev_err(dev, "Unsupported class: %d\n", class);
72		return -EINVAL;
73	}
74
75	if (class == ELFCLASS64 && fw->size < sizeof(struct elf64_hdr)) {
76		dev_err(dev, "elf64 header is too small\n");
77		return -EINVAL;
78	}
79
80	/* We assume the firmware has the same endianness as the host */
81# ifdef __LITTLE_ENDIAN
82	if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
83# else /* BIG ENDIAN */
84	if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
85# endif
86		dev_err(dev, "Unsupported firmware endianness\n");
87		return -EINVAL;
88	}
89
90	phoff = elf_hdr_get_e_phoff(class, fw->data);
91	shoff = elf_hdr_get_e_shoff(class, fw->data);
92	phnum =  elf_hdr_get_e_phnum(class, fw->data);
93	elf_shdr_get_size = elf_size_of_shdr(class);
94
95	if (fw->size < shoff + elf_shdr_get_size) {
96		dev_err(dev, "Image is too small\n");
97		return -EINVAL;
98	}
99
100	if (phnum == 0) {
101		dev_err(dev, "No loadable segments\n");
102		return -EINVAL;
103	}
104
105	if (phoff > fw->size) {
106		dev_err(dev, "Firmware size is too small\n");
107		return -EINVAL;
108	}
109
110	dev_dbg(dev, "Firmware is an elf%d file\n",
111		class == ELFCLASS32 ? 32 : 64);
112
113	return 0;
114}
115EXPORT_SYMBOL(rproc_elf_sanity_check);
116
117/**
118 * rproc_elf_get_boot_addr() - Get rproc's boot address.
119 * @rproc: the remote processor handle
120 * @fw: the ELF firmware image
121 *
122 * Note that the boot address is not a configurable property of all remote
123 * processors. Some will always boot at a specific hard-coded address.
124 *
125 * Return: entry point address of the ELF image
126 *
127 */
128u64 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
129{
130	return elf_hdr_get_e_entry(fw_elf_get_class(fw), fw->data);
131}
132EXPORT_SYMBOL(rproc_elf_get_boot_addr);
133
134/**
135 * rproc_elf_load_segments() - load firmware segments to memory
136 * @rproc: remote processor which will be booted using these fw segments
137 * @fw: the ELF firmware image
138 *
139 * This function loads the firmware segments to memory, where the remote
140 * processor expects them.
141 *
142 * Some remote processors will expect their code and data to be placed
143 * in specific device addresses, and can't have them dynamically assigned.
144 *
145 * We currently support only those kind of remote processors, and expect
146 * the program header's paddr member to contain those addresses. We then go
147 * through the physically contiguous "carveout" memory regions which we
148 * allocated (and mapped) earlier on behalf of the remote processor,
149 * and "translate" device address to kernel addresses, so we can copy the
150 * segments where they are expected.
151 *
152 * Currently we only support remote processors that required carveout
153 * allocations and got them mapped onto their iommus. Some processors
154 * might be different: they might not have iommus, and would prefer to
155 * directly allocate memory for every segment/resource. This is not yet
156 * supported, though.
157 *
158 * Return: 0 on success and an appropriate error code otherwise
159 */
160int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
161{
162	struct device *dev = &rproc->dev;
163	const void *ehdr, *phdr;
164	int i, ret = 0;
165	u16 phnum;
166	const u8 *elf_data = fw->data;
167	u8 class = fw_elf_get_class(fw);
168	u32 elf_phdr_get_size = elf_size_of_phdr(class);
169
170	ehdr = elf_data;
171	phnum = elf_hdr_get_e_phnum(class, ehdr);
172	phdr = elf_data + elf_hdr_get_e_phoff(class, ehdr);
173
174	/* go through the available ELF segments */
175	for (i = 0; i < phnum; i++, phdr += elf_phdr_get_size) {
176		u64 da = elf_phdr_get_p_paddr(class, phdr);
177		u64 memsz = elf_phdr_get_p_memsz(class, phdr);
178		u64 filesz = elf_phdr_get_p_filesz(class, phdr);
179		u64 offset = elf_phdr_get_p_offset(class, phdr);
180		u32 type = elf_phdr_get_p_type(class, phdr);
181		bool is_iomem = false;
182		void *ptr;
183
184		if (type != PT_LOAD || !memsz)
185			continue;
186
187		dev_dbg(dev, "phdr: type %d da 0x%llx memsz 0x%llx filesz 0x%llx\n",
188			type, da, memsz, filesz);
189
190		if (filesz > memsz) {
191			dev_err(dev, "bad phdr filesz 0x%llx memsz 0x%llx\n",
192				filesz, memsz);
193			ret = -EINVAL;
194			break;
195		}
196
197		if (offset + filesz > fw->size) {
198			dev_err(dev, "truncated fw: need 0x%llx avail 0x%zx\n",
199				offset + filesz, fw->size);
200			ret = -EINVAL;
201			break;
202		}
203
204		if (!rproc_u64_fit_in_size_t(memsz)) {
205			dev_err(dev, "size (%llx) does not fit in size_t type\n",
206				memsz);
207			ret = -EOVERFLOW;
208			break;
209		}
210
211		/* grab the kernel address for this device address */
212		ptr = rproc_da_to_va(rproc, da, memsz, &is_iomem);
213		if (!ptr) {
214			dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da,
215				memsz);
216			ret = -EINVAL;
217			break;
218		}
219
220		/* put the segment where the remote processor expects it */
221		if (filesz) {
222			if (is_iomem)
223				memcpy_toio((void __iomem *)ptr, elf_data + offset, filesz);
224			else
225				memcpy(ptr, elf_data + offset, filesz);
226		}
227
228		/*
229		 * Zero out remaining memory for this segment.
230		 *
231		 * This isn't strictly required since dma_alloc_coherent already
232		 * did this for us. albeit harmless, we may consider removing
233		 * this.
234		 */
235		if (memsz > filesz) {
236			if (is_iomem)
237				memset_io((void __iomem *)(ptr + filesz), 0, memsz - filesz);
238			else
239				memset(ptr + filesz, 0, memsz - filesz);
240		}
241	}
242
243	return ret;
244}
245EXPORT_SYMBOL(rproc_elf_load_segments);
246
247static const void *
248find_table(struct device *dev, const struct firmware *fw)
249{
250	const void *shdr, *name_table_shdr;
251	int i;
252	const char *name_table;
253	struct resource_table *table = NULL;
254	const u8 *elf_data = (void *)fw->data;
255	u8 class = fw_elf_get_class(fw);
256	size_t fw_size = fw->size;
257	const void *ehdr = elf_data;
258	u16 shnum = elf_hdr_get_e_shnum(class, ehdr);
259	u32 elf_shdr_get_size = elf_size_of_shdr(class);
260	u16 shstrndx = elf_hdr_get_e_shstrndx(class, ehdr);
261
262	/* look for the resource table and handle it */
263	/* First, get the section header according to the elf class */
264	shdr = elf_data + elf_hdr_get_e_shoff(class, ehdr);
265	/* Compute name table section header entry in shdr array */
266	name_table_shdr = shdr + (shstrndx * elf_shdr_get_size);
267	/* Finally, compute the name table section address in elf */
268	name_table = elf_data + elf_shdr_get_sh_offset(class, name_table_shdr);
269
270	for (i = 0; i < shnum; i++, shdr += elf_shdr_get_size) {
271		u64 size = elf_shdr_get_sh_size(class, shdr);
272		u64 offset = elf_shdr_get_sh_offset(class, shdr);
273		u32 name = elf_shdr_get_sh_name(class, shdr);
274
275		if (strcmp(name_table + name, ".resource_table"))
276			continue;
277
278		table = (struct resource_table *)(elf_data + offset);
279
280		/* make sure we have the entire table */
281		if (offset + size > fw_size || offset + size < size) {
282			dev_err(dev, "resource table truncated\n");
283			return NULL;
284		}
285
286		/* make sure table has at least the header */
287		if (sizeof(struct resource_table) > size) {
288			dev_err(dev, "header-less resource table\n");
289			return NULL;
290		}
291
292		/* we don't support any version beyond the first */
293		if (table->ver != 1) {
294			dev_err(dev, "unsupported fw ver: %d\n", table->ver);
295			return NULL;
296		}
297
298		/* make sure reserved bytes are zeroes */
299		if (table->reserved[0] || table->reserved[1]) {
300			dev_err(dev, "non zero reserved bytes\n");
301			return NULL;
302		}
303
304		/* make sure the offsets array isn't truncated */
305		if (struct_size(table, offset, table->num) > size) {
306			dev_err(dev, "resource table incomplete\n");
307			return NULL;
308		}
309
310		return shdr;
311	}
312
313	return NULL;
314}
315
316/**
317 * rproc_elf_load_rsc_table() - load the resource table
318 * @rproc: the rproc handle
319 * @fw: the ELF firmware image
320 *
321 * This function finds the resource table inside the remote processor's
322 * firmware, load it into the @cached_table and update @table_ptr.
323 *
324 * Return: 0 on success, negative errno on failure.
325 */
326int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw)
327{
328	const void *shdr;
329	struct device *dev = &rproc->dev;
330	struct resource_table *table = NULL;
331	const u8 *elf_data = fw->data;
332	size_t tablesz;
333	u8 class = fw_elf_get_class(fw);
334	u64 sh_offset;
335
336	shdr = find_table(dev, fw);
337	if (!shdr)
338		return -EINVAL;
339
340	sh_offset = elf_shdr_get_sh_offset(class, shdr);
341	table = (struct resource_table *)(elf_data + sh_offset);
342	tablesz = elf_shdr_get_sh_size(class, shdr);
343
344	/*
345	 * Create a copy of the resource table. When a virtio device starts
346	 * and calls vring_new_virtqueue() the address of the allocated vring
347	 * will be stored in the cached_table. Before the device is started,
348	 * cached_table will be copied into device memory.
349	 */
350	rproc->cached_table = kmemdup(table, tablesz, GFP_KERNEL);
351	if (!rproc->cached_table)
352		return -ENOMEM;
353
354	rproc->table_ptr = rproc->cached_table;
355	rproc->table_sz = tablesz;
356
357	return 0;
358}
359EXPORT_SYMBOL(rproc_elf_load_rsc_table);
360
361/**
362 * rproc_elf_find_loaded_rsc_table() - find the loaded resource table
363 * @rproc: the rproc handle
364 * @fw: the ELF firmware image
365 *
366 * This function finds the location of the loaded resource table. Don't
367 * call this function if the table wasn't loaded yet - it's a bug if you do.
368 *
369 * Return: pointer to the resource table if it is found or NULL otherwise.
370 * If the table wasn't loaded yet the result is unspecified.
371 */
372struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
373						       const struct firmware *fw)
374{
375	const void *shdr;
376	u64 sh_addr, sh_size;
377	u8 class = fw_elf_get_class(fw);
378	struct device *dev = &rproc->dev;
379
380	shdr = find_table(&rproc->dev, fw);
381	if (!shdr)
382		return NULL;
383
384	sh_addr = elf_shdr_get_sh_addr(class, shdr);
385	sh_size = elf_shdr_get_sh_size(class, shdr);
386
387	if (!rproc_u64_fit_in_size_t(sh_size)) {
388		dev_err(dev, "size (%llx) does not fit in size_t type\n",
389			sh_size);
390		return NULL;
391	}
392
393	return rproc_da_to_va(rproc, sh_addr, sh_size, NULL);
394}
395EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);
396