diff options
Diffstat (limited to 'drivers/most/core.c')
| -rw-r--r-- | drivers/most/core.c | 1488 |
1 files changed, 1488 insertions, 0 deletions
diff --git a/drivers/most/core.c b/drivers/most/core.c new file mode 100644 index 000000000..e4412c7d2 --- /dev/null +++ b/drivers/most/core.c @@ -0,0 +1,1488 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * core.c - Implementation of core module of MOST Linux driver stack + * + * Copyright (C) 2013-2020 Microchip Technology Germany II GmbH & Co. KG + */ + +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/list.h> +#include <linux/poll.h> +#include <linux/wait.h> +#include <linux/kobject.h> +#include <linux/mutex.h> +#include <linux/completion.h> +#include <linux/sysfs.h> +#include <linux/kthread.h> +#include <linux/dma-mapping.h> +#include <linux/idr.h> +#include <linux/most.h> + +#define MAX_CHANNELS 64 +#define STRING_SIZE 80 + +static struct ida mdev_id; +static int dummy_num_buffers; +static struct list_head comp_list; + +struct pipe { + struct most_component *comp; + int refs; + int num_buffers; +}; + +struct most_channel { + struct device dev; + struct completion cleanup; + atomic_t mbo_ref; + atomic_t mbo_nq_level; + u16 channel_id; + char name[STRING_SIZE]; + bool is_poisoned; + struct mutex start_mutex; /* channel activation synchronization */ + struct mutex nq_mutex; /* nq thread synchronization */ + int is_starving; + struct most_interface *iface; + struct most_channel_config cfg; + bool keep_mbo; + bool enqueue_halt; + struct list_head fifo; + spinlock_t fifo_lock; /* fifo access synchronization */ + struct list_head halt_fifo; + struct list_head list; + struct pipe pipe0; + struct pipe pipe1; + struct list_head trash_fifo; + struct task_struct *hdm_enqueue_task; + wait_queue_head_t hdm_fifo_wq; + +}; + +#define to_channel(d) container_of(d, struct most_channel, dev) + +struct interface_private { + int dev_id; + char name[STRING_SIZE]; + struct most_channel *channel[MAX_CHANNELS]; + struct list_head channel_list; +}; + +static const struct { + int most_ch_data_type; + const char *name; +} ch_data_type[] = { + { MOST_CH_CONTROL, "control" }, + { MOST_CH_ASYNC, "async" }, + { MOST_CH_SYNC, "sync" }, + { MOST_CH_ISOC, "isoc"}, + { MOST_CH_ISOC, "isoc_avp"}, +}; + +/** + * list_pop_mbo - retrieves the first MBO of the list and removes it + * @ptr: the list head to grab the MBO from. + */ +#define list_pop_mbo(ptr) \ +({ \ + struct mbo *_mbo = list_first_entry(ptr, struct mbo, list); \ + list_del(&_mbo->list); \ + _mbo; \ +}) + +/** + * most_free_mbo_coherent - free an MBO and its coherent buffer + * @mbo: most buffer + */ +static void most_free_mbo_coherent(struct mbo *mbo) +{ + struct most_channel *c = mbo->context; + u16 const coherent_buf_size = c->cfg.buffer_size + c->cfg.extra_len; + + if (c->iface->dma_free) + c->iface->dma_free(mbo, coherent_buf_size); + else + kfree(mbo->virt_address); + kfree(mbo); + if (atomic_sub_and_test(1, &c->mbo_ref)) + complete(&c->cleanup); +} + +/** + * flush_channel_fifos - clear the channel fifos + * @c: pointer to channel object + */ +static void flush_channel_fifos(struct most_channel *c) +{ + unsigned long flags, hf_flags; + struct mbo *mbo, *tmp; + + if (list_empty(&c->fifo) && list_empty(&c->halt_fifo)) + return; + + spin_lock_irqsave(&c->fifo_lock, flags); + list_for_each_entry_safe(mbo, tmp, &c->fifo, list) { + list_del(&mbo->list); + spin_unlock_irqrestore(&c->fifo_lock, flags); + most_free_mbo_coherent(mbo); + spin_lock_irqsave(&c->fifo_lock, flags); + } + spin_unlock_irqrestore(&c->fifo_lock, flags); + + spin_lock_irqsave(&c->fifo_lock, hf_flags); + list_for_each_entry_safe(mbo, tmp, &c->halt_fifo, list) { + list_del(&mbo->list); + spin_unlock_irqrestore(&c->fifo_lock, hf_flags); + most_free_mbo_coherent(mbo); + spin_lock_irqsave(&c->fifo_lock, hf_flags); + } + spin_unlock_irqrestore(&c->fifo_lock, hf_flags); + + if (unlikely((!list_empty(&c->fifo) || !list_empty(&c->halt_fifo)))) + dev_warn(&c->dev, "Channel or trash fifo not empty\n"); +} + +/** + * flush_trash_fifo - clear the trash fifo + * @c: pointer to channel object + */ +static int flush_trash_fifo(struct most_channel *c) +{ + struct mbo *mbo, *tmp; + unsigned long flags; + + spin_lock_irqsave(&c->fifo_lock, flags); + list_for_each_entry_safe(mbo, tmp, &c->trash_fifo, list) { + list_del(&mbo->list); + spin_unlock_irqrestore(&c->fifo_lock, flags); + most_free_mbo_coherent(mbo); + spin_lock_irqsave(&c->fifo_lock, flags); + } + spin_unlock_irqrestore(&c->fifo_lock, flags); + return 0; +} + +static ssize_t available_directions_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + unsigned int i = c->channel_id; + + strcpy(buf, ""); + if (c->iface->channel_vector[i].direction & MOST_CH_RX) + strcat(buf, "rx "); + if (c->iface->channel_vector[i].direction & MOST_CH_TX) + strcat(buf, "tx "); + strcat(buf, "\n"); + return strlen(buf); +} + +static ssize_t available_datatypes_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + unsigned int i = c->channel_id; + + strcpy(buf, ""); + if (c->iface->channel_vector[i].data_type & MOST_CH_CONTROL) + strcat(buf, "control "); + if (c->iface->channel_vector[i].data_type & MOST_CH_ASYNC) + strcat(buf, "async "); + if (c->iface->channel_vector[i].data_type & MOST_CH_SYNC) + strcat(buf, "sync "); + if (c->iface->channel_vector[i].data_type & MOST_CH_ISOC) + strcat(buf, "isoc "); + strcat(buf, "\n"); + return strlen(buf); +} + +static ssize_t number_of_packet_buffers_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + unsigned int i = c->channel_id; + + return snprintf(buf, PAGE_SIZE, "%d\n", + c->iface->channel_vector[i].num_buffers_packet); +} + +static ssize_t number_of_stream_buffers_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + unsigned int i = c->channel_id; + + return snprintf(buf, PAGE_SIZE, "%d\n", + c->iface->channel_vector[i].num_buffers_streaming); +} + +static ssize_t size_of_packet_buffer_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + unsigned int i = c->channel_id; + + return snprintf(buf, PAGE_SIZE, "%d\n", + c->iface->channel_vector[i].buffer_size_packet); +} + +static ssize_t size_of_stream_buffer_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + unsigned int i = c->channel_id; + + return snprintf(buf, PAGE_SIZE, "%d\n", + c->iface->channel_vector[i].buffer_size_streaming); +} + +static ssize_t channel_starving_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", c->is_starving); +} + +static ssize_t set_number_of_buffers_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.num_buffers); +} + +static ssize_t set_buffer_size_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.buffer_size); +} + +static ssize_t set_direction_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + + if (c->cfg.direction & MOST_CH_TX) + return snprintf(buf, PAGE_SIZE, "tx\n"); + else if (c->cfg.direction & MOST_CH_RX) + return snprintf(buf, PAGE_SIZE, "rx\n"); + return snprintf(buf, PAGE_SIZE, "unconfigured\n"); +} + +static ssize_t set_datatype_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int i; + struct most_channel *c = to_channel(dev); + + for (i = 0; i < ARRAY_SIZE(ch_data_type); i++) { + if (c->cfg.data_type & ch_data_type[i].most_ch_data_type) + return snprintf(buf, PAGE_SIZE, "%s", + ch_data_type[i].name); + } + return snprintf(buf, PAGE_SIZE, "unconfigured\n"); +} + +static ssize_t set_subbuffer_size_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.subbuffer_size); +} + +static ssize_t set_packets_per_xact_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_channel *c = to_channel(dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.packets_per_xact); +} + +static ssize_t set_dbr_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct most_channel *c = to_channel(dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.dbr_size); +} + +#define to_dev_attr(a) container_of(a, struct device_attribute, attr) +static umode_t channel_attr_is_visible(struct kobject *kobj, + struct attribute *attr, int index) +{ + struct device_attribute *dev_attr = to_dev_attr(attr); + struct device *dev = kobj_to_dev(kobj); + struct most_channel *c = to_channel(dev); + + if (!strcmp(dev_attr->attr.name, "set_dbr_size") && + (c->iface->interface != ITYPE_MEDIALB_DIM2)) + return 0; + if (!strcmp(dev_attr->attr.name, "set_packets_per_xact") && + (c->iface->interface != ITYPE_USB)) + return 0; + + return attr->mode; +} + +#define DEV_ATTR(_name) (&dev_attr_##_name.attr) + +static DEVICE_ATTR_RO(available_directions); +static DEVICE_ATTR_RO(available_datatypes); +static DEVICE_ATTR_RO(number_of_packet_buffers); +static DEVICE_ATTR_RO(number_of_stream_buffers); +static DEVICE_ATTR_RO(size_of_stream_buffer); +static DEVICE_ATTR_RO(size_of_packet_buffer); +static DEVICE_ATTR_RO(channel_starving); +static DEVICE_ATTR_RO(set_buffer_size); +static DEVICE_ATTR_RO(set_number_of_buffers); +static DEVICE_ATTR_RO(set_direction); +static DEVICE_ATTR_RO(set_datatype); +static DEVICE_ATTR_RO(set_subbuffer_size); +static DEVICE_ATTR_RO(set_packets_per_xact); +static DEVICE_ATTR_RO(set_dbr_size); + +static struct attribute *channel_attrs[] = { + DEV_ATTR(available_directions), + DEV_ATTR(available_datatypes), + DEV_ATTR(number_of_packet_buffers), + DEV_ATTR(number_of_stream_buffers), + DEV_ATTR(size_of_stream_buffer), + DEV_ATTR(size_of_packet_buffer), + DEV_ATTR(channel_starving), + DEV_ATTR(set_buffer_size), + DEV_ATTR(set_number_of_buffers), + DEV_ATTR(set_direction), + DEV_ATTR(set_datatype), + DEV_ATTR(set_subbuffer_size), + DEV_ATTR(set_packets_per_xact), + DEV_ATTR(set_dbr_size), + NULL, +}; + +static const struct attribute_group channel_attr_group = { + .attrs = channel_attrs, + .is_visible = channel_attr_is_visible, +}; + +static const struct attribute_group *channel_attr_groups[] = { + &channel_attr_group, + NULL, +}; + +static ssize_t description_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_interface *iface = dev_get_drvdata(dev); + + return snprintf(buf, PAGE_SIZE, "%s\n", iface->description); +} + +static ssize_t interface_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct most_interface *iface = dev_get_drvdata(dev); + + switch (iface->interface) { + case ITYPE_LOOPBACK: + return snprintf(buf, PAGE_SIZE, "loopback\n"); + case ITYPE_I2C: + return snprintf(buf, PAGE_SIZE, "i2c\n"); + case ITYPE_I2S: + return snprintf(buf, PAGE_SIZE, "i2s\n"); + case ITYPE_TSI: + return snprintf(buf, PAGE_SIZE, "tsi\n"); + case ITYPE_HBI: + return snprintf(buf, PAGE_SIZE, "hbi\n"); + case ITYPE_MEDIALB_DIM: + return snprintf(buf, PAGE_SIZE, "mlb_dim\n"); + case ITYPE_MEDIALB_DIM2: + return snprintf(buf, PAGE_SIZE, "mlb_dim2\n"); + case ITYPE_USB: + return snprintf(buf, PAGE_SIZE, "usb\n"); + case ITYPE_PCIE: + return snprintf(buf, PAGE_SIZE, "pcie\n"); + } + return snprintf(buf, PAGE_SIZE, "unknown\n"); +} + +static DEVICE_ATTR_RO(description); +static DEVICE_ATTR_RO(interface); + +static struct attribute *interface_attrs[] = { + DEV_ATTR(description), + DEV_ATTR(interface), + NULL, +}; + +static const struct attribute_group interface_attr_group = { + .attrs = interface_attrs, +}; + +static const struct attribute_group *interface_attr_groups[] = { + &interface_attr_group, + NULL, +}; + +static struct most_component *match_component(char *name) +{ + struct most_component *comp; + + list_for_each_entry(comp, &comp_list, list) { + if (!strcmp(comp->name, name)) + return comp; + } + return NULL; +} + +struct show_links_data { + int offs; + char *buf; +}; + +static int print_links(struct device *dev, void *data) +{ + struct show_links_data *d = data; + int offs = d->offs; + char *buf = d->buf; + struct most_channel *c; + struct most_interface *iface = dev_get_drvdata(dev); + + list_for_each_entry(c, &iface->p->channel_list, list) { + if (c->pipe0.comp) { + offs += scnprintf(buf + offs, + PAGE_SIZE - offs, + "%s:%s:%s\n", + c->pipe0.comp->name, + dev_name(iface->dev), + dev_name(&c->dev)); + } + if (c->pipe1.comp) { + offs += scnprintf(buf + offs, + PAGE_SIZE - offs, + "%s:%s:%s\n", + c->pipe1.comp->name, + dev_name(iface->dev), + dev_name(&c->dev)); + } + } + d->offs = offs; + return 0; +} + +static int most_match(struct device *dev, struct device_driver *drv) +{ + if (!strcmp(dev_name(dev), "most")) + return 0; + else + return 1; +} + +static struct bus_type mostbus = { + .name = "most", + .match = most_match, +}; + +static ssize_t links_show(struct device_driver *drv, char *buf) +{ + struct show_links_data d = { .buf = buf }; + + bus_for_each_dev(&mostbus, NULL, &d, print_links); + return d.offs; +} + +static ssize_t components_show(struct device_driver *drv, char *buf) +{ + struct most_component *comp; + int offs = 0; + + list_for_each_entry(comp, &comp_list, list) { + offs += scnprintf(buf + offs, PAGE_SIZE - offs, "%s\n", + comp->name); + } + return offs; +} + +/** + * get_channel - get pointer to channel + * @mdev: name of the device interface + * @mdev_ch: name of channel + */ +static struct most_channel *get_channel(char *mdev, char *mdev_ch) +{ + struct device *dev = NULL; + struct most_interface *iface; + struct most_channel *c, *tmp; + + dev = bus_find_device_by_name(&mostbus, NULL, mdev); + if (!dev) + return NULL; + put_device(dev); + iface = dev_get_drvdata(dev); + list_for_each_entry_safe(c, tmp, &iface->p->channel_list, list) { + if (!strcmp(dev_name(&c->dev), mdev_ch)) + return c; + } + return NULL; +} + +static +inline int link_channel_to_component(struct most_channel *c, + struct most_component *comp, + char *name, + char *comp_param) +{ + int ret; + struct most_component **comp_ptr; + + if (!c->pipe0.comp) + comp_ptr = &c->pipe0.comp; + else if (!c->pipe1.comp) + comp_ptr = &c->pipe1.comp; + else + return -ENOSPC; + + *comp_ptr = comp; + ret = comp->probe_channel(c->iface, c->channel_id, &c->cfg, name, + comp_param); + if (ret) { + *comp_ptr = NULL; + return ret; + } + return 0; +} + +int most_set_cfg_buffer_size(char *mdev, char *mdev_ch, u16 val) +{ + struct most_channel *c = get_channel(mdev, mdev_ch); + + if (!c) + return -ENODEV; + c->cfg.buffer_size = val; + return 0; +} + +int most_set_cfg_subbuffer_size(char *mdev, char *mdev_ch, u16 val) +{ + struct most_channel *c = get_channel(mdev, mdev_ch); + + if (!c) + return -ENODEV; + c->cfg.subbuffer_size = val; + return 0; +} + +int most_set_cfg_dbr_size(char *mdev, char *mdev_ch, u16 val) +{ + struct most_channel *c = get_channel(mdev, mdev_ch); + + if (!c) + return -ENODEV; + c->cfg.dbr_size = val; + return 0; +} + +int most_set_cfg_num_buffers(char *mdev, char *mdev_ch, u16 val) +{ + struct most_channel *c = get_channel(mdev, mdev_ch); + + if (!c) + return -ENODEV; + c->cfg.num_buffers = val; + return 0; +} + +int most_set_cfg_datatype(char *mdev, char *mdev_ch, char *buf) +{ + int i; + struct most_channel *c = get_channel(mdev, mdev_ch); + + if (!c) + return -ENODEV; + for (i = 0; i < ARRAY_SIZE(ch_data_type); i++) { + if (!strcmp(buf, ch_data_type[i].name)) { + c->cfg.data_type = ch_data_type[i].most_ch_data_type; + break; + } + } + + if (i == ARRAY_SIZE(ch_data_type)) + dev_warn(&c->dev, "Invalid attribute settings\n"); + return 0; +} + +int most_set_cfg_direction(char *mdev, char *mdev_ch, char *buf) +{ + struct most_channel *c = get_channel(mdev, mdev_ch); + + if (!c) + return -ENODEV; + if (!strcmp(buf, "dir_rx")) { + c->cfg.direction = MOST_CH_RX; + } else if (!strcmp(buf, "rx")) { + c->cfg.direction = MOST_CH_RX; + } else if (!strcmp(buf, "dir_tx")) { + c->cfg.direction = MOST_CH_TX; + } else if (!strcmp(buf, "tx")) { + c->cfg.direction = MOST_CH_TX; + } else { + dev_err(&c->dev, "Invalid direction\n"); + return -ENODATA; + } + return 0; +} + +int most_set_cfg_packets_xact(char *mdev, char *mdev_ch, u16 val) +{ + struct most_channel *c = get_channel(mdev, mdev_ch); + + if (!c) + return -ENODEV; + c->cfg.packets_per_xact = val; + return 0; +} + +int most_cfg_complete(char *comp_name) +{ + struct most_component *comp; + + comp = match_component(comp_name); + if (!comp) + return -ENODEV; + + return comp->cfg_complete(); +} + +int most_add_link(char *mdev, char *mdev_ch, char *comp_name, char *link_name, + char *comp_param) +{ + struct most_channel *c = get_channel(mdev, mdev_ch); + struct most_component *comp = match_component(comp_name); + + if (!c || !comp) + return -ENODEV; + + return link_channel_to_component(c, comp, link_name, comp_param); +} + +int most_remove_link(char *mdev, char *mdev_ch, char *comp_name) +{ + struct most_channel *c; + struct most_component *comp; + + comp = match_component(comp_name); + if (!comp) + return -ENODEV; + c = get_channel(mdev, mdev_ch); + if (!c) + return -ENODEV; + + if (comp->disconnect_channel(c->iface, c->channel_id)) + return -EIO; + if (c->pipe0.comp == comp) + c->pipe0.comp = NULL; + if (c->pipe1.comp == comp) + c->pipe1.comp = NULL; + return 0; +} + +#define DRV_ATTR(_name) (&driver_attr_##_name.attr) + +static DRIVER_ATTR_RO(links); +static DRIVER_ATTR_RO(components); + +static struct attribute *mc_attrs[] = { + DRV_ATTR(links), + DRV_ATTR(components), + NULL, +}; + +static const struct attribute_group mc_attr_group = { + .attrs = mc_attrs, +}; + +static const struct attribute_group *mc_attr_groups[] = { + &mc_attr_group, + NULL, +}; + +static struct device_driver mostbus_driver = { + .name = "most_core", + .bus = &mostbus, + .groups = mc_attr_groups, +}; + +static inline void trash_mbo(struct mbo *mbo) +{ + unsigned long flags; + struct most_channel *c = mbo->context; + + spin_lock_irqsave(&c->fifo_lock, flags); + list_add(&mbo->list, &c->trash_fifo); + spin_unlock_irqrestore(&c->fifo_lock, flags); +} + +static bool hdm_mbo_ready(struct most_channel *c) +{ + bool empty; + + if (c->enqueue_halt) + return false; + + spin_lock_irq(&c->fifo_lock); + empty = list_empty(&c->halt_fifo); + spin_unlock_irq(&c->fifo_lock); + + return !empty; +} + +static void nq_hdm_mbo(struct mbo *mbo) +{ + unsigned long flags; + struct most_channel *c = mbo->context; + + spin_lock_irqsave(&c->fifo_lock, flags); + list_add_tail(&mbo->list, &c->halt_fifo); + spin_unlock_irqrestore(&c->fifo_lock, flags); + wake_up_interruptible(&c->hdm_fifo_wq); +} + +static int hdm_enqueue_thread(void *data) +{ + struct most_channel *c = data; + struct mbo *mbo; + int ret; + typeof(c->iface->enqueue) enqueue = c->iface->enqueue; + + while (likely(!kthread_should_stop())) { + wait_event_interruptible(c->hdm_fifo_wq, + hdm_mbo_ready(c) || + kthread_should_stop()); + + mutex_lock(&c->nq_mutex); + spin_lock_irq(&c->fifo_lock); + if (unlikely(c->enqueue_halt || list_empty(&c->halt_fifo))) { + spin_unlock_irq(&c->fifo_lock); + mutex_unlock(&c->nq_mutex); + continue; + } + + mbo = list_pop_mbo(&c->halt_fifo); + spin_unlock_irq(&c->fifo_lock); + + if (c->cfg.direction == MOST_CH_RX) + mbo->buffer_length = c->cfg.buffer_size; + + ret = enqueue(mbo->ifp, mbo->hdm_channel_id, mbo); + mutex_unlock(&c->nq_mutex); + + if (unlikely(ret)) { + dev_err(&c->dev, "Buffer enqueue failed\n"); + nq_hdm_mbo(mbo); + c->hdm_enqueue_task = NULL; + return 0; + } + } + + return 0; +} + +static int run_enqueue_thread(struct most_channel *c, int channel_id) +{ + struct task_struct *task = + kthread_run(hdm_enqueue_thread, c, "hdm_fifo_%d", + channel_id); + + if (IS_ERR(task)) + return PTR_ERR(task); + + c->hdm_enqueue_task = task; + return 0; +} + +/** + * arm_mbo - recycle MBO for further usage + * @mbo: most buffer + * + * This puts an MBO back to the list to have it ready for up coming + * tx transactions. + * + * In case the MBO belongs to a channel that recently has been + * poisoned, the MBO is scheduled to be trashed. + * Calls the completion handler of an attached component. + */ +static void arm_mbo(struct mbo *mbo) +{ + unsigned long flags; + struct most_channel *c; + + c = mbo->context; + + if (c->is_poisoned) { + trash_mbo(mbo); + return; + } + + spin_lock_irqsave(&c->fifo_lock, flags); + ++*mbo->num_buffers_ptr; + list_add_tail(&mbo->list, &c->fifo); + spin_unlock_irqrestore(&c->fifo_lock, flags); + + if (c->pipe0.refs && c->pipe0.comp->tx_completion) + c->pipe0.comp->tx_completion(c->iface, c->channel_id); + + if (c->pipe1.refs && c->pipe1.comp->tx_completion) + c->pipe1.comp->tx_completion(c->iface, c->channel_id); +} + +/** + * arm_mbo_chain - helper function that arms an MBO chain for the HDM + * @c: pointer to interface channel + * @dir: direction of the channel + * @compl: pointer to completion function + * + * This allocates buffer objects including the containing DMA coherent + * buffer and puts them in the fifo. + * Buffers of Rx channels are put in the kthread fifo, hence immediately + * submitted to the HDM. + * + * Returns the number of allocated and enqueued MBOs. + */ +static int arm_mbo_chain(struct most_channel *c, int dir, + void (*compl)(struct mbo *)) +{ + unsigned int i; + struct mbo *mbo; + unsigned long flags; + u32 coherent_buf_size = c->cfg.buffer_size + c->cfg.extra_len; + + atomic_set(&c->mbo_nq_level, 0); + + for (i = 0; i < c->cfg.num_buffers; i++) { + mbo = kzalloc(sizeof(*mbo), GFP_KERNEL); + if (!mbo) + goto flush_fifos; + + mbo->context = c; + mbo->ifp = c->iface; + mbo->hdm_channel_id = c->channel_id; + if (c->iface->dma_alloc) { + mbo->virt_address = + c->iface->dma_alloc(mbo, coherent_buf_size); + } else { + mbo->virt_address = + kzalloc(coherent_buf_size, GFP_KERNEL); + } + if (!mbo->virt_address) + goto release_mbo; + + mbo->complete = compl; + mbo->num_buffers_ptr = &dummy_num_buffers; + if (dir == MOST_CH_RX) { + nq_hdm_mbo(mbo); + atomic_inc(&c->mbo_nq_level); + } else { + spin_lock_irqsave(&c->fifo_lock, flags); + list_add_tail(&mbo->list, &c->fifo); + spin_unlock_irqrestore(&c->fifo_lock, flags); + } + } + return c->cfg.num_buffers; + +release_mbo: + kfree(mbo); + +flush_fifos: + flush_channel_fifos(c); + return 0; +} + +/** + * most_submit_mbo - submits an MBO to fifo + * @mbo: most buffer + */ +void most_submit_mbo(struct mbo *mbo) +{ + if (WARN_ONCE(!mbo || !mbo->context, + "Bad buffer or missing channel reference\n")) + return; + + nq_hdm_mbo(mbo); +} +EXPORT_SYMBOL_GPL(most_submit_mbo); + +/** + * most_write_completion - write completion handler + * @mbo: most buffer + * + * This recycles the MBO for further usage. In case the channel has been + * poisoned, the MBO is scheduled to be trashed. + */ +static void most_write_completion(struct mbo *mbo) +{ + struct most_channel *c; + + c = mbo->context; + if (unlikely(c->is_poisoned || (mbo->status == MBO_E_CLOSE))) + trash_mbo(mbo); + else + arm_mbo(mbo); +} + +int channel_has_mbo(struct most_interface *iface, int id, + struct most_component *comp) +{ + struct most_channel *c = iface->p->channel[id]; + unsigned long flags; + int empty; + + if (unlikely(!c)) + return -EINVAL; + + if (c->pipe0.refs && c->pipe1.refs && + ((comp == c->pipe0.comp && c->pipe0.num_buffers <= 0) || + (comp == c->pipe1.comp && c->pipe1.num_buffers <= 0))) + return 0; + + spin_lock_irqsave(&c->fifo_lock, flags); + empty = list_empty(&c->fifo); + spin_unlock_irqrestore(&c->fifo_lock, flags); + return !empty; +} +EXPORT_SYMBOL_GPL(channel_has_mbo); + +/** + * most_get_mbo - get pointer to an MBO of pool + * @iface: pointer to interface instance + * @id: channel ID + * @comp: driver component + * + * This attempts to get a free buffer out of the channel fifo. + * Returns a pointer to MBO on success or NULL otherwise. + */ +struct mbo *most_get_mbo(struct most_interface *iface, int id, + struct most_component *comp) +{ + struct mbo *mbo; + struct most_channel *c; + unsigned long flags; + int *num_buffers_ptr; + + c = iface->p->channel[id]; + if (unlikely(!c)) + return NULL; + + if (c->pipe0.refs && c->pipe1.refs && + ((comp == c->pipe0.comp && c->pipe0.num_buffers <= 0) || + (comp == c->pipe1.comp && c->pipe1.num_buffers <= 0))) + return NULL; + + if (comp == c->pipe0.comp) + num_buffers_ptr = &c->pipe0.num_buffers; + else if (comp == c->pipe1.comp) + num_buffers_ptr = &c->pipe1.num_buffers; + else + num_buffers_ptr = &dummy_num_buffers; + + spin_lock_irqsave(&c->fifo_lock, flags); + if (list_empty(&c->fifo)) { + spin_unlock_irqrestore(&c->fifo_lock, flags); + return NULL; + } + mbo = list_pop_mbo(&c->fifo); + --*num_buffers_ptr; + spin_unlock_irqrestore(&c->fifo_lock, flags); + + mbo->num_buffers_ptr = num_buffers_ptr; + mbo->buffer_length = c->cfg.buffer_size; + return mbo; +} +EXPORT_SYMBOL_GPL(most_get_mbo); + +/** + * most_put_mbo - return buffer to pool + * @mbo: most buffer + */ +void most_put_mbo(struct mbo *mbo) +{ + struct most_channel *c = mbo->context; + + if (c->cfg.direction == MOST_CH_TX) { + arm_mbo(mbo); + return; + } + nq_hdm_mbo(mbo); + atomic_inc(&c->mbo_nq_level); +} +EXPORT_SYMBOL_GPL(most_put_mbo); + +/** + * most_read_completion - read completion handler + * @mbo: most buffer + * + * This function is called by the HDM when data has been received from the + * hardware and copied to the buffer of the MBO. + * + * In case the channel has been poisoned it puts the buffer in the trash queue. + * Otherwise, it passes the buffer to an component for further processing. + */ +static void most_read_completion(struct mbo *mbo) +{ + struct most_channel *c = mbo->context; + + if (unlikely(c->is_poisoned || (mbo->status == MBO_E_CLOSE))) { + trash_mbo(mbo); + return; + } + + if (mbo->status == MBO_E_INVAL) { + nq_hdm_mbo(mbo); + atomic_inc(&c->mbo_nq_level); + return; + } + + if (atomic_sub_and_test(1, &c->mbo_nq_level)) + c->is_starving = 1; + + if (c->pipe0.refs && c->pipe0.comp->rx_completion && + c->pipe0.comp->rx_completion(mbo) == 0) + return; + + if (c->pipe1.refs && c->pipe1.comp->rx_completion && + c->pipe1.comp->rx_completion(mbo) == 0) + return; + + most_put_mbo(mbo); +} + +/** + * most_start_channel - prepares a channel for communication + * @iface: pointer to interface instance + * @id: channel ID + * @comp: driver component + * + * This prepares the channel for usage. Cross-checks whether the + * channel's been properly configured. + * + * Returns 0 on success or error code otherwise. + */ +int most_start_channel(struct most_interface *iface, int id, + struct most_component *comp) +{ + int num_buffer; + int ret; + struct most_channel *c = iface->p->channel[id]; + + if (unlikely(!c)) + return -EINVAL; + + mutex_lock(&c->start_mutex); + if (c->pipe0.refs + c->pipe1.refs > 0) + goto out; /* already started by another component */ + + if (!try_module_get(iface->mod)) { + dev_err(&c->dev, "Failed to acquire HDM lock\n"); + mutex_unlock(&c->start_mutex); + return -ENOLCK; + } + + c->cfg.extra_len = 0; + if (c->iface->configure(c->iface, c->channel_id, &c->cfg)) { + dev_err(&c->dev, "Channel configuration failed. Go check settings...\n"); + ret = -EINVAL; + goto err_put_module; + } + + init_waitqueue_head(&c->hdm_fifo_wq); + + if (c->cfg.direction == MOST_CH_RX) + num_buffer = arm_mbo_chain(c, c->cfg.direction, + most_read_completion); + else + num_buffer = arm_mbo_chain(c, c->cfg.direction, + most_write_completion); + if (unlikely(!num_buffer)) { + ret = -ENOMEM; + goto err_put_module; + } + + ret = run_enqueue_thread(c, id); + if (ret) + goto err_put_module; + + c->is_starving = 0; + c->pipe0.num_buffers = c->cfg.num_buffers / 2; + c->pipe1.num_buffers = c->cfg.num_buffers - c->pipe0.num_buffers; + atomic_set(&c->mbo_ref, num_buffer); + +out: + if (comp == c->pipe0.comp) + c->pipe0.refs++; + if (comp == c->pipe1.comp) + c->pipe1.refs++; + mutex_unlock(&c->start_mutex); + return 0; + +err_put_module: + module_put(iface->mod); + mutex_unlock(&c->start_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(most_start_channel); + +/** + * most_stop_channel - stops a running channel + * @iface: pointer to interface instance + * @id: channel ID + * @comp: driver component + */ +int most_stop_channel(struct most_interface *iface, int id, + struct most_component *comp) +{ + struct most_channel *c; + + if (unlikely((!iface) || (id >= iface->num_channels) || (id < 0))) { + pr_err("Bad interface or index out of range\n"); + return -EINVAL; + } + c = iface->p->channel[id]; + if (unlikely(!c)) + return -EINVAL; + + mutex_lock(&c->start_mutex); + if (c->pipe0.refs + c->pipe1.refs >= 2) + goto out; + + if (c->hdm_enqueue_task) + kthread_stop(c->hdm_enqueue_task); + c->hdm_enqueue_task = NULL; + + if (iface->mod) + module_put(iface->mod); + + c->is_poisoned = true; + if (c->iface->poison_channel(c->iface, c->channel_id)) { + dev_err(&c->dev, "Failed to stop channel %d of interface %s\n", c->channel_id, + c->iface->description); + mutex_unlock(&c->start_mutex); + return -EAGAIN; + } + flush_trash_fifo(c); + flush_channel_fifos(c); + +#ifdef CMPL_INTERRUPTIBLE + if (wait_for_completion_interruptible(&c->cleanup)) { + dev_err(&c->dev, "Interrupted while cleaning up channel %d\n", c->channel_id); + mutex_unlock(&c->start_mutex); + return -EINTR; + } +#else + wait_for_completion(&c->cleanup); +#endif + c->is_poisoned = false; + +out: + if (comp == c->pipe0.comp) + c->pipe0.refs--; + if (comp == c->pipe1.comp) + c->pipe1.refs--; + mutex_unlock(&c->start_mutex); + return 0; +} +EXPORT_SYMBOL_GPL(most_stop_channel); + +/** + * most_register_component - registers a driver component with the core + * @comp: driver component + */ +int most_register_component(struct most_component *comp) +{ + if (!comp) { + pr_err("Bad component\n"); + return -EINVAL; + } + list_add_tail(&comp->list, &comp_list); + return 0; +} +EXPORT_SYMBOL_GPL(most_register_component); + +static int disconnect_channels(struct device *dev, void *data) +{ + struct most_interface *iface; + struct most_channel *c, *tmp; + struct most_component *comp = data; + + iface = dev_get_drvdata(dev); + list_for_each_entry_safe(c, tmp, &iface->p->channel_list, list) { + if (c->pipe0.comp == comp || c->pipe1.comp == comp) + comp->disconnect_channel(c->iface, c->channel_id); + if (c->pipe0.comp == comp) + c->pipe0.comp = NULL; + if (c->pipe1.comp == comp) + c->pipe1.comp = NULL; + } + return 0; +} + +/** + * most_deregister_component - deregisters a driver component with the core + * @comp: driver component + */ +int most_deregister_component(struct most_component *comp) +{ + if (!comp) { + pr_err("Bad component\n"); + return -EINVAL; + } + + bus_for_each_dev(&mostbus, NULL, comp, disconnect_channels); + list_del(&comp->list); + return 0; +} +EXPORT_SYMBOL_GPL(most_deregister_component); + +static void release_channel(struct device *dev) +{ + struct most_channel *c = to_channel(dev); + + kfree(c); +} + +/** + * most_register_interface - registers an interface with core + * @iface: device interface + * + * Allocates and initializes a new interface instance and all of its channels. + * Returns a pointer to kobject or an error pointer. + */ +int most_register_interface(struct most_interface *iface) +{ + unsigned int i; + int id; + struct most_channel *c; + + if (!iface || !iface->enqueue || !iface->configure || + !iface->poison_channel || (iface->num_channels > MAX_CHANNELS)) + return -EINVAL; + + id = ida_simple_get(&mdev_id, 0, 0, GFP_KERNEL); + if (id < 0) { + dev_err(iface->dev, "Failed to allocate device ID\n"); + return id; + } + + iface->p = kzalloc(sizeof(*iface->p), GFP_KERNEL); + if (!iface->p) { + ida_simple_remove(&mdev_id, id); + return -ENOMEM; + } + + INIT_LIST_HEAD(&iface->p->channel_list); + iface->p->dev_id = id; + strscpy(iface->p->name, iface->description, sizeof(iface->p->name)); + iface->dev->bus = &mostbus; + iface->dev->groups = interface_attr_groups; + dev_set_drvdata(iface->dev, iface); + if (device_register(iface->dev)) { + dev_err(iface->dev, "Failed to register interface device\n"); + kfree(iface->p); + put_device(iface->dev); + ida_simple_remove(&mdev_id, id); + return -ENOMEM; + } + + for (i = 0; i < iface->num_channels; i++) { + const char *name_suffix = iface->channel_vector[i].name_suffix; + + c = kzalloc(sizeof(*c), GFP_KERNEL); + if (!c) + goto err_free_resources; + if (!name_suffix) + snprintf(c->name, STRING_SIZE, "ch%d", i); + else + snprintf(c->name, STRING_SIZE, "%s", name_suffix); + c->dev.init_name = c->name; + c->dev.parent = iface->dev; + c->dev.groups = channel_attr_groups; + c->dev.release = release_channel; + iface->p->channel[i] = c; + c->is_starving = 0; + c->iface = iface; + c->channel_id = i; + c->keep_mbo = false; + c->enqueue_halt = false; + c->is_poisoned = false; + c->cfg.direction = 0; + c->cfg.data_type = 0; + c->cfg.num_buffers = 0; + c->cfg.buffer_size = 0; + c->cfg.subbuffer_size = 0; + c->cfg.packets_per_xact = 0; + spin_lock_init(&c->fifo_lock); + INIT_LIST_HEAD(&c->fifo); + INIT_LIST_HEAD(&c->trash_fifo); + INIT_LIST_HEAD(&c->halt_fifo); + init_completion(&c->cleanup); + atomic_set(&c->mbo_ref, 0); + mutex_init(&c->start_mutex); + mutex_init(&c->nq_mutex); + list_add_tail(&c->list, &iface->p->channel_list); + if (device_register(&c->dev)) { + dev_err(&c->dev, "Failed to register channel device\n"); + goto err_free_most_channel; + } + } + most_interface_register_notify(iface->description); + return 0; + +err_free_most_channel: + put_device(&c->dev); + +err_free_resources: + while (i > 0) { + c = iface->p->channel[--i]; + device_unregister(&c->dev); + } + kfree(iface->p); + device_unregister(iface->dev); + ida_simple_remove(&mdev_id, id); + return -ENOMEM; +} +EXPORT_SYMBOL_GPL(most_register_interface); + +/** + * most_deregister_interface - deregisters an interface with core + * @iface: device interface + * + * Before removing an interface instance from the list, all running + * channels are stopped and poisoned. + */ +void most_deregister_interface(struct most_interface *iface) +{ + int i; + struct most_channel *c; + + for (i = 0; i < iface->num_channels; i++) { + c = iface->p->channel[i]; + if (c->pipe0.comp) + c->pipe0.comp->disconnect_channel(c->iface, + c->channel_id); + if (c->pipe1.comp) + c->pipe1.comp->disconnect_channel(c->iface, + c->channel_id); + c->pipe0.comp = NULL; + c->pipe1.comp = NULL; + list_del(&c->list); + device_unregister(&c->dev); + } + + ida_simple_remove(&mdev_id, iface->p->dev_id); + kfree(iface->p); + device_unregister(iface->dev); +} +EXPORT_SYMBOL_GPL(most_deregister_interface); + +/** + * most_stop_enqueue - prevents core from enqueueing MBOs + * @iface: pointer to interface + * @id: channel id + * + * This is called by an HDM that _cannot_ attend to its duties and + * is imminent to get run over by the core. The core is not going to + * enqueue any further packets unless the flagging HDM calls + * most_resume enqueue(). + */ +void most_stop_enqueue(struct most_interface *iface, int id) +{ + struct most_channel *c = iface->p->channel[id]; + + if (!c) + return; + + mutex_lock(&c->nq_mutex); + c->enqueue_halt = true; + mutex_unlock(&c->nq_mutex); +} +EXPORT_SYMBOL_GPL(most_stop_enqueue); + +/** + * most_resume_enqueue - allow core to enqueue MBOs again + * @iface: pointer to interface + * @id: channel id + * + * This clears the enqueue halt flag and enqueues all MBOs currently + * sitting in the wait fifo. + */ +void most_resume_enqueue(struct most_interface *iface, int id) +{ + struct most_channel *c = iface->p->channel[id]; + + if (!c) + return; + + mutex_lock(&c->nq_mutex); + c->enqueue_halt = false; + mutex_unlock(&c->nq_mutex); + + wake_up_interruptible(&c->hdm_fifo_wq); +} +EXPORT_SYMBOL_GPL(most_resume_enqueue); + +static int __init most_init(void) +{ + int err; + + INIT_LIST_HEAD(&comp_list); + ida_init(&mdev_id); + + err = bus_register(&mostbus); + if (err) { + pr_err("Failed to register most bus\n"); + return err; + } + err = driver_register(&mostbus_driver); + if (err) { + pr_err("Failed to register core driver\n"); + goto err_unregister_bus; + } + configfs_init(); + return 0; + +err_unregister_bus: + bus_unregister(&mostbus); + return err; +} + +static void __exit most_exit(void) +{ + driver_unregister(&mostbus_driver); + bus_unregister(&mostbus); + ida_destroy(&mdev_id); +} + +subsys_initcall(most_init); +module_exit(most_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Christian Gromm <christian.gromm@microchip.com>"); +MODULE_DESCRIPTION("Core module of stacked MOST Linux driver"); |