swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 1c23f9e627a7b412978b4e852793c5e3c3efc555 authored by Linus Torvalds on 22 August 2022, 00:32:54 UTC
Linux 6.0-rc2
Linux 6.0-rc2
Tip revision: 1c23f9e
qcom_pil_info.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2019-2020 Linaro Ltd.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_address.h>
#include "qcom_pil_info.h"
/*
* The PIL relocation information region is used to communicate memory regions
* occupied by co-processor firmware for post mortem crash analysis.
*
* It consists of an array of entries with an 8 byte textual identifier of the
* region followed by a 64 bit base address and 32 bit size, both little
* endian.
*/
#define PIL_RELOC_NAME_LEN 8
#define PIL_RELOC_ENTRY_SIZE (PIL_RELOC_NAME_LEN + sizeof(__le64) + sizeof(__le32))
struct pil_reloc {
void __iomem *base;
size_t num_entries;
};
static struct pil_reloc _reloc __read_mostly;
static DEFINE_MUTEX(pil_reloc_lock);
static int qcom_pil_info_init(void)
{
struct device_node *np;
struct resource imem;
void __iomem *base;
int ret;
/* Already initialized? */
if (_reloc.base)
return 0;
np = of_find_compatible_node(NULL, NULL, "qcom,pil-reloc-info");
if (!np)
return -ENOENT;
ret = of_address_to_resource(np, 0, &imem);
of_node_put(np);
if (ret < 0)
return ret;
base = ioremap(imem.start, resource_size(&imem));
if (!base) {
pr_err("failed to map PIL relocation info region\n");
return -ENOMEM;
}
memset_io(base, 0, resource_size(&imem));
_reloc.base = base;
_reloc.num_entries = (u32)resource_size(&imem) / PIL_RELOC_ENTRY_SIZE;
return 0;
}
/**
* qcom_pil_info_store() - store PIL information of image in IMEM
* @image: name of the image
* @base: base address of the loaded image
* @size: size of the loaded image
*
* Return: 0 on success, negative errno on failure
*/
int qcom_pil_info_store(const char *image, phys_addr_t base, size_t size)
{
char buf[PIL_RELOC_NAME_LEN];
void __iomem *entry;
int ret;
int i;
mutex_lock(&pil_reloc_lock);
ret = qcom_pil_info_init();
if (ret < 0) {
mutex_unlock(&pil_reloc_lock);
return ret;
}
for (i = 0; i < _reloc.num_entries; i++) {
entry = _reloc.base + i * PIL_RELOC_ENTRY_SIZE;
memcpy_fromio(buf, entry, PIL_RELOC_NAME_LEN);
/*
* An empty record means we didn't find it, given that the
* records are packed.
*/
if (!buf[0])
goto found_unused;
if (!strncmp(buf, image, PIL_RELOC_NAME_LEN))
goto found_existing;
}
pr_warn("insufficient PIL info slots\n");
mutex_unlock(&pil_reloc_lock);
return -ENOMEM;
found_unused:
memcpy_toio(entry, image, strnlen(image, PIL_RELOC_NAME_LEN));
found_existing:
/* Use two writel() as base is only aligned to 4 bytes on odd entries */
writel(base, entry + PIL_RELOC_NAME_LEN);
writel((u64)base >> 32, entry + PIL_RELOC_NAME_LEN + 4);
writel(size, entry + PIL_RELOC_NAME_LEN + sizeof(__le64));
mutex_unlock(&pil_reloc_lock);
return 0;
}
EXPORT_SYMBOL_GPL(qcom_pil_info_store);
static void __exit pil_reloc_exit(void)
{
mutex_lock(&pil_reloc_lock);
iounmap(_reloc.base);
_reloc.base = NULL;
mutex_unlock(&pil_reloc_lock);
}
module_exit(pil_reloc_exit);
MODULE_DESCRIPTION("Qualcomm PIL relocation info");
MODULE_LICENSE("GPL v2");