linux/drivers/firmware/meson/meson_sm.c

310 lines
6.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Amlogic Secure Monitor driver
*
* Copyright (C) 2016 Endless Mobile, Inc.
* Author: Carlo Caione <carlo@endlessm.com>
*/
#define pr_fmt(fmt) "meson-sm: " fmt
#include <linux/arm-smccc.h>
#include <linux/bug.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/types.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/firmware/meson/meson_sm.h>
struct meson_sm_cmd {
unsigned int index;
u32 smc_id;
};
#define CMD(d, s) { .index = (d), .smc_id = (s), }
struct meson_sm_chip {
unsigned int shmem_size;
u32 cmd_shmem_in_base;
u32 cmd_shmem_out_base;
struct meson_sm_cmd cmd[];
};
struct meson_sm_chip gxbb_chip = {
.shmem_size = SZ_4K,
.cmd_shmem_in_base = 0x82000020,
.cmd_shmem_out_base = 0x82000021,
.cmd = {
CMD(SM_EFUSE_READ, 0x82000030),
CMD(SM_EFUSE_WRITE, 0x82000031),
CMD(SM_EFUSE_USER_MAX, 0x82000033),
CMD(SM_GET_CHIP_ID, 0x82000044),
{ /* sentinel */ },
},
};
struct meson_sm_firmware {
const struct meson_sm_chip *chip;
void __iomem *sm_shmem_in_base;
void __iomem *sm_shmem_out_base;
};
static struct meson_sm_firmware fw;
static u32 meson_sm_get_cmd(const struct meson_sm_chip *chip,
unsigned int cmd_index)
{
const struct meson_sm_cmd *cmd = chip->cmd;
while (cmd->smc_id && cmd->index != cmd_index)
cmd++;
return cmd->smc_id;
}
static u32 __meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2,
u32 arg3, u32 arg4)
{
struct arm_smccc_res res;
arm_smccc_smc(cmd, arg0, arg1, arg2, arg3, arg4, 0, 0, &res);
return res.a0;
}
static void __iomem *meson_sm_map_shmem(u32 cmd_shmem, unsigned int size)
{
u32 sm_phy_base;
sm_phy_base = __meson_sm_call(cmd_shmem, 0, 0, 0, 0, 0);
if (!sm_phy_base)
return 0;
return ioremap_cache(sm_phy_base, size);
}
/**
* meson_sm_call - generic SMC32 call to the secure-monitor
*
* @cmd_index: Index of the SMC32 function ID
* @ret: Returned value
* @arg0: SMC32 Argument 0
* @arg1: SMC32 Argument 1
* @arg2: SMC32 Argument 2
* @arg3: SMC32 Argument 3
* @arg4: SMC32 Argument 4
*
* Return: 0 on success, a negative value on error
*/
int meson_sm_call(unsigned int cmd_index, u32 *ret, u32 arg0,
u32 arg1, u32 arg2, u32 arg3, u32 arg4)
{
u32 cmd, lret;
if (!fw.chip)
return -ENOENT;
cmd = meson_sm_get_cmd(fw.chip, cmd_index);
if (!cmd)
return -EINVAL;
lret = __meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4);
if (ret)
*ret = lret;
return 0;
}
EXPORT_SYMBOL(meson_sm_call);
/**
* meson_sm_call_read - retrieve data from secure-monitor
*
* @buffer: Buffer to store the retrieved data
* @bsize: Size of the buffer
* @cmd_index: Index of the SMC32 function ID
* @arg0: SMC32 Argument 0
* @arg1: SMC32 Argument 1
* @arg2: SMC32 Argument 2
* @arg3: SMC32 Argument 3
* @arg4: SMC32 Argument 4
*
* Return: size of read data on success, a negative value on error
* When 0 is returned there is no guarantee about the amount of
* data read and bsize bytes are copied in buffer.
*/
int meson_sm_call_read(void *buffer, unsigned int bsize, unsigned int cmd_index,
u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
{
u32 size;
int ret;
if (!fw.chip)
return -ENOENT;
if (!fw.chip->cmd_shmem_out_base)
return -EINVAL;
if (bsize > fw.chip->shmem_size)
return -EINVAL;
if (meson_sm_call(cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)
return -EINVAL;
if (size > bsize)
return -EINVAL;
ret = size;
if (!size)
size = bsize;
if (buffer)
memcpy(buffer, fw.sm_shmem_out_base, size);
return ret;
}
EXPORT_SYMBOL(meson_sm_call_read);
/**
* meson_sm_call_write - send data to secure-monitor
*
* @buffer: Buffer containing data to send
* @size: Size of the data to send
* @cmd_index: Index of the SMC32 function ID
* @arg0: SMC32 Argument 0
* @arg1: SMC32 Argument 1
* @arg2: SMC32 Argument 2
* @arg3: SMC32 Argument 3
* @arg4: SMC32 Argument 4
*
* Return: size of sent data on success, a negative value on error
*/
int meson_sm_call_write(void *buffer, unsigned int size, unsigned int cmd_index,
u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
{
u32 written;
if (!fw.chip)
return -ENOENT;
if (size > fw.chip->shmem_size)
return -EINVAL;
if (!fw.chip->cmd_shmem_in_base)
return -EINVAL;
memcpy(fw.sm_shmem_in_base, buffer, size);
if (meson_sm_call(cmd_index, &written, arg0, arg1, arg2, arg3, arg4) < 0)
return -EINVAL;
if (!written)
return -EINVAL;
return written;
}
EXPORT_SYMBOL(meson_sm_call_write);
#define SM_CHIP_ID_LENGTH 119
#define SM_CHIP_ID_OFFSET 4
#define SM_CHIP_ID_SIZE 12
static ssize_t serial_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
uint8_t *id_buf;
int ret;
id_buf = kmalloc(SM_CHIP_ID_LENGTH, GFP_KERNEL);
if (!id_buf)
return -ENOMEM;
ret = meson_sm_call_read(id_buf, SM_CHIP_ID_LENGTH, SM_GET_CHIP_ID,
0, 0, 0, 0, 0);
if (ret < 0) {
kfree(id_buf);
return ret;
}
ret = sprintf(buf, "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n",
id_buf[SM_CHIP_ID_OFFSET + 0],
id_buf[SM_CHIP_ID_OFFSET + 1],
id_buf[SM_CHIP_ID_OFFSET + 2],
id_buf[SM_CHIP_ID_OFFSET + 3],
id_buf[SM_CHIP_ID_OFFSET + 4],
id_buf[SM_CHIP_ID_OFFSET + 5],
id_buf[SM_CHIP_ID_OFFSET + 6],
id_buf[SM_CHIP_ID_OFFSET + 7],
id_buf[SM_CHIP_ID_OFFSET + 8],
id_buf[SM_CHIP_ID_OFFSET + 9],
id_buf[SM_CHIP_ID_OFFSET + 10],
id_buf[SM_CHIP_ID_OFFSET + 11]);
kfree(id_buf);
return ret;
}
static DEVICE_ATTR_RO(serial);
static struct attribute *meson_sm_sysfs_attributes[] = {
&dev_attr_serial.attr,
NULL,
};
static const struct attribute_group meson_sm_sysfs_attr_group = {
.attrs = meson_sm_sysfs_attributes,
};
static const struct of_device_id meson_sm_ids[] = {
{ .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip },
{ /* sentinel */ },
};
static int __init meson_sm_probe(struct platform_device *pdev)
{
const struct meson_sm_chip *chip;
chip = of_match_device(meson_sm_ids, &pdev->dev)->data;
if (chip->cmd_shmem_in_base) {
fw.sm_shmem_in_base = meson_sm_map_shmem(chip->cmd_shmem_in_base,
chip->shmem_size);
if (WARN_ON(!fw.sm_shmem_in_base))
goto out;
}
if (chip->cmd_shmem_out_base) {
fw.sm_shmem_out_base = meson_sm_map_shmem(chip->cmd_shmem_out_base,
chip->shmem_size);
if (WARN_ON(!fw.sm_shmem_out_base))
goto out_in_base;
}
fw.chip = chip;
pr_info("secure-monitor enabled\n");
if (sysfs_create_group(&pdev->dev.kobj, &meson_sm_sysfs_attr_group))
goto out_in_base;
return 0;
out_in_base:
iounmap(fw.sm_shmem_in_base);
out:
return -EINVAL;
}
static struct platform_driver meson_sm_driver = {
.driver = {
.name = "meson-sm",
.of_match_table = of_match_ptr(meson_sm_ids),
},
};
module_platform_driver_probe(meson_sm_driver, meson_sm_probe);