+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/* Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved. */
-
-#include <linux/kernel.h>
-#include <linux/mhi.h>
-#include <linux/mod_devicetable.h>
-#include <linux/module.h>
-#include <linux/poll.h>
-#include <linux/xarray.h>
-#include <uapi/linux/eventpoll.h>
-
-#include "mhi_qaic_ctrl.h"
-#include "qaic.h"
-
-#define MHI_QAIC_CTRL_DRIVER_NAME "mhi_qaic_ctrl"
-#define MHI_QAIC_CTRL_MAX_MINORS 128
-#define MHI_MAX_MTU 0xffff
-static DEFINE_XARRAY_ALLOC(mqc_xa);
-static struct class *mqc_dev_class;
-static int mqc_dev_major;
-
-/**
- * struct mqc_buf - Buffer structure used to receive data from device
- * @data: Address of data to read from
- * @odata: Original address returned from *alloc() API. Used to free this buf.
- * @len: Length of data in byte
- * @node: This buffer will be part of list managed in struct mqc_dev
- */
-struct mqc_buf {
- void *data;
- void *odata;
- size_t len;
- struct list_head node;
-};
-
-/**
- * struct mqc_dev - MHI QAIC Control Device
- * @minor: MQC device node minor number
- * @mhi_dev: Associated mhi device object
- * @mtu: Max TRE buffer length
- * @enabled: Flag to track the state of the MQC device
- * @lock: Mutex lock to serialize access to open_count
- * @read_lock: Mutex lock to serialize readers
- * @write_lock: Mutex lock to serialize writers
- * @ul_wq: Wait queue for writers
- * @dl_wq: Wait queue for readers
- * @dl_queue_lock: Spin lock to serialize access to download queue
- * @dl_queue: Queue of downloaded buffers
- * @open_count: Track open counts
- * @ref_count: Reference count for this structure
- */
-struct mqc_dev {
- u32 minor;
- struct mhi_device *mhi_dev;
- size_t mtu;
- bool enabled;
- struct mutex lock;
- struct mutex read_lock;
- struct mutex write_lock;
- wait_queue_head_t ul_wq;
- wait_queue_head_t dl_wq;
- spinlock_t dl_queue_lock;
- struct list_head dl_queue;
- unsigned int open_count;
- struct kref ref_count;
-};
-
-static void mqc_dev_release(struct kref *ref)
-{
- struct mqc_dev *mqcdev = container_of(ref, struct mqc_dev, ref_count);
-
- mutex_destroy(&mqcdev->read_lock);
- mutex_destroy(&mqcdev->write_lock);
- mutex_destroy(&mqcdev->lock);
- kfree(mqcdev);
-}
-
-static int mhi_qaic_ctrl_fill_dl_queue(struct mqc_dev *mqcdev)
-{
- struct mhi_device *mhi_dev = mqcdev->mhi_dev;
- struct mqc_buf *ctrlbuf;
- int rx_budget;
- int ret = 0;
- void *data;
-
- rx_budget = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE);
- if (rx_budget < 0)
- return -EIO;
-
- while (rx_budget--) {
- data = kzalloc(mqcdev->mtu + sizeof(*ctrlbuf), GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
- ctrlbuf = data + mqcdev->mtu;
- ctrlbuf->odata = data;
-
- ret = mhi_queue_buf(mhi_dev, DMA_FROM_DEVICE, data, mqcdev->mtu, MHI_EOT);
- if (ret) {
- kfree(data);
- dev_err(&mhi_dev->dev, "Failed to queue buffer\n");
- return ret;
- }
- }
-
- return ret;
-}
-
-static int mhi_qaic_ctrl_dev_start_chan(struct mqc_dev *mqcdev)
-{
- struct device *dev = &mqcdev->mhi_dev->dev;
- int ret = 0;
-
- ret = mutex_lock_interruptible(&mqcdev->lock);
- if (ret)
- return ret;
- if (!mqcdev->enabled) {
- ret = -ENODEV;
- goto release_dev_lock;
- }
- if (!mqcdev->open_count) {
- ret = mhi_prepare_for_transfer(mqcdev->mhi_dev);
- if (ret) {
- dev_err(dev, "Error starting transfer channels\n");
- goto release_dev_lock;
- }
-
- ret = mhi_qaic_ctrl_fill_dl_queue(mqcdev);
- if (ret) {
- dev_err(dev, "Error filling download queue.\n");
- goto mhi_unprepare;
- }
- }
- mqcdev->open_count++;
- mutex_unlock(&mqcdev->lock);
-
- return 0;
-
-mhi_unprepare:
- mhi_unprepare_from_transfer(mqcdev->mhi_dev);
-release_dev_lock:
- mutex_unlock(&mqcdev->lock);
- return ret;
-}
-
-static struct mqc_dev *mqc_dev_get_by_minor(unsigned int minor)
-{
- struct mqc_dev *mqcdev;
-
- xa_lock(&mqc_xa);
- mqcdev = xa_load(&mqc_xa, minor);
- if (mqcdev)
- kref_get(&mqcdev->ref_count);
- xa_unlock(&mqc_xa);
-
- return mqcdev;
-}
-
-static int mhi_qaic_ctrl_open(struct inode *inode, struct file *filp)
-{
- struct mqc_dev *mqcdev;
- int ret;
-
- mqcdev = mqc_dev_get_by_minor(iminor(inode));
- if (!mqcdev) {
- pr_debug("mqc: minor %d not found\n", iminor(inode));
- return -EINVAL;
- }
-
- ret = mhi_qaic_ctrl_dev_start_chan(mqcdev);
- if (ret) {
- kref_put(&mqcdev->ref_count, mqc_dev_release);
- return ret;
- }
-
- filp->private_data = mqcdev;
-
- return 0;
-}
-
-static void mhi_qaic_ctrl_buf_free(struct mqc_buf *ctrlbuf)
-{
- list_del(&ctrlbuf->node);
- kfree(ctrlbuf->odata);
-}
-
-static void __mhi_qaic_ctrl_release(struct mqc_dev *mqcdev)
-{
- struct mqc_buf *ctrlbuf, *tmp;
-
- mhi_unprepare_from_transfer(mqcdev->mhi_dev);
- wake_up_interruptible(&mqcdev->ul_wq);
- wake_up_interruptible(&mqcdev->dl_wq);
- /*
- * Free the dl_queue. As we have already unprepared mhi transfers, we
- * do not expect any callback functions that update dl_queue hence no need
- * to grab dl_queue lock.
- */
- mutex_lock(&mqcdev->read_lock);
- list_for_each_entry_safe(ctrlbuf, tmp, &mqcdev->dl_queue, node)
- mhi_qaic_ctrl_buf_free(ctrlbuf);
- mutex_unlock(&mqcdev->read_lock);
-}
-
-static int mhi_qaic_ctrl_release(struct inode *inode, struct file *file)
-{
- struct mqc_dev *mqcdev = file->private_data;
-
- mutex_lock(&mqcdev->lock);
- mqcdev->open_count--;
- if (!mqcdev->open_count && mqcdev->enabled)
- __mhi_qaic_ctrl_release(mqcdev);
- mutex_unlock(&mqcdev->lock);
-
- kref_put(&mqcdev->ref_count, mqc_dev_release);
-
- return 0;
-}
-
-static __poll_t mhi_qaic_ctrl_poll(struct file *file, poll_table *wait)
-{
- struct mqc_dev *mqcdev = file->private_data;
- struct mhi_device *mhi_dev;
- __poll_t mask = 0;
-
- mhi_dev = mqcdev->mhi_dev;
-
- poll_wait(file, &mqcdev->ul_wq, wait);
- poll_wait(file, &mqcdev->dl_wq, wait);
-
- mutex_lock(&mqcdev->lock);
- if (!mqcdev->enabled) {
- mutex_unlock(&mqcdev->lock);
- return EPOLLERR;
- }
-
- spin_lock_bh(&mqcdev->dl_queue_lock);
- if (!list_empty(&mqcdev->dl_queue))
- mask |= EPOLLIN | EPOLLRDNORM;
- spin_unlock_bh(&mqcdev->dl_queue_lock);
-
- if (mutex_lock_interruptible(&mqcdev->write_lock)) {
- mutex_unlock(&mqcdev->lock);
- return EPOLLERR;
- }
- if (mhi_get_free_desc_count(mhi_dev, DMA_TO_DEVICE) > 0)
- mask |= EPOLLOUT | EPOLLWRNORM;
- mutex_unlock(&mqcdev->write_lock);
- mutex_unlock(&mqcdev->lock);
-
- dev_dbg(&mhi_dev->dev, "Client attempted to poll, returning mask 0x%x\n", mask);
-
- return mask;
-}
-
-static int mhi_qaic_ctrl_tx(struct mqc_dev *mqcdev)
-{
- int ret;
-
- ret = wait_event_interruptible(mqcdev->ul_wq, !mqcdev->enabled ||
- mhi_get_free_desc_count(mqcdev->mhi_dev, DMA_TO_DEVICE) > 0);
-
- if (!mqcdev->enabled)
- return -ENODEV;
-
- return ret;
-}
-
-static ssize_t mhi_qaic_ctrl_write(struct file *file, const char __user *buf, size_t count,
- loff_t *offp)
-{
- struct mqc_dev *mqcdev = file->private_data;
- struct mhi_device *mhi_dev;
- size_t bytes_xfered = 0;
- struct device *dev;
- int ret, nr_desc;
-
- mhi_dev = mqcdev->mhi_dev;
- dev = &mhi_dev->dev;
-
- if (!mhi_dev->ul_chan)
- return -EOPNOTSUPP;
-
- if (!buf || !count)
- return -EINVAL;
-
- dev_dbg(dev, "Request to transfer %zu bytes\n", count);
-
- ret = mhi_qaic_ctrl_tx(mqcdev);
- if (ret)
- return ret;
-
- if (mutex_lock_interruptible(&mqcdev->write_lock))
- return -EINTR;
-
- nr_desc = mhi_get_free_desc_count(mhi_dev, DMA_TO_DEVICE);
- if (nr_desc * mqcdev->mtu < count) {
- ret = -EMSGSIZE;
- dev_dbg(dev, "Buffer too big to transfer\n");
- goto unlock_mutex;
- }
-
- while (count != bytes_xfered) {
- enum mhi_flags flags;
- size_t to_copy;
- void *kbuf;
-
- to_copy = min_t(size_t, count - bytes_xfered, mqcdev->mtu);
- kbuf = kmalloc(to_copy, GFP_KERNEL);
- if (!kbuf) {
- ret = -ENOMEM;
- goto unlock_mutex;
- }
-
- ret = copy_from_user(kbuf, buf + bytes_xfered, to_copy);
- if (ret) {
- kfree(kbuf);
- ret = -EFAULT;
- goto unlock_mutex;
- }
-
- if (bytes_xfered + to_copy == count)
- flags = MHI_EOT;
- else
- flags = MHI_CHAIN;
-
- ret = mhi_queue_buf(mhi_dev, DMA_TO_DEVICE, kbuf, to_copy, flags);
- if (ret) {
- kfree(kbuf);
- dev_err(dev, "Failed to queue buf of size %zu\n", to_copy);
- goto unlock_mutex;
- }
-
- bytes_xfered += to_copy;
- }
-
- mutex_unlock(&mqcdev->write_lock);
- dev_dbg(dev, "bytes xferred: %zu\n", bytes_xfered);
-
- return bytes_xfered;
-
-unlock_mutex:
- mutex_unlock(&mqcdev->write_lock);
- return ret;
-}
-
-static int mhi_qaic_ctrl_rx(struct mqc_dev *mqcdev)
-{
- int ret;
-
- ret = wait_event_interruptible(mqcdev->dl_wq,
- !mqcdev->enabled || !list_empty(&mqcdev->dl_queue));
-
- if (!mqcdev->enabled)
- return -ENODEV;
-
- return ret;
-}
-
-static ssize_t mhi_qaic_ctrl_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
-{
- struct mqc_dev *mqcdev = file->private_data;
- struct mqc_buf *ctrlbuf;
- size_t to_copy;
- int ret;
-
- if (!mqcdev->mhi_dev->dl_chan)
- return -EOPNOTSUPP;
-
- ret = mhi_qaic_ctrl_rx(mqcdev);
- if (ret)
- return ret;
-
- if (mutex_lock_interruptible(&mqcdev->read_lock))
- return -EINTR;
-
- ctrlbuf = list_first_entry_or_null(&mqcdev->dl_queue, struct mqc_buf, node);
- if (!ctrlbuf) {
- mutex_unlock(&mqcdev->read_lock);
- ret = -ENODEV;
- goto error_out;
- }
-
- to_copy = min_t(size_t, count, ctrlbuf->len);
- if (copy_to_user(buf, ctrlbuf->data, to_copy)) {
- mutex_unlock(&mqcdev->read_lock);
- dev_dbg(&mqcdev->mhi_dev->dev, "Failed to copy data to user buffer\n");
- ret = -EFAULT;
- goto error_out;
- }
-
- ctrlbuf->len -= to_copy;
- ctrlbuf->data += to_copy;
-
- if (!ctrlbuf->len) {
- spin_lock_bh(&mqcdev->dl_queue_lock);
- mhi_qaic_ctrl_buf_free(ctrlbuf);
- spin_unlock_bh(&mqcdev->dl_queue_lock);
- mhi_qaic_ctrl_fill_dl_queue(mqcdev);
- dev_dbg(&mqcdev->mhi_dev->dev, "Read buf freed\n");
- }
-
- mutex_unlock(&mqcdev->read_lock);
- return to_copy;
-
-error_out:
- mutex_unlock(&mqcdev->read_lock);
- return ret;
-}
-
-static const struct file_operations mhidev_fops = {
- .owner = THIS_MODULE,
- .open = mhi_qaic_ctrl_open,
- .release = mhi_qaic_ctrl_release,
- .read = mhi_qaic_ctrl_read,
- .write = mhi_qaic_ctrl_write,
- .poll = mhi_qaic_ctrl_poll,
-};
-
-static void mhi_qaic_ctrl_ul_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result)
-{
- struct mqc_dev *mqcdev = dev_get_drvdata(&mhi_dev->dev);
-
- dev_dbg(&mhi_dev->dev, "%s: status: %d xfer_len: %zu\n", __func__,
- mhi_result->transaction_status, mhi_result->bytes_xferd);
-
- kfree(mhi_result->buf_addr);
-
- if (!mhi_result->transaction_status)
- wake_up_interruptible(&mqcdev->ul_wq);
-}
-
-static void mhi_qaic_ctrl_dl_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result)
-{
- struct mqc_dev *mqcdev = dev_get_drvdata(&mhi_dev->dev);
- struct mqc_buf *ctrlbuf;
-
- dev_dbg(&mhi_dev->dev, "%s: status: %d receive_len: %zu\n", __func__,
- mhi_result->transaction_status, mhi_result->bytes_xferd);
-
- if (mhi_result->transaction_status &&
- mhi_result->transaction_status != -EOVERFLOW) {
- kfree(mhi_result->buf_addr);
- return;
- }
-
- ctrlbuf = mhi_result->buf_addr + mqcdev->mtu;
- ctrlbuf->data = mhi_result->buf_addr;
- ctrlbuf->len = mhi_result->bytes_xferd;
- spin_lock_bh(&mqcdev->dl_queue_lock);
- list_add_tail(&ctrlbuf->node, &mqcdev->dl_queue);
- spin_unlock_bh(&mqcdev->dl_queue_lock);
-
- wake_up_interruptible(&mqcdev->dl_wq);
-}
-
-static int mhi_qaic_ctrl_probe(struct mhi_device *mhi_dev, const struct mhi_device_id *id)
-{
- struct mqc_dev *mqcdev;
- struct device *dev;
- int ret;
-
- mqcdev = kzalloc(sizeof(*mqcdev), GFP_KERNEL);
- if (!mqcdev)
- return -ENOMEM;
-
- kref_init(&mqcdev->ref_count);
- mutex_init(&mqcdev->lock);
- mqcdev->mhi_dev = mhi_dev;
-
- ret = xa_alloc(&mqc_xa, &mqcdev->minor, mqcdev, XA_LIMIT(0, MHI_QAIC_CTRL_MAX_MINORS),
- GFP_KERNEL);
- if (ret) {
- kfree(mqcdev);
- return ret;
- }
-
- init_waitqueue_head(&mqcdev->ul_wq);
- init_waitqueue_head(&mqcdev->dl_wq);
- mutex_init(&mqcdev->read_lock);
- mutex_init(&mqcdev->write_lock);
- spin_lock_init(&mqcdev->dl_queue_lock);
- INIT_LIST_HEAD(&mqcdev->dl_queue);
- mqcdev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
- mqcdev->enabled = true;
- mqcdev->open_count = 0;
- dev_set_drvdata(&mhi_dev->dev, mqcdev);
-
- dev = device_create(mqc_dev_class, &mhi_dev->dev, MKDEV(mqc_dev_major, mqcdev->minor),
- mqcdev, "%s", dev_name(&mhi_dev->dev));
- if (IS_ERR(dev)) {
- xa_erase(&mqc_xa, mqcdev->minor);
- dev_set_drvdata(&mhi_dev->dev, NULL);
- kfree(mqcdev);
- return PTR_ERR(dev);
- }
-
- return 0;
-};
-
-static void mhi_qaic_ctrl_remove(struct mhi_device *mhi_dev)
-{
- struct mqc_dev *mqcdev = dev_get_drvdata(&mhi_dev->dev);
-
- device_destroy(mqc_dev_class, MKDEV(mqc_dev_major, mqcdev->minor));
-
- mutex_lock(&mqcdev->lock);
- mqcdev->enabled = false;
- if (mqcdev->open_count)
- __mhi_qaic_ctrl_release(mqcdev);
- mutex_unlock(&mqcdev->lock);
-
- xa_erase(&mqc_xa, mqcdev->minor);
- kref_put(&mqcdev->ref_count, mqc_dev_release);
-}
-
-/* .driver_data stores max mtu */
-static const struct mhi_device_id mhi_qaic_ctrl_match_table[] = {
- { .chan = "QAIC_SAHARA", .driver_data = SZ_32K},
- {},
-};
-MODULE_DEVICE_TABLE(mhi, mhi_qaic_ctrl_match_table);
-
-static struct mhi_driver mhi_qaic_ctrl_driver = {
- .id_table = mhi_qaic_ctrl_match_table,
- .remove = mhi_qaic_ctrl_remove,
- .probe = mhi_qaic_ctrl_probe,
- .ul_xfer_cb = mhi_qaic_ctrl_ul_xfer_cb,
- .dl_xfer_cb = mhi_qaic_ctrl_dl_xfer_cb,
- .driver = {
- .name = MHI_QAIC_CTRL_DRIVER_NAME,
- },
-};
-
-int mhi_qaic_ctrl_init(void)
-{
- int ret;
-
- ret = register_chrdev(0, MHI_QAIC_CTRL_DRIVER_NAME, &mhidev_fops);
- if (ret < 0)
- return ret;
-
- mqc_dev_major = ret;
- mqc_dev_class = class_create(THIS_MODULE, MHI_QAIC_CTRL_DRIVER_NAME);
- if (IS_ERR(mqc_dev_class)) {
- ret = PTR_ERR(mqc_dev_class);
- goto unregister_chrdev;
- }
-
- ret = mhi_driver_register(&mhi_qaic_ctrl_driver);
- if (ret)
- goto destroy_class;
-
- return 0;
-
-destroy_class:
- class_destroy(mqc_dev_class);
-unregister_chrdev:
- unregister_chrdev(mqc_dev_major, MHI_QAIC_CTRL_DRIVER_NAME);
- return ret;
-}
-
-void mhi_qaic_ctrl_deinit(void)
-{
- mhi_driver_unregister(&mhi_qaic_ctrl_driver);
- class_destroy(mqc_dev_class);
- unregister_chrdev(mqc_dev_major, MHI_QAIC_CTRL_DRIVER_NAME);
- xa_destroy(&mqc_xa);
-}
projects / platform / kernel / linux-rpi.git / commitdiff