1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2019-2020 Linaro Ltd.
4 */
5#include <linux/kernel.h>
6#include <linux/module.h>
7#include <linux/mutex.h>
8#include <linux/of_address.h>
9#include "qcom_pil_info.h"
10
11/*
12 * The PIL relocation information region is used to communicate memory regions
13 * occupied by co-processor firmware for post mortem crash analysis.
14 *
15 * It consists of an array of entries with an 8 byte textual identifier of the
16 * region followed by a 64 bit base address and 32 bit size, both little
17 * endian.
18 */
19#define PIL_RELOC_NAME_LEN	8
20#define PIL_RELOC_ENTRY_SIZE	(PIL_RELOC_NAME_LEN + sizeof(__le64) + sizeof(__le32))
21
22struct pil_reloc {
23	void __iomem *base;
24	size_t num_entries;
25};
26
27static struct pil_reloc _reloc __read_mostly;
28static DEFINE_MUTEX(pil_reloc_lock);
29
30static int qcom_pil_info_init(void)
31{
32	struct device_node *np;
33	struct resource imem;
34	void __iomem *base;
35	int ret;
36
37	/* Already initialized? */
38	if (_reloc.base)
39		return 0;
40
41	np = of_find_compatible_node(NULL, NULL, "qcom,pil-reloc-info");
42	if (!np)
43		return -ENOENT;
44
45	ret = of_address_to_resource(np, 0, &imem);
46	of_node_put(np);
47	if (ret < 0)
48		return ret;
49
50	base = ioremap(imem.start, resource_size(&imem));
51	if (!base) {
52		pr_err("failed to map PIL relocation info region\n");
53		return -ENOMEM;
54	}
55
56	memset_io(base, 0, resource_size(&imem));
57
58	_reloc.base = base;
59	_reloc.num_entries = (u32)resource_size(&imem) / PIL_RELOC_ENTRY_SIZE;
60
61	return 0;
62}
63
64/**
65 * qcom_pil_info_store() - store PIL information of image in IMEM
66 * @image:	name of the image
67 * @base:	base address of the loaded image
68 * @size:	size of the loaded image
69 *
70 * Return: 0 on success, negative errno on failure
71 */
72int qcom_pil_info_store(const char *image, phys_addr_t base, size_t size)
73{
74	char buf[PIL_RELOC_NAME_LEN];
75	void __iomem *entry;
76	int ret;
77	int i;
78
79	mutex_lock(&pil_reloc_lock);
80	ret = qcom_pil_info_init();
81	if (ret < 0) {
82		mutex_unlock(&pil_reloc_lock);
83		return ret;
84	}
85
86	for (i = 0; i < _reloc.num_entries; i++) {
87		entry = _reloc.base + i * PIL_RELOC_ENTRY_SIZE;
88
89		memcpy_fromio(buf, entry, PIL_RELOC_NAME_LEN);
90
91		/*
92		 * An empty record means we didn't find it, given that the
93		 * records are packed.
94		 */
95		if (!buf[0])
96			goto found_unused;
97
98		if (!strncmp(buf, image, PIL_RELOC_NAME_LEN))
99			goto found_existing;
100	}
101
102	pr_warn("insufficient PIL info slots\n");
103	mutex_unlock(&pil_reloc_lock);
104	return -ENOMEM;
105
106found_unused:
107	memcpy_toio(entry, image, strnlen(image, PIL_RELOC_NAME_LEN));
108found_existing:
109	/* Use two writel() as base is only aligned to 4 bytes on odd entries */
110	writel(base, entry + PIL_RELOC_NAME_LEN);
111	writel((u64)base >> 32, entry + PIL_RELOC_NAME_LEN + 4);
112	writel(size, entry + PIL_RELOC_NAME_LEN + sizeof(__le64));
113	mutex_unlock(&pil_reloc_lock);
114
115	return 0;
116}
117EXPORT_SYMBOL_GPL(qcom_pil_info_store);
118
119static void __exit pil_reloc_exit(void)
120{
121	mutex_lock(&pil_reloc_lock);
122	iounmap(_reloc.base);
123	_reloc.base = NULL;
124	mutex_unlock(&pil_reloc_lock);
125}
126module_exit(pil_reloc_exit);
127
128MODULE_DESCRIPTION("Qualcomm PIL relocation info");
129MODULE_LICENSE("GPL v2");
130