1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Qualcomm Peripheral Image Loader
  4 *
  5 * Copyright (C) 2016 Linaro Ltd
  6 * Copyright (C) 2015 Sony Mobile Communications Inc
  7 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
  8 */
  9
 10#include <linux/cleanup.h>
 11#include <linux/device.h>
 12#include <linux/elf.h>
 13#include <linux/firmware.h>
 14#include <linux/kernel.h>
 15#include <linux/module.h>
 16#include <linux/firmware/qcom/qcom_scm.h>
 17#include <linux/sizes.h>
 18#include <linux/slab.h>
 19#include <linux/soc/qcom/mdt_loader.h>
 20
 21static bool mdt_phdr_valid(const struct elf32_phdr *phdr)
 22{
 23	if (phdr->p_type != PT_LOAD)
 24		return false;
 25
 26	if ((phdr->p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH)
 27		return false;
 28
 29	if (!phdr->p_memsz)
 30		return false;
 31
 32	return true;
 33}
 34
 35static ssize_t mdt_load_split_segment(void *ptr, const struct elf32_phdr *phdrs,
 36				      unsigned int segment, const char *fw_name,
 37				      struct device *dev)
 38{
 39	const struct elf32_phdr *phdr = &phdrs[segment];
 40	const struct firmware *seg_fw;
 41	ssize_t ret;
 42
 43	if (strlen(fw_name) < 4)
 44		return -EINVAL;
 45
 46	char *seg_name __free(kfree) = kstrdup(fw_name, GFP_KERNEL);
 47	if (!seg_name)
 48		return -ENOMEM;
 49
 50	sprintf(seg_name + strlen(fw_name) - 3, "b%02d", segment);
 51	ret = request_firmware_into_buf(&seg_fw, seg_name, dev,
 52					ptr, phdr->p_filesz);
 53	if (ret) {
 54		dev_err(dev, "error %zd loading %s\n", ret, seg_name);
 55		return ret;
 56	}
 57
 58	if (seg_fw->size != phdr->p_filesz) {
 59		dev_err(dev,
 60			"failed to load segment %d from truncated file %s\n",
 61			segment, seg_name);
 62		ret = -EINVAL;
 63	}
 64
 65	release_firmware(seg_fw);
 66
 67	return ret;
 68}
 69
 70/**
 71 * qcom_mdt_get_size() - acquire size of the memory region needed to load mdt
 72 * @fw:		firmware object for the mdt file
 73 *
 74 * Returns size of the loaded firmware blob, or -EINVAL on failure.
 75 */
 76ssize_t qcom_mdt_get_size(const struct firmware *fw)
 77{
 78	const struct elf32_phdr *phdrs;
 79	const struct elf32_phdr *phdr;
 80	const struct elf32_hdr *ehdr;
 81	phys_addr_t min_addr = PHYS_ADDR_MAX;
 82	phys_addr_t max_addr = 0;
 83	int i;
 84
 85	ehdr = (struct elf32_hdr *)fw->data;
 86	phdrs = (struct elf32_phdr *)(ehdr + 1);
 87
 88	for (i = 0; i < ehdr->e_phnum; i++) {
 89		phdr = &phdrs[i];
 90
 91		if (!mdt_phdr_valid(phdr))
 92			continue;
 93
 94		if (phdr->p_paddr < min_addr)
 95			min_addr = phdr->p_paddr;
 96
 97		if (phdr->p_paddr + phdr->p_memsz > max_addr)
 98			max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
 99	}
100
101	return min_addr < max_addr ? max_addr - min_addr : -EINVAL;
102}
103EXPORT_SYMBOL_GPL(qcom_mdt_get_size);
104
105/**
106 * qcom_mdt_read_metadata() - read header and metadata from mdt or mbn
107 * @fw:		firmware of mdt header or mbn
108 * @data_len:	length of the read metadata blob
109 * @fw_name:	name of the firmware, for construction of segment file names
110 * @dev:	device handle to associate resources with
111 *
112 * The mechanism that performs the authentication of the loading firmware
113 * expects an ELF header directly followed by the segment of hashes, with no
114 * padding inbetween. This function allocates a chunk of memory for this pair
115 * and copy the two pieces into the buffer.
116 *
117 * In the case of split firmware the hash is found directly following the ELF
118 * header, rather than at p_offset described by the second program header.
119 *
120 * The caller is responsible to free (kfree()) the returned pointer.
121 *
122 * Return: pointer to data, or ERR_PTR()
123 */
124void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len,
125			     const char *fw_name, struct device *dev)
126{
127	const struct elf32_phdr *phdrs;
128	const struct elf32_hdr *ehdr;
129	unsigned int hash_segment = 0;
130	size_t hash_offset;
131	size_t hash_size;
132	size_t ehdr_size;
133	unsigned int i;
134	ssize_t ret;
135	void *data;
136
137	ehdr = (struct elf32_hdr *)fw->data;
138	phdrs = (struct elf32_phdr *)(ehdr + 1);
139
140	if (ehdr->e_phnum < 2)
141		return ERR_PTR(-EINVAL);
142
143	if (phdrs[0].p_type == PT_LOAD)
144		return ERR_PTR(-EINVAL);
145
146	for (i = 1; i < ehdr->e_phnum; i++) {
147		if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH) {
148			hash_segment = i;
149			break;
150		}
151	}
152
153	if (!hash_segment) {
154		dev_err(dev, "no hash segment found in %s\n", fw_name);
155		return ERR_PTR(-EINVAL);
156	}
157
158	ehdr_size = phdrs[0].p_filesz;
159	hash_size = phdrs[hash_segment].p_filesz;
160
161	data = kmalloc(ehdr_size + hash_size, GFP_KERNEL);
162	if (!data)
163		return ERR_PTR(-ENOMEM);
164
165	/* Copy ELF header */
166	memcpy(data, fw->data, ehdr_size);
167
168	if (ehdr_size + hash_size == fw->size) {
169		/* Firmware is split and hash is packed following the ELF header */
170		hash_offset = phdrs[0].p_filesz;
171		memcpy(data + ehdr_size, fw->data + hash_offset, hash_size);
172	} else if (phdrs[hash_segment].p_offset + hash_size <= fw->size) {
173		/* Hash is in its own segment, but within the loaded file */
174		hash_offset = phdrs[hash_segment].p_offset;
175		memcpy(data + ehdr_size, fw->data + hash_offset, hash_size);
176	} else {
177		/* Hash is in its own segment, beyond the loaded file */
178		ret = mdt_load_split_segment(data + ehdr_size, phdrs, hash_segment, fw_name, dev);
179		if (ret) {
180			kfree(data);
181			return ERR_PTR(ret);
182		}
183	}
184
185	*data_len = ehdr_size + hash_size;
186
187	return data;
188}
189EXPORT_SYMBOL_GPL(qcom_mdt_read_metadata);
190
191/**
192 * qcom_mdt_pas_init() - initialize PAS region for firmware loading
193 * @dev:	device handle to associate resources with
194 * @fw:		firmware object for the mdt file
195 * @fw_name:	name of the firmware, for construction of segment file names
196 * @pas_id:	PAS identifier
197 * @mem_phys:	physical address of allocated memory region
198 * @ctx:	PAS metadata context, to be released by caller
199 *
200 * Returns 0 on success, negative errno otherwise.
201 */
202int qcom_mdt_pas_init(struct device *dev, const struct firmware *fw,
203		      const char *fw_name, int pas_id, phys_addr_t mem_phys,
204		      struct qcom_scm_pas_metadata *ctx)
205{
206	const struct elf32_phdr *phdrs;
207	const struct elf32_phdr *phdr;
208	const struct elf32_hdr *ehdr;
209	phys_addr_t min_addr = PHYS_ADDR_MAX;
210	phys_addr_t max_addr = 0;
211	bool relocate = false;
212	size_t metadata_len;
213	void *metadata;
214	int ret;
215	int i;
216
217	ehdr = (struct elf32_hdr *)fw->data;
218	phdrs = (struct elf32_phdr *)(ehdr + 1);
219
220	for (i = 0; i < ehdr->e_phnum; i++) {
221		phdr = &phdrs[i];
222
223		if (!mdt_phdr_valid(phdr))
224			continue;
225
226		if (phdr->p_flags & QCOM_MDT_RELOCATABLE)
227			relocate = true;
228
229		if (phdr->p_paddr < min_addr)
230			min_addr = phdr->p_paddr;
231
232		if (phdr->p_paddr + phdr->p_memsz > max_addr)
233			max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
234	}
235
236	metadata = qcom_mdt_read_metadata(fw, &metadata_len, fw_name, dev);
237	if (IS_ERR(metadata)) {
238		ret = PTR_ERR(metadata);
239		dev_err(dev, "error %d reading firmware %s metadata\n", ret, fw_name);
240		goto out;
241	}
242
243	ret = qcom_scm_pas_init_image(pas_id, metadata, metadata_len, ctx);
244	kfree(metadata);
245	if (ret) {
246		/* Invalid firmware metadata */
247		dev_err(dev, "error %d initializing firmware %s\n", ret, fw_name);
248		goto out;
249	}
250
251	if (relocate) {
252		ret = qcom_scm_pas_mem_setup(pas_id, mem_phys, max_addr - min_addr);
253		if (ret) {
254			/* Unable to set up relocation */
255			dev_err(dev, "error %d setting up firmware %s\n", ret, fw_name);
256			goto out;
257		}
258	}
259
260out:
261	return ret;
262}
263EXPORT_SYMBOL_GPL(qcom_mdt_pas_init);
264
265static bool qcom_mdt_bins_are_split(const struct firmware *fw, const char *fw_name)
266{
267	const struct elf32_phdr *phdrs;
268	const struct elf32_hdr *ehdr;
269	uint64_t seg_start, seg_end;
270	int i;
271
272	ehdr = (struct elf32_hdr *)fw->data;
273	phdrs = (struct elf32_phdr *)(ehdr + 1);
274
275	for (i = 0; i < ehdr->e_phnum; i++) {
276		/*
277		 * The size of the MDT file is not padded to include any
278		 * zero-sized segments at the end. Ignore these, as they should
279		 * not affect the decision about image being split or not.
280		 */
281		if (!phdrs[i].p_filesz)
282			continue;
283
284		seg_start = phdrs[i].p_offset;
285		seg_end = phdrs[i].p_offset + phdrs[i].p_filesz;
286		if (seg_start > fw->size || seg_end > fw->size)
287			return true;
288	}
289
290	return false;
291}
292
293static int __qcom_mdt_load(struct device *dev, const struct firmware *fw,
294			   const char *fw_name, int pas_id, void *mem_region,
295			   phys_addr_t mem_phys, size_t mem_size,
296			   phys_addr_t *reloc_base, bool pas_init)
297{
298	const struct elf32_phdr *phdrs;
299	const struct elf32_phdr *phdr;
300	const struct elf32_hdr *ehdr;
301	phys_addr_t mem_reloc;
302	phys_addr_t min_addr = PHYS_ADDR_MAX;
303	ssize_t offset;
304	bool relocate = false;
305	bool is_split;
306	void *ptr;
307	int ret = 0;
308	int i;
309
310	if (!fw || !mem_region || !mem_phys || !mem_size)
311		return -EINVAL;
312
313	is_split = qcom_mdt_bins_are_split(fw, fw_name);
314	ehdr = (struct elf32_hdr *)fw->data;
315	phdrs = (struct elf32_phdr *)(ehdr + 1);
316
317	for (i = 0; i < ehdr->e_phnum; i++) {
318		phdr = &phdrs[i];
319
320		if (!mdt_phdr_valid(phdr))
321			continue;
322
323		if (phdr->p_flags & QCOM_MDT_RELOCATABLE)
324			relocate = true;
325
326		if (phdr->p_paddr < min_addr)
327			min_addr = phdr->p_paddr;
328	}
329
330	if (relocate) {
331		/*
332		 * The image is relocatable, so offset each segment based on
333		 * the lowest segment address.
334		 */
335		mem_reloc = min_addr;
336	} else {
337		/*
338		 * Image is not relocatable, so offset each segment based on
339		 * the allocated physical chunk of memory.
340		 */
341		mem_reloc = mem_phys;
342	}
343
344	for (i = 0; i < ehdr->e_phnum; i++) {
345		phdr = &phdrs[i];
346
347		if (!mdt_phdr_valid(phdr))
348			continue;
349
350		offset = phdr->p_paddr - mem_reloc;
351		if (offset < 0 || offset + phdr->p_memsz > mem_size) {
352			dev_err(dev, "segment outside memory range\n");
353			ret = -EINVAL;
354			break;
355		}
356
357		if (phdr->p_filesz > phdr->p_memsz) {
358			dev_err(dev,
359				"refusing to load segment %d with p_filesz > p_memsz\n",
360				i);
361			ret = -EINVAL;
362			break;
363		}
364
365		ptr = mem_region + offset;
366
367		if (phdr->p_filesz && !is_split) {
368			/* Firmware is large enough to be non-split */
369			if (phdr->p_offset + phdr->p_filesz > fw->size) {
370				dev_err(dev, "file %s segment %d would be truncated\n",
371					fw_name, i);
372				ret = -EINVAL;
373				break;
374			}
375
376			memcpy(ptr, fw->data + phdr->p_offset, phdr->p_filesz);
377		} else if (phdr->p_filesz) {
378			/* Firmware not large enough, load split-out segments */
379			ret = mdt_load_split_segment(ptr, phdrs, i, fw_name, dev);
380			if (ret)
381				break;
382		}
383
384		if (phdr->p_memsz > phdr->p_filesz)
385			memset(ptr + phdr->p_filesz, 0, phdr->p_memsz - phdr->p_filesz);
386	}
387
388	if (reloc_base)
389		*reloc_base = mem_reloc;
390
391	return ret;
392}
393
394/**
395 * qcom_mdt_load() - load the firmware which header is loaded as fw
396 * @dev:	device handle to associate resources with
397 * @fw:		firmware object for the mdt file
398 * @firmware:	name of the firmware, for construction of segment file names
399 * @pas_id:	PAS identifier
400 * @mem_region:	allocated memory region to load firmware into
401 * @mem_phys:	physical address of allocated memory region
402 * @mem_size:	size of the allocated memory region
403 * @reloc_base:	adjusted physical address after relocation
404 *
405 * Returns 0 on success, negative errno otherwise.
406 */
407int qcom_mdt_load(struct device *dev, const struct firmware *fw,
408		  const char *firmware, int pas_id, void *mem_region,
409		  phys_addr_t mem_phys, size_t mem_size,
410		  phys_addr_t *reloc_base)
411{
412	int ret;
413
414	ret = qcom_mdt_pas_init(dev, fw, firmware, pas_id, mem_phys, NULL);
415	if (ret)
416		return ret;
417
418	return __qcom_mdt_load(dev, fw, firmware, pas_id, mem_region, mem_phys,
419			       mem_size, reloc_base, true);
420}
421EXPORT_SYMBOL_GPL(qcom_mdt_load);
422
423/**
424 * qcom_mdt_load_no_init() - load the firmware which header is loaded as fw
425 * @dev:	device handle to associate resources with
426 * @fw:		firmware object for the mdt file
427 * @firmware:	name of the firmware, for construction of segment file names
428 * @pas_id:	PAS identifier
429 * @mem_region:	allocated memory region to load firmware into
430 * @mem_phys:	physical address of allocated memory region
431 * @mem_size:	size of the allocated memory region
432 * @reloc_base:	adjusted physical address after relocation
433 *
434 * Returns 0 on success, negative errno otherwise.
435 */
436int qcom_mdt_load_no_init(struct device *dev, const struct firmware *fw,
437			  const char *firmware, int pas_id,
438			  void *mem_region, phys_addr_t mem_phys,
439			  size_t mem_size, phys_addr_t *reloc_base)
440{
441	return __qcom_mdt_load(dev, fw, firmware, pas_id, mem_region, mem_phys,
442			       mem_size, reloc_base, false);
443}
444EXPORT_SYMBOL_GPL(qcom_mdt_load_no_init);
445
446MODULE_DESCRIPTION("Firmware parser for Qualcomm MDT format");
447MODULE_LICENSE("GPL v2");