LXR linux/drivers/remoteproc/qcom_pil

   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, 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