--- /dev/null
+/*
+ * core.c - Implementation of core module of MOST Linux driver stack
+ *
+ * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * This file is licensed under GPLv2.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#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 "mostcore.h"
+
+#define MAX_CHANNELS 64
+#define STRING_SIZE 80
+
+static struct class *most_class;
+static struct device *class_glue_dir;
+static struct ida mdev_id;
+static int dummy_num_buffers;
+
+struct most_c_aim_obj {
+ struct most_aim *ptr;
+ int refs;
+ int num_buffers;
+};
+
+struct most_c_obj {
+ struct kobject kobj;
+ struct completion cleanup;
+ atomic_t mbo_ref;
+ atomic_t mbo_nq_level;
+ u16 channel_id;
+ bool is_poisoned;
+ struct mutex start_mutex;
+ int is_starving;
+ struct most_interface *iface;
+ struct most_inst_obj *inst;
+ struct most_channel_config cfg;
+ bool keep_mbo;
+ bool enqueue_halt;
+ struct list_head fifo;
+ spinlock_t fifo_lock;
+ struct list_head halt_fifo;
+ struct list_head list;
+ struct most_c_aim_obj aim0;
+ struct most_c_aim_obj aim1;
+ struct list_head trash_fifo;
+ struct task_struct *hdm_enqueue_task;
+ wait_queue_head_t hdm_fifo_wq;
+};
+
+#define to_c_obj(d) container_of(d, struct most_c_obj, kobj)
+
+struct most_inst_obj {
+ int dev_id;
+ struct most_interface *iface;
+ struct list_head channel_list;
+ struct most_c_obj *channel[MAX_CHANNELS];
+ struct kobject kobj;
+ struct list_head list;
+};
+
+#define to_inst_obj(d) container_of(d, struct most_inst_obj, kobj)
+
+/**
+ * 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; \
+})
+
+/* ___ ___
+ * ___C H A N N E L___
+ */
+
+/**
+ * struct most_c_attr - to access the attributes of a channel object
+ * @attr: attributes of a channel
+ * @show: pointer to the show function
+ * @store: pointer to the store function
+ */
+struct most_c_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct most_c_obj *d,
+ struct most_c_attr *attr,
+ char *buf);
+ ssize_t (*store)(struct most_c_obj *d,
+ struct most_c_attr *attr,
+ const char *buf,
+ size_t count);
+};
+
+#define to_channel_attr(a) container_of(a, struct most_c_attr, attr)
+
+#define MOST_CHNL_ATTR(_name, _mode, _show, _store) \
+ struct most_c_attr most_chnl_attr_##_name = \
+ __ATTR(_name, _mode, _show, _store)
+
+/**
+ * channel_attr_show - show function of channel object
+ * @kobj: pointer to its kobject
+ * @attr: pointer to its attributes
+ * @buf: buffer
+ */
+static ssize_t channel_attr_show(struct kobject *kobj, struct attribute *attr,
+ char *buf)
+{
+ struct most_c_attr *channel_attr = to_channel_attr(attr);
+ struct most_c_obj *c_obj = to_c_obj(kobj);
+
+ if (!channel_attr->show)
+ return -EIO;
+
+ return channel_attr->show(c_obj, channel_attr, buf);
+}
+
+/**
+ * channel_attr_store - store function of channel object
+ * @kobj: pointer to its kobject
+ * @attr: pointer to its attributes
+ * @buf: buffer
+ * @len: length of buffer
+ */
+static ssize_t channel_attr_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct most_c_attr *channel_attr = to_channel_attr(attr);
+ struct most_c_obj *c_obj = to_c_obj(kobj);
+
+ if (!channel_attr->store)
+ return -EIO;
+ return channel_attr->store(c_obj, channel_attr, buf, len);
+}
+
+static const struct sysfs_ops most_channel_sysfs_ops = {
+ .show = channel_attr_show,
+ .store = channel_attr_store,
+};
+
+/**
+ * most_free_mbo_coherent - free an MBO and its coherent buffer
+ * @mbo: buffer to be released
+ *
+ */
+static void most_free_mbo_coherent(struct mbo *mbo)
+{
+ struct most_c_obj *c = mbo->context;
+ u16 const coherent_buf_size = c->cfg.buffer_size + c->cfg.extra_len;
+
+ dma_free_coherent(NULL, coherent_buf_size, mbo->virt_address,
+ mbo->bus_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_c_obj *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))))
+ pr_info("WARN: fifo | trash fifo not empty\n");
+}
+
+/**
+ * flush_trash_fifo - clear the trash fifo
+ * @c: pointer to channel object
+ */
+static int flush_trash_fifo(struct most_c_obj *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;
+}
+
+/**
+ * most_channel_release - release function of channel object
+ * @kobj: pointer to channel's kobject
+ */
+static void most_channel_release(struct kobject *kobj)
+{
+ struct most_c_obj *c = to_c_obj(kobj);
+
+ kfree(c);
+}
+
+static ssize_t show_available_directions(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ unsigned int i = c->channel_id;
+
+ strcpy(buf, "");
+ if (c->iface->channel_vector[i].direction & MOST_CH_RX)
+ strcat(buf, "dir_rx ");
+ if (c->iface->channel_vector[i].direction & MOST_CH_TX)
+ strcat(buf, "dir_tx ");
+ strcat(buf, "\n");
+ return strlen(buf) + 1;
+}
+
+static ssize_t show_available_datatypes(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ 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_AVP)
+ strcat(buf, "isoc_avp ");
+ strcat(buf, "\n");
+ return strlen(buf) + 1;
+}
+
+static
+ssize_t show_number_of_packet_buffers(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ unsigned int i = c->channel_id;
+
+ return snprintf(buf, PAGE_SIZE, "%d\n",
+ c->iface->channel_vector[i].num_buffers_packet);
+}
+
+static
+ssize_t show_number_of_stream_buffers(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ unsigned int i = c->channel_id;
+
+ return snprintf(buf, PAGE_SIZE, "%d\n",
+ c->iface->channel_vector[i].num_buffers_streaming);
+}
+
+static
+ssize_t show_size_of_packet_buffer(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ unsigned int i = c->channel_id;
+
+ return snprintf(buf, PAGE_SIZE, "%d\n",
+ c->iface->channel_vector[i].buffer_size_packet);
+}
+
+static
+ssize_t show_size_of_stream_buffer(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ unsigned int i = c->channel_id;
+
+ return snprintf(buf, PAGE_SIZE, "%d\n",
+ c->iface->channel_vector[i].buffer_size_streaming);
+}
+
+static ssize_t show_channel_starving(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", c->is_starving);
+}
+
+#define create_show_channel_attribute(val) \
+ static MOST_CHNL_ATTR(val, S_IRUGO, show_##val, NULL)
+
+create_show_channel_attribute(available_directions);
+create_show_channel_attribute(available_datatypes);
+create_show_channel_attribute(number_of_packet_buffers);
+create_show_channel_attribute(number_of_stream_buffers);
+create_show_channel_attribute(size_of_stream_buffer);
+create_show_channel_attribute(size_of_packet_buffer);
+create_show_channel_attribute(channel_starving);
+
+static ssize_t show_set_number_of_buffers(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.num_buffers);
+}
+
+static ssize_t store_set_number_of_buffers(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ const char *buf,
+ size_t count)
+{
+ int ret = kstrtou16(buf, 0, &c->cfg.num_buffers);
+
+ if (ret)
+ return ret;
+ return count;
+}
+
+static ssize_t show_set_buffer_size(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.buffer_size);
+}
+
+static ssize_t store_set_buffer_size(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ const char *buf,
+ size_t count)
+{
+ int ret = kstrtou16(buf, 0, &c->cfg.buffer_size);
+
+ if (ret)
+ return ret;
+ return count;
+}
+
+static ssize_t show_set_direction(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ if (c->cfg.direction & MOST_CH_TX)
+ return snprintf(buf, PAGE_SIZE, "dir_tx\n");
+ else if (c->cfg.direction & MOST_CH_RX)
+ return snprintf(buf, PAGE_SIZE, "dir_rx\n");
+ return snprintf(buf, PAGE_SIZE, "unconfigured\n");
+}
+
+static ssize_t store_set_direction(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ const char *buf,
+ size_t count)
+{
+ if (!strcmp(buf, "dir_rx\n")) {
+ c->cfg.direction = MOST_CH_RX;
+ } else if (!strcmp(buf, "dir_tx\n")) {
+ c->cfg.direction = MOST_CH_TX;
+ } else {
+ pr_info("WARN: invalid attribute settings\n");
+ return -EINVAL;
+ }
+ return count;
+}
+
+static ssize_t show_set_datatype(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ if (c->cfg.data_type & MOST_CH_CONTROL)
+ return snprintf(buf, PAGE_SIZE, "control\n");
+ else if (c->cfg.data_type & MOST_CH_ASYNC)
+ return snprintf(buf, PAGE_SIZE, "async\n");
+ else if (c->cfg.data_type & MOST_CH_SYNC)
+ return snprintf(buf, PAGE_SIZE, "sync\n");
+ else if (c->cfg.data_type & MOST_CH_ISOC_AVP)
+ return snprintf(buf, PAGE_SIZE, "isoc_avp\n");
+ return snprintf(buf, PAGE_SIZE, "unconfigured\n");
+}
+
+static ssize_t store_set_datatype(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ const char *buf,
+ size_t count)
+{
+ if (!strcmp(buf, "control\n")) {
+ c->cfg.data_type = MOST_CH_CONTROL;
+ } else if (!strcmp(buf, "async\n")) {
+ c->cfg.data_type = MOST_CH_ASYNC;
+ } else if (!strcmp(buf, "sync\n")) {
+ c->cfg.data_type = MOST_CH_SYNC;
+ } else if (!strcmp(buf, "isoc_avp\n")) {
+ c->cfg.data_type = MOST_CH_ISOC_AVP;
+ } else {
+ pr_info("WARN: invalid attribute settings\n");
+ return -EINVAL;
+ }
+ return count;
+}
+
+static ssize_t show_set_subbuffer_size(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.subbuffer_size);
+}
+
+static ssize_t store_set_subbuffer_size(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ const char *buf,
+ size_t count)
+{
+ int ret = kstrtou16(buf, 0, &c->cfg.subbuffer_size);
+
+ if (ret)
+ return ret;
+ return count;
+}
+
+static ssize_t show_set_packets_per_xact(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.packets_per_xact);
+}
+
+static ssize_t store_set_packets_per_xact(struct most_c_obj *c,
+ struct most_c_attr *attr,
+ const char *buf,
+ size_t count)
+{
+ int ret = kstrtou16(buf, 0, &c->cfg.packets_per_xact);
+
+ if (ret)
+ return ret;
+ return count;
+}
+
+#define create_channel_attribute(value) \
+ static MOST_CHNL_ATTR(value, S_IRUGO | S_IWUSR, \
+ show_##value, \
+ store_##value)
+
+create_channel_attribute(set_buffer_size);
+create_channel_attribute(set_number_of_buffers);
+create_channel_attribute(set_direction);
+create_channel_attribute(set_datatype);
+create_channel_attribute(set_subbuffer_size);
+create_channel_attribute(set_packets_per_xact);
+
+/**
+ * most_channel_def_attrs - array of default attributes of channel object
+ */
+static struct attribute *most_channel_def_attrs[] = {
+ &most_chnl_attr_available_directions.attr,
+ &most_chnl_attr_available_datatypes.attr,
+ &most_chnl_attr_number_of_packet_buffers.attr,
+ &most_chnl_attr_number_of_stream_buffers.attr,
+ &most_chnl_attr_size_of_packet_buffer.attr,
+ &most_chnl_attr_size_of_stream_buffer.attr,
+ &most_chnl_attr_set_number_of_buffers.attr,
+ &most_chnl_attr_set_buffer_size.attr,
+ &most_chnl_attr_set_direction.attr,
+ &most_chnl_attr_set_datatype.attr,
+ &most_chnl_attr_set_subbuffer_size.attr,
+ &most_chnl_attr_set_packets_per_xact.attr,
+ &most_chnl_attr_channel_starving.attr,
+ NULL,
+};
+
+static struct kobj_type most_channel_ktype = {
+ .sysfs_ops = &most_channel_sysfs_ops,
+ .release = most_channel_release,
+ .default_attrs = most_channel_def_attrs,
+};
+
+static struct kset *most_channel_kset;
+
+/**
+ * create_most_c_obj - allocates a channel object
+ * @name: name of the channel object
+ * @parent: parent kobject
+ *
+ * This create a channel object and registers it with sysfs.
+ * Returns a pointer to the object or NULL when something went wrong.
+ */
+static struct most_c_obj *
+create_most_c_obj(const char *name, struct kobject *parent)
+{
+ struct most_c_obj *c;
+ int retval;
+
+ c = kzalloc(sizeof(*c), GFP_KERNEL);
+ if (!c)
+ return NULL;
+ c->kobj.kset = most_channel_kset;
+ retval = kobject_init_and_add(&c->kobj, &most_channel_ktype, parent,
+ "%s", name);
+ if (retval) {
+ kobject_put(&c->kobj);
+ return NULL;
+ }
+ kobject_uevent(&c->kobj, KOBJ_ADD);
+ return c;
+}
+
+/* ___ ___
+ * ___I N S T A N C E___
+ */
+#define MOST_INST_ATTR(_name, _mode, _show, _store) \
+ struct most_inst_attribute most_inst_attr_##_name = \
+ __ATTR(_name, _mode, _show, _store)
+
+static struct list_head instance_list;
+
+/**
+ * struct most_inst_attribute - to access the attributes of instance object
+ * @attr: attributes of an instance
+ * @show: pointer to the show function
+ * @store: pointer to the store function
+ */
+struct most_inst_attribute {
+ struct attribute attr;
+ ssize_t (*show)(struct most_inst_obj *d,
+ struct most_inst_attribute *attr,
+ char *buf);
+ ssize_t (*store)(struct most_inst_obj *d,
+ struct most_inst_attribute *attr,
+ const char *buf,
+ size_t count);
+};
+
+#define to_instance_attr(a) \
+ container_of(a, struct most_inst_attribute, attr)
+
+/**
+ * instance_attr_show - show function for an instance object
+ * @kobj: pointer to kobject
+ * @attr: pointer to attribute struct
+ * @buf: buffer
+ */
+static ssize_t instance_attr_show(struct kobject *kobj,
+ struct attribute *attr,
+ char *buf)
+{
+ struct most_inst_attribute *instance_attr;
+ struct most_inst_obj *instance_obj;
+
+ instance_attr = to_instance_attr(attr);
+ instance_obj = to_inst_obj(kobj);
+
+ if (!instance_attr->show)
+ return -EIO;
+
+ return instance_attr->show(instance_obj, instance_attr, buf);
+}
+
+/**
+ * instance_attr_store - store function for an instance object
+ * @kobj: pointer to kobject
+ * @attr: pointer to attribute struct
+ * @buf: buffer
+ * @len: length of buffer
+ */
+static ssize_t instance_attr_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct most_inst_attribute *instance_attr;
+ struct most_inst_obj *instance_obj;
+
+ instance_attr = to_instance_attr(attr);
+ instance_obj = to_inst_obj(kobj);
+
+ if (!instance_attr->store)
+ return -EIO;
+
+ return instance_attr->store(instance_obj, instance_attr, buf, len);
+}
+
+static const struct sysfs_ops most_inst_sysfs_ops = {
+ .show = instance_attr_show,
+ .store = instance_attr_store,
+};
+
+/**
+ * most_inst_release - release function for instance object
+ * @kobj: pointer to instance's kobject
+ *
+ * This frees the allocated memory for the instance object
+ */
+static void most_inst_release(struct kobject *kobj)
+{
+ struct most_inst_obj *inst = to_inst_obj(kobj);
+
+ kfree(inst);
+}
+
+static ssize_t show_description(struct most_inst_obj *instance_obj,
+ struct most_inst_attribute *attr,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%s\n",
+ instance_obj->iface->description);
+}
+
+static ssize_t show_interface(struct most_inst_obj *instance_obj,
+ struct most_inst_attribute *attr,
+ char *buf)
+{
+ switch (instance_obj->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");
+}
+
+#define create_inst_attribute(value) \
+ static MOST_INST_ATTR(value, S_IRUGO, show_##value, NULL)
+
+create_inst_attribute(description);
+create_inst_attribute(interface);
+
+static struct attribute *most_inst_def_attrs[] = {
+ &most_inst_attr_description.attr,
+ &most_inst_attr_interface.attr,
+ NULL,
+};
+
+static struct kobj_type most_inst_ktype = {
+ .sysfs_ops = &most_inst_sysfs_ops,
+ .release = most_inst_release,
+ .default_attrs = most_inst_def_attrs,
+};
+
+static struct kset *most_inst_kset;
+
+/**
+ * create_most_inst_obj - creates an instance object
+ * @name: name of the object to be created
+ *
+ * This allocates memory for an instance structure, assigns the proper kset
+ * and registers it with sysfs.
+ *
+ * Returns a pointer to the instance object or NULL when something went wrong.
+ */
+static struct most_inst_obj *create_most_inst_obj(const char *name)
+{
+ struct most_inst_obj *inst;
+ int retval;
+
+ inst = kzalloc(sizeof(*inst), GFP_KERNEL);
+ if (!inst)
+ return NULL;
+ inst->kobj.kset = most_inst_kset;
+ retval = kobject_init_and_add(&inst->kobj, &most_inst_ktype, NULL,
+ "%s", name);
+ if (retval) {
+ kobject_put(&inst->kobj);
+ return NULL;
+ }
+ kobject_uevent(&inst->kobj, KOBJ_ADD);
+ return inst;
+}
+
+/**
+ * destroy_most_inst_obj - MOST instance release function
+ * @inst: pointer to the instance object
+ *
+ * This decrements the reference counter of the instance object.
+ * If the reference count turns zero, its release function is called
+ */
+static void destroy_most_inst_obj(struct most_inst_obj *inst)
+{
+ struct most_c_obj *c, *tmp;
+
+ list_for_each_entry_safe(c, tmp, &inst->channel_list, list) {
+ flush_trash_fifo(c);
+ flush_channel_fifos(c);
+ kobject_put(&c->kobj);
+ }
+ kobject_put(&inst->kobj);
+}
+
+/* ___ ___
+ * ___A I M___
+ */
+struct most_aim_obj {
+ struct kobject kobj;
+ struct list_head list;
+ struct most_aim *driver;
+ char add_link[STRING_SIZE];
+ char remove_link[STRING_SIZE];
+};
+
+#define to_aim_obj(d) container_of(d, struct most_aim_obj, kobj)
+
+static struct list_head aim_list;
+
+/**
+ * struct most_aim_attribute - to access the attributes of AIM object
+ * @attr: attributes of an AIM
+ * @show: pointer to the show function
+ * @store: pointer to the store function
+ */
+struct most_aim_attribute {
+ struct attribute attr;
+ ssize_t (*show)(struct most_aim_obj *d,
+ struct most_aim_attribute *attr,
+ char *buf);
+ ssize_t (*store)(struct most_aim_obj *d,
+ struct most_aim_attribute *attr,
+ const char *buf,
+ size_t count);
+};
+
+#define to_aim_attr(a) container_of(a, struct most_aim_attribute, attr)
+
+/**
+ * aim_attr_show - show function of an AIM object
+ * @kobj: pointer to kobject
+ * @attr: pointer to attribute struct
+ * @buf: buffer
+ */
+static ssize_t aim_attr_show(struct kobject *kobj,
+ struct attribute *attr,
+ char *buf)
+{
+ struct most_aim_attribute *aim_attr;
+ struct most_aim_obj *aim_obj;
+
+ aim_attr = to_aim_attr(attr);
+ aim_obj = to_aim_obj(kobj);
+
+ if (!aim_attr->show)
+ return -EIO;
+
+ return aim_attr->show(aim_obj, aim_attr, buf);
+}
+
+/**
+ * aim_attr_store - store function of an AIM object
+ * @kobj: pointer to kobject
+ * @attr: pointer to attribute struct
+ * @buf: buffer
+ * @len: length of buffer
+ */
+static ssize_t aim_attr_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct most_aim_attribute *aim_attr;
+ struct most_aim_obj *aim_obj;
+
+ aim_attr = to_aim_attr(attr);
+ aim_obj = to_aim_obj(kobj);
+
+ if (!aim_attr->store)
+ return -EIO;
+ return aim_attr->store(aim_obj, aim_attr, buf, len);
+}
+
+static const struct sysfs_ops most_aim_sysfs_ops = {
+ .show = aim_attr_show,
+ .store = aim_attr_store,
+};
+
+/**
+ * most_aim_release - AIM release function
+ * @kobj: pointer to AIM's kobject
+ */
+static void most_aim_release(struct kobject *kobj)
+{
+ struct most_aim_obj *aim_obj = to_aim_obj(kobj);
+
+ kfree(aim_obj);
+}
+
+static ssize_t show_add_link(struct most_aim_obj *aim_obj,
+ struct most_aim_attribute *attr,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%s\n", aim_obj->add_link);
+}
+
+/**
+ * split_string - parses and changes string in the buffer buf and
+ * splits it into two mandatory and one optional substrings.
+ *
+ * @buf: complete string from attribute 'add_channel'
+ * @a: address of pointer to 1st substring (=instance name)
+ * @b: address of pointer to 2nd substring (=channel name)
+ * @c: optional address of pointer to 3rd substring (=user defined name)
+ *
+ * Examples:
+ *
+ * Input: "mdev0:ch0@ep_81:my_channel\n" or
+ * "mdev0:ch0@ep_81:my_channel"
+ *
+ * Output: *a -> "mdev0", *b -> "ch0@ep_81", *c -> "my_channel"
+ *
+ * Input: "mdev0:ch0@ep_81\n"
+ * Output: *a -> "mdev0", *b -> "ch0@ep_81", *c -> ""
+ *
+ * Input: "mdev0:ch0@ep_81"
+ * Output: *a -> "mdev0", *b -> "ch0@ep_81", *c == NULL
+ */
+static int split_string(char *buf, char **a, char **b, char **c)
+{
+ *a = strsep(&buf, ":");
+ if (!*a)
+ return -EIO;
+
+ *b = strsep(&buf, ":\n");
+ if (!*b)
+ return -EIO;
+
+ if (c)
+ *c = strsep(&buf, ":\n");
+
+ return 0;
+}
+
+/**
+ * get_channel_by_name - get pointer to channel object
+ * @mdev: name of the device instance
+ * @mdev_ch: name of the respective channel
+ *
+ * This retrieves the pointer to a channel object.
+ */
+static struct
+most_c_obj *get_channel_by_name(char *mdev, char *mdev_ch)
+{
+ struct most_c_obj *c, *tmp;
+ struct most_inst_obj *i, *i_tmp;
+ int found = 0;
+
+ list_for_each_entry_safe(i, i_tmp, &instance_list, list) {
+ if (!strcmp(kobject_name(&i->kobj), mdev)) {
+ found++;
+ break;
+ }
+ }
+ if (unlikely(!found))
+ return ERR_PTR(-EIO);
+
+ list_for_each_entry_safe(c, tmp, &i->channel_list, list) {
+ if (!strcmp(kobject_name(&c->kobj), mdev_ch)) {
+ found++;
+ break;
+ }
+ }
+ if (unlikely(found < 2))
+ return ERR_PTR(-EIO);
+ return c;
+}
+
+/**
+ * store_add_link - store() function for add_link attribute
+ * @aim_obj: pointer to AIM object
+ * @attr: its attributes
+ * @buf: buffer
+ * @len: buffer length
+ *
+ * This parses the string given by buf and splits it into
+ * three substrings. Note: third substring is optional. In case a cdev
+ * AIM is loaded the optional 3rd substring will make up the name of
+ * device node in the /dev directory. If omitted, the device node will
+ * inherit the channel's name within sysfs.
+ *
+ * Searches for a pair of device and channel and probes the AIM
+ *
+ * Example:
+ * (1) echo -n -e "mdev0:ch0@ep_81:my_rxchannel\n" >add_link
+ * (2) echo -n -e "mdev0:ch0@ep_81\n" >add_link
+ *
+ * (1) would create the device node /dev/my_rxchannel
+ * (2) would create the device node /dev/mdev0-ch0@ep_81
+ */
+static ssize_t store_add_link(struct most_aim_obj *aim_obj,
+ struct most_aim_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct most_c_obj *c;
+ struct most_aim **aim_ptr;
+ char buffer[STRING_SIZE];
+ char *mdev;
+ char *mdev_ch;
+ char *mdev_devnod;
+ char devnod_buf[STRING_SIZE];
+ int ret;
+ size_t max_len = min_t(size_t, len + 1, STRING_SIZE);
+
+ strlcpy(buffer, buf, max_len);
+ strlcpy(aim_obj->add_link, buf, max_len);
+
+ ret = split_string(buffer, &mdev, &mdev_ch, &mdev_devnod);
+ if (ret)
+ return ret;
+
+ if (!mdev_devnod || *mdev_devnod == 0) {
+ snprintf(devnod_buf, sizeof(devnod_buf), "%s-%s", mdev,
+ mdev_ch);
+ mdev_devnod = devnod_buf;
+ }
+
+ c = get_channel_by_name(mdev, mdev_ch);
+ if (IS_ERR(c))
+ return -ENODEV;
+
+ if (!c->aim0.ptr)
+ aim_ptr = &c->aim0.ptr;
+ else if (!c->aim1.ptr)
+ aim_ptr = &c->aim1.ptr;
+ else
+ return -ENOSPC;
+
+ *aim_ptr = aim_obj->driver;
+ ret = aim_obj->driver->probe_channel(c->iface, c->channel_id,
+ &c->cfg, &c->kobj, mdev_devnod);
+ if (ret) {
+ *aim_ptr = NULL;
+ return ret;
+ }
+
+ return len;
+}
+
+static struct most_aim_attribute most_aim_attr_add_link =
+ __ATTR(add_link, S_IRUGO | S_IWUSR, show_add_link, store_add_link);
+
+static ssize_t show_remove_link(struct most_aim_obj *aim_obj,
+ struct most_aim_attribute *attr,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%s\n", aim_obj->remove_link);
+}
+
+/**
+ * store_remove_link - store function for remove_link attribute
+ * @aim_obj: pointer to AIM object
+ * @attr: its attributes
+ * @buf: buffer
+ * @len: buffer length
+ *
+ * Example:
+ * echo -n -e "mdev0:ch0@ep_81\n" >remove_link
+ */
+static ssize_t store_remove_link(struct most_aim_obj *aim_obj,
+ struct most_aim_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct most_c_obj *c;
+ char buffer[STRING_SIZE];
+ char *mdev;
+ char *mdev_ch;
+ int ret;
+ size_t max_len = min_t(size_t, len + 1, STRING_SIZE);
+
+ strlcpy(buffer, buf, max_len);
+ strlcpy(aim_obj->remove_link, buf, max_len);
+ ret = split_string(buffer, &mdev, &mdev_ch, NULL);
+ if (ret)
+ return ret;
+
+ c = get_channel_by_name(mdev, mdev_ch);
+ if (IS_ERR(c))
+ return -ENODEV;
+
+ if (aim_obj->driver->disconnect_channel(c->iface, c->channel_id))
+ return -EIO;
+ if (c->aim0.ptr == aim_obj->driver)
+ c->aim0.ptr = NULL;
+ if (c->aim1.ptr == aim_obj->driver)
+ c->aim1.ptr = NULL;
+ return len;
+}
+
+static struct most_aim_attribute most_aim_attr_remove_link =
+ __ATTR(remove_link, S_IRUGO | S_IWUSR, show_remove_link,
+ store_remove_link);
+
+static struct attribute *most_aim_def_attrs[] = {
+ &most_aim_attr_add_link.attr,
+ &most_aim_attr_remove_link.attr,
+ NULL,
+};
+
+static struct kobj_type most_aim_ktype = {
+ .sysfs_ops = &most_aim_sysfs_ops,
+ .release = most_aim_release,
+ .default_attrs = most_aim_def_attrs,
+};
+
+static struct kset *most_aim_kset;
+
+/**
+ * create_most_aim_obj - creates an AIM object
+ * @name: name of the AIM
+ *
+ * This creates an AIM object assigns the proper kset and registers
+ * it with sysfs.
+ * Returns a pointer to the object or NULL if something went wrong.
+ */
+static struct most_aim_obj *create_most_aim_obj(const char *name)
+{
+ struct most_aim_obj *most_aim;
+ int retval;
+
+ most_aim = kzalloc(sizeof(*most_aim), GFP_KERNEL);
+ if (!most_aim)
+ return NULL;
+ most_aim->kobj.kset = most_aim_kset;
+ retval = kobject_init_and_add(&most_aim->kobj, &most_aim_ktype,
+ NULL, "%s", name);
+ if (retval) {
+ kobject_put(&most_aim->kobj);
+ return NULL;
+ }
+ kobject_uevent(&most_aim->kobj, KOBJ_ADD);
+ return most_aim;
+}
+
+/**
+ * destroy_most_aim_obj - AIM release function
+ * @p: pointer to AIM object
+ *
+ * This decrements the reference counter of the AIM object. If the
+ * reference count turns zero, its release function will be called.
+ */
+static void destroy_most_aim_obj(struct most_aim_obj *p)
+{
+ kobject_put(&p->kobj);
+}
+
+/* ___ ___
+ * ___C O R E___
+ */
+
+/**
+ * Instantiation of the MOST bus
+ */
+static struct bus_type most_bus = {
+ .name = "most",
+};
+
+/**
+ * Instantiation of the core driver
+ */
+static struct device_driver mostcore = {
+ .name = "mostcore",
+ .bus = &most_bus,
+};
+
+static inline void trash_mbo(struct mbo *mbo)
+{
+ unsigned long flags;
+ struct most_c_obj *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 struct mbo *get_hdm_mbo(struct most_c_obj *c)
+{
+ unsigned long flags;
+ struct mbo *mbo;
+
+ spin_lock_irqsave(&c->fifo_lock, flags);
+ if (c->enqueue_halt || list_empty(&c->halt_fifo))
+ mbo = NULL;
+ else
+ mbo = list_pop_mbo(&c->halt_fifo);
+ spin_unlock_irqrestore(&c->fifo_lock, flags);
+ return mbo;
+}
+
+static void nq_hdm_mbo(struct mbo *mbo)
+{
+ unsigned long flags;
+ struct most_c_obj *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_c_obj *c = data;
+ struct mbo *mbo;
+ typeof(c->iface->enqueue) enqueue = c->iface->enqueue;
+
+ while (likely(!kthread_should_stop())) {
+ wait_event_interruptible(c->hdm_fifo_wq,
+ (mbo = get_hdm_mbo(c)) ||
+ kthread_should_stop());
+
+ if (unlikely(!mbo))
+ continue;
+
+ if (c->cfg.direction == MOST_CH_RX)
+ mbo->buffer_length = c->cfg.buffer_size;
+
+ if (unlikely(enqueue(mbo->ifp, mbo->hdm_channel_id, mbo))) {
+ pr_err("hdm enqueue failed\n");
+ nq_hdm_mbo(mbo);
+ c->hdm_enqueue_task = NULL;
+ return 0;
+ }
+ }
+
+ return 0;
+}
+
+static int run_enqueue_thread(struct most_c_obj *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: buffer object
+ *
+ * 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 AIM.
+ */
+static void arm_mbo(struct mbo *mbo)
+{
+ unsigned long flags;
+ struct most_c_obj *c;
+
+ BUG_ON((!mbo) || (!mbo->context));
+ 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->aim0.refs && c->aim0.ptr->tx_completion)
+ c->aim0.ptr->tx_completion(c->iface, c->channel_id);
+
+ if (c->aim1.refs && c->aim1.ptr->tx_completion)
+ c->aim1.ptr->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_c_obj *c, int dir,
+ void (*compl)(struct mbo *))
+{
+ unsigned int i;
+ int retval;
+ struct mbo *mbo;
+ 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) {
+ pr_info("WARN: Allocation of MBO failed.\n");
+ retval = i;
+ goto _exit;
+ }
+ mbo->context = c;
+ mbo->ifp = c->iface;
+ mbo->hdm_channel_id = c->channel_id;
+ mbo->virt_address = dma_alloc_coherent(NULL,
+ coherent_buf_size,
+ &mbo->bus_address,
+ GFP_KERNEL);
+ if (!mbo->virt_address) {
+ pr_info("WARN: No DMA coherent buffer.\n");
+ retval = i;
+ goto _error1;
+ }
+ 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 {
+ arm_mbo(mbo);
+ }
+ }
+ return i;
+
+_error1:
+ kfree(mbo);
+_exit:
+ return retval;
+}
+
+/**
+ * most_submit_mbo - submits an MBO to fifo
+ * @mbo: pointer to the MBO
+ *
+ */
+int most_submit_mbo(struct mbo *mbo)
+{
+ if (unlikely((!mbo) || (!mbo->context))) {
+ pr_err("Bad MBO or missing channel reference\n");
+ return -EINVAL;
+ }
+
+ nq_hdm_mbo(mbo);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(most_submit_mbo);
+
+/**
+ * most_write_completion - write completion handler
+ * @mbo: pointer to MBO
+ *
+ * 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_c_obj *c;
+
+ BUG_ON((!mbo) || (!mbo->context));
+
+ c = mbo->context;
+ if (mbo->status == MBO_E_INVAL)
+ pr_info("WARN: Tx MBO status: invalid\n");
+ if (unlikely(c->is_poisoned || (mbo->status == MBO_E_CLOSE)))
+ trash_mbo(mbo);
+ else
+ arm_mbo(mbo);
+}
+
+/**
+ * get_channel_by_iface - get pointer to channel object
+ * @iface: pointer to interface instance
+ * @id: channel ID
+ *
+ * This retrieves a pointer to a channel of the given interface and channel ID.
+ */
+static struct
+most_c_obj *get_channel_by_iface(struct most_interface *iface, int id)
+{
+ struct most_inst_obj *i;
+
+ if (unlikely(!iface)) {
+ pr_err("Bad interface\n");
+ return NULL;
+ }
+ if (unlikely((id < 0) || (id >= iface->num_channels))) {
+ pr_err("Channel index (%d) out of range\n", id);
+ return NULL;
+ }
+ i = iface->priv;
+ if (unlikely(!i)) {
+ pr_err("interface is not registered\n");
+ return NULL;
+ }
+ return i->channel[id];
+}
+
+int channel_has_mbo(struct most_interface *iface, int id, struct most_aim *aim)
+{
+ struct most_c_obj *c = get_channel_by_iface(iface, id);
+ unsigned long flags;
+ int empty;
+
+ if (unlikely(!c))
+ return -EINVAL;
+
+ if (c->aim0.refs && c->aim1.refs &&
+ ((aim == c->aim0.ptr && c->aim0.num_buffers <= 0) ||
+ (aim == c->aim1.ptr && c->aim1.num_buffers <= 0)))
+ return false;
+
+ 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
+ *
+ * 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_aim *aim)
+{
+ struct mbo *mbo;
+ struct most_c_obj *c;
+ unsigned long flags;
+ int *num_buffers_ptr;
+
+ c = get_channel_by_iface(iface, id);
+ if (unlikely(!c))
+ return NULL;
+
+ if (c->aim0.refs && c->aim1.refs &&
+ ((aim == c->aim0.ptr && c->aim0.num_buffers <= 0) ||
+ (aim == c->aim1.ptr && c->aim1.num_buffers <= 0)))
+ return NULL;
+
+ if (aim == c->aim0.ptr)
+ num_buffers_ptr = &c->aim0.num_buffers;
+ else if (aim == c->aim1.ptr)
+ num_buffers_ptr = &c->aim1.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: buffer object
+ */
+void most_put_mbo(struct mbo *mbo)
+{
+ struct most_c_obj *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: pointer to MBO
+ *
+ * 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 AIM for further processing.
+ */
+static void most_read_completion(struct mbo *mbo)
+{
+ struct most_c_obj *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)) {
+ pr_info("WARN: rx device out of buffers\n");
+ c->is_starving = 1;
+ }
+
+ if (c->aim0.refs && c->aim0.ptr->rx_completion &&
+ c->aim0.ptr->rx_completion(mbo) == 0)
+ return;
+
+ if (c->aim1.refs && c->aim1.ptr->rx_completion &&
+ c->aim1.ptr->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
+ *
+ * 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_aim *aim)
+{
+ int num_buffer;
+ int ret;
+ struct most_c_obj *c = get_channel_by_iface(iface, id);
+
+ if (unlikely(!c))
+ return -EINVAL;
+
+ mutex_lock(&c->start_mutex);
+ if (c->aim0.refs + c->aim1.refs > 0)
+ goto out; /* already started by other aim */
+
+ if (!try_module_get(iface->mod)) {
+ pr_info("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)) {
+ pr_info("channel configuration failed. Go check settings...\n");
+ ret = -EINVAL;
+ goto error;
+ }
+
+ 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)) {
+ pr_info("failed to allocate memory\n");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ ret = run_enqueue_thread(c, id);
+ if (ret)
+ goto error;
+
+ c->is_starving = 0;
+ c->aim0.num_buffers = c->cfg.num_buffers / 2;
+ c->aim1.num_buffers = c->cfg.num_buffers - c->aim0.num_buffers;
+ atomic_set(&c->mbo_ref, num_buffer);
+
+out:
+ if (aim == c->aim0.ptr)
+ c->aim0.refs++;
+ if (aim == c->aim1.ptr)
+ c->aim1.refs++;
+ mutex_unlock(&c->start_mutex);
+ return 0;
+
+error:
+ 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
+ */
+int most_stop_channel(struct most_interface *iface, int id,
+ struct most_aim *aim)
+{
+ struct most_c_obj *c;
+
+ if (unlikely((!iface) || (id >= iface->num_channels) || (id < 0))) {
+ pr_err("Bad interface or index out of range\n");
+ return -EINVAL;
+ }
+ c = get_channel_by_iface(iface, id);
+ if (unlikely(!c))
+ return -EINVAL;
+
+ mutex_lock(&c->start_mutex);
+ if (c->aim0.refs + c->aim1.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)) {
+ pr_err("Cannot stop channel %d of mdev %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)) {
+ pr_info("Interrupted while clean up ch %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 (aim == c->aim0.ptr)
+ c->aim0.refs--;
+ if (aim == c->aim1.ptr)
+ c->aim1.refs--;
+ mutex_unlock(&c->start_mutex);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(most_stop_channel);
+
+/**
+ * most_register_aim - registers an AIM (driver) with the core
+ * @aim: instance of AIM to be registered
+ */
+int most_register_aim(struct most_aim *aim)
+{
+ struct most_aim_obj *aim_obj;
+
+ if (!aim) {
+ pr_err("Bad driver\n");
+ return -EINVAL;
+ }
+ aim_obj = create_most_aim_obj(aim->name);
+ if (!aim_obj) {
+ pr_info("failed to alloc driver object\n");
+ return -ENOMEM;
+ }
+ aim_obj->driver = aim;
+ aim->context = aim_obj;
+ pr_info("registered new application interfacing module %s\n",
+ aim->name);
+ list_add_tail(&aim_obj->list, &aim_list);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(most_register_aim);
+
+/**
+ * most_deregister_aim - deregisters an AIM (driver) with the core
+ * @aim: AIM to be removed
+ */
+int most_deregister_aim(struct most_aim *aim)
+{
+ struct most_aim_obj *aim_obj;
+ struct most_c_obj *c, *tmp;
+ struct most_inst_obj *i, *i_tmp;
+
+ if (!aim) {
+ pr_err("Bad driver\n");
+ return -EINVAL;
+ }
+
+ aim_obj = aim->context;
+ if (!aim_obj) {
+ pr_info("driver not registered.\n");
+ return -EINVAL;
+ }
+ list_for_each_entry_safe(i, i_tmp, &instance_list, list) {
+ list_for_each_entry_safe(c, tmp, &i->channel_list, list) {
+ if (c->aim0.ptr == aim || c->aim1.ptr == aim)
+ aim->disconnect_channel(
+ c->iface, c->channel_id);
+ if (c->aim0.ptr == aim)
+ c->aim0.ptr = NULL;
+ if (c->aim1.ptr == aim)
+ c->aim1.ptr = NULL;
+ }
+ }
+ list_del(&aim_obj->list);
+ destroy_most_aim_obj(aim_obj);
+ pr_info("deregistering application interfacing module %s\n", aim->name);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(most_deregister_aim);
+
+/**
+ * most_register_interface - registers an interface with core
+ * @iface: pointer to the instance of the interface description.
+ *
+ * Allocates and initializes a new interface instance and all of its channels.
+ * Returns a pointer to kobject or an error pointer.
+ */
+struct kobject *most_register_interface(struct most_interface *iface)
+{
+ unsigned int i;
+ int id;
+ char name[STRING_SIZE];
+ char channel_name[STRING_SIZE];
+ struct most_c_obj *c;
+ struct most_inst_obj *inst;
+
+ if (!iface || !iface->enqueue || !iface->configure ||
+ !iface->poison_channel || (iface->num_channels > MAX_CHANNELS)) {
+ pr_err("Bad interface or channel overflow\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ id = ida_simple_get(&mdev_id, 0, 0, GFP_KERNEL);
+ if (id < 0) {
+ pr_info("Failed to alloc mdev ID\n");
+ return ERR_PTR(id);
+ }
+ snprintf(name, STRING_SIZE, "mdev%d", id);
+
+ inst = create_most_inst_obj(name);
+ if (!inst) {
+ pr_info("Failed to allocate interface instance\n");
+ ida_simple_remove(&mdev_id, id);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ iface->priv = inst;
+ INIT_LIST_HEAD(&inst->channel_list);
+ inst->iface = iface;
+ inst->dev_id = id;
+ list_add_tail(&inst->list, &instance_list);
+
+ for (i = 0; i < iface->num_channels; i++) {
+ const char *name_suffix = iface->channel_vector[i].name_suffix;
+
+ if (!name_suffix)
+ snprintf(channel_name, STRING_SIZE, "ch%d", i);
+ else if (name_suffix[0] == '@')
+ snprintf(channel_name, STRING_SIZE, "ch%d%s", i,
+ name_suffix);
+ else
+ snprintf(channel_name, STRING_SIZE, "%s", name_suffix);
+
+ /* this increments the reference count of this instance */
+ c = create_most_c_obj(channel_name, &inst->kobj);
+ if (!c)
+ goto free_instance;
+ inst->channel[i] = c;
+ c->is_starving = 0;
+ c->iface = iface;
+ c->inst = inst;
+ 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);
+ list_add_tail(&c->list, &inst->channel_list);
+ }
+ pr_info("registered new MOST device mdev%d (%s)\n",
+ inst->dev_id, iface->description);
+ return &inst->kobj;
+
+free_instance:
+ pr_info("Failed allocate channel(s)\n");
+ list_del(&inst->list);
+ ida_simple_remove(&mdev_id, id);
+ destroy_most_inst_obj(inst);
+ return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL_GPL(most_register_interface);
+
+/**
+ * most_deregister_interface - deregisters an interface with core
+ * @iface: pointer to the interface instance description.
+ *
+ * Before removing an interface instance from the list, all running
+ * channels are stopped and poisoned.
+ */
+void most_deregister_interface(struct most_interface *iface)
+{
+ struct most_inst_obj *i = iface->priv;
+ struct most_c_obj *c;
+
+ if (unlikely(!i)) {
+ pr_info("Bad Interface\n");
+ return;
+ }
+ pr_info("deregistering MOST device %s (%s)\n", i->kobj.name,
+ iface->description);
+
+ list_for_each_entry(c, &i->channel_list, list) {
+ if (c->aim0.ptr)
+ c->aim0.ptr->disconnect_channel(c->iface,
+ c->channel_id);
+ if (c->aim1.ptr)
+ c->aim1.ptr->disconnect_channel(c->iface,
+ c->channel_id);
+ c->aim0.ptr = NULL;
+ c->aim1.ptr = NULL;
+ }
+
+ ida_simple_remove(&mdev_id, i->dev_id);
+ list_del(&i->list);
+ destroy_most_inst_obj(i);
+}
+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_c_obj *c = get_channel_by_iface(iface, id);
+
+ if (likely(c))
+ c->enqueue_halt = true;
+}
+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_c_obj *c = get_channel_by_iface(iface, id);
+
+ if (unlikely(!c))
+ return;
+ c->enqueue_halt = false;
+
+ wake_up_interruptible(&c->hdm_fifo_wq);
+}
+EXPORT_SYMBOL_GPL(most_resume_enqueue);
+
+static int __init most_init(void)
+{
+ pr_info("init()\n");
+ INIT_LIST_HEAD(&instance_list);
+ INIT_LIST_HEAD(&aim_list);
+ ida_init(&mdev_id);
+
+ if (bus_register(&most_bus)) {
+ pr_info("Cannot register most bus\n");
+ goto exit;
+ }
+
+ most_class = class_create(THIS_MODULE, "most");
+ if (IS_ERR(most_class)) {
+ pr_info("No udev support.\n");
+ goto exit_bus;
+ }
+ if (driver_register(&mostcore)) {
+ pr_info("Cannot register core driver\n");
+ goto exit_class;
+ }
+
+ class_glue_dir =
+ device_create(most_class, NULL, 0, NULL, "mostcore");
+ if (!class_glue_dir)
+ goto exit_driver;
+
+ most_aim_kset =
+ kset_create_and_add("aims", NULL, &class_glue_dir->kobj);
+ if (!most_aim_kset)
+ goto exit_class_container;
+
+ most_inst_kset =
+ kset_create_and_add("devices", NULL, &class_glue_dir->kobj);
+ if (!most_inst_kset)
+ goto exit_driver_kset;
+
+ return 0;
+
+exit_driver_kset:
+ kset_unregister(most_aim_kset);
+exit_class_container:
+ device_destroy(most_class, 0);
+exit_driver:
+ driver_unregister(&mostcore);
+exit_class:
+ class_destroy(most_class);
+exit_bus:
+ bus_unregister(&most_bus);
+exit:
+ return -ENOMEM;
+}
+
+static void __exit most_exit(void)
+{
+ struct most_inst_obj *i, *i_tmp;
+ struct most_aim_obj *d, *d_tmp;
+
+ pr_info("exit core module\n");
+ list_for_each_entry_safe(d, d_tmp, &aim_list, list) {
+ destroy_most_aim_obj(d);
+ }
+
+ list_for_each_entry_safe(i, i_tmp, &instance_list, list) {
+ list_del(&i->list);
+ destroy_most_inst_obj(i);
+ }
+ kset_unregister(most_inst_kset);
+ kset_unregister(most_aim_kset);
+ device_destroy(most_class, 0);
+ driver_unregister(&mostcore);
+ class_destroy(most_class);
+ bus_unregister(&most_bus);
+ ida_destroy(&mdev_id);
+}
+
+module_init(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");
Code Review / AGL / meta-agl-demo.git / blobdiff