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");