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alistair23-linux/drivers/firmware/imx/seco_mu.c

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// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
* Copyright 2019-2020 NXP
*/
/*
* This driver allows to send messages to the SECO using a shared mailbox. The
* messages must follow the protocol defined.
*/
/*
* Architecture of the driver:
*
* Non-Secure + Secure
* |
* |
* +---------+ +-------------+ |
* |seco_mu.c+<---->+imx-mailbox.c| |
* | | | mailbox.c +<-->+------+ +------+
* +---+-----+ +-------------+ | MU X +<-->+ SECO |
* | +------+ +------+
* +----------------+ |
* | | |
* v v |
* logical logical |
* receiver waiter |
* + + |
* | | |
* | | |
* | +----+------+ |
* | | | |
* | | | |
* device_ctx device_ctx device_ctx |
* |
* User 0 User 1 User Y |
* +------+ +------+ +------+ |
* |misc.c| |misc.c| |misc.c| |
* kernel space +------+ +------+ +------+ |
* |
* +------------------------------------------------------ |
* | | | |
* userspace /dev/seco_muXch0 | | |
* /dev/seco_muXch1 | |
* /dev/seco_muXchY |
* |
*
* When a user sends a command to the seco, it registers its device_ctx as
* waiter of a response from SECO
*
* A user can be registered as receiver of command by the SECO.
*
* When a message is received, the driver select the device_ctx receiving the
* message depending on the tag in the message. It selects the device_ctx
* accordingly.
*/
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/miscdevice.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/uaccess.h>
#include <linux/firmware/imx/sci.h>
#include <dt-bindings/firmware/imx/rsrc.h>
#include <linux/firmware/imx/seco_mu_ioctl.h>
#include <linux/mailbox_client.h>
#define MAX_RECV_SIZE 31
#define MAX_RECV_SIZE_BYTES (MAX_RECV_SIZE * sizeof(u32))
#define MAX_MESSAGE_SIZE 31
#define MAX_MESSAGE_SIZE_BYTES (MAX_MESSAGE_SIZE * sizeof(u32))
#define MESSAGE_SIZE(hdr) (((struct she_mu_hdr *)(&(hdr)))->size)
#define MESSAGE_TAG(hdr) (((struct she_mu_hdr *)(&(hdr)))->tag)
#define DEFAULT_MESSAGING_TAG_COMMAND (0x17u)
#define DEFAULT_MESSAGING_TAG_RESPONSE (0xe1u)
#define SECURE_RAM_BASE_ADDRESS (0x31800000ULL)
#define SECURE_RAM_BASE_ADDRESS_SCU (0x20800000u)
#define SECURE_RAM_SIZE (0x10000ULL)
#define SECO_MU_DEFAULT_MAX_USERS 4
#define SECO_MU_INTERRUPT_INDEX (0u)
#define SECO_DEFAULT_MU_INDEX (1u)
#define SECO_DEFAULT_TZ (0u)
#define DEFAULT_DID (0u)
#define MAX_DATA_SIZE_PER_USER (65 * 1024)
/* Header of the messages exchange with the SECO */
struct she_mu_hdr {
u8 ver;
u8 size;
u8 command;
u8 tag;
} __packed;
/* Status of a char device */
enum mu_device_status_t {
MU_FREE,
MU_OPENED
};
struct seco_shared_mem {
dma_addr_t dma_addr;
u32 size;
u32 pos;
u8 *ptr;
};
struct seco_out_buffer_desc {
u8 *out_ptr;
u8 *out_usr_ptr;
u32 out_size;
struct list_head link;
};
/* Private struct for each char device instance. */
struct seco_mu_device_ctx {
struct device *dev;
struct seco_mu_priv *mu_priv;
struct miscdevice miscdev;
enum mu_device_status_t status;
wait_queue_head_t wq;
struct semaphore fops_lock;
u32 pending_hdr;
struct list_head pending_out;
struct seco_shared_mem secure_mem;
struct seco_shared_mem non_secure_mem;
u32 temp_cmd[MAX_MESSAGE_SIZE];
u32 temp_resp[MAX_RECV_SIZE];
u32 temp_resp_size;
};
/* Private struct for seco MU driver. */
struct seco_mu_priv {
struct seco_mu_device_ctx *cmd_receiver_dev;
struct seco_mu_device_ctx *waiting_rsp_dev;
/*
* prevent parallel access to the MU registers
* e.g. a user trying to send a command while the other one is
* sending a response.
*/
struct mutex mu_lock;
/*
* prevent a command to be sent on the MU while another one is still
* processing. (response to a command is allowed)
*/
struct mutex mu_cmd_lock;
struct device *dev;
u32 seco_mu_id;
u8 cmd_tag;
u8 rsp_tag;
struct mbox_client cl;
struct mbox_chan *tx_chan;
struct mbox_chan *rx_chan;
struct imx_sc_ipc *ipc_scu;
u8 seco_part_owner;
};
/* macro to log operation of a misc device */
#define miscdev_dbg(p_miscdev, fmt, va_args...) \
({ \
struct miscdevice *_p_miscdev = p_miscdev; \
dev_dbg((_p_miscdev)->parent, "%s: " fmt, (_p_miscdev)->name, \
##va_args); \
})
#define miscdev_info(p_miscdev, fmt, va_args...) \
({ \
struct miscdevice *_p_miscdev = p_miscdev; \
dev_info((_p_miscdev)->parent, "%s: " fmt, (_p_miscdev)->name, \
##va_args); \
})
#define miscdev_err(p_miscdev, fmt, va_args...) \
({ \
struct miscdevice *_p_miscdev = p_miscdev; \
dev_err((_p_miscdev)->parent, "%s: " fmt, (_p_miscdev)->name, \
##va_args); \
})
/* macro to log operation of a device context */
#define devctx_dbg(p_devctx, fmt, va_args...) \
miscdev_dbg(&((p_devctx)->miscdev), fmt, ##va_args)
#define devctx_info(p_devctx, fmt, va_args...) \
miscdev_info(&((p_devctx)->miscdev), fmt, ##va_args)
#define devctx_err(p_devctx, fmt, va_args...) \
miscdev_err((&(p_devctx)->miscdev), fmt, ##va_args)
#define IMX_SC_RM_PERM_FULL 7U /* Full access */
/* Give access to SECU to the memory we want to share */
static int seco_mu_setup_seco_memory_access(struct seco_mu_device_ctx *dev_ctx,
u64 addr, u32 len)
{
struct seco_mu_priv *priv = dev_get_drvdata(dev_ctx->dev);
int ret;
u8 mr;
ret = imx_sc_rm_find_memreg(priv->ipc_scu, &mr, addr, addr + len);
if (ret) {
devctx_err(dev_ctx, "Fail find memreg\n");
goto exit;
}
ret = imx_sc_rm_set_memreg_permissions(priv->ipc_scu, mr,
priv->seco_part_owner,
IMX_SC_RM_PERM_FULL);
if (ret) {
devctx_err(dev_ctx, "Fail set permission for resource\n");
goto exit;
}
exit:
return ret;
}
/*
* File operations for user-space
*/
/* Open a char device. */
static int seco_mu_fops_open(struct inode *nd, struct file *fp)
{
struct seco_mu_device_ctx *dev_ctx = container_of(fp->private_data,
struct seco_mu_device_ctx, miscdev);
int err;
/* Avoid race if opened at the same time */
if (down_trylock(&dev_ctx->fops_lock))
return -EBUSY;
/* Authorize only 1 instance. */
if (dev_ctx->status != MU_FREE) {
err = -EBUSY;
goto exit;
}
/*
* Allocate some memory for data exchanges with SECO.
* This will be used for data not requiring secure memory.
*/
dev_ctx->non_secure_mem.ptr = dmam_alloc_coherent(dev_ctx->dev,
MAX_DATA_SIZE_PER_USER,
&dev_ctx->non_secure_mem.dma_addr,
GFP_KERNEL);
if (!dev_ctx->non_secure_mem.ptr) {
err = -ENOMEM;
devctx_err(dev_ctx, "Failed to map shared memory with SECO\n");
goto exit;
}
err = seco_mu_setup_seco_memory_access(dev_ctx,
dev_ctx->non_secure_mem.dma_addr,
MAX_DATA_SIZE_PER_USER);
if (err) {
err = -EPERM;
devctx_err(dev_ctx,
"Failed to share access to shared memory\n");
goto free_coherent;
}
dev_ctx->non_secure_mem.size = MAX_DATA_SIZE_PER_USER;
dev_ctx->non_secure_mem.pos = 0;
dev_ctx->status = MU_OPENED;
dev_ctx->pending_hdr = 0;
goto exit;
free_coherent:
dmam_free_coherent(dev_ctx->mu_priv->dev, MAX_DATA_SIZE_PER_USER,
dev_ctx->non_secure_mem.ptr,
dev_ctx->non_secure_mem.dma_addr);
exit:
up(&dev_ctx->fops_lock);
return err;
}
/* Close a char device. */
static int seco_mu_fops_close(struct inode *nd, struct file *fp)
{
struct seco_mu_device_ctx *dev_ctx = container_of(fp->private_data,
struct seco_mu_device_ctx, miscdev);
struct seco_mu_priv *mu_priv = dev_ctx->mu_priv;
struct seco_out_buffer_desc *out_buf_desc;
/* Avoid race if closed at the same time */
if (down_trylock(&dev_ctx->fops_lock))
return -EBUSY;
/* The device context has not been opened */
if (dev_ctx->status != MU_OPENED)
goto exit;
/* check if this device was registered as command receiver. */
if (mu_priv->cmd_receiver_dev == dev_ctx)
mu_priv->cmd_receiver_dev = NULL;
/* check if this device was registered as waiting response. */
if (mu_priv->waiting_rsp_dev == dev_ctx) {
mu_priv->waiting_rsp_dev = NULL;
mutex_unlock(&mu_priv->mu_cmd_lock);
}
/* Unmap secure memory shared buffer. */
if (dev_ctx->secure_mem.ptr)
devm_iounmap(dev_ctx->dev, dev_ctx->secure_mem.ptr);
dev_ctx->secure_mem.ptr = NULL;
dev_ctx->secure_mem.dma_addr = 0;
dev_ctx->secure_mem.size = 0;
dev_ctx->secure_mem.pos = 0;
/* Free non-secure shared buffer. */
dmam_free_coherent(dev_ctx->mu_priv->dev, MAX_DATA_SIZE_PER_USER,
dev_ctx->non_secure_mem.ptr,
dev_ctx->non_secure_mem.dma_addr);
dev_ctx->non_secure_mem.ptr = NULL;
dev_ctx->non_secure_mem.dma_addr = 0;
dev_ctx->non_secure_mem.size = 0;
dev_ctx->non_secure_mem.pos = 0;
while (!list_empty(&dev_ctx->pending_out)) {
out_buf_desc = list_first_entry_or_null(&dev_ctx->pending_out,
struct seco_out_buffer_desc,
link);
__list_del_entry(&out_buf_desc->link);
devm_kfree(dev_ctx->dev, out_buf_desc);
}
dev_ctx->status = MU_FREE;
exit:
up(&dev_ctx->fops_lock);
return 0;
}
/* Write a message to the MU. */
static ssize_t seco_mu_fops_write(struct file *fp, const char __user *buf,
size_t size, loff_t *ppos)
{
struct seco_mu_device_ctx *dev_ctx = container_of(fp->private_data,
struct seco_mu_device_ctx, miscdev);
struct seco_mu_priv *mu_priv = dev_ctx->mu_priv;
u32 nb_words = 0, header;
int err;
devctx_dbg(dev_ctx, "write from buf (%p)%ld, ppos=%lld\n", buf, size,
((ppos) ? *ppos : 0));
if (down_interruptible(&dev_ctx->fops_lock))
return -EBUSY;
if (dev_ctx->status != MU_OPENED) {
err = -EINVAL;
goto exit;
}
if (size < sizeof(struct she_mu_hdr)) {
devctx_err(dev_ctx, "User buffer too small(%ld < %lu)\n", size,
sizeof(struct she_mu_hdr));
err = -ENOSPC;
goto exit;
}
if (size > MAX_MESSAGE_SIZE_BYTES) {
devctx_err(dev_ctx, "User buffer too big(%ld > %lu)\n", size,
MAX_MESSAGE_SIZE_BYTES);
err = -ENOSPC;
goto exit;
}
/* Copy data to buffer */
err = (int)copy_from_user(dev_ctx->temp_cmd, buf, size);
if (err) {
err = -EFAULT;
devctx_err(dev_ctx, "Fail copy message from user\n");
goto exit;
}
print_hex_dump_debug("from user ", DUMP_PREFIX_OFFSET, 4, 4,
dev_ctx->temp_cmd, size, false);
header = dev_ctx->temp_cmd[0];
/* Check the message is valid according to tags */
if (MESSAGE_TAG(header) == mu_priv->cmd_tag) {
/*
* unlocked in seco_mu_receive_work_handler when the
* response to this command is received.
*/
mutex_lock(&mu_priv->mu_cmd_lock);
mu_priv->waiting_rsp_dev = dev_ctx;
} else if (MESSAGE_TAG(header) == mu_priv->rsp_tag) {
/* Check the device context can send the command */
if (dev_ctx != mu_priv->cmd_receiver_dev) {
devctx_err(dev_ctx,
"This channel is not configured to send response to SECO\n");
err = -EPERM;
goto exit;
}
} else {
devctx_err(dev_ctx, "The message does not have a valid TAG\n");
err = -EINVAL;
goto exit;
}
/*
* Check that the size passed as argument matches the size
* carried in the message.
*/
nb_words = MESSAGE_SIZE(header);
if (nb_words * sizeof(u32) > size) {
devctx_err(dev_ctx, "User buffer too small\n");
goto exit;
}
mutex_lock(&mu_priv->mu_lock);
/* Send message */
devctx_dbg(dev_ctx, "sending message\n");
err = mbox_send_message(mu_priv->tx_chan, dev_ctx->temp_cmd);
if (err < 0) {
devctx_err(dev_ctx, "Failed to send message\n");
goto unlock;
}
err = nb_words * (u32)sizeof(u32);
unlock:
mutex_unlock(&mu_priv->mu_lock);
exit:
up(&dev_ctx->fops_lock);
return err;
}
/*
* Read a message from the MU.
* Blocking until a message is available.
*/
static ssize_t seco_mu_fops_read(struct file *fp, char __user *buf,
size_t size, loff_t *ppos)
{
struct seco_mu_device_ctx *dev_ctx = container_of(fp->private_data,
struct seco_mu_device_ctx, miscdev);
u32 data_size = 0, size_to_copy = 0;
struct seco_out_buffer_desc *b_desc;
int err;
devctx_dbg(dev_ctx, "read to buf %p(%ld), ppos=%lld\n", buf, size,
((ppos) ? *ppos : 0));
if (down_interruptible(&dev_ctx->fops_lock))
return -EBUSY;
if (dev_ctx->status != MU_OPENED) {
err = -EINVAL;
goto exit;
}
/* Wait until the complete message is received on the MU. */
err = wait_event_interruptible(dev_ctx->wq, dev_ctx->pending_hdr != 0);
if (err) {
devctx_err(dev_ctx, "Interrupted by signal\n");
goto exit;
}
devctx_dbg(dev_ctx, "%s %s\n", __func__,
"message received, start transmit to user");
/* Check that the size passed as argument is larger than
* the one carried in the message.
*/
data_size = dev_ctx->temp_resp_size * sizeof(u32);
size_to_copy = data_size;
if (size_to_copy > size) {
devctx_dbg(dev_ctx, "User buffer too small (%ld < %d)\n",
size, size_to_copy);
size_to_copy = size;
}
/* We may need to copy the output data to user before
* delivering the completion message.
*/
while (!list_empty(&dev_ctx->pending_out)) {
b_desc = list_first_entry_or_null(&dev_ctx->pending_out,
struct seco_out_buffer_desc,
link);
if (b_desc->out_usr_ptr && b_desc->out_ptr) {
devctx_dbg(dev_ctx, "Copy output data to user\n");
err = (int)copy_to_user(b_desc->out_usr_ptr,
b_desc->out_ptr,
b_desc->out_size);
if (err) {
devctx_err(dev_ctx,
"Failed to copy output data to user\n");
err = -EFAULT;
goto exit;
}
}
__list_del_entry(&b_desc->link);
devm_kfree(dev_ctx->dev, b_desc);
}
/* Copy data from the buffer */
print_hex_dump_debug("to user ", DUMP_PREFIX_OFFSET, 4, 4,
dev_ctx->temp_resp, size_to_copy, false);
err = (int)copy_to_user(buf, dev_ctx->temp_resp, size_to_copy);
if (err) {
devctx_err(dev_ctx, "Failed to copy to user\n");
err = -EFAULT;
goto exit;
}
err = size_to_copy;
/* free memory allocated on the shared buffers. */
dev_ctx->secure_mem.pos = 0;
dev_ctx->non_secure_mem.pos = 0;
dev_ctx->pending_hdr = 0;
exit:
up(&dev_ctx->fops_lock);
return err;
}
/* Configure the shared memory according to user config */
static int
seco_mu_ioctl_shared_mem_cfg_handler(struct seco_mu_device_ctx *dev_ctx,
unsigned long arg)
{
struct seco_mu_ioctl_shared_mem_cfg cfg;
int err = -EINVAL;
u64 high_boundary;
/* Check if not already configured. */
if (dev_ctx->secure_mem.dma_addr != 0u) {
devctx_err(dev_ctx, "Shared memory not configured\n");
goto exit;
}
err = (int)copy_from_user(&cfg, (u8 *)arg,
sizeof(cfg));
if (err) {
devctx_err(dev_ctx, "Fail copy shared memory config to user\n");
err = -EFAULT;
goto exit;
}
devctx_dbg(dev_ctx, "cfg offset: %u(%d)\n", cfg.base_offset, cfg.size);
high_boundary = cfg.base_offset;
if (high_boundary > SECURE_RAM_SIZE) {
devctx_err(dev_ctx, "base offset is over secure memory\n");
err = -ENOMEM;
goto exit;
}
high_boundary += cfg.size;
if (high_boundary > SECURE_RAM_SIZE) {
devctx_err(dev_ctx, "total memory is over secure memory\n");
err = -ENOMEM;
goto exit;
}
dev_ctx->secure_mem.dma_addr = (dma_addr_t)cfg.base_offset;
dev_ctx->secure_mem.size = cfg.size;
dev_ctx->secure_mem.pos = 0;
dev_ctx->secure_mem.ptr = devm_ioremap(dev_ctx->dev,
(phys_addr_t)(SECURE_RAM_BASE_ADDRESS +
(u64)dev_ctx->secure_mem.dma_addr),
dev_ctx->secure_mem.size);
if (!dev_ctx->secure_mem.ptr) {
devctx_err(dev_ctx, "Failed to map secure memory\n");
err = -ENOMEM;
goto exit;
}
exit:
return err;
}
/*
* Copy a buffer of daa to/from the user and return the address to use in
* messages
*/
static int seco_mu_ioctl_setup_iobuf_handler(struct seco_mu_device_ctx *dev_ctx,
unsigned long arg)
{
struct seco_out_buffer_desc *out_buf_desc;
struct seco_mu_ioctl_setup_iobuf io;
struct seco_shared_mem *shared_mem;
int err = -EINVAL;
u32 pos;
err = (int)copy_from_user(&io,
(u8 *)arg,
sizeof(io));
if (err) {
devctx_err(dev_ctx, "Failed copy iobuf config from user\n");
err = -EFAULT;
goto exit;
}
devctx_dbg(dev_ctx, "io [buf: %p(%d) flag: %x]\n",
io.user_buf, io.length, io.flags);
if (io.length == 0 || !io.user_buf) {
/*
* Accept NULL pointers since some buffers are optional
* in SECO commands. In this case we should return 0 as
* pointer to be embedded into the message.
* Skip all data copy part of code below.
*/
io.seco_addr = 0;
goto copy;
}
/* Select the shared memory to be used for this buffer. */
if (io.flags & SECO_MU_IO_FLAGS_USE_SEC_MEM) {
/* App requires to use secure memory for this buffer.*/
shared_mem = &dev_ctx->secure_mem;
} else {
/* No specific requirement for this buffer. */
shared_mem = &dev_ctx->non_secure_mem;
}
/* Check there is enough space in the shared memory. */
if (io.length >= shared_mem->size - shared_mem->pos) {
devctx_err(dev_ctx, "Not enough space in shared memory\n");
err = -ENOMEM;
goto exit;
}
/* Allocate space in shared memory. 8 bytes aligned. */
pos = shared_mem->pos;
shared_mem->pos += round_up(io.length, 8u);
io.seco_addr = (u64)shared_mem->dma_addr + pos;
if ((io.flags & SECO_MU_IO_FLAGS_USE_SEC_MEM) &&
!(io.flags & SECO_MU_IO_FLAGS_USE_SHORT_ADDR))
/*Add base address to get full address.*/
io.seco_addr += SECURE_RAM_BASE_ADDRESS_SCU;
if (io.flags & SECO_MU_IO_FLAGS_IS_INPUT) {
/*
* buffer is input:
* copy data from user space to this allocated buffer.
*/
err = (int)copy_from_user(shared_mem->ptr + pos, io.user_buf,
io.length);
if (err) {
devctx_err(dev_ctx,
"Failed copy data to shared memory\n");
err = -EFAULT;
goto exit;
}
} else {
/*
* buffer is output:
* add an entry in the "pending buffers" list so data
* can be copied to user space when receiving SECO
* response.
*/
out_buf_desc = devm_kmalloc(dev_ctx->dev, sizeof(*out_buf_desc),
GFP_KERNEL);
if (!out_buf_desc) {
err = -ENOMEM;
devctx_err(dev_ctx,
"Failed allocating mem for pending buffer\n"
);
goto exit;
}
out_buf_desc->out_ptr = shared_mem->ptr + pos;
out_buf_desc->out_usr_ptr = io.user_buf;
out_buf_desc->out_size = io.length;
list_add_tail(&out_buf_desc->link, &dev_ctx->pending_out);
}
copy:
/* Provide the seco address to user space only if success. */
err = (int)copy_to_user((u8 *)arg, &io,
sizeof(io));
if (err) {
devctx_err(dev_ctx, "Failed to copy iobuff setup to user\n");
err = -EFAULT;
goto exit;
}
exit:
return err;
}
/* Retrieve info about the MU */
static int seco_mu_ioctl_get_mu_info_handler(struct seco_mu_device_ctx *dev_ctx,
unsigned long arg)
{
struct seco_mu_priv *priv = dev_get_drvdata(dev_ctx->dev);
struct seco_mu_ioctl_get_mu_info info;
int err = -EINVAL;
info.seco_mu_idx = (u8)priv->seco_mu_id;
info.interrupt_idx = SECO_MU_INTERRUPT_INDEX;
info.tz = SECO_DEFAULT_TZ;
err = imx_sc_rm_get_did(priv->ipc_scu, &info.did);
if (err) {
devctx_err(dev_ctx, "Get did failed\n");
goto exit;
}
devctx_dbg(dev_ctx,
"info [mu_idx: %d, irq_idx: %d, tz: 0x%x, did: 0x%x]\n",
info.seco_mu_idx, info.interrupt_idx, info.tz, info.did);
err = (int)copy_to_user((u8 *)arg, &info,
sizeof(info));
if (err) {
devctx_err(dev_ctx, "Failed to copy mu info to user\n");
err = -EFAULT;
goto exit;
}
exit:
return err;
}
static int seco_mu_ioctl_signed_msg_handler(struct seco_mu_device_ctx *dev_ctx,
unsigned long arg)
{
struct seco_shared_mem *shared_mem = &dev_ctx->non_secure_mem;
struct seco_mu_priv *priv = dev_get_drvdata(dev_ctx->dev);
struct seco_mu_ioctl_signed_message msg;
int err = -EINVAL;
u64 addr;
u32 pos;
err = (int)copy_from_user(&msg,
(u8 *)arg,
sizeof(msg));
if (err) {
devctx_err(dev_ctx, "Failed to copy from user: %d\n", err);
err = -EFAULT;
goto exit;
}
/* Check there is enough space in the shared memory. */
if (msg.msg_size >= shared_mem->size - shared_mem->pos) {
devctx_err(dev_ctx, "Not enough mem: %d left, %d required\n",
shared_mem->size - shared_mem->pos, msg.msg_size);
err = -ENOMEM;
goto exit;
}
/* Allocate space in shared memory. 8 bytes aligned. */
pos = shared_mem->pos;
/* get physical address from the pos */
addr = (u64)shared_mem->dma_addr + pos;
/* copy signed message from user space to this allocated buffer */
err = (int)copy_from_user(shared_mem->ptr + pos, msg.message,
msg.msg_size);
if (err) {
devctx_err(dev_ctx, "Failed to signed message from user: %d\n",
err);
err = -EFAULT;
goto exit;
}
/* Send the message to SECO through SCU */
msg.error_code = imx_sc_seco_sab_msg(priv->ipc_scu, addr);
err = (int)copy_to_user((u8 *)arg, &msg,
sizeof(msg));
if (err) {
devctx_err(dev_ctx, "Failed to copy to user: %d\n", err);
err = -EFAULT;
goto exit;
}
exit:
return err;
}
/* IOCTL entry point of a char device */
static long seco_mu_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
{
struct seco_mu_device_ctx *dev_ctx = container_of(fp->private_data,
struct seco_mu_device_ctx, miscdev);
struct seco_mu_priv *mu_priv = dev_ctx->mu_priv;
int err = -EINVAL;
/* Prevent race during change of device context */
if (down_interruptible(&dev_ctx->fops_lock))
return -EBUSY;
switch (cmd) {
case SECO_MU_IOCTL_ENABLE_CMD_RCV:
if (!mu_priv->cmd_receiver_dev) {
devctx_dbg(dev_ctx, "setting as receiver\n");
mu_priv->cmd_receiver_dev = dev_ctx;
err = 0;
};
break;
case SECO_MU_IOCTL_SHARED_BUF_CFG:
err = seco_mu_ioctl_shared_mem_cfg_handler(dev_ctx, arg);
break;
case SECO_MU_IOCTL_SETUP_IOBUF:
err = seco_mu_ioctl_setup_iobuf_handler(dev_ctx, arg);
break;
case SECO_MU_IOCTL_GET_MU_INFO:
err = seco_mu_ioctl_get_mu_info_handler(dev_ctx, arg);
break;
case SECO_MU_IOCTL_SIGNED_MESSAGE:
err = seco_mu_ioctl_signed_msg_handler(dev_ctx, arg);
break;
default:
err = -EINVAL;
devctx_dbg(dev_ctx, "IOCTL %.8x not supported\n", cmd);
}
up(&dev_ctx->fops_lock);
return (long)err;
}
/*
* Callback called by mailbox FW when data are received
*/
static void seco_mu_rx_callback(struct mbox_client *c, void *msg)
{
struct device *dev = c->dev;
struct seco_mu_priv *priv = dev_get_drvdata(dev);
struct seco_mu_device_ctx *dev_ctx;
bool is_response = false;
int msg_size;
u32 header;
dev_dbg(dev, "Message received on mailbox\n");
/* The function can be called with NULL msg */
if (!msg) {
dev_err(dev, "Message is invalid\n");
return;
}
if (IS_ERR(msg)) {
dev_err(dev, "Error during reception of message: %ld\n",
PTR_ERR(msg));
return;
}
header = *(u32 *)msg;
dev_dbg(dev, "Selecting device\n");
/* Incoming command: wake up the receiver if any. */
if (MESSAGE_TAG(header) == priv->cmd_tag) {
dev_dbg(dev, "Selecting cmd receiver\n");
dev_ctx = priv->cmd_receiver_dev;
} else if (MESSAGE_TAG(header) == priv->rsp_tag) {
dev_dbg(dev, "Selecting rsp waiter\n");
dev_ctx = priv->waiting_rsp_dev;
is_response = true;
} else {
dev_err(dev, "Failed to select a device for message: %.8x\n",
header);
return;
}
if (!dev_ctx) {
dev_err(dev, "No device context selected for message: %.8x\n",
header);
return;
}
/* Init reception */
msg_size = MESSAGE_SIZE(header);
if (msg_size > MAX_RECV_SIZE) {
devctx_err(dev_ctx, "Message is too big (%d > %d)", msg_size,
MAX_RECV_SIZE);
return;
}
memcpy(dev_ctx->temp_resp, msg, msg_size * sizeof(u32));
dev_ctx->temp_resp_size = msg_size;
/* Allow user to read */
dev_ctx->pending_hdr = dev_ctx->temp_resp[0];
wake_up_interruptible(&dev_ctx->wq);
if (is_response) {
/* Allow user to send new command */
mutex_unlock(&priv->mu_cmd_lock);
}
}
#define SECO_FW_VER_FEAT_MASK (0x0000FFF0u)
#define SECO_FW_VER_FEAT_SHIFT (0x04u)
#define SECO_FW_VER_FEAT_MIN_ALL_MU (0x04u)
/*
* Get SECO FW version and check if it supports receiving commands on all MUs
* The version is retrieved through SCU since this is the only communication
* channel to SECO always present.
*/
static int seco_mu_check_all_mu_supported(struct device *dev)
{
struct seco_mu_priv *priv = dev_get_drvdata(dev);
u32 seco_ver;
int ret;
ret = imx_sc_seco_build_info(priv->ipc_scu, &seco_ver, NULL);
if (ret) {
dev_err(dev, "failed to retrieve SECO build info\n");
goto exit;
}
if (((seco_ver & SECO_FW_VER_FEAT_MASK) >> SECO_FW_VER_FEAT_SHIFT)
< SECO_FW_VER_FEAT_MIN_ALL_MU) {
dev_err(dev, "current SECO FW do not support MU with Linux\n");
ret = -ENOTSUPP;
goto exit;
}
exit:
return ret;
}
/* Char driver setup */
static const struct file_operations seco_mu_fops = {
.open = seco_mu_fops_open,
.owner = THIS_MODULE,
.read = seco_mu_fops_read,
.release = seco_mu_fops_close,
.write = seco_mu_fops_write,
.unlocked_ioctl = seco_mu_ioctl,
};
/* interface for managed res to free a mailbox channel */
static void if_mbox_free_channel(void *mbox_chan)
{
mbox_free_channel(mbox_chan);
}
/* interface for managed res to unregister a char device */
static void if_misc_deregister(void *miscdevice)
{
misc_deregister(miscdevice);
}
static int seco_mu_request_channel(struct device *dev,
struct mbox_chan **chan,
const char *name)
{
struct seco_mu_priv *priv = dev_get_drvdata(dev);
struct mbox_chan *t_chan;
int ret = 0;
t_chan = mbox_request_channel_byname(&priv->cl, name);
if (IS_ERR(t_chan)) {
ret = PTR_ERR(t_chan);
if (ret != -EPROBE_DEFER)
dev_err(dev,
"Failed to request chan %s ret %d\n", name,
ret);
goto exit;
}
ret = devm_add_action(dev, if_mbox_free_channel, t_chan);
if (ret) {
dev_err(dev, "failed to add devm removal of mbox %s\n", name);
goto exit;
}
*chan = t_chan;
exit:
return ret;
}
/* Driver probe.*/
static int seco_mu_probe(struct platform_device *pdev)
{
struct seco_mu_device_ctx *dev_ctx;
struct device *dev = &pdev->dev;
struct seco_mu_priv *priv;
struct device_node *np;
int max_nb_users = 0;
char *devname;
int ret;
int i;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv) {
ret = -ENOMEM;
dev_err(dev, "Fail allocate mem for private data\n");
goto exit;
}
priv->dev = dev;
dev_set_drvdata(dev, priv);
/*
* Get the address of MU to be used for communication with the SCU
*/
np = pdev->dev.of_node;
if (!np) {
dev_err(dev, "Cannot find MU User entry in device tree\n");
ret = -ENOTSUPP;
goto exit;
}
ret = imx_scu_get_handle(&priv->ipc_scu);
if (ret) {
dev_err(dev, "Fail to retrieve IPC handle\n");
goto exit;
}
ret = imx_sc_rm_get_resource_owner(priv->ipc_scu, IMX_SC_R_SECO,
&priv->seco_part_owner);
if (ret) {
dev_err(dev, "Fail get owner of SECO resource\n");
goto exit;
}
ret = seco_mu_check_all_mu_supported(dev);
if (ret) {
dev_err(dev, "Fail seco_mu_check_all_mu_supported\n");
goto exit;
}
/* Initialize the mutex. */
mutex_init(&priv->mu_cmd_lock);
mutex_init(&priv->mu_lock);
priv->cmd_receiver_dev = NULL;
priv->waiting_rsp_dev = NULL;
ret = of_property_read_u32(np, "fsl,seco_mu_id", &priv->seco_mu_id);
if (ret) {
dev_warn(dev, "%s: Not able to read mu_id", __func__);
priv->seco_mu_id = SECO_DEFAULT_MU_INDEX;
}
ret = of_property_read_u32(np, "fsl,seco_max_users", &max_nb_users);
if (ret) {
dev_warn(dev, "%s: Not able to read mu_max_user", __func__);
max_nb_users = SECO_MU_DEFAULT_MAX_USERS;
}
ret = of_property_read_u8(np, "fsl,cmd_tag", &priv->cmd_tag);
if (ret)
priv->cmd_tag = DEFAULT_MESSAGING_TAG_COMMAND;
ret = of_property_read_u8(np, "fsl,rsp_tag", &priv->rsp_tag);
if (ret)
priv->rsp_tag = DEFAULT_MESSAGING_TAG_RESPONSE;
/* Mailbox client configuration */
priv->cl.dev = dev;
priv->cl.knows_txdone = true;
priv->cl.rx_callback = seco_mu_rx_callback;
ret = seco_mu_request_channel(dev, &priv->tx_chan, "txdb");
if (ret) {
if (ret != -EPROBE_DEFER)
dev_err(dev, "Failed to request txdb channel\n");
goto exit;
}
ret = seco_mu_request_channel(dev, &priv->rx_chan, "rxdb");
if (ret) {
if (ret != -EPROBE_DEFER)
dev_err(dev, "Failed to request rxdb channel\n");
goto exit;
}
/* Create users */
for (i = 0; i < max_nb_users; i++) {
dev_ctx = devm_kzalloc(dev, sizeof(*dev_ctx), GFP_KERNEL);
if (!dev_ctx) {
ret = -ENOMEM;
dev_err(dev,
"Fail to allocate memory for device context\n");
goto exit;
}
dev_ctx->dev = dev;
dev_ctx->status = MU_FREE;
dev_ctx->mu_priv = priv;
/* Default value invalid for an header. */
init_waitqueue_head(&dev_ctx->wq);
INIT_LIST_HEAD(&dev_ctx->pending_out);
sema_init(&dev_ctx->fops_lock, 1);
devname = devm_kasprintf(dev, GFP_KERNEL, "seco_mu%d_ch%d",
priv->seco_mu_id, i);
if (!devname) {
ret = -ENOMEM;
dev_err(dev,
"Fail to allocate memory for misc dev name\n");
goto exit;
}
dev_ctx->miscdev.name = devname;
dev_ctx->miscdev.minor = MISC_DYNAMIC_MINOR;
dev_ctx->miscdev.fops = &seco_mu_fops;
dev_ctx->miscdev.parent = dev;
ret = misc_register(&dev_ctx->miscdev);
if (ret) {
dev_err(dev, "failed to register misc device %d\n",
ret);
goto exit;
}
ret = devm_add_action(dev, if_misc_deregister,
&dev_ctx->miscdev);
if (ret)
dev_warn(dev,
"failed to add managed removal of miscdev\n");
}
exit:
return ret;
}
static const struct of_device_id seco_mu_match[] = {
{
.compatible = "fsl,imx-seco-mu",
},
{},
};
MODULE_DEVICE_TABLE(of, seco_mu_match);
static struct platform_driver seco_mu_driver = {
.driver = {
.name = "seco_mu",
.of_match_table = seco_mu_match,
},
.probe = seco_mu_probe,
};
module_platform_driver(seco_mu_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("IMX Seco MU");
MODULE_AUTHOR("NXP");
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