linux/drivers/firmware/google/cbmem.c
Nícolas F. R. A. Prado 8a0a62941a firmware: coreboot: Replace tag with id table in driver struct
Switch the plain 'tag' field in struct coreboot_driver for the newly
created coreboot_device_id struct, which also contains a tag field and
has the benefit of allowing modalias generation, and update all coreboot
drivers accordingly.

While at it, also add the id table for each driver to the module device
table to allow automatically loading the module.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20240212-coreboot-mod-defconfig-v4-3-d14172676f6d@collabora.com
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
2024-02-17 08:53:06 +08:00

136 lines
3.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* cbmem.c
*
* Driver for exporting cbmem entries in sysfs.
*
* Copyright 2022 Google LLC
*/
#include <linux/device.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include "coreboot_table.h"
struct cbmem_entry {
char *mem_file_buf;
u32 size;
};
static struct cbmem_entry *to_cbmem_entry(struct kobject *kobj)
{
return dev_get_drvdata(kobj_to_dev(kobj));
}
static ssize_t mem_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf, loff_t pos,
size_t count)
{
struct cbmem_entry *entry = to_cbmem_entry(kobj);
return memory_read_from_buffer(buf, count, &pos, entry->mem_file_buf,
entry->size);
}
static ssize_t mem_write(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf, loff_t pos,
size_t count)
{
struct cbmem_entry *entry = to_cbmem_entry(kobj);
if (pos < 0 || pos >= entry->size)
return -EINVAL;
if (count > entry->size - pos)
count = entry->size - pos;
memcpy(entry->mem_file_buf + pos, buf, count);
return count;
}
static BIN_ATTR_ADMIN_RW(mem, 0);
static ssize_t address_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct coreboot_device *cbdev = dev_to_coreboot_device(dev);
return sysfs_emit(buf, "0x%llx\n", cbdev->cbmem_entry.address);
}
static DEVICE_ATTR_RO(address);
static ssize_t size_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct coreboot_device *cbdev = dev_to_coreboot_device(dev);
return sysfs_emit(buf, "0x%x\n", cbdev->cbmem_entry.entry_size);
}
static DEVICE_ATTR_RO(size);
static struct attribute *attrs[] = {
&dev_attr_address.attr,
&dev_attr_size.attr,
NULL,
};
static struct bin_attribute *bin_attrs[] = {
&bin_attr_mem,
NULL,
};
static const struct attribute_group cbmem_entry_group = {
.attrs = attrs,
.bin_attrs = bin_attrs,
};
static const struct attribute_group *dev_groups[] = {
&cbmem_entry_group,
NULL,
};
static int cbmem_entry_probe(struct coreboot_device *dev)
{
struct cbmem_entry *entry;
entry = devm_kzalloc(&dev->dev, sizeof(*entry), GFP_KERNEL);
if (!entry)
return -ENOMEM;
dev_set_drvdata(&dev->dev, entry);
entry->mem_file_buf = devm_memremap(&dev->dev, dev->cbmem_entry.address,
dev->cbmem_entry.entry_size,
MEMREMAP_WB);
if (IS_ERR(entry->mem_file_buf))
return PTR_ERR(entry->mem_file_buf);
entry->size = dev->cbmem_entry.entry_size;
return 0;
}
static const struct coreboot_device_id cbmem_ids[] = {
{ .tag = LB_TAG_CBMEM_ENTRY },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(coreboot, cbmem_ids);
static struct coreboot_driver cbmem_entry_driver = {
.probe = cbmem_entry_probe,
.drv = {
.name = "cbmem",
.owner = THIS_MODULE,
.dev_groups = dev_groups,
},
.id_table = cbmem_ids,
};
module_coreboot_driver(cbmem_entry_driver);
MODULE_AUTHOR("Jack Rosenthal <jrosenth@chromium.org>");
MODULE_LICENSE("GPL");